A kind of nanoporous carbon has been successfully prepared from sugarcane bagasse through a facile microwave-induced ZnCl2 activation and tested as electrode material in ionic liquid supercapacitor. The as-prepared nanoporous carbons are systematically characterized by a variety of means such as N-2 adsorption, SEM (scanning electron microscope) and TEM (transmission electron microscope). Characterization results reveal that the pore size of nanoporous carbons can be tuned from 2.5 nm to 7 nm by simply adjusting the concentration of ZnCl2 solution from 20 wt\% to 60 wt\%. The nanoporous carbons are tested as electrode materials in ionic liquid using different electrochemical means such as cyclic voltammetry, constant current charge-discharge and electrochemical impedance spectroscopy. As evidenced by electrochemical measurements, the capacitive performances of the carbons are closely related to their pore sizes. It has been demonstrated that large pore size benefits the good capacitive performance of nanoporous carbon in ionic liquid electrolyte.
The aims of this research are to study and compare energy efficiency or Net Energy Gain (NEG) and Water Footprint (WF) of corn-based 99.5\% purified ethanol production with different kinds of raw materials for ethanol production using the Life Cycle Assessment (LCA) technique. 1 L of corn-based ethanol product was set as a functional unit. System boundary was considered from corn plantation, ethanol production, transportation, and using. For the energy analysis, the results show that corn-based ethanol production has lower energy efficiency than sugarcane, cassava, and molasses-based ethanol about 3.72, 3.48 and 1.82 times, respectively. The WF in the whole life cycle of corn-based ethanol production chain is 3.67 m(3) per L ethanol, wtih the green contribution of 53.7\%, the grey contribution of 43.8, and the blue contribution of 2.4\%. The amount of water consumption to meet the capacity in year 2013 of bioethanol (949.1 millions L) in Thailand in scenarion 1 (72\% sugarcane, 18\% cassava and 10\% corn) and scenario 2 (62\% sugarcane, 28\% cassava and 10\% corn) are lower than basecase (72\% sugarcane and 28\% cassava) by 8.7\% and 3.4\%, respectively. Because corn-base ethanol production has lower WF than sugarcane and cassava-based ethanol production about 1.65 and 2.71 times, respectively. (C) 2017 The Authors. Published by Elsevier Ltd
Novel cationic hemicelluloses from sugarcane bagasse were synthesized by quaternization with 3-chloro-2-hydroxypropyltrimethy-lammonium chloride (CHMAC) using sodium hydroxide as a catalyst in aqueous ethanol solution. The parameters including the molar ratio of NaOH/CHMAC (0.8-2.0), the molar ratio of CHMAC to anhydroxylose units in hemicelluloses (0.5-3.0), reaction time (0.5-2.5 h), and reaction temperature (50-80 degrees C) were optimized and the extent of quaternization was measured by yield and degree of substitution (DS). A CHMAC/hemicellulose molar ratio of 1.0 and a NaOH/CHMAC molar ratio of 1.2 were found to be an optimum condition for the reaction to proceed smoothly and to yield a product with an expected DS. The structure of the cationic hemicellulosic derivative was characterized by gel permeation chromatography (GPC), Fourier transform infrared (FT-IR), and C-13 nuclear magnetic resonance (NMR) spectroscopy as well as thermal analysis. It was found that the thermal stability and weight-average molecular weight of modified hemicelluloses decreased after chemical modification. (c) 2006 Elsevier Ltd. All rights reserved.
Novel and sustainable pretreatment approaches are desired to improve the techno-commercial feasibility of biorefineries in the future. In this study, 10 renewable deep eutectic solvents (DESs) were evaluated for their pretreatment efficiency at facile conditions with sugar cane bagasse as substrate and compared with conventional pretreatment approaches (dilute alkali, dilute acid, and ionic liquid (IL)) for lignin removal, saccharification yield, cellulose accessibility, crystallinity, and physiochemical properties. Although, the highest delignification was obtained with dilute alkali (S9.7\%) and choline chloride:lactic acid or ChCl:LA (50.6\%), the maximum enzymatic conversion of 98.0\% and 90.4\% was observed with IL (1-butyl-3-methylimidazolium acetate) and ChCl:LA, respectively. uclear magnetic resonance analysis of ChCl:LA-derived lignin showed selective removal of guaiacyl lignin without condensation structure formation observed. Interestingly, unlike IL, the lignin was substantially depolymerized after ChCl:LA pretreatment as determined by gel permeation chromatography. Further, high compatibility of ChCl:LA with cellulase in comparison of IL with easy recyclability and recycling showed that DESs synthesized from a renewable resource are promising ``green{''
Studies are still scarce about silicate fertilization as a silicon (Si) supply to drought-tolerant contrasting sugarcane cultivars. The objective was determined whether the increase of Si rates up to 1000 kg ha(-1)Si improves the Si in soil, Si uptake, and biomass of aerial part and root system of sugarcane without prejudicial effects in chemical attributes of soil and in nutrients absorption and whether Si concentration and biomass of drought-sensitive are increased similar to that of drought-tolerant sugarcane cultivar in the function of Si rates. An experiment was conducted in randomized blocks with cultivars (RB86-7515 = drought-tolerant; RB85-5536 = and drought-sensitive) and Si rates (0, 250, 500, 750, and 1000 kg ha(-1)Si) using silicate in sandy soil. Fertilization increased Si contents in soil, Si contents and biomass of straw and stalks, Si in green leaves, and biomass of roots, independent of cultivars. The Si rates improved also the Ca in green leaves and Mn in straw, but reduced Ca and Mg in the soil and Mg concentration in the straw. Lower biomass and higher Si concentration were found in RB85-5536, and it was also true in RB86-7515 for the roots. Fertilization with Si rates up to 1000 kg ha(-1)Si as silicate in sandy soil was not excessive, increasing Si availability, Si uptake in straw, green leaves, and stalks, and aerial part and root biomass, independently of cultivar without prejudicial effects in chemical attributes of soil and nutrient uptake in sugarcane.
The understanding of the kinetic properties of invertase activity is that it is always produced during yeast fermentation and helps in the pretreatment and raw material preparation of ethanol production which usually uses molasses to achieve high efficiency of ethanol yield and productivity. Normally, the activity of enzymes is limited by many parameters including invertase. Thus, this research focused on some inhibitors that affected invertase activity produced from Saccharomyces cerevisiae, using cultivation on different carbon sources (pure sucrose solution and sugarcane molasses) compared with commercial invertase. Metal contamination from fertilizer during sugarcane cultivation has resulted in significant levels of calcium ions (Ca2+), potassium ions (K+), and magnesium ions (Mg2+) in harvested sugarcane at approximately 0.09, 0.18, and 0.05\% (w/w), respectively. Consequently, harvested sugarcane and contamination from sugar processing were investigated in the current study, particularly the levels of the metal ions; Ca2+, K+, and Mg2+ that contaminated molasses. Moreover, the substrate and enzyme concentration were studied. The results showed that both crude invertases (sucrose and molasses invertase) had lower activity (lower V-max and higher K-m) than commercial invertase, probably due to enzyme impurities. Furthermore, the substrate and enzyme concentrations also affected the invertase activity, with increased values of V-0 and Q(p) indicating increased invertase activity at a sucrose concentration less than 100 g/L. Furthermore, increasing the crude invertase concentration had a negative effect on enzyme activity because of the greater interference by the impurities in sugar invertase compared to commercial invertase. Moreover, all metal ions were identified as competitive inhibitors and severely inhibited the activity of invertase at 0.6\% (w/v) of metal ion concentration, especially with Ca2+ contamination.
Optimization of saccharification of rice straw plays a crucial role in harnessing maximum fermentable sugars through enzymatic hydrolysis of this complex polymer. The present study was aimed to evaluate the applicability of A. tubingensis NKBP-55 cellulolytic cocktail for generation of fermentable sugars and to carry out parametric optimization of the saccharification process followed by batch ethanolic fermentation of the rice straw hydrolysate. Also, evaluation of the alterations (composition, crystallinity and structural morphology) occurring in the wall polymer structure after sequential treatments was studied. The cellulolytic cocktail, under the statistically optimized conditions (rice straw 4\% w/v and pH 5.0) liberated 578 mg fermentable sugars (glucose 463 mg, xylose 114.35 and cellobiose 0.71 mg) per gram of pretreated rice straw showing 2.17-fold enhancement. Candida shehatae NCIM 3501 utilized both glucose and xylose and produced 16.15 g/L bioethanol along with yield (Y-P/S) 0.50 after 24 h of fermentation. Its bioethanol production was observed to be better than Saccharomyces cerevisiae (13.39 g/L) and their co-culture (15.57 g/L). Sequential changes brought about by the enzymatic treatment of the solid substrate revealed by X-ray diffraction and FTIR analyses showed decrease in the absolute crystallinity (CrI) (54.80 to 48.31\%) and total crystallinity index (TCI) (1.002 to 0.991) and confirmed the degradation of the crystalline domain of cellulose by enzyme. The study demonstrated the potential of cellulolytic cocktail produced by A. tubingensis NKBP-55 in rice straw saccharification and its efficient fermentation by conventional and xylose-fermenting yeast in batch ethanolic fermentation.
Fiber reinforcement is the most common method for modifying polylactic acid (PLA). However, poor compatibility between fibers and PLA, especially at high cellulose contents, can promote cellulose agglomeration in the continuous phase, which damages the mechanical properties of composite materials. To address these issues, bagasse cellulose (BC) was used as a substrate and bifunctional glycidyl methacrylate (GMA) was used as a reactive monomer for graft modification. GMA-modified BC (BC-GMA)/PLA composite materials with different particle sizes were prepared using a blending grafting method, and the influence of the type and content of BC-GMA on the mechanical properties of the composite materials was explored. During the grafting modification of BC, a longer reaction time was found to result in smaller BC particles and a higher degree of grafting. For BC-GMA, the degree of grafting reached 27.02\% with a maximum thermal decomposition temperature of 359.31 degrees C. Furthermore, the BC-GMA/PLA composite material had a greater relative crystallinity of PLA, indicating that BC-GMA was evenly dispersed in the continuous phase. This study demonstrates that grafting modification can successfully achieve high cellulose loading in composite materials and thus reduce the production costs of PLA-based packaging materials.
Root-knot disease caused by Meloidogyne incognita is a matter of grave concern because it affects several economically important crop plants. The use of solid-state fermentation (SSF) may help to elaborate efficient formulations with fungi to be employed in the biologic control of nematodes. Attempts were made to select low-cost substrates for spore production of a strain of Paecilomyces lilacinus with known nematicide capacity. Coffee husks, cassava bagasse, and defatted soybean cake were utilized as substrates, and sugarcane bagasse was used as support. Fermentations were carried out in flasks covered with filter paper at 28degreesC for 10 d. The products obtained by SSF were evaluated for their nematicide activity in pot experiments containing one seedling of the plant Coleus inoculated with the nematode M. incognita. The plants were evaluated 2 mo after inoculation. Fermented products showed a reduction in the number of nematodes. The best results were obtained with defatted soybean cake, which showed almost 100\% reduction in the number of nematodes; the reduction with coffee husk was 80\% and with cassava bagasse was about 60\%.
Treated and untreated rice straw extensively exists in the soil. In order to elucidate its possible effect on the fate of organic pollutants, sorption of pyrene by rice straw and its main constituents (lignin, cellulose, and hemi-cellulose) were studied, as single solute and in the presence of other co-existing organic pollutants, phenanthrene (Phen), benzo{[
Wastes materials produced from bio-energy plants such as ash, slurry etc., may be problematic if they are not safely disposed. The wastes utilization as soil amendments is a viable approach as these are rich source of mineral nutrients. Therefore, the present experiment was conducted to evaluate the nutrient release and changes in physicochemical properties of soil after incubation with a different combination of bio-energy residues. Two variants of sugarcane bagasse ash, (A) combustion ash from sugarcane industry and (G) ash from gasification plant were mixed in 1:1 ratio with wheat straw biochar (B) and dairy manure digestate (D) @ 10, 15 and 20 t ha(-1). Soil samples were taken after 15, 30, 45, and 60 days of incubation and analyzed for soil physico-chemical and biological parameters. Various amendments significantly influenced the soil pH, electrical conductivity, soil respiration, P, and K contents at each sampling interval. The P and K contents in soil amended with digestate+ combustion ash were significantly increased after 60 days of incubation compared to their initial soil contents. Ammonium contents were increased up to 15 days of incubation and then decreased while nitrate contents increased in the same treatment. While macro-aggregate (77 g kg(-1)) and organic carbon contents (1.40\%) were maximum in biochar + combustion ash treatment. The application of bioenergy wastes improved respiration, soil organic carbon, soil P and K contents. The study warrants that these wastes combinations should be tested under field conditions for further recommendations.
Approximately 1.5 trillion tons are the estimated yearly biomass production, making it an essentially unlimited source of raw material for environmentally friendly and biocompatible products transformed by microorganism, specially fungi and actinomycetes. Several lignocellulosic residues, such as sisal waste and sugarcane bagasse contain starch in their structures which could become important sources for the production of amylases. This study evaluated the production of amylolytic enzymes using Streptomyces sp. SLBA-08 strain, isolated from a semi-arid soil, according to their ability to grow on soluble starch as the sole carbon source. The effect of the carbon source (sisal waste and sugarcane bagasse) on alpha-amylase production was studied using submerged cultivations at 30 degrees C. The highest level of alpha-amylase activity corresponded to 10.1 U. mL(-1) and was obtained using sisal waste (2.7\%) and urea (0.8\%) in submerged fermentation after 3 days of cultivation. The partial characterization showed the best alpha-amylase activity at 50 degrees C and pH 7.0. These results are of great importance for the use of sisal waste as a substrate for biotechnological proposes.
This work makes a technical and economic evaluation of incorporation of reheating and regeneration, as a way to increase efficiency of energetic systems and bagasse surplus, in cogeneration systems of Brazilian sugar and ethanol sector. Four scenarios were analyzed: Conventional (CO), with Reheat (C1), Regenerative (C2) and with Reheat and Regeneration (C3). Some of thermodynamic indicators used in evaluation were Surplus Bagasse Index and Exergetic Efficiency, for economic evaluation the Monte Carlo Method was used to give a Net Present Value (NPV) > 0 for each scenario. Technical evaluation indicates that Reheating (Cl) increases bagasse surplus by 39.9\% and exergetic efficiency by 1.90\%, with respect to CO. Incorporation of 1-8 regenerators (C2) increases surplus bagasse and exergetic efficiency in the ranges of 103-160\% and 5.03-8.07\%, respectively. Reheat stage incorporation of 1-8 regenerators (C3) increases surplus bagasse in the range of 121-166\% and increases exergetic efficiency in a range of 5.91 8.46\%. Finally, it was estimated the potential of additional electric power generation during off-season and second generation ethanol production from surplus bagasse, with satisfactory results. (C) 2018 Elsevier Ltd. All rights reserved.
The utilization of bagasse as a raw material to prepare activated carbon adsorbents is an effective way to solve the water pollution problem, while achieving the goal of treating waste simultaneously. An effective activated carbon-based adsorbent was prepared from sugar cane bagasse with a one-step method of pyrolysis and ZnCl2 activation for efficient Cr(VI) removal from water. Morphology, physicochemical properties and structure of the adsorbent samples were studied by Scanning Electron Microscope, Energy Dispersive Spectroscopy, X-ray Diffraction, N-2 adsorption and desorption, Fourier Transform infrared spectroscopy and X-ray Photoelectron Spectroscopy. The batch and fixed bed adsorption experiments were adopted to confirm the one-step preparation of pyrolysis and ZnCl2 during the activation process and to investigate the adsorption mechanism of Cr(VI). The maximum adsorption capacity was 80.880mgg(-1), while the adsorption behavior fitted better with Freundlich equation and pseudo-second-order kinetics. These results confirmed that chemical adsorption is the strongest adsorption interaction during the adsorbing process of Cr(VI), and the adsorbents could effectively capture Cr(VI) to form monodentate and bidentate complexes. {[
Nature provides perfect varying models of hierarchical porous structures, but it remains a great challenge to accurately transfer these models intact to laboratory through carbonization during processing. In this study we report a new class of carbon materials whose hierarchical porous structure is accurately inherited from bagasse through a process consisting of a hydrothermal treatment with thiourea at 180 degrees C and then carbonization at 800 degrees C. The resulting composite structure consists of nanopores, supermicropores and ultramicropores with a high specific surface area of 2419 m(2) g(-1). The treatment with thiourea not only results in N and S doping but creates many papillae of a few hundreds of nanometer in diameter on the tubular wall. As a supercapacitor electrode working at 1 A g(-1) in aqueous electrolyte, it shows a capacitance of 312 F g(-1) (125 F cm(-3)), with 69\% retention even at a very high current density of 20 A g(-1). The material renders a good energy density of 11 Wh kg(-1) at a power density of 125W kg(-1) and shows good cycling stability, 99.7\% of initial capacitance remained after 10,000 charge/discharge cycles. As a lithium ion battery anode, it exhibited capacity of 621 mA h g(-1) at 100 mA g(-1) and the capacity remained at 310 mA h g(-1) at 1000 mA g(-1).
PHB is an important class of PHA-based biopolymers that parallel in material properties with that of many petrochemical polymers. The present work focuses on the fabrication of PHB-based active green composites with the reinforcement of natural fiber-sugar cane bagasse (SCB) and chloroform extract of Curcuma longa. L for the anti-microbial activity. With varying PHB/SCB content (100/0, 80/20 and 70/30 wt/wt \%) the biocomposite's mechanical, thermal, morphological, antimicrobial, and degradation potential were characterized. Thermogravimetric analysis (TGA) and Differential Scanning Colorimetry (DSC) analysis showed that the composite displayed significant improvisation than the neat polymer and the tensile modulus of the biocomposite increased with the addition of the fiber from 416 to 740 MPa. Fabricated material exhibited significant anti-microbial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi and Streptococcus pyogenes, making it an active composite against food-borne pathogens. Moreover, the biodegradation tests based on both soil and water indicated that the biocomposites degraded within a period of 07-18 weeks proving it to be a completely eco-friendly green composite.
This study provided an estimate of the potential of bio-hydrogen production from dark fermentation of crop residues on a worldwide scale. The different crop residues reviewed included sugarcane tops, leaves and bagasse, corn straw, corn cob and corn stover, wheat straw, rice straw and husk, soybean straw, oil palm trunk and empty fruit bunch, sugar beet pulp, cassava residue, barley straw and sweet sorghum bagasse. Among these crop residues, wheat and rice straws are produced in the highest amount although sugarcane dominates crop production on a worldwide scale. Based on the bio-hydrogen yields reported in literature, estimated worldwide bio-hydrogen potential is highest for untreated rice straw at 58,002 Mm(3)/year followed by untreated wheat straw at 34,680 Mm(3)/year. This corresponds to a bio-energy potential of 623 PJ/year and 373 PJ/year for raw rice straw and wheat straw respectively while pre-treatment of the crop residues significantly increases the bio-hydrogen and bio-energy potential. While dark fermentation of crop residues offers a huge bio-energy potential, the process suffers from several constraints that hinder its implementation. As such, coupling of the dark fermentation process with the anaerobic digestion process as a two-stage process seems the most economically viable option for large-scale implementation. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Sugarcane bagasse (SB) and sugarcane trash (SCT) containing 30\% hemicellulose content are the waste from the sugarcane industry. Hemicellulose being heterogeneous, more complex, and less abundant than cellulose remains less explored. The optimized conditions for the pretreatment of SB and SCT for maximizing the delignification are soaking in aqueous ammonia (SAA), 18.5 wt \%, followed by heating at 70 degrees C for 14 h. The optimization of hydrolysis of SAA pretreated (ptd) SB and SCT by the Box-Behnken design in the first step of saccharification by xylanase (CtXyn11A) and alpha-L-arabinofuranosidase (PsGH43\_12) resulted in the total reducing sugar ( TRS) yield of xylooligosaccharides (TRS(XOS)) of 93.2 mg/g ptd SB and 85.1 mg/g ptd SCT, respectively. The second step of saccharification by xylosidase (BoGH43) gave the TRS yield of 164.7 mg/g ptd SB and 147.2 mg/g ptd SCT. The high-performance liquid chromatography analysis of hydrolysate obtained after the second step of saccharification showed 69.6\% xylan-to-xylose conversion for SB and 64.1\% for SCT. This study demonstrated the optimization of the pretreatment method and of the enzymatic saccharification by recombinant xylanolytic enzymes, resulting in the efficient saccharification of ptd hemicellulose to TRS by giving 73.5\% conversion for SB and 71.1\% for SCT. These optimized conditions for the pretreatment and saccharification of sugarcane waste can also be used at a large scale.
In this study, cellobiose, a reducing disaccharide was used to produce succinic acid by Actinobacillus succinogenes Nj113. A final succinic acid concentration of 30.3 g/1 with a yield of 67.8\% was achieved from an initial cellobiose concentration of 50 g/1 via batch fermentation in anaerobic bottles. The cellobiose uptake mechanism was investigated and the results of enzyme assays revealed that the phosphoenolpyruvate phosphotransferase system (PEP-PTS) played an important role in the cellobiose uptake process. In batch fermentation with 18 g/1 of cellobiose and 17 g/I of other sugars from sugarcane bagasse cellulose hydrolysates, a succinic acid concentration of 20.0 g/1 was obtained, with a corresponding yield of 64.7\%. This study found that cellobiose from incomplete hydrolysis of cellulose could be a potential carbon source for economical and efficient succinic acid production by A. succinogenes. (C) 2012 Elsevier Ltd. All rights reserved.
The present research work aimed at developing robust yeast cell factory via adaptive laboratory evolution (ALE) for improved cellulosic bioethanol production. Kluyveromyces marxianus JKH5, a newly isolated thermotolerant ethanologenic yeast, was engineered by serial passaging for 60 generations in medium supplemented with gradually higher concentration of inhibitors (acetic acid, furfural, and vanillin) that are generated during dilute acid pretreatment. The improved strain K. marxianus JKH5 C60, showed 3.3-fold higher specific growth rate, 56\% reduced lag phase and 80\% enhanced fermentation efficiency at 42 degrees C in comparison to parent strain in inhibitor cocktail comprising medium. Bioethanol production by simultaneous saccharification and fermentation of sequential dilute acid-alkali pretreated sugarcane bagasse in presence of inhibitors, resulted in ethanol titre and yield, respectively, 54.8 +/- 0.9 g/L and 0.40 g/g. The adapted yeast can be used to ferment unwashed pretreated biomass, thereby, reducing overall cost, time, and wastewater generation, hence making bioethanol production sustainable.
To survey the anaerobic co-digestion (AcoD) of oil refinery wastewater (ORWW) with sugarcane bagasse (SCB), six different AcoD compositions were evaluated. Results including cumulative biogas production (BGP), bio-methane contents (BMP), and soluble chemical oxygen demand (CODs) removal rate were experimentally obtained. The negligible BGP by ORWW mono-digestion revealed that it could not support any microbial activity. However, increasing the SCB ratio in the AcoD compositions led to increased BGP and BMP contents. By considering the statistical test (LSD0.05) results for the kinetic parameters, the 1: 4 ratio treatment was the most favorable AcoD composition. Moreover, the CODs removal rate from 22.34 +/- 1.63\% for the SCB mono-digestion was improved to 49.67 +/- 0.38\% for the 2:3 AcoD composition and BMP content from 54.12 +/- 0.45\% for the SCB mono-digestion was enhanced to 62.69 +/- 1.22\% for the 1: 4 AcoD composition with 20\% lower SCB usage. The results computed by applying three mathematical models determined that the modified Gompertz model provided the best fit. Also, implementing artificial neural network algorithms to model the BGP data revealed that the Back Propagation algorithm was the best suited for the experimental BGP data, with 0.6444 and 0.9658 for MSE and R-2, respectively.
Rice straw was pretreated with ethylene glycol (EG) and AlCl3 for enzymatic hydrolysis. EG-AlCl3 pretreatment had an extremely good selectivity for component fractionation, resulting in 88\% delignification and 90\% hemicellulose removal, with 100\% cellulose recovered or 76\% (w/w) cellulose content in solid residue at 150 degrees C with 0.055 mol/L AlCl3. The pretreated residue (5\%, w/v) presented a higher enzymatic hydrolysis rate (glucose yield increased 2 times to 94\%) for 24 hat cellulase loading of 10 FPU/g. The hydrolysis behavior was correlated with the composition and structure of substrates characterized by SEM, FT-IR, BET, XRD and TGA. The enzyme adsorption ability of pretreated straw was 12-folds that for the original sample. EG-AlCl3 solution was further cycled for 3 times with 100\% cellulose recovery but only 29\% lignin removal due to the loss of AlCl3. EG-AlCl3 pretreatment is an efficient method with little loss of cellulose for lignocelluloses.
In this study, the tetracycline (TC) removal performance of iron-loaded biochar (BPFSB) derived from sugarcane bagasse and polymerized iron sulfate was investigated, and the mechanism of TC removal was also explored by study of isotherms, kinetics and thermodynamics and characterization of fresh and used BPFSB (XRD, FTIR, SEM and XPS). The results showed that under optimized conditions (initial pH 2; BPFSB dosage 0.8 g \& BULL;L-1; TC initial concentration 100 mg \& BULL;L-1; Contact time 24 h; temperature 298 K), the removal efficiency of TC was as high as 99.03\%. The isothermal removal of TC followed well the Langmuir, Freundlich, and Temkin models, indicating that multilayer surface chemisorption dominated the TC removal. The maximum removal capacity of TC by BPFSB at different temperatures was 185.5 mg \& BULL;g(-1) (298 K), 192.7 mg \& BULL;g(-1) (308 K), and 230.9 mg \& BULL;g(-1) (318 K), respectively. The pseudo-second-kinetic model described the TC removal better, while its rate-controlling step was a combination of liquid film diffusion, intraparticle diffusion, and chemical reaction. Meanwhile, TC removal was also a spontaneous and endothermic process, during which the randomness and disorder between the solid-liquid interface was increased. According to the characterization of BPFSBs before and after TC removal, H-bonding and complexation were the major interactions for TC surface adsorption. Furthermore, BPFSB was efficiently regenerated by NaOH. In summary, BPFSB had the potential for practical application in TC removal.
Rice straw, an abundant agricultural waste, possesses immense potential to serve as renewable, eco-friendly and non-edible feedstock to generate value-added products. Therefore, the present study aimed to obtain prebiotic neutral xylooligosaccharides (XOS)-rich autohydrolysate from rice straw xylan. The central composite design of response surface methodology was employed to optimize the conditions for the alkaline extraction of xylan, i.e. NaOH concentration (6-14\%, w/v), reaction time (1-3.5 h) and temperature (50-100 degrees C). Autohydrolysis of xylan was carried out at 121 degrees C and 15 psi for varied hydrolysis times (10, 25 and 40 min) and sulphuric acid concentrations (0.1, 0.5 and 1.0M) to obtain XOS-rich autohydrolysate. The optimum conditions were found to be as follows: 11.04\% (w/v) NaOH, 3.126 h and 80.146 degrees C, so that the maximum xylan yield of 19.97\% was predicted by the software. This value was quite close to the experimental yield of 19.4\%, with 80.83\% xylan being recovered per gram of rice straw. The best autohydrolysis treatment for xylan was found to be using 0.1M sulphuric acid for 10 min, which allowed 34.5\% of 100 mg xylan to be depolymerized to produce neutral XOS (degree of polymerization up to 7), with xylose, xylobiose and xylotriose constituting 4.45, 10.14 and 7.83 mg, respectively. These autohydrolysates promoted higher growth of Lactobacillus rhamnosus and Lactobacillus casei than established prebiotic fructooligosaccharides. The study attempts to solve disposal issues of rice straw through production of XOS-rich autohydrolysates in demand on the global nutraceuticals market.
The objective of this work was to evaluate the effects of land use change on the dynamics of organic carbon, on total nitrogen, and on microbial soil properties over time, in irrigated sugarcane crops. The systems were evaluated in four areas with sugarcane in a chronosequence of 5, 7, 8, and 9 years of cultivation, besides a native vegetation area. The soil samples were analyzed for C and N stocks, and for the microbiological properties of the soil. The system with 8 years showed the highest C values of microbial biomass and basal respiration, and the lowest ones for microbial metabolic quotient (qCO(2)). The highest values of C and N stocks were observed in the native vegetation area. These results are associated with the constant deposition of litter and intense biological activity in the native vegetation. The deposition of sugarcane straw on the soil surface, over time, improved soil quality and kept the soil stocks of C and N similar to those observed in the native vegetation area.
This research investigates the soil conditioning effect of sugar cane fields with biochar produced from sugarcane bagasse. Its influence on the physicochemical and microbiological conditions of the soil and the agronomic performance of sugarcane seedlings was verified. To this end, the biochar from sugarcane bagasse was produced by pyrolysis in a double drum oven and mixed with soil at rates of 0, 1\%, 3\%, and 5\% (in weight). The experiment was installed in a greenhouse with two evaluation periods (30 days and 60 days) and five replicates. Each pot received a pre-sprouted cane seedling, and the analysis of colony-forming units (bacteria and fungi), physicochemical characteristics of the soil, and growth and development of sugarcane were performed per pot. The biochar showed a high fixed carbon content (72\%) and a specific surface area estimated by the adsorption of methylene blue of 50 m2 g-1. Furthermore, its structure is porous and contains important nutrients (e.g., CaO, K2O, and P2O5). In the periods evaluated, the applications of the 3\% and 5\% (in weight) rates of biochar reduced most of the soil fertility parameters. However, the chemical analyses indicated that the sugarcane field soil collected already possessed high fertility. The microbiota was influenced, but only the application of the 3\% (in weight) rate at 60 days after planting showed a significant positive effect on the number of bacteria forming units, with an increase of approximately 385\%. On the other hand, no significant positive effect on sugarcane development was found. Therefore, biochar application in high-fertility sugarcane plantation soil did not result in gains for sugarcane development in the periods evaluated.
This study was designed to prepare the sugarcane bagasse (SB) composite with polyani-line (PAn), polypyrrole (Ppy) and sodium alginate (NaA) and employed as an adsorbent for the adsorptive removal of herbicide (2,4-dicholorophenoxyacetic acid, 2,4-D). Fabricated composites were characterized by SEM and FTIR techniques. The affecting variables, i.e., temperature, contact time, initial herbicide concentration, medium pH and adsorbent dose were studied in batch mode. Different isotherms were employed on the adsorption data and the maximum adsorption capacity of SB was recorded to be 77.75 mg/g at pH 3.0, 150 mg/L 2,4-D initial concentration at 30 degrees C. The models (pseudo-second-order and Freundlich) best explained the adsorption experimental data with R2 values > 0.90 and > 0.96, respectively. The thermodynamics parameters (DG, DH, and DS) were computed and the herbicide adsorption onto the composites was an exothermic and spontaneous process. Results revealed that sugarcane bagasse composites with PAn, Ppy, and NaA are efficient adsorbents, which could be used for the remediation of 2,4-D in the effluents.(c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Agro-industrial by-products are being explored as alternative low-cost nutrients to produce hyaluronic acid (HA) by Streptococcus zooepidemicus. In this study, we formulated three culture media containing corn steep liquor (CSL) and sugarcane molasses (M), to produce microbial HA using batch bioreactor conditions (pH 6.7, 500 rpm and 1 vvm aeration). Final HA concentrations of 3.48 g L-1 were produced in culture medium containing corn steep liquor (10\% v/v) and glucose, being comparable (3.60 g L-1) to the control medium containing tryptone and glucose. The use of molasses (10\% v/v) as carbon source produced a marked inhibition of S. zooepidemicus growth and HA production due to a low sugar consumption. The HA produced in CSL culture media had a high molecular weight of 3.8 x 10(3) kDa, greater than HA produced in tryptone-containing medium (3.0 x 10(3) kDa). This is the first report achieving HA productions comparable to synthetic a medium in a batch bioreactor using CSL as the main nitrogen source. However, further optimization of culture conditions must be carried out towards using this agricultural by-product for the sustainable industrial production of HA. (C) 2016 Elsevier B.V. All rights reserved.
Purpose This research aimed at isolating and characterizing an ethanol and H-2-producing strain from a thermophilic consortium, obtained from sludge from anaerobic reactors applied to sugarcane vinasse treatment, evaluating its fermentative activity and its main metabolites in optimal pH and substrate (xylose) ranges by means of Rotational Central Composite Design (RCCD). Methods An anaerobic strain 99\% similar to Thermoanaerobacterium calidifontis (VCS1) was isolated from enriched Upflow Anaerobic Sludge Blanket (UASB) sludge, by using Anaerobic Mineral Medium (AMM) under 55 degrees C and pH 7.0. Its kinetics parameters were evaluated using xylose as the sole substrate, it was possible to establish the generation time (Tg = 9.12 h) and the specific growth rate (mu = 0.076 h(-1)). Besides that, the statistical method of RCCD was efficiently applied in order to find the optimal xylose concentration (3.6 to 69.5 mmol L-1) and pH (5.9 to 8.1) ranges to H-2 and/or ethanol production. Results The H-2 production was 20.4\% improved at pH 6.8 and 33.8 mmol xylose/L, while ethanol production was 82.1\% improved at pH 7.0 and 36.6 mmol xylose L-1. For the simultaneous production of H-2 and ethanol, the best conditions were pH 7.0 and 36.0 mmol xylose L-1. Conclusion The cultivation and enrichment of T. calidifontis VCS1 to degrade xylose-containing wastes might enhance the production of by-products of biotechnological interest, such as H-2 and ethanol. The results reported may subside future studies regarding up-scaling xylose biodegradation processes, by using the optimal range described.
Sugarcane ethanol biorefineries in Brazil produce carbon dioxide, electricity and heat as byproducts. These are essential inputs for algae biodiesel production. In this paper, we assessed ethanol's life cycle greenhouse gas emissions and fossil energy use produced in an integrated sugarcane and algae biorefinery where biodiesel replaces petroleum diesel for all agricultural operations. Carbon dioxide from cane juice fermentation is used as the carbon source for algae cultivation, and sugarcane bagasse is the sole source of energy for the entire facility. Glycerin produced from the biodiesel plant is consumed by algae during the mixotrophic growth phase. We assessed the uncertainties through a detailed Monte-Carlo analysis. We found that this integrated system can improve both the life cycle greenhouse gas emissions and the fossil energy use of sugarcane ethanol by around 10\% and 50\%, respectively, compared to a traditional Brazilian sugarcane ethanol distillery. (C) 2014 Elsevier Ltd. All rights reserved.
Organosolv lignins were extracted from corn stover, wheat, rice straw, reed straw, and sugarcane bagasse using a mixture of acetic and formic acids, at relatively low temperature and atmospheric pressure. Lignin content, residual carbohydrates, ash levels, proteins, and molecular weights were determined in each extracted lignin. The lignin content of all samples was relatively high, confirming the performance of the pretreatment process. The low molecular weights were in a narrow range, in accordance with the organosolv lignin molar masses. However, some differences between studied lignins were highlighted, in particular in rice straw lignin, which contained the highest silica, calcium, and nitrogen contents. Nuclear magnetic resonance spectroscopies (31P and semiquantitative Heteronuclear Single Quantum Correlation) underlined the structural similarities and differences between these organosolv lignins. Corn stover and sugarcane bagasse lignins were rich in non-methoxylated (H-Unit) or mono-methoxylated (G-Unit) phenolic units, making them the best promising candidates for production of phenolic resins. Wheat straw lignin was richer in aliphatic OH than in phenolic OH. This is an advantage for use as polyol substitute in polyurethane synthesis. Reed straw lignin was less specific, with a balanced content of OH groups. However, it contained a high concentration of beta-O-4 linkages, which is favorable for depolymerization.
Biosurfactants are microbial metabolites with possible applications in various industrial sectors that are considered ecofriendly molecules. In recent years, some studies identified these compounds as alternatives for the elimination of vectors of tropical diseases, such as Aedes aegypti. The major bottlenecks of biosurfactant industrial production have been the use of conventional raw materials that increase production costs as well as opportunistic or pathogenic bacteria, which restrict the application of these biomolecules. The present study shows the potential of hemicellulosic sugarcane bagasse hydrolysate as a raw material for the production of a crystalline glycolipidic BS by Scheffersomyces stipitis NRRL Y-7124, which resulted in an emulsifying index (EI24) of 70 +/- 3.4\% and a superficial tension of 52 +/- 2.9 mN.m(-1). Additionally, a possible new application of these compounds as biolarvicides, mainly against A. aegypti, was evaluated. At a concentration of 800 mg.L-1, the produced biosurfactant caused destruction to the larval exoskeletons 12 h after application and presented an letal concentration (LC50) of 660 mg.L-1. Thus, a new alternative for biosurfactant production using vegetal biomass as raw material within the concept of biorefineries was proposed, and the potential of the crystalline glycolipidic biosurfactant in larvicidal formulations against neglected tropical disease vectors was demonstrated.
In this work, production of inulinase was studied. Media formulation was optimized by experimental design and response surface techniques, as well as the pretreatment of the agro-industry residues used in the formulation of fermentation medium. Two agro-industry residues were investigated: sugarcane molasses (SCM) and corn steep liquor (CSL). Pretreatment with sulfuric acid was the most effective for clarification of SCM (pH 5.0, 24 h of resting time and final pH 4.0). Clarification of CSL was accomplished with phosphoric acid (pH 3.0, 24 h of resting time and final pH 5.5). A color reduction of approximately 70\% was achieved for both substrates. The highest production of inulinase was obtained in a medium containing 100 g l(-1) of pretreated SCM, 100 g l(-1) of pretreated CSL and 6 g l(-1) of Prodex Lac (yeast hydrolysate), yielding 1,139 U ml(-1).
Aspergillus niger grew well and secreted high phytase titres in solid state (SSF) and submerged (SmF) fermentations using sugarcane bagasse and cane molasses medium, respectively. Optimization of culture conditions increased the phytase production in both SSF and SmF. High enzymes production was recorded at 32A degrees C and pH 4.0 after 48 h of incubation in SmF using 8\% (v/v) cane molasses supplemented with ammonium nitrate (0.4\% w/v). The mould secreted high enzyme titres using sugarcane bagasse in SSF at 32A degrees C with a substrate to moisture ratio of 1 : 2.5 after an incubation of 48 h. Supplementation of sugarcane bagasse with starch and ammonium nitrate further increased phytase production. An overall 23- and 10-fold enhancement in phytase production was attained under SmF and SSF conditions, respectively. The crude enzyme was optimally active at pH 3.0 and 50A degrees C that resulted in the hydrolysis of phytic acid in a time dependent manner. The enzyme resulted in dephytinization of wheat and gram flours with concomitant release of inorganic phosphate, soluble protein and reducing sugars. The enzyme being acid stable and thermostable could find application in dephytinization of food and feed ingredients of monogastric animals.
Agro-industries have the potential to make a substantial contribution to sustainable energy supply in Africa, including energy access in rural areas. This paper focuses on the drivers and barriers to wider use of cogeneration from sugarcane bagasse in Malawi as there is a potential for the technology to enable access to electricity in rural areas. The paper gives an overview of the policy landscape for the energy sector and the sugar industry in Malawi. The research involved site visits, focus group discussions, and individual semi-structured interviews with participants from key government departments, businesses, research institutes and international agencies. It was found that energy sector reform, the proposed feed-in tariff for renewable energy, and risk are the key issues for investment in this area.
This study was conducted to establish the potential of bagasse, the fibrous by-product of sugarcane milling operation, as a precursor for preparing adsorbents for gold-thiourea complex. It was also of interest to identify the carbon properties, which promotes adsorption. Bagasse was activated in this study by physical (gasification) and chemical techniques. It was found bagasse is more amenable to activation by physical techniques producing activated carbon with surface areas exceeding 1000 m(2)/g. Among the chemical activating agents, it was found that ZnCl2 was most effective in developing the surface structure of bagasse. Gold-thiourea adsorption was found to be favoured in carbon exhibiting high surface area. Finer pore sizes are developed with higher surface area. As such the extent to which the surface area could improve adsorption was limited by steric hindrance in the finer pore size. It was found that steric hindrance affected gold-thiourea adsorption in mean pore sizes less 20 Angstrom. The effect was particularly significant when the carbon pH was greater than 7.0, where the alkaline nature of the carbon may have shifted the Tu/Au ratio to higher values such that the formation of the larger AuTu(2)(+) and AuTu(3)(+) are promoted. The greater development of physically activated bagasse 2 3 favoured gold-thiourea adsorption. The optimum adsorption capacity by the physically activated bagasse was approximately 318 mg Au/g of adsorbent (ash free), achieved after 25 h of gasification in 15\% CO2. This was comparable to adsorption capacities obtained from commercial activated carbon and resins of 197-321 mg Au/g adsorbent (ash free). These results are encouraging and confirm the potential of activated bagasse as gold-thiourea adsorbent. (C) 2003 Elsevier Science Ltd. All rights reserved.
Sugarcane cultivation supports Brazil as one of the largest world sugar and ethanol producer. In order to understand the impact of changing sugarcane harvest from manual to mechanized harvest, we studied the effect of machinery traffic on soil and consequently soil compaction upon soil microbial communities involved in nitrogen cycling. The impact of sugarcane harvest was dependent on soil depth and texture. At deeper soil layers, mechanized harvesting increases the abundance of nitrogen fixers and denitrifying communities (specificallynosZ clade I and II) while manual harvesting increases the abundance of ammonia oxidizers (specifically AOA) and increases denitrifying communities (nosZ clade I and II) on top and at intermediate depth. The effect of change on the harvest system is more evident on sandy soil than on clay soil, where soil indicators of compaction (bulk density and penetration resistance) were negatively correlated with soil microorganisms associated with the nitrogen cycle. Our results point to connections between soil compaction and N transformations in sugarcane fields, besides naming biological variables to be used as proxies for alterations in soil structure.
Ethanol steam reforming of synthetic bioethanol (i.e., anhydrous ethanol plus water), as well as bioethanol obtained from glucose standards and sugarcane press-mud was evaluated on monoliths washcoated with RhPt/CeO2-SiO2. Tests with synthetic bioethanol indicated that the lower pressure drop favors higher ethanol conversion in the monoliths with respect to the powder samples. Also, two monoliths in series with 0.08 g(cat)/cm(3) improved H-2 yield compared to just one monolith with 0.16 g(cat)/cm(3). Similarly, a decrease in the amount of carrier gas contributes to diffusion limitations in the monoliths, reducing the H-2/CO ratio. Monoliths stability was also evaluated with ``real{''
Developing optimum treatment and separation procedures for hemicellulose components of lignocellulosic biomass could be useful in ethanol fermentation processes and obtaining pure hemicelluloses as biopolymers. Sugarcane bagasse analyses indicate that xylose is the major hemicellulose component constituting 17.7\% of dry bagasse weight. In this study the effects of treatment conditions such as time, temperature and pressure on the yields of extracted hemicelluloses were studied. The optimum conditions were achieved at 180 degrees C for 30 min and 1 MPa pressure, with the yield of xylose reaching to 85\% and the concentrations of sugar degradation products such as HMF and furfural remaining minimal at 0.95 and 0.07 g/L, respectively. Further, isolation of hemicelluloses from extracted hemicelluloses solutions was performed using Alfa Laval M20 membrane filtration system in two steps: (1) concentration of high molar mass hemicelluloses by ultrafiltration; and (2) separation of low molar mass hemicelluloses and oligomeric sugars by nanofiltration. The isolated hemicelluloses with the optimum pretreatment conditions were characterized by FT-IR and C-13 NMR techniques, resulting in agreement with typical spectra of xylan-type hemicelluloses. (C) 2013 Elsevier Ltd. All rights reserved.
Energy cane bagasse (ECB) is the major residue after the cane is milled to extract juice for sugar, biochemical, and/or biofuel production. The sustainable conversion of ECB into high value-added products can help reduce agricultural waste, and enhance utilization of bioresources. In the present work, we demonstrate that ECB can be converted into cellulose nanofibers (CNFs) that can serve as high value-added additives in bentonite water-based fluids (BT-WDFs). Particularly, cellulose fibers (CFs) were rapidly isolated from ECB by microwave-assisted NaOH / NaClO2 treatments. CFs treated with the higher NaOH concentration and microwave irradiation lost more lignin (96.2 \% delignification) and their crystal structure was more completely transformed from cellulose I to II, resulting in smaller diameters (8.5 mu m). CNFs suspensions from subsequent wet-grinding and microfluidization of the CFs exhibited typical shear-thinning behaviors and solid-like viscoelastic properties due to the entangled network structure of the CNFs. Formulated fluids with 0.5 wt\% of the manufactured CNFs showed good rheological and filtration properties, demonstrating their potential applications in the oil service industry.
The rice straw (RS) is a kind of recalcitrant lignocellulosic material. The Fenton reaction has been widely used for the degradation of organic compounds and toxic chemicals. Therefore, applying it to pretreatment straw seems to have good, potential. This study was to investigate the degradation of the pretreated RS by the mixed solid-state culture with Phanerochaete cluysosporiwn and Aspergillus nigert. The results showed that the degree of delignifition was 15.01\% by using an optimized Fenton reagent (6 g/L of FeSO4 center dot 7H(2)O and 15\% concentration of H2O2) at a solids loading of 5\% (w/v) and a moderate temperature for 15 h. The analysis of the Fenton pretreated RS by Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) showed significant changes in physicochemical structure, favoring the subsequently susceptibility of ligninolytic enzymes. The volatile organic compounds collected from the mixed solid-state culture implied the degradation degree of the lignocellulose to some extent. In conclusion, Fenton pretreatment could effectively disrupt the recalcitrant structure of RS and accelerate its biodegradation, which has high potential application in the energy conversion and utilization of lignocellulose.
Concrete is widely used as a building material all over the world, and its use is increasing the demand of cement and sand in the construction industry. However, the limited resources and environmental degradation are driving scientists to develop alternative materials from vast volumes of agro-industrial wastes as a partial replacement for conventional cement. In the manufacture of concrete, cement is a major binding resource. This study looked into recycling agro-industrial wastes into cement, such as sugarcane bagasse ash (SCBA), coal bottom ash (CBA), and others, to create sustainable and environmentally friendly concrete. This study aims to see how the combined effects of agricultural by-product wastes affected the characteristics of concrete. SCBA is used to replace fine aggregate (FA) ranging from 0 to 40\% by weight of FA, while CBA is used to replace cement content ranging from 0 to 20\% by weight of the total binder. In this case, a total of 204 concrete samples (cubes and cylinders) are made using a mixed proportion of 1:1.5:3 and a water-cement ratio of 0.54. Workability, density, water absorption, and mechanical characteristics in terms of compressive and splitting tensile strengths were examined in this study. In addition, for each mix percentage, the total embodied carbon was determined. Workability, density, and water absorption were found to be considerably decreased when CBA and SCBA concentration increased. Due to the pozzolanic nature of CBA and SCBA, an increase in compressive and splitting tensile strengths were seen for specific concrete mixtures, and further addition of CBA and SCBA, the decrease in strength. The embodied carbon of SCBA has augmented the total embodied carbon of concrete, though it can be seen that C15S40, which comprises of 15\% CBA and 40\% SCBA, is the optimum mix that attained tensile and compressive strength by 3.05 MPa and 28.75 MPa correspondingly, with a 4\% reduction in total embodied carbon.
In order to improve the pretreatment behavior of neutral deep eutectic solvent (DES), a novel method was proposed by using three types of Lewis base (sodium carbonate, sodium sulfite and sodium acetate as catalysts to pretreat corn straw at 120 degrees C for 3 h. As compared to DES, DES with Na2SO3, DES with NaAC and DES with Na2CO3, all can remove most of hemicellulose and lignin in pretreated corn straw. Meanwhile, the 94.5\% of glucose yield was obtained treated by DES with Na2CO3 and was approximately five-fold higher than that of the untreated substrate at an enzyme loading of 15 FPU/g material. The regenerated lignin displayed well-preserved structures, and possessed a high purity (more than 84\%), narrow molecular weight distribution (PDI < 2.4), excellent thermal stability. Overall, this work provided detailed analysis for efficient deconstruction of corn straw for future industrialized application. (C) 2022 Elsevier Ltd. All rights reserved.
This study aimed at evaluating different enzyme combinations in the saccharification of sugarcane bagasse (SCB), soybean husks (SBH) and oil palm empty fruit bunches (EFB) submitted to mild acid and alkaline pretreatments. Enzyme pools were represented by B1 host (crude cellulase/xylanase complexes of Penicillium verruculosum); B1-XylA (Penicillium canescens xylanase A expressed in P. verruculosum B1 host strain); and F10 (Aspergillus niger beta-glucosidase expressed in B1 host strain). Enzyme loading was 10 mg protein/g dry substrate and 40 U/g of beta-glucosidase (F10) activity. SCB was efficiently hydrolyzed by B1 host after alkaline pretreatment, yielding glucose and reducing sugars at 71 g/L or 65 g/100 g of dry pretreated substrate and 91 g/L or 83 g/100 g, respectively. B1 host performed better also for EFB, regardless of the pretreatment method, but yields were lower (glucose 27-30 g/L, 25-27 g/100 g; reducing sugars 37-42 g/L, 34-38 g/100 g). SBH was efficiently saccharified by the combination of B1 host and B1-XylA, yielding similar concentrations of reducing sugars for both pretreatments (92-96 g/L, 84-87 g/100 g); glucose recovery, however, was higher with alkaline pretreatment (81 g/L, 74 g/100 g). Glucose and reducing sugar yields from initial substrate mass were 42\% and 54\% for SCB, 36\% and 42-47\% for SBH and 16-18\% and 21-26\% for EFB, respectively.
Ethanol and biodiesel industries generate large volumes of by-products, such as vinasse and glycerol, which are suitable for biogas exploitation. This paper assessed the applicability and process performance of the anaerobic structured-bed reactor (AnSTBR) for the mesophilic (30 ?) continuous (105 days) anaerobic co-digestion of sugarcane vinasse and distilled glycerol under increasing organic loading rates (OLR) (0.5-5.0 kgCOD m(-3)d(-1)). The highest methane yield (211 NmL g(-1)CODr(em.)) and volumetric production (668 NmL L(-1)d(-1)) occurred at an OLR of 3.5 kgCOD m(-3)d(-1). The performance of the AnSTBR showed high removal efficiencies of total COD (77.1\%), carbohydrates (81.9\%), and glycerol content (99.7\%). Biofilm growth enhancement within the reactor offset the impairment of methanogenesis activity at high organic loads. The prompt biodegradability of glycerol reinforced the importance of gradually increase the organic load to prevent the buildup of volatile acids and maintain a stable long-term co-digestion system.
This study attempted to directly integrate a continuous stirred tank reactor (CSTR) with an up-flow anaerobic sludge blanket (UASB) reactor for two-stage hydrogen and methane production. CSTR was used to produce hydrogen from a 25 g-COD/L sugarcane syrup. The hydrogenogenic effluent from CSTR was directly fed to UASB for methane production. The working volumes of CSTR and UASB reactors were 1 and 24 L, respectively. Optimization of hydraulic retention times (HRT) for two-stage hydrogen and methane production after an integration were examined. A maximum hydrogen production rate of 17.5 L/L.d and methane production rate of 2.25 L/L.d were achieved at optimal HRTs of 3 h in the CSTR and 3 d in the UASB with a total energy production rate of 270 kJ/L.d. The two-stage reactors performed well in producing hydrogen and methane over 200 days with a total COD removal of 97.5\%. The natural microflora in sugarcane syrup was greatly affected by HRT but HRT did not affect the archaea community. The volatile fatty acids to alkalinity ratio in the UASB reactor was below the critical value of 0.4 at every HRT, indicating stability of a long term methane production process with direct feeding of non-pretreated hydrogenogenic effluent. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Water contamination of As is a big issue in many areas around the globe. Therefore, cheap and efficient techniques are essential facing traditional treatment methods. Then, biochars (BC) emerged recently as material that can be used for As removal. However, research about efficiency of BC produced from local feedstock is still needed. The purpose of this study is to assess the efficiency of BC produced from sugarcane bagasse (SB) together with corncob husk (CH) with and without Fe(III) (BCFe) modification to be used for removal of As(III) from waters. The BC and BCFe produced at different pyrolysis temperatures were characterised using FTIR and SEM/EDS. Adsorption capacities of BC and BCFe were evaluated via batch adsorption, desorption and column tests and their performance was compared with adsorption using activated carbon. The results showed that Fe modification improve substantially the As(III) adsorption in a way that both BCFe-SB and BCFe-CH removed from 85\% to 99.9\% from 1000 mu g/L As(III) solutions. Both materials fitted well in Langmuir model and the maximum adsorption capacity was 20 mg/g for BCFe-SB and 50 mg/g for BCFe-CH. The adsorption kinetics of BCFe was fast (<= 30 min) and it had a better performance than activated carbon. The column tests showed that the process is efficient even at high As(III) concentrations. The fast removal process and good removal results make the BCFe-SB and BCFe-CH attractive for in situ and commercial (filters) use, since time and efficiency are required in new technologies.
Low temperature pyrolysis investigations were carried out on waste lignin, a coproduct of bioethanol production from sugarcane bagasse, in the temperature range 200-800 degrees C for 15 to 60 min under argon atmosphere. In-depth characterization of resulting chars was carried out using a range of analytical techniques including XRD, HRSEM, EDS, NMR, FTIR, Raman and BET analysis. In addition to good agreement with the published literature, we report the formation of range of multidimensional carbons from waste lignin in the form of nanofibers, micro-ribbons, complex 3D structures and their blends. XRD data showed the evolution of crystalline as well as amorphous structures as a function of temperature. Reaction pathways for structure evolution and associated phase transformations were also identified. The preparation of these novel carbon structural forms from an abundant, waste bioresource could help realize the untapped potential of waste lignin, the exploration of their properties and future applications. (C) 2017 Elsevier B.V. All rights reserved.
The mechanized harvesting is best performed in shallow furrows. The straw promotes greater retention of water, reduces evaporation from the surface, but affects the budding. The polymers modify the physiology providing water and nutrients. The objective of this study was to understand the relationship of form of planting, straw and polymers with bioenergy (of the stalk, straw and system), productivity (stalks, straw and biomass), fiber and total recoverable sugar (TRS). The sugarcane ratoon has been used in plots (2 x 4), that is, two depths and four doses of the polymer. The plots were subdivided into treatments with four doses of dry matter and three repetitions. The use of dose of 5 t ha(-1) as top dressing was detrimental to the productivity of sugarcane, biomass and bioenergy. The form of planting and the use of polymer did not affect the studied variables. There is a linear relationship between productivity and bioenergy stalk, straw and bioenergy productivity of trash. The bioenergy system has a linear relationship with biomass, fiber and TRS. The bioenergy is divided into 82.6\% in stalk and 17.4\% in straw.
Crop management systems that favor soil organic matter can improve the available nutrient content for plants and reduce the use of industrial fertilizer. Despite the importance of organic compounds as a P source, little is known about its dynamics in tropical environments. The objective of this study was to identify organic P species present in humic acids by NMR P-31 analysis in a fine clay Fluventic Eutrochrepts in Campos dos Goytacazes, in the north of Rio de Janeiro State, Brazil, under long-term sugarcane cultivation with preservation of trash and stillage addition. NMR P-31 showed an accumulation of organic P in more easily mineralizable forms such as P in diester linkages in the areas with organic matter preservation. In the areas where the crop trash was burned prior to harvesting, more stable organic P forms such as orthophosphates in monoester linkages were observed. These results obtained with NMR P-31 would suggest that the humic acids constitute an important pool of labile organic P in the areas with higher organic matter content. In the areas with sugarcane burning, however, the recalcitrant organic P is accumulated in humic acids. This suggests that available P in humic substances is an important source of P for plant nutrition.
IntroductionGreater amounts of fertilizer are applied every year to meet the growing demand for food. Sugarcane is one of the important food sources for human beings. MethodsHere, we evaluated the effects of a sugarcane-Dictyophora indusiata (DI) intercropping system on soil health by conducting an experiment with three different treatments: (1) bagasse application (BAS process), (2) bagasse + DI (DIS process), and (3) the control (CK). We then analyzed soil chemistry, the diversity of soil bacteria and fungi, and the composition of metabolites to clarify the mechanism underlying the effects of this intercropping system on soil properties. Results and discussionSoil chemistry analyses revealed that the content of several soil nutrients such as nitrogen (N) and phosphorus (P) was higher in the BAS process than in the CK. In the DIS process, a large amount of soil P was consumed by DI. At the same time, the urease activity was inhibited, thus slowing down the loss of soil in the DI process, while the activity of other enzymes such as beta-glucosidase and laccase was increased. It was also noticed that the content of lanthanum and calcium was higher in the BAS process than in the other treatments, and DI did not significantly alter the concentrations of these soil metal ions. Bacterial diversity was higher in the BAS process than in the other treatments, and fungal diversity was lower in the DIS process than in the other treatments. The soil metabolome analysis revealed that the abundance of carbohydrate metabolites was significantly lower in the BAS process than in the CK and the DIS process. The abundance of D(+)-talose was correlated with the content of soil nutrients. Path analysis revealed that the content of soil nutrients in the DIS process was mainly affected by fungi, bacteria, the soil metabolome, and soil enzyme activity. Our findings indicate that the sugarcane-DIS intercropping system can enhance soil health.
The development of sustainable materials, considering the design aspects is one of the real challenges among the researchers. In general. the renewable resources used in several applications, should not harm ecosystems and maintain the environmental sustainability. In this context, local agricultural by-products or wastes are focused on as an alternative material due to their lightweight and can be easily disposed of after their usage. Agro-waste and biomass materials are plentifully available in the world. The fibers obtained from the agricultural by-products are often used as fillers or reinforcement. Presently, biodegradable polymer matrixes are becoming popular and are finding in number of applications in manufacturing components used in automobiles, medical, domestic, and others. Polylactide (PLA) is a compostable and biodegradable thermoplastic polymer that is derived from renewable agro-sources such as potatoes, corn, or sugarcane. When suitable filler materials are reinforced with these polymers, an improvement in the strength can be seen. In the present work, the rice straw reinforced polylactide (PLA) composites are fabricated with the standard procedure, in accordance with ASTM standards. The experimental studies for the three types of polylactide composites are carried out to characterize their Impact and hardness strength. It is found a higher impact strength for 20 wt\% un-treated fiber content of PLA composites. The hardness value is better for treated fiber content PLA composites. Copyright (c) 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Smart and Sustainable Developments in Materials, Manufacturing and Energy Engineering
The increased dependence on fossil fuels has led to its shortage. Adding to this, awareness around the world has risen about the ill effects of fossil fuels and thus there has been an increasing shift to green sources of fuel. At the production level, ethanol has a significant effect on agricultural commodity markets, and with the price of the commodities approximately doubling in the past few years, feedstock prices have increased significantly. Bio-ethanol obtained from non-food sources can also eliminate the dependence on oil. In this work, two models are developed using Aspen Plus V11 for the production of bioethanol using second-generation feedstocks (waste materials) i.e., sugarcane bagasse and brown algae. The basic process involves four main steps which are the Pretreatment of the raw materials, the saccharification, the fermentation process of the pre-treated product using the necessary enzymes, and the purification process. A detailed exergy analysis for the processes was carried out which showed that for 2000 tons per day of feed used in the processes, the exergy losses were around 625 kW and 180 kW for sugar cane bagasse and brown algae as feedstocks respectively. An economic analysis was performed using the Aspen economic analyzer which estimated the Total capital investment per gallon of bioethanol at around USD 17 and USD 12 for the production processes of bioethanol using sugar cane bagasse and brown algae respectively.
Separation of extraneous matter (EM) from sugarcane stalks to prevent yield losses during extraction, detrimental impacts on sugar manufacture, and to provide separated extraneous matter (SEM) for energy generation in mills requires an effective dry cleaning system (DCS). This study evaluated different types of DCS operating in Brazilian sugar-energy plants, located in the states of Sao Paulo (SP) and Goias (GO), using a standard methodology. The separation efficiency of leafy extraneous matter (LEM), i.e., brown and green leaves, measured for DCS operating at full ventilation capacity varied from 17 to 49 wt\% (kg LEM separated per 100 kg LEM fed, wet basis). The efficiency for inorganic extraneous matter (IEM) varied from 18 to 78 wt\% (kg IEM separated per 100 kg IEM fed, wet basis). These DCS efficiencies are lower than those reported in literature, presumably because of differences in methodologies and system processing capacity. This commercial-scale study also identified deficiencies during the trials associated with design, operation, and maintenance parameters of the various DCSs. These commercial-scale results are important for improving future DCS operation because even with moderate efficiencies, the systems are important for the integrated sugarcane green-harvesting system.
The one-pot biomass conversion process is a promising strategy to minimize potential product loss and reduce processing costs. However, this strategy has technical limitations due to the inhibitory effects of biomass components like lignin as well as the generated inhibitors (e.g., furans, phenols) during biomass processing. In this study, the inhibitory effects of liquid hydrolysates formed by hydrothermal pretreatment of soybean straw with either sodium hydroxide (NaOH) or hydrogen peroxide (H2O2) on cellulolytic enzyme activity were investigated. Hydrothermal pretreatment of soybean straw (10\% w/v) was carried out with either sodium hydroxide (1\% v/v) or hydrogen peroxide (1\% v/v) at 121 degrees C for 60 min to evaluate the effect of water-soluble inhibitors released from soybean pretreatment on cellulolytic enzyme activity. The fraction of cellulose in pretreated solids (1\% w/v glucan) was enzymatically hydrolyzed for 72 h with 45 IU/g glucan (corresponding to 25 mg enzyme protein/g glucan) in the presence of either buffer or liquid hydrolysate generated from the pretreatments. Hydrolysis of NaOH and H2O2 pretreated solids resulted in 57\% and 39\% of glucose yields in buffer, respectively. In the presence of the liquid hydrolysates, NaOH and H2O2 pretreated biomass showed 20\% and 30\% glucose yield, respectively, indicating the enzyme suppression by inhibitors in the liquid hydrolysates. Of the enzyme activities in hydrolysates tested, NaOH hydrolysate showed a higher inhibitory effect on enzyme activities (mainly beta-glucosidase) compared to H2O2 liquid, where enzyme deactivation has a first-order correlation and the manner in which the vacuum-filtered inhibitors were generated from pretreated soybean straw.
In recent years, graphene oxide (GO) and reduced graphene oxide (r-GO) are being produced using graphite powder as precursor material but the preparation of graphene derivatives from a non-graphitic material without an additional oxidizing agent has not been reported so far. In this work, an agrowaste namely sugarcane bagasse was subjected to pyrolysis at three different temperatures, bypassing the use of toxic chemicals and graphite as a precursor. The chemistry of the effect of temperature and time on the development of graphitic planes in a non-graphitic material was studied. The formation of nanosheets of GO suggested that aromatization and condensation of the glucose monomers might have taken place which led to the glycosidic bond formation, further converging into polyaromatic rings on pyrolysis. The GO was further reduced at 95 degrees C using thiourea which resulted in the formation of r-GO after 8 hrs.
About 50\% is of harvest is wasted when producing rattan furniture. With such huge amount of waste, we undertook a study to convert rattan waste into binderless board with superior properties. This study compared the mechanical and physical properties and morphologies of binderless boards manufactured from rattan fibres with boards made from kenaf, coconut husk and sugarcane bagasse using hot press process. Raw fibres were characterised using scanning electron microscopy and thermal analysis to study their suitability in producing self-bonded board, and then dried in the oven before being hot pressed at a pressure of 147.5 kPa. Modulus of rupture (MOR), internal bonding strength, thickness swelling and water absorption of the manufactured binderless boards were evaluated based on the Japanese Industrial Standards. Results showed that rattan binderless boards exhibited slightly lower MOR and higher internal bonding strength with good dimensional stability compared with the rest of the binderless boards. It was concluded that rattan fibres have high potential to be used as binderless boards under hot press conditions.
PurposeBarley straw from brewing process is an attractive and renewable raw material for the production of biofuel and useful chemicals, such as xylitol. It is necessary to determine the best conditions of biomass hydrolysis and fermentation for boosting the incorporation of this biomass in a biorefinery.MethodsWe optimized the conditions for acid hydrolysis of barley straw to obtain a hemicellulosic hydrolysate rich in xylose with low energy consumption. Moreover, the energy consumption was simulated per quantity of xylose extracted. In order to obtain a hydrolysate with the highest xylose extraction efficiency (99\%), low inhibitors concentration and energy consumption (8.41 KW/Kg Xylose), we used 1.0\% H2SO4 (w/v) at 120 degrees C, with 1:10 dry-weight/acid solution for 40 min. We also optimized the medium composition to improve xylitol production by Candida guilliermondii.ResultsThe hemicellulosic hydrolysate was used as a fermentation medium and the best condition showing the highest xylitol volumetric productivity (0.69 g L-1 h(-1)) by C. guilliermondii was found to be 60 g L-1 initial xylose supplemented with 1.5 g L-1 (NH4)(2)SO4, 0.75 CaCl2 and 8.75 g L-1 rice bran extract.ConclusionsIt can be concluded that barley straw can be used in biorefinery, wherein the hemicellulose fraction would be utilized to produce xylitol and the cellulosic fraction (more accessible to enzymatic hydrolysis after pre-treatment) would be used for the production of cellulosic ethanol.
This study was conducted to evaluate effects of replacing steam pressure treated sugar cane bagasse by two types of raw sugar cane bagasse extracted through grinding or diffusion, on performance and ingestive behavior of beef cattle. Eighty four young bulls (Nelore, Canchim and Holstein) with 270kg of body weight at the beginning of the experiment were used in a randomized block design. Ingestive behavior was evaluated using four Nelore young bulls in a 4 x 4 Latin square design. Treatments were the direct substitution of steam pressure treated sugarcane bagasse by raw bagasse (RB), corresponding to the experimental treatments: 5\% RB from grinding; 5\% RB from diffusion; 10\% RB from diffusion and 15\% RB from diffusion. Dry matter intake was lower in treatment with 15\% of bagasse obtained by diffusion (BINdif) in comparison to 10\% BINdif. There were no differences (P>0.05) among treatments for average daily gain, feed conversion and final live weight. Ruminating time (minutes/kg of DM) and chewing time (minutes/kg of DM or NDF) was greater (P>0.05) when BINdif was added at 15\% level to diets. BINdif can be added up to 15\% of the dietary DM with no detrimental effect on beef cattle performance.
With sugarcane bagasse as the carrier and iron chloride hexahydrate (FeCl3 center dot 6H(2)O) as the iron source, Fe3O4@C materials were prepared in this study. Then the adsorption properties of the prepared adsorbents were characterized by XRD, SEM and VSM analysis. The effects of adsorption time, initial pH value and initial methylene blue concentration on methylene blue adsorption performance were studied and the adsorption mechanism was discussed. The Fe3O4@C materials synergistically exerted the good adsorption capacity and magnetic properties. The adsorption process of methylene blue on Fe3O4@C adsorbent was in accordance with Freundlich isothermal equation and quasi-second-order kinetic model. The saturated adsorption capacity in the experiment of Fe3O4@C material was 270.51 mg/g. The adsorption capacity was high in both acidic and alkaline environments, especially the alkaline environment.
New solvents for pretreating wheat straw, mixtures of cholinium amino acids ionic liquids ({[
Recent advancements in biorefinery processes necessitate search for cost effective and thermostable cellulases. This study was designed to characterize the cellulase obtained from a thermophilic bacterium, Neobacillus sedimentimangrovi UE25. A combined pretreatment of NaOH and methyltrioctylammonium chloride was given to sugarcane bagasse (SB) for lignin removal and the pretreated SB was utilized as a carbon source for the cellulase production. The thermostable cellulase thus obtained was characterized by adopting central composite design which has not been reported earlier for this purpose. Cellulase showed its maximum activity at pH 7 and temperature 60 degrees C and it remained active in the presence of many salts and detergents. Endoglucanase (EG) was found to be stable for 30 min at 80 degrees C. The purification of EG by using DEAE column yielded specific activity and purification fold of 365.866 IU mg(-1) and 4.264, respectively. The purified EG had a molecular weight of similar to 45 kDa. End product tolerance of EG was also evident, as an activity of 228.57 IU mL(-1) was observed in the presence of 60 mM glucose which revealed that it does not lose its activity upon accumulation of end-product when the reaction is prolonged. The purified EG exhibited V-max and K-m of 294 U mL(-1) min(-1) and 36 mu M, respectively, in the presence of 60 mM glucose. This novel thermostable cellulase can finds its applications in industrial sector.
In the present study, sugarcane bagasse (SB) was subjected to different pretreatments. The pretreated SB was characterized chemically and structurally and was enzymatically hydrolyzed using a commercial enzyme preparation. Pretreatment with sulfite-NaOH was the most efficient for removing lignin while keeping cellulose intact. In addition, sulfite-NaOH pretreatment presented the best response to the enzymatic hydrolysis of cellulose and xylan, reaching conversions of 90\%. The increase in consistency (>10\%) in the enzymatic hydrolysis of SB pretreated with sulfite-NaOH showed a loss of cellulose and xylan conversions efficiencies of 28 and 37\%, respectively. However, enzymatic hydrolysis with a consistency of 20\% resulted in a maximum rate of glucose and xylose formation of 8.5 and 3.0 g L-1 h(-1), respectively, and an enzymatic hydrolysate containing 80 and 33 g L-1 of glucose and xylose, respectively. The enzymatic hydrolysis assay in a bioreactor with 20\% consistency promoted faster liquefaction of SB, resulting in a higher maximum rate of glucose production (10.6 g L-1 h(-1)). The increase in the concentration and rate of formation of fermentable sugars in the enzymatic hydrolysate can partially avoid steps of concentration of the hydrolysate, resulting in less energy consumption and greater productivity of the bioproducts obtained from the hydrolysate, such as cellulosic ethanol (2G ethanol). (C) 2020 Elsevier Ltd. All rights reserved.
Sugarcane molasses is a carbohydrate-rich carbon source with potential to develop the biorefinery model in the sugarcane industry. Two of the most well-known renewable products from the dark fermentation of cane molasses are succinic acid and biohydrogen, with both having valuable applications in different industries. However, the continuous dark fermentation of cane molasses is a process regulated by many operational conditions, like reactor temperature and hydraulic retention time. It is important to control these conditions to shift metabolic pathways in order to increase production rates and yields. Thus, this research evaluates the response of mesophilic and thermophilic dark fermentation of cane molasses by mixed culture on hydrogen and succinic acid generation in fluidized bed reactors by changing the hydraulic retention time (8, 6, 4, 2, and 1 hour). In the thermophilic reactor (55 degrees C), higher hydraulic retention times (from 8 to 4 hours) favored the succinate production (molar fractions between 75.0\% and 81.4\%). Similarly, in the mesophilic reactor (30 degrees C), the molar fractions of succinate were 45.5\% at the hydraulic retention time of 8 hours and 74.7\% at 6 hours. The reduction of the hydraulic retention time to 1 hour decreased the succinic acid concentration to undetectable values and increased the hydrogen yield in both reactors. The lower hydraulic retention time also enhanced the hydrogen productivity to 171.1 mL/L-bed center dot h in the mesophilic reactor and to 303.4 mL/L-bed center dot h in the thermophilic reactor. These values were coincident with the predominant production of butyric and acetic acids. All of these points to the fact that the hydraulic retention time is an efficient parameter to control and select the production of hydrogen or succinic acid by mixed cultures under different temperatures.
A beta-glucosidase obtained from Thermobifida halotolerans YIM 90462(T) was expressed in Escherichia coli BL21 and subsequently characterized. The recombinant enzyme ThBGL1A showed optimal activity at 45 degrees C and pH 6, but also showed high activity from 40 to 55 degrees C and pH 5.6-6.6. Its half-life activity was 58 min at 50 degrees C. ThBGL1A exhibited notable cold-adapted activity, retaining 13.1\%, 49.4\%, and 83.5\% of its optimal activity at 5, 25, and 30 degrees C, respectively. Kinetic characterization revealed an enzymatic turnover (Kcat) of 30 s(-1) (cellobiose), 41.8 s(-1) (p-nitrophenyl-beta-d-glucopyranoside), and 52.6 s(-1) (p-nitrophenyl-beta-d-galactopyranoside). Moreover, ThBGL1A had high tolerance for salt, xylose, and glucose, which are extremely desirable features for industrial applications. Interestingly, its Ki for glucose was 932 mM and more than 80\% of its optimal activity in the presence of 2000 mM xylose. After the addition of ThBGL1A (0.05 mg/ml) to a commercial cellulase reaction system, glucose yields from sugarcane bagasse were increased 20\% and 18\% after 1 day at 30 degrees C and 45 degrees C, respectively. Overall, this work identifies a cold-adapted, salt- and glucose-tolerant beta-glucosidase with potential applications in commercial cellulose utilization and the bioenergy industry.
The study was conducted to compare the cellulase production using organic and inorganic supplements by isolating a tree bark (Mangifera indica) fungus, for a cost-effective cellulase production. Three fungi (f(1), f(2) and f(3)) were isolated from the bark of the tree, of which f(3) was found to be potential in cellulase production which was confirmed by primary screening (congo red activity staining). Through endoglucanase and total cellulase activity assays, it was observed that the isolated strain exhibited cellulase activity of 0.25 U/ml for endoglucanase when 1\% CMC was supplemented to the medium. An activity of 8 IU/g towards Rase and for endoglucanase 10.35 U/g was obtained on non-purified inorganic supplements. Sugarcane bagasse was found to be the best inorganic supplement for cellulase production. Here, we try to adopt a cost-effective production strategy of cellulase. The future perspective of this investigation is to identify the strain and purification of the enzyme for industrial purpose.
This study involves the remediation of dye containing synthetic wastewater using bagasse, a low cost agricultural waste by batch and column methods. The simulated wastewater was prepared using Indosol Turquoise FBL, commonly used dye in the textile industry. Sugarcane bagasse was used in native, HCl-treated and Na-alginate-immobilized forms. The effect of different process parameters such as medium pH, biosorbent dose, contact time, initial dye concentration and temperature on the biosorption capacity of bagasse was investigated in batch study. Maximum dye removal (65.09mg/g) was obtained with HCl-treated bagasse. Pseudo-second-order kinetic model was better fitted to the experimental data. The equilibrium data were best described by Langmuir adsorption isotherm model. The thermodynamic study indicated the thermodynamic nature of biosorption process. Effect of surfactants, heavy metal ions and salt concentration was also explored. Breakthrough capacities were also investigated in column mode study. Effect of bed height, flow rate and initial dye concentration were investigated in column study. Maximum dye removal in continuous mode study was 28.8mg/g. The experimental data was subjected to Thomas Model and bed depth service time models. Surface analysis of sugarcane bagasse was carried out using Fourier transform infrared (FTIR) spectrometer and scanning electron microscopy (SEM). FTIR analysis of unloaded and Indosol Turquoise FBL loaded bagasse showed the involvement of hydroxyl and carboxylic groups in the biosorption process. The results indicated that bagasse could be used to treat dye containing effluents.
Sugarcane bagasse was variously treated by three different processing protocols to improve the pozzolanic activity of the resulting sugarcane bagasse ash (SCBA). Three pa-rameters were examined namely, the particle size, the calcination temperature and the duration of calcination. The resulting SCBA was blended with Portland cement to examine potential benefits upon the strength and chloride resistance of mortar specimens. As ex-pected, the particle sizing and re-calcination, together imparted greater pozzolanic activity to SCBA. The results demonstrate that the optimal SCBA, possessing an acidic oxide (SiO2+Fe2O3+Al2O3) content over 70\% and LOI can be reduced to 4.3\%, resulted from grinding the boiler residue to 35 mm, followed by calcination for 90 min at 600 degrees C (P3-T90). In addition, the XRD test reveals that increasing the calcination temperature up to 600 degrees C could remove the residual carbon and other volatile compounds effectively. However, any further increase was noted to convert amorphous silica to cristobalite in SCBA itself and, also to enlarge the microcrack at ITZ in the hardened mortar. Furthermore, the optimal SCBA was found as P3-T90 in this study to produce the best blended mortar, as evident from an 18\% increase in compressive strength, a 15\% increase in flexural strength and a 43\% decrease in chloride diffusion coefficient. This is firstly attributed to the improved pozzolanic activity and in turn, to the increasing C-S-H phase. Besides, the associated porosity and mean pore size were minimized to 15.78\% and 36 nm, respectively. (c) 2022 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
The enzymatic hydrolysis of sugar cane bagasse (SCB) releases simple fermentable sugars however, phenolic compounds (PCs) are also released from the lignin present in the structure of the lignocellulosic biomass limiting the production of sugars and therefore the fermentative process to convert these sugars to bioethanol. During the saccharification of SCB with holocellulases from Cellulomonas flavigena PR-22, 46 mu g mL(-1) of PCs were produced, which inhibited 87 and 74\% carboxymethyl cellulase (CMCase) and xylanases respectively resulting in a low concentration of reducing sugars (5.5 g L-1) at the end of the process. Polymers such as polyethylene glycol 4000 (PEG) and polyvinylpyrrolidone (PVP) can prevent this inhibition due to their ability to chemically adsorb PCs. PEG and PVP were added to C flavigena PR-22 enzyme extracts at 0.4\% (w/v). PEG 4000 prevented CMCase inhibition, maintaining the original activity after the saccharification process, whereas xylanase production was increased by 47\% when PVP was added. (C) 2017 Elsevier Ltd. All rights reserved.
A review of 55 pretreatment and bio-conversion methods for the production of lignocellulose-ethanol was carried out. Bio-conversion studies include enzymatic fermentation, simultaneous saccharffication and fermentation, process modelling, supply chain simulations, Life Cycle Assessment and other experimental studies. A new sustainability indicator labeled Land Footprint, from farm-to-fuel, was introduced. The Land Footprint (LF) results are projected for bio-ethanol derived from stover and switchgrass from U.S., sugarcane bagasse from Brazil and India, and rice husk and straw from China and India. In order to produce 1 million L bio-ethanol, bagasse and rice straw are observed to have the highest potential to be sustainable resources that demand the least amount of agricultural land. The Land Footprints for both countries are 85 ha-yr for bagasse-ethanol and 80 ha-yr for China rice straw-ethanol. The Land Footprints per 1 million bio-ethanol from switchgrass and stover in the U.S. are 140 ha-yr and 366 ha-yr, respectively. Utilizing stover as a feedstock, an estimated LF of 14.7 million ha-yr is required to satisfy up to 50\% of U.S.'s year 2022 bio-ethanol mandate. The more efficient switchgrass-ethanol would require 4.4-6.6 million ha-yr agricultural land to meet 40-60\% of bio-ethanol demands for year 2022. As the most productive crop per hectare of land, sugarcane bagasse require about 2.4 million ha-yr land to supply sufficient amount of bagasse to meet up to 60\% of bio-ethanol national demands. (C) 2015 Elsevier Ltd. All rights reserved.
Studies are still needed to increase the stability and efficiency of methane production from vinasse. Therefore, operations strategies, such as the anaerobic digestion with one or more wastes and adding micronutrients, especially iron, become attractive. The performance of two treatment systems, each one composed of two UASB reactors in series, operated under mesophilic (R1M and R2M) and thermophilic (R1T and R2T) temperature conditions, was evaluated in the anaerobic digestion of vinasse (ADV). First, the reactors were operated with the effluent recirculation and increasing organic loading rate (OLR) up to 20 g CODtotal L-1d-1 in the R1M and R1T. Then, the anaerobic digestion of vinasse and water treatment plant (WTP) sludge (ADVS) was performed in the proportions of 25:75 to 50:50 (\% v/v) in both systems. In the ADV, applying the highest OLR, the mesophilic and thermophilic reactors instabilities happened. The ADVS of over 35\% of WTP sludge promoted the recovery of the mesophilic and thermophilic UASB reactors with significantly reduced total volatile acids and increased alka-linity and biogas production. The higher average values of the volumetric methane production (VMP) occurred in the ADVS at 50\% of WTP; in the R1M and R1T, they were 3.23 and 3.00 L CH4 L-1d-1, respectively. In the ADV, the thermophilic system presented higher VMP concerning the mesophilic for OLR up to 15 g CODtotal L-1d-1. For higher OLR, the mesophilic system showed better carrying capacity and stability. The ADVS with above 35\% of WTP sludge promoted similar benefits in the two systems, with no significant differences in CODtotal removal and VMP. Therefore, adding iron by WTP sludge in ADVS improves methane production and increases the stability of UASB reactors under mesophilic and thermophilic conditions.
Efforts to improve water quality have led to the development of green and sustainable water treatment approaches. Herein, nitrogen-doped magnetized hydrochar (mSBHC-N) was synthesized, characterized, and used for the removal of post-transition and transition heavy metals, viz. Pb2+ and Cd2+ from aqueous environment. mSBHC-N was found to be mesoporous (BET surface area - 62.5 m(2)/g) and paramagnetic (saturation magnetization - 44 emu/g). Both, FT-IR (with peaks at 577, 1065, 1609 and 3440 cm(-1) corresponding to Fe - O stretching vibrations, C - N stretching, N - H in-plane deformation and stretching) and XPS analyses (with peaks at 284.4, 400, 530, 710 eV due to C 1s, N 1s, O 1s, and Fe 2p) confirmed the presence of oxygen and nitrogen containing functional groups on mSBHC-N. The adsorption of Pb2+ and Cd2+ was governed by oxygen and nitrogen functionalities through electrostatic and co-ordination forces. 75-80\% of Pb2+ and Cd(2 + )adsorption at C-o: 25 mg/L, either from deionized water or humic acid solution was accomplished within 15 min. The data was fitted to pseudo-second-order kinetic and Langmuir isotherm models, with maximum monolayer adsorption capacities being 323 and 357 mg/g for Cd2+ and Pb2+ at 318 K, respectively. Maximum Cd2+ (82.6\%) and Pb2+ (78.7\%) were eluted with 0.01 M HCl, simultaneously allowing minimum iron leaching (2.73\%) from mSBHC-N. In conclusion, the study may provide a novel, economical, and clean route to utilize agro-waste, such as sugarcane bagasse (SB), for aquatic environment remediation. (C) 2018 Elsevier Ltd. All rights reserved.
For degradation of sugarcane bagasse (SCB), several enzymes are needed but beta-glucosidase is rate limiting in cellulose hydrolysis. Since different microorganisms synthetize characteristic pool of enzymes, mixing extracts produced by different species may increase hydrolytic efficiency due to synergism between enzymes in cocktails. This paper reports the study of beta-glucosidase production in solid state cultivation (SSC) of two filamentous fungi, thermophilic Thermoascus aurantiacus and mesophilic Trichoderma reesei, and application of the enzymatic extracts on non-pretreated SCB saccharification. Enzyme extract obtained from the thermophilic fungus presented higher beta-glucosidase and FPU activities (1.8 U/mL and 10 FPU/mL) than the one from mesophilic (0.2 U/mL and 6 FPU/mL). Optimal SCB hydrolysis was achieved when applying enzymatic cocktail composed of equal volumes of both fungal extracts (3.6 FPU/g(SCB), filter paper units per gram SCB, 2.25 FPU/g(SCB) provided by extract from T. aurantiacus and 1.35 FPU/g(SCB) from T. reesei) at 65 degrees C. The hydrolysis yield applying the enzyme cocktail, 124 mg total reducing sugars (TRS) per g(SCB), was higher than any yield achieved when using the enzyme extracts separately (105 mg(TRS)/g(SCB) using 12.5 FPU per g(SCB) from T. aurantiacus at 65 degrees C; 79 mg(TRS)/g(SCB) using 7.5 FPU per g(SCB) from T. reesei at 45 degrees C). Therefore, the use of the cocktail (3.6 FPU/g(SCB)) at 65 degrees C released 18 and 57\% more TRS respectively than when extracts from T. aurantiacus or from T. reesei were applied alone, respectively, even reducing enzyme load (FPU) by 70\%, corroborating the synergistic effect when both extracts are used together.
Bagasse-derived hierarchical structured carbon (BDHSC) with tunable porosity and improved electrochemical performance is prepared via simple and efficient hydrothermal carbonization combined with KOH activation. Experimental results show that sewage sludge acts as a cheap and efficient structure-directing agent to regulate the morphology, adjust the porosity, and thus improve the supercapacitive performance of BDHSC. The as-resulted BDHSC exhibits an interconnected framework with high specific surface area (2296 m(2) g(-1)), high pore volume (1.34 cm(3) g(-1)), and hierarchical porosity, which offer a more favorable pathway for electrolyte penetration and transportation. Compared to the product obtained from bagasse without sewage sludge, the unique interconnected BDHSC exhibits enhanced supercapacitive performances such as higher specific capacitance (320 F g(-1)), and better rate capability (capacitance retention over 70.8\% at a high current density of 50 A g(-1)). Moreover, the BDHSC-based symmetric supercapacitor delivers a maximum energy density of over 20 Wh kg(-1) at 182 W kg(-1) and presents an excellent long-term cycling stability. The developed approach in the present work can be useful not only in production of a variety of novel hierarchical structured carbon with promising applications in high-performance energy storage devices, but also in high-value utilization of biomass wastes and high-ash-content sewage sludge. (C) 2015 Elsevier B.V. All rights reserved.
The use of cellulose-containing agricultural by-products modified with the cross-linking reagent dimethyloldihydroxyethylene urea (DMDHEU) and the quaternary amine, choline chloride, as anion exchange resins, has not been reported. The objective of the present study was to convert the readily available by-products, soybean hulls, sugarcane bagasse and corn stover to functional anion exchange resins using DMDHEU and choline chloride. Optimization of the modification method was achieved using soybean hulls as a substrate. The optimized method was additionally used to modify sugarcane bagasse and corn stover. Adsorption efficiency results with chromate ion showed that modification with both DMDHEU and choline chloride was required for the highest efficiencies. Adsorption capacities of the modified by-products were determined using chromate ion and found to be 1.97, 1.61 and 1.12 mmol/g for sugarcane bagasse, corn stover and soybean hulls, respectively. Competitive adsorption studies were conducted at 10 and 50 times US Environmental Protection Agency (US EPA) limits for arsenic, chromium and selenium in a simulated wastewater at pH 7. The results showed preferential adsorption of chromate ion over arsenate or selenate ion. Estimated product costs for the three resins ranged from \$0.88/kg to \$0.99/kg, which was considerably lower than the market costs for the two commercial anion exchange resins QA-52 and IRA-400 also used in this study. DMDHEU/choline chloride modification of the three by-products produced an anion exchange resin with a high capacity to adsorb chromate ion singly or competitively in the presence of other anions from aqueous solutions. Published by Elsevier Ltd.
LaTi0.2Fe0.8O3 (LTF) was prepared by the sol-gel method, and the effects of calcination temperature on the structure and properties were investigated. A new method of preparing aryl oxygen-containing compounds from bagasse lignin (BL) by the catalytic pyrolysis over LTF was proposed. The results show that LTF has cubic crystal phase and porous structure and its optimal calcination temperature is 800 degrees C (LTF-800). In the test for catalytic pyrolysis of BL, with the addition of LTF-800, the yield of liquid product reaches the maximum; the contents of phenolics, guaiacols, syringols, phenylates and furans increase obviously, while those of benzenes, esters and carboxylic acid decrease. The total content of aryl oxygen-compounds (including phenolics, guaiacols, syringols and phenylates) in liquid product is more than 74 wt\% with the addition of LTF-800, larger than that obtained by single BL pyrolysis (62 wt\%). LTF could avoid oxygen-containing functional groups from being excessively destroyed. It has nice regeneration performance by controlled combustion of char even after 5 cycles. (C) 2019 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.
The alcoholic fermentation for fuel ethanol production in Brazil occurs in the presence of several microorganisms present with the starter strain of Saccharomyces cerevisiae in sugarcane musts. It is expected that a multitude of microbial interactions may exist and impact on the fermentation yield. The yeast Dekkera bruxellensis and the bacterium Lactobacillus fermentum are important and frequent contaminants of industrial processes, although reports on the effects of both microorganisms simultaneously in ethanolic fermentation are scarce. The aim of this work was to determine the effects and interactions of both contaminants on the ethanolic fermentation carried out by the industrial yeast S. cerevisiae PE-2 in two different feedstocks (sugarcane juice and molasses) by running multiple batch fermentations with the starter yeast in pure or co-cultures with D. bruxellensis and/or L. fermentum. The fermentations contaminated with D. bruxellensis or L. fermentum or both together resulted in a lower average yield of ethanol, but it was higher in molasses than that of sugarcane juice. The decrease in the CFU number of S. cerevisiae was verified only in co-cultures with both D. bruxellensis and L. fermentum concomitant with higher residual sucrose concentration, lower glycerol and organic acid production in spite of a high reduction in the medium pH in both feedstocks. The growth of D. bruxellensis was stimulated in the presence of L. fermentum resulting in a more pronounced effect on the fermentation parameters than the effects of contamination by each microorganism individually.
The impact of various degrees of acetylation on improving the thermal stability of xylan isolated from different botanical source has been studied; methylglucuronoxylan from birch and eucalyptus, arabinoglucuronoxylan from spruce and glucuronoarabinoxylan from sugarcane bagasse and straw. The lower molecular weight of nonacetylated methylglucuronoxylan (17.7-23.7 kDa) and arabinoglucuronoxylan (16.8 kDa) meant that they were more soluble in water than glucuronoarabinoxylan (43.0-47.0 kDa). The temperature at the onset of degradation increased by 17-61 degrees C and by 75-145 degrees C for low and high acetylated xylans respectively, as a result of acetylation. A glass transition temperature in the range of 121-132 degrees C was observed for the samples non-acetylated and acetylated at low degree of acetylation (0.0-0.6). The acetylation to higher degrees (1.4-1.8) increased the glass transition temperature of the samples to 189-206 degrees C. Acetylation proved to be an efficient method for functionalization of the xylan to increase the thermal stability.
This study assesses the performance of waste sugarcane bagasse ash (SBA)-based ceramic membrane in anaerobic membrane bioreactor (AnMBR) treating low-strength wastewater. The AnMBR was operated in sequential batch reactor (SBR) mode at hydraulic retention time (HRT) of 24 h, 18 h, and 10 h to understand the effect on organics removal and membrane performance. Feast-famine conditions were also examined to evaluate system performance under variable influent loadings. An average removal of >90\% chemical oxygen demand (COD) was obtained at each HRT and starvation periods up to 96 days did not significantly affect removal efficiency. However, feast-famine conditions affected extracellular polymeric substances (EPS) production and consequently the membrane fouling. EPS production was high (135 mg/g MLVSS) when the system was restarted at 18 h HRT after shutdown (96 days) with corresponding high transmembrane pressure (TMP) build-up; however, the EPS content stabilized at similar to 60-80 mg/g MLVSS after a week of operation. Similar phenomenon of high EPS and high TMP was experienced after other shutdowns (94 and 48 days) as well. Permeate flux was 8.8 +/- 0.3, 11.2 +/- 0.1 and 18.4 +/- 3.4 L/m(2) h at 24 h, 18 h and 10 h HRT, respectively. Filtration-relaxation (4 min - 1 min) and backflush (up to 4 times operating flux) helped control fouling rate. Surface deposits (that significantly attributed to fouling) could be effectively removed by physical cleaning, resulting in nearly complete flux recovery. Overall, SBR-AnMBR system equipped with waste-based ceramic membrane appears promising for treatment of low-strength wastewater with disruptions in feeding.
The production and disposal of agro-industrial waste can be detrimental to the sustainable development of natural and energy resources, when this waste is not properly handled. The use of these residues is a desire not yet reached by Brazil, so it is necessary to search for alternatives to minimize this problem. Among the thermochemical processes for converting biomass, pyrolysis (thermal degradation of any solid organic material in the partial or total absence of an oxidizing agent) is a promising tool for obtaining bio-oil, which can be used as a fuel or chemical supply. In addition to bio-oil, the pyrolysis process generates biochar and pyrolysis gases. In this work, the results confirmed the potential of sugarcane in the thermochemical process, on the other hand, thermogravimetric analyzes demonstrated that there is a relationship between the main components of biomass (lignin, hemicellulose and cellulose) and the components present in bio- oil. The bio-oils obtained have a chemical composition rich in oxygenated compounds, especially phenols, which are important industrial inputs, in addition to ketones and aldehydes.
The down flow structured bed bioreactor (DFSBR) was applied to treat synthetic acid mine drainage (AMD) to reduce sulfate, increase the pH and precipitate metals in solutions (Co, Cu, Fe, Mn, Ni and Zn) using vinasse as an electron donor for sulfate-reducing bacteria (SRB). DFSBR achieved sulfate removal efficiencies between 55 and 91\%, removal of Co and Ni were obtained with efficiencies greater than 80\%, while Fe, Zn, Cu and Mn were removed with average efficiencies of 70, 80, 73 and 60\%, respectively. Sulfate reduction increased pH from moderately acidic to 6.7?7.5. Modelling data confirmed the experimental results and metal sulfide precipitation was the mainly responsible for metal removal. The main genera responsible for sulfate and metal reduction were Geobacter and Desulfovibrio while fermenters were Parabacteroides and Sulfurovum. Moreover, in syntrophism with SRB, they played an important role in the efficiency of metal and sulfate removal.
Xylose from rice straw hemicellulose hydrolysate was fermented for xylitol production using Candida subtropicalis WF79 cells immobilized in polyacrylic hydrogel thin films of 200 gm thickness. Cell immobilization was conducted by first suspending the yeast cells in a mixture of 2-hydroxyethyl methacrylate (HEMA, hydrophilic monomer), polyethylene glycol diacrylate (PEG-DA, crosslinking agent), and benzoin isopropyl ether (photoinitiator). The mixture was then allowed to form polyacrylic hydrogel thin films, between two pieces of glass sheets, by UV-initiated photopolymerization. The hemicellulose of rice straw was hydrolyzed using dilute sulfuric acid at 126 degrees C. The hydrolysate was neutralized with calcium hydroxide. After separating the solid residues and calcium sulfate precipitates by filtration, the hydrolysate was treated with charcoal to partially remove potential inhibitory substances, followed by vacuum concentration to obtain solutions of desired xylose concentrations for yeast fermentation. The thin films with immobilized yeast cells were submerged in the xylose solution from rice straw hydrolysate for fermentation in an Erlenmeyer flask. The maximum yield was 0.73 g of xylitol per gram of xylose consumed. In the 52.5-day long durability test, after 40 d of repeated batchwise operation, the fermentation activities of the cell immobilized in thin films began to decline to a yield of 0.57 g/g at the end.
Agricultural by-products applied as soil amendments have the potential to improve crop production on low organic matter (OM) soils. This two-year study investigated the use of two readily available sugarcane (Saccharum spp.) milling by-products, mill mud, and mill ash, as soil amendments to improve first sugarcane crop (plant cane) and subsequent crop (first ratoon) grown on a sandy Spodosol. Sugarcane was grown in lysimeters receiving mill mud, mill ash, and a 50:50 (v:v) mill mud to mill ash mix. Amendments were applied at low, medium, and high application rates (5, 10, and 15cm depths, respectively) and then incorporated 30cm deep. Amendment effects on plant nutrition, soil characteristics, and crop yield were determined. High rate applied mill mud and mill ash had the highest soil OM content for both years and soil OM did not significantly change between crops for all treatments except for high rate mill mud, which increased the second year (ratoon crop). Leaf nutrient levels for nitrogen (N), iron (Fe), and copper (Cu) for all treatments both years were insufficient; nutrient levels for magnesium (Mg), manganese (Mn), and silicon (Si) were within marginal to sufficient range for all treatments both years. All amendments produced significantly higher biomass and sucrose yields for plant cane and first ratoon crops compared to the control. Mill ash treatments produced the greatest increase in sucrose and biomass yields from plant cane to ratoon crops, which corresponded with an increase in potassium (K) in leaf tissue. However, mid and high rates of mix produced the highest sugarcane biomass and sucrose yields for the both the plant cane and ratoon crops.
The National Alcohol Program (Proalcool) was a strategic policy of the Brazilian government to replace petroleum-based fuels with alcohol (ethanol). Based on the review, we can choose the 1960s as a start point for a leap in development. Over the 500 years of sugarcane history in Brazil, the crop enters the second decade of the 21' century with extraordinary strength and prestige, reaching its highest production in history. This made Brazil a leader in sugar and ethanol productions worldwide, with an energy-independent agribusiness. Moreover, effluents and polluting wastes were transformed into high-value inputs (e.g., vinasse, filter cake, and others). Environmentally friendly actions included developing organic cane production technology, ceasing sugarcane field burning, relocating workers from field cutting activities, reducing atmospheric CO2 emissions. Besides, Brazilian agribusiness has led the search for the ``philosopher's stone,{''
A salt-tolerant cellulase secreted by a marine Bacillus sp. SR22 strain with wide resistance to temperature and pH was purified and characterized. Its approximate mass was 37 kDa. The endoglucanase, named as Bc22Cel, was purified by ammonium sulfate precipitation, gel filtration chromatography, and extraction from the gel after non-reducing sodium dodecyl sufate-polyacrylamide gel electrophoresis. The optimal pH value and temperature of Bc22Cel were 6.5 and 60 degrees C, respectively. The purified Bc22Cel showed a considerable halophilic property, being able to maintain more than 70\% of residual activity even when pre-incubated with 1.5 M NaCl for 1 h. Kinetic analysis of the purified enzyme showed the K-m and V-max to be 0.704 mg/ml and 29.85 umol.ml(-1).min(-1), respectively. Taken together, the present data indicate Bc22Cel as a potential and useful candidate for industrial applications, such as the bioconversion of sugarcane bagasse to its derivatives.
Yeast strains were isolated from sugar cane molasses (S1), dates (S2) and figs (S3) and the ethanol production was evaluated in batch condition. A comparison was made with the yeast Saccharomyces cerevisiae. The strains showed tolerant characteristics to stressful conditions like salinity and ethanol. The isolated strains produced ethanol; at 20 h of fermentation ethanol yields were 0.38-0.39 g.g(-1), and the productivities were almost 0.58 g.L-1. S. cerevisiae and Si tolerated up to 14\% (v/v) of ethanol; while interestingly the isolates S2 and S3 were highly tolerant, up to 20\% (v/v) ethanol. Thus, S2 and S3 could serve as potential strains for ethanol fermentation, with 0.27 and 0.29 g.g(-1) yield of ethanol in the presence of 1.37 mol.L-1 NaCl. These values were higher than the value obtained using the yeast of reference and SI (0.16 g.g(-1)). Co-cultures of S2 and S3 enhanced the ethanol production, increasing the yield of ethanol by 12.5\% compared with the single culture. The strains were identified as species S.cerevisiae, and S2 and S3 were very similar. For an application in the valorization of biomass such as green macro-algae, some assays were done on a synthetic model medium of hydrolysate of macro-algae and the strains S2 and S3 demonstrated excellent fermentative performances.
Catalytic valorization of renewable aromatic lignin is attracting increasing attention. In this study, an efficient method for direct liquefaction of sugarcane bagasse lignin using acidic ionic liquid (IL) 1-(4-sulfobutyl)-3-methyl imidazolium hydrosulfate ({[
This study investigated the effects of torrefaction temperatures and dilute acid pretreatment on the quality of pyrolysis bio-oil and the distribution toward gaseous, liquid bio-oil, and char products from rice straw. Torrefaction of rice straw was conducted at different temperatures (225 degrees C, 250 degrees C, and 275 degrees C) for 30 minutes in a Py-GC/MS reactor. After the torrefaction process was completed, fast pyrolysis of torrefied rice straw was then performed at temperatures of 450 degrees C, 500 degrees C and 550 degrees C with a heating rate of 1000 degrees C/s and held for 20 seconds in the same micropyrolysis reactor. The results showed that the decrease of pyrolysis bio-oil, gas, and water, are observed when the torrefaction temperature increases. However, the decreasing trend of pyrolysis char yield was observed when the torrefaction severity increases at pyrolysis temperatures 450 degrees C and 500 degrees C, but an increasing trend was noticeable at pyrolysis temperature 550 degrees C. The phenolic components in pyrolysis bio-oil from torrefied rice straw were lower compare to raw rice straw. The torrefaction process helps improve the quality of pyrolysis bio-oil in terms of reducing some water, acid, and oxygenated species. The torrefaction temperature of 225 degrees C with the pyrolysis temperature of 550 degrees C is indicated as the optimum condition in our study. Additionally, the removal of mineral content from rice straw promoted higher yields of pyrolysis bio-oil, particularly levoglucosan. The acid pretreatment method also improved the pyrolysis product distribution in terms of enhancing bio-oil yield and reducing water, gas, and char.
Aedes aegypti is the vector of Dengue disease, responsible for 20,000 deaths/year worldwide. Bacillus thuringiensis var israelensis -Bti releases selective and effective toxins (crystal proteins) against A. aegypti larvae. We present a low cost bioprocess for toxin production, accomplished by a selected Brazilian strain Bti (BR-LPB01) and employment of low cost substrates. Soybean meal and sugarcane molasses lead to high toxic effectiveness after 2L bioreactor fermentation (LD50=26ng/mL), near to the reference strain IPS82 (LD50=17.3ng/mL). The pH ranged between 5.8 and 7.0 during the exponential growth period and between 7.0 and 8.4 during the stationary phase, with low activity. Thus, control of foam and pH 7.0 were started and proved to be crucial for high activity. It was verified that the fermentation could be discontinued after 20 hours, when the highest activity was present.
This study prepared a carboxylic functionalized bioadsorbent that met the ``4-E{''
Our objective was to evaluate the productive and economic performances of bulls fed increasing levels of sugarcane tops, as a substitute for sugarcane. Sixteen, 24-month-old, Nellore bulls (initial bodyweight = 360 +/- 14.7 kg) were kept in a feedlot for 84 days, receiving a high-concentrate diet (80:20 concentrate:roughage ratio). Four levels of substitution were evaluated: T0 = no addition of sugarcane tops; T33 = 33\% substitution; T66 = 66\% substitution; and T100 = total substitution of sugarcane by sugarcane tops. Dry matter, organic matter, crude protein and neutral detergent fibre intake, bodyweight gain, feed conversion and feed efficiency were evaluated as productive performance parameters, and as economic indicators, total revenue, total operating expenses, gross margin, and net margin. No effect (P 0.66) of diet was found for the studied variables. Average values of total bodyweight gain, average daily gain, feed conversion, and feed efficiency were 102 +/- 10.0 kg/animal, 1.2 +/- 0.12 kg/day, 8.6 +/- 0.72 and 0.12 +/- 0.010, respectively. Unlike other treatments, the T100 net margin was positive, because of the lower cost of acquiring sugarcane tops compared with sugarcane. Partial or total substitution of sugarcane by sugarcane tops in high-concentrate diets did not affect performance of feedlot bulls, but total substitution reduced production costs, with positive net margin. We conclude that sugarcane tops can be utilised as a low-cost roughage source in diets for beef bulls.
In this study, nanocomposite film was fabricated using cellulose nanocrystals (CNCs) as nanofiller in a polymer matrix of polyvinyl alcohol (PVA) and gum tragacanth (GT) via solution casting. CNCs were extracted from sugarcane bagasse using a steam explosion technique followed by acid hydrolysis. Initial analysis of CNCs by transmission electron microscopy (TEM) showed nanosized particles of 104 nm in length and 7 nm in width. Physical and chemical characteristics of neat PVA, PVA/GT, and PVA/GT/CNC films with varying concentrations of CNCs (from 2\% to 10\%) were analyzed by the scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectrometry, mechanical test, and swelling test. The SEM analysis showed cluster formation of CNCs in the polymer matrix at high concentration. The developed films were transparent. FTIR spectrometry analysis confirmed the chemical functional groups of the various components in the film. The presence of GT and CNCs in the polymer matrix improved the characteristics of films as evident in the prolonged stability for 7 days and increased mechanical properties. The highest elastic modulus of 1526.11 \& PLUSMN; 31.86 MPa and tensile strength of 80.39 MPa were recorded in PVA/GT/CNC2 film. The swelling ability, however, decreased from 260\% to 230\%. Cytotoxicity analysis of the PVA/GT/CNC film showed that it is nontoxic to mouse fibroblast cells L929 with 95\% cell viability. Films loaded with betel leaf extract exhibited excellent antibacterial activities against Staphylococcus aureus DMST 8840 and Pseudomonas aeruginosa TISTR 781 with 28.20 \& PLUSMN; 0.84 mm and 23.60 \& PLUSMN; 0.55 mm inhibition zones, respectively. These results demonstrate that PVA/GT/CNC loaded with the betel leaf extract could act as promising and versatile wound dressings to protect the wound surface from infection and dehydration.
Globally a huge amount of municipal solid waste (MSW) is being produced which is very difficult to dispose. Composting of MSW is one of the options of solid waste recycling, but its use by the farmers is limited because of its low nutrient status. This study has considered some organic amendments to increase nutrient status of MSW compost for its potential use as an organic fertilizer in rice cultivation. We prepared three types of amended compost by mixing 20\% mustard oil cake (MOC) and 30\% poultry manure (PM) or cow dung (CD) or sugarcane press mud (SPM) with 50\% MSW compost. The inoculum of Trichoderma viride was used to accelerate the composting process. The use of different amendments improved the nutrient level of MSW compost. A field experiment was conducted to evaluate the performances of amended MSW composts alone and in combination with chemical fertilizers on yield, nutrient content and balance in rice (var. BRRI dhan28). The experiment was conducted in 2018 at Bangladesh Agricultural University (BAU) farm, Mymensingh having silt loam texture, pH in water of 6.7 and 2.79\% organic matter; the soil was Aeric Haplaquept under the order Inceptisols. There were 10 treatments consisting of chemical fertilizers (urea, triple superphosphate, muriate of potash, gypsum and zinc sulphate) and four types of MSW compost (three amended and one unamended). Based on the results of yield and N, P, K and S concentration of rice grain, the treatment containing 50\% fertilizers +10 t ha(-1) of amended compost (MSW + MOC + SPM in a ratio of 5:2:3) performed the best. There were apparent negative balances for N (11-45 kg ha(-1)) and K (6-48 kg ha(-1)), and positive balances for P (8-71 kg ha(-1)) and S (4-46 kg ha(-1)) in soils, across the treatments. Results of this study have significant value in fertilizer management strategies for rice cultivation in sub-tropical countries.
Members of Cohnella sp. isolated from a variety of environments have been shown to be glycoside hydrolase producers. Nevertheless, most evaluations of members of this genus are limited to their taxonomic description. The strain AR92, previously identified as belonging to the genus Cohnella, formed a well-supported cluster with C. thailandensis and C. formosensis (> 80\% bootstrap confidence). Its growth and xylanase production were approached by using a mineral-based medium containing alkali-pretreated sugarcane bagasse as the main carbon source, which was assayed as a convenient source to produce biocatalysts potentially fitting its degradation. By means of a two-step statistical approach, the production of endoxylanase was moderately improved (20\%). However, a far more significant improvement was observed (145\%), by increasing the inoculum size and lowering the fermentation temperature to 25 degrees C, which is below the optimal growth temperature of the strain AR92 (37 degrees C). The xylanolytic preparation produced by Cohnella sp. AR92 contained mild temperature-active endoxylanase (identified as redundant GH10 family) for the main activity which resulted in xylobiose and xylo-oligosaccharides as the main products from birchwood xylan. (c) 2017 S. Karger AG, Basel
Biofuels are important to reduce greenhouse gases (GHGs) emissions to atmosphere. In Brazil, the main biofuel is ethanol from sugarcane. Beyond stalk, sugarcane sheets are also stating to be used to produce second generation ethanol. The objective of this work was evaluate soil GHGs (CO2, CH4 and N2O) emissions induced by sugarcane trash on soil surface. Three experiments were done in an Oxisol, in Piracicaba region, taking in account three periods: immediately after sugarcane harvest, six and twelve months after harvest. In each experiment, we evaluated the effects of three sugarcane trash rates (0\%, 50\% and 100\% of the quantity available at soil surface). Immediately after harvest, CO2 and CH4 emissions increased linearly with trash rate on soil surface. Six months after harvest there were CH4 consumption by soil as trash on surface increased. Twelve months after harvest, emissions of the three gases were similar in all trash rates. Removing sugarcane straw from soil surface do not increase soil GHGs emissions as compared to the current management, in which 100\% of trash is maintained on the soil surface. However, other studies are needed to investigate its effects under sugarcane yield, soil erosion and under other soil attributes.
An endo-acting xylanase is isolated from the culture medium of Clostridium sp. BOH3 when xylan, glucose, xylose, or sugarcane bagasse hydrolysate (SBH) is used as a carbon source. Crude xylanase is purified by using an anionic Q-column with a yield of 39 \%. The pure xylanase has a molecular weight of 35.8 kDa, and it shows optimal activity at pH 5 and 60 A degrees C. When beechwood xylan is used as a substrate, this xylanase liberates short oligosaccharides (XOS) predominantly, ranging from xylobiose (X2) to xylopentaose (X5). However, no xylose can be detected, suggesting that this is an endo-beta-1,4-xylanase. Kinetic study of this xylanase reveals that K (m) and V (max) are 1.36 mg/ml and 212 mu mol/(min. mg protein), respectively. On the basis of amino acid sequence, this enzyme shows homology to xylanase (xynb) from Clostridium acetobutylicum ATCC 824, but this enzyme has several distinctive characteristics. For example, its activity can be enhanced with the addition of divalent metal ions, and it produces XOS exclusively when xylan is used as a substrate. These unique characteristics suggest that this is a new enzyme.
There is a global problem involving the generation, management, disposal, and treatment of agro-industrial waste, since it requires technologies for its transformation into the sustainable production of food, fodder, biofuels, fibers, bioproducts, and biofertilizers. The citrus and sugarcane agroindustries generate waste or byproducts that require a special treatment to be reused. Sugarcane byproducts already have an established but unsustainable use. In the case of citrus fruits, 50-60\% of the organic waste has an acidic pH (3-4), 95\% organic matter, and 80-90\% moisture. The objective of this research was to evaluate and model the pile composting method applied to byproducts of the orange and sugarcane agroindustries to obtain compost with competitive physicochemical parameters for use as a soil improver. The pile was designed with a pyramidal-rectangular arrangement, and 9 points were established for temperature sampling in three different sections during composting. An average of 55 degrees C and a pH of 9,1 were obtained at the end of the process. Compared to the regional control, the C/N ratio (27,5), organic matter (65,5\%), and macro- and microelements show improved characteristics for use in food production in agro-ecological agriculture.
The objective of present study was to evaluate the effects of chemical additives on the quality parameters and nutritive value of sugarcane tops (SCT) silages. The trial was carried out in a completely randomized experimental design with total twelve treatments including two controls, C1 (without additive) and C2 (with common additives viz., 0.5\% Urea, 0.5\% NaCl and 2\% molasses on wet basis). However, ten treatments (C2+ other chemical additives viz., SB; Soidum benzoate, PS; Potassium sorbate, PA; propionic acid and their combinations) were applied @ 0.1\% (wet basis) onto the fresh SCT and ensiled for 30 days in 3.5 L vacuum sealed plastic jars in two replicates of each treatment. The analyzed variables were: chemical composition, quality parameters and nutritive values. Selection of most promising additive/combination was done with Flieg point and fitness values. The addition of chemical additive before ensiling produced silages with better quality indices (pH, lactic acid, Flieg point and fitness values), higher nutritive value (crude protein and ME) and low NDF as compared to control with additive (C2). Ammonia Nitrogen (NH3N\% TN) and protein fractionation (NDICP and ADICP) were also considered for the identification of best SCT top silage and chemical additive effect. The results of present study indicate that PA and PS+PA were the most promising additive treatments for the improving the SCT silage quality and nutritive value. Furthermore, information extended from the present study is giving future direction towards animal feeding trials with SCT silage with chemical additive.
The occurrence of the sugarcane weevil Sphenophorus levis Vaurie is important in sugarcane in some regions in Brazil. Damage is caused by the larvae as they bore into the nodes and can reach 30 ton/ha/year. Many control alternatives have been attempted, but none were satisfactory, except for the use of toxic baits. Therefore, it is necessary to optimize their efficiency or to propose new techniques. The objective of the current study was to evaluate the attractiveness of adults of S. levis to sugarcane nodes and pineapple peelings in an ``Y{''
Sugarcane residues - leaves (SL) and tops (ST) from Thailand were pyrolysed in a fluidised bed reactor incorporated with a hot filter. The aim was to investigate the effects of reaction temperatures and hot filtration on pyrolysis products. The bio-oils were characterised by water, solids and ash contents, density, heating value, pH, viscosity and stability. The optimum pyrolysis temperatures for SL and ST were 429 degrees C and 403 degrees C, which gave maximum bio-oil yields of 52.5 wt\% and 59.0 wt\%, respectively. Using the hot filter reduced bio-oil yield by 7-8 wt\%. However, the filtered bio-oils had better viscosity, solids and ash contents and stability. (C) 2015 Energy Institute. Published by Elsevier Ltd. All rights reserved.
Near-infrared spectroscopic calibrations for sugarcane lignocellulose composition (ash, lignin, and structural carbohydrates) have been developed on a total dry weight and extractives-free dry weight basis. Reference spectra were measured from crude preparations of bagasse and fibrated sugarcane stalks. Spectral interference attributed to extractives in the crude preparations adversely affected the fitting of calibrations derived from extractives-free reference data. Extractives content varied between 5 and 68 \% of total dry weight and depended on the nature of the sample preparation process. Applying DOSC (direct orthogonal signal correction) to the spectra circumvented the need to physically remove these extractives from the samples prior to spectroscopic measurement. DOSC enhanced the correlation between the extractives-free reference data and the measured absorbances. Meanwhile, the correlation between the extractives reference data and the measured absorbances was attenuated. This indicated that DOSC removed the spectral contribution of the extractives. This mathematical treatment of the spectra improved the cross-validation performance of the calibrations for extractives-free lignin and some structural carbohydrates (arabinan, glucan, and xylan). The DOSC-based models explained greater than 90\% of the variance in the calibration data and led to relative standard errors of prediction under cross-validation and independent testing that were less than 10 \%. Although DOSC also improved the cross-validation performance of ash and galactan calibrations, their relative standard errors under independent testing were high (> 10 \%). DOSC was also advantageous for total dry weight calibrations as it reduced the number of latent variables employed in the models.
The practice of burning the sugarcane straw in Brazilian plantations has to be eliminated, which will increase the usage of mechanical harvesting, owing to changes in the production systems and the environmental demands. In this paper studies about the influence of cane harvesting management (green and burnt cane) in the attributes of Tableland soils are resumed, also pointing to research demands. In general, the studies investigated the attributes of the arable layer, i.e., little has been studied about effects of the burning practice in the deeper soil layers, even though Tableland soils show a cohesive character that lead to differences in the soil management. About the experiments duration, the usually short term studies did not show differences in the soil attributes due to changes of the sugarcane harvesting system; though they indicated that these effects could happen in medium or long terms. Chemical soil attributes were the most studied followed by biological and physical. The data acquired indicate that harvesting sugarcane without burning alters positively the soil attributes and the soil quality. However, the studies are generally with manual harvesting and, thus, not sufficient to inform about the effect of mechanized harvesting without burning of sugarcane straw in the Tableland soils.
Sugarcane (Saccharum spp.) harvested without burning provides a substantial amount of remains (trash) on soil profiles which can be decomposed and release nutrients contributing to reduce fertilizer needs. The contribution of nitrogen (N) from sugarcane plant residues and fertilizer in sugarcane nutrition was assessed. Plant cane treatments were micro plots of N-15-labeled urea, sugarcane trash and root system; the last two to simulate the previous crop residues incorporated into the soil after crop renewal. For ratoons, N-ammonium nitrate (N-AN) micro plots, 150 kg ha(-1) of N-AN and control (0 kg ha(-1)) were set up to evaluate the contribution of trash in N supply and quantify the effects of N-fertilizer on N-trash mineralization. The N balances derived from each N-15 source were calculated after four crops and resulted in: N-15-urea applied at planting, 31 \% was recovered by plant cane, 12 \% by the following ratoons, 20 \% remained in the soil and 37 \% was not found in the soil-system (NOC). For crop residues N-15-trash + roots 26 \% was recovered by sugarcane, 51 \% remained in soil, and 23 \% was NOC. N-fertilizer applied to ratoons nearly doubled the amount of N from green harvest residues recovered by sugarcane; 17 vs. 31 \%. Water balances and crop evapotranspiration were correlated with N-15-sources recoveries and cumulative N recovery presented a positive correlation with evapotranspiration (2005 to 2009). The N-15 balances indicated that crop residues are supplementary sources of N for sugarcane and may contribute to reduce N fertilizer needs since trash is annually added to the soil.
The objective of this work was to evaluate the outplanting growth of Eucalyptus grandis e E. saligna clones, produced by cuttings in tubes (50cm(3)) and in pressed blocks (40x60x07cm)-175 cm(3)/seedlings, with different substrates (BT-sugarcane bagasse+sugarcane filter cake; AR-carbonized rice hull + eucalyptus bark; TF-peat). The experiment was arranged in a randomized block design, in a 2x7 factorial (2 clones and 7 treatments), with four replicates with 25 plants. Survival was evaluated two months later. Plant growth was monitored through height and ground level diameter at 20, 40, 60, 120 and 180 days after outplanting. To evaluate the effect of the containers on stem and root biomass in both clones, 180 days after outplanting, the cuttings grown in BT substrate with fertilizer were selected. One plant per plot of each clone, grown in tubes and in pressed blocks was selected. The E. grandis and E. saligna cuttings grown in pressed blocks with sugarcane bagasse+sugarcane filter cake presented greater height and diameter after out planting. Both clones presented larger root, bark, log and branch biomass production in plants produced in the block system. Cuttings of E. saligna grown in pressed blocks showed 80\% most wood biomass 180 days after outplanting, compared to that grown in tubes. In E. grandis, the differences in diameter and height, in function of the cutting production system, decreased along time, while in E. saligna these differences increased along the evaluation period.
A new method for CO2 recovery was proposed for cultivation of different microalgae. First, a chemical fixation, where CO2 was injected in alkalinized vinasse to form (bi)carbonate salts, was performed. In addition, biological fixation with CO2-enriched air injection was also accomplished for evaluation of the most promising results. Two bioreactor systems, a stirred-tank reactor and a bubble column reactor, were employed. A higher carbon transfer rate (43.35 g.L-1.h(-1)) was achieved in the bubble column reactor using NaOH-alkalinized vinasse, along with reductions of the chemical oxygen demand (COD), biological oxygen demand (BOD) and turbidity (TD). This allowed the cultivation of microalgae and cyanobacteria at vinasse concentrations between 70 and 100\%, reaching a biomass production of 2.25 g.L-1 in 15 days of culture. The viability of chemical CO2 fixation together with the use of 100\% treated vinasse from a bioethanol production unit for microalgae cultivation has been demonstrated in a successfully integrated biorefinery approach.
The simultaneous ethanol production and removal during sequential cell recycle fed batch fermentation provides a complementary route to produce this biofuel from sugar mixtures, which may greatly improve yields and productivity from lignocellulosic hydrolysates. Spathaspora passalidarum is a wild-type strain able to naturally convert glucose, fructose, xylose and arabinose into ethanol. Therefore, the present work has focused on 2G bioethanol production by S. passalidarum aiming at the consumption of all sugars released after pre-treatment and enzymatic hydrolysis of sugarcane bagasse in a single fermentation step. The fermentation strategy with sequential cell recycle, fed-batch mode and ethanol removal in situ was performed on a hemicellulosic hydrolysate medium supplemented with molasses. This strategy gave improved fermentation performance and enabled the co-fermention of all sugars under microaerobic conditions. The maximum ethanol yield and productivity was 0.482 g.g(-1) and 9.5 g.L-1.h(-1), respectively, showing a process efficiency of 94.3\%. The selective ethanol removal enables the operation of the bioreactor at low levels of ethanol (20-30 g.L-1), even with high sugar concentration inputs, accelerating the fermentation performance and avoiding inhibitory effects on yeast metabolism. Applying the cell recycle strategy, S. passalidarum was able to increase its robustness, as shown by a 10-fold increase in ethanol productivity, and it was also able to tolerate a high acetic acid concentration (4.5 g.L-1) during long-term fermentations. These results demonstrate that the bioprocess strategy has a strong potential to improve bioethanol production of rich mixed sugar from lignocellulosic hydrolysates in a single fermentation step.
The development of new cost-effective bioprocesses for the production of cellulolytic enzymes is needed in order to ensure that the conversion of biomass becomes economically viable. The aim of this study was to determine whether a novel sequential solid-state and submerged fermentation method (SF) could be validated for different strains of the Trichoderma genus. Cultivation of the Trichoderma reesei Rut-C30 reference strain under SF using sugarcane bagasse as substrate was shown to be favorable for endoglucanase (EGase) production, resulting in up to 4.2-fold improvement compared with conventional submerged fermentation. Characterization of the enzymes in terms of the optimum pH and temperature for EGase activity and comparison of the hydrolysis profiles obtained using a synthetic substrate did not reveal any qualitative differences among the different cultivation conditions investigated. However, the thermostability of the EGase was influenced by the type of carbon source and cultivation system. All three strains of Trichoderma tested (T. reesei Rut-C30, Trichoderma harzianum, and Trichoderma sp INPA 666) achieved higher enzymatic productivity when cultivated under SF, hence validating the proposed SF method for use with different Trichoderma strains. The results suggest that this bioprocess configuration is a very promising development for the cellulosic biofuels industry.
In this work, we propose an adaptation strategy for Scheffersomyces stipitis NRRL Y-7124 to increase its tolerance to inhibitors of hemicellulosic hydrolysates in the production of bioethanol. Sugarcane bagasse pretreated with 0.5\% (v/v) of sulfuric acid at 140 degrees C for 15 min was used as feedstock. The microorganism was subjected to a cell recycle batch fermentation system with increased inhibitors pressure, characterized by five consecutive batches with 33\% of hydrolysate, followed by five subsequent batches with 67\% of hydrolysate. The remaining composition of the culture media for each sequential batch (necessary to complete 100\% of carbohydrate content) was synthetic substrate. Finally, the strain was used in a fed-batch fermentation with 100\% of hydrolysate, resulting in an adapted strain of S. stipitis at the end. In order to validate the adaptation strategy, the fermentative performances of the adapted and non-adapted strains were compared under different acetic acid concentrations using synthetic substrate. 0.7 g/L of acetic acid significantly affected the fermentative performance of the non-adapted strain, while for the adapted strain, this value was 3.7-fold higher (2.6 g/L), confirming the increased tolerance. Through proteomic analysis, genes related to the defense mechanisms of S. stipitis against oxidative stress due to the presence of inhibitory compounds were identified, which plays a key role on the comprehension of the cell adaptation metabolism.
Sugarcane stands out as the most used renewable energy source in Brazil. Its yield and adaptation respond perfectly to tropical edaphoclimatic conditions. This study evaluates the K dynamics in the soil-plant system for sugarcane crops under tropical conditions. Treatments were arranged in randomized blocks design with five doses of K2O (0, 50, 100, 150, and 200 kg ha(-1)) and five replications. The following analyses were performed: K content in the soil, plant uptake, availability and decomposition of sugarcane straw, and K balance in the soil-plant system. Data on response variables were subjected to the analysis of variance and F test at 5\% probability. Quantitative factors were subjected to polynomial regression analysis by selecting the model of higher significance. The potassium dose of 200 kg ha(-1) increased K levels at 0.8 m by 20\% relative to the control. After 70 days, 50\% of the 79 kg K ha(-1) was available from sugarcane straw mineralization. The treatment that improved K in soil was 150 kg ha(-1) of K annual application. This dose causes a positive balance of K in the soil with 133.32 kg ha(-1) year(-1).
The ongoing research toward meeting global energy demands requires novel materials from abundant renewable resources. This work involves an investigation on nitrogen-doped carbon nanotubes (N-CNTs) synthesized from relatively low-cost and readily available biomass as carbon precursors and their use as electrodes for supercapacitors. The influence of the ionic liquid 1-butyl-3-methylimidazolium chloride, or its combination with either sugarcane bagasse or cellulose (IL-CNTs, ILBag-CNTs, and ILCel-CNTs, respectively), in the synthesis of N-CNTs and the resultant effect on their physical and electrochemical properties was studied. Systematic characterizations of the N-CNTs employing transmission electron microscopy (TEM), thermogravimetric analysis, X-ray photoelectron spectroscopy (XPS), elemental analysis, nitrogen sorption analysis, cyclic voltammetry, and electrochemical impedance spectroscopy were performed. TEM data analysis showed that the mean outer diameters decreased, in the order of IL-CNTs > ILBag-CNTs > ILCel-CNTs. The N-CNTs possess only pyridinic and pyrrolic nitrogen-doping moieties. The pyridinic nitrogen-doping content is lowest in IL-CNTs and highest in ILCel-CNTs. The N-CNTs are mesoporous with surface areas in the range of 21-52 m(2) g(-1). The ILCel-CNTs had the highest specific capacitance of 30 F g(-1), while IL-CNTs has the least, 10 F g(-1). The source of biomass is beneficial for tuning physicochemical properties such as the size and surface areas of N-CNTs, the pyridinic nitrogen-doping content, and ultimately capacitance, leading to materials with excellent properties for electrochemical applications.
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Polyphenolic compounds have many benefits, one of which being their efficacy as antioxidants. They can be extracted from various parts of plants and from agricultural waste. In this research, sugarcane pulp, and empty palm fruit bunches from the palm oil production were investigated as potential raw materials. This study aims to determine solvents and easy-to-perform extraction methods that show the highest effectivity in regards to total phenolic and flavonoid yield and the correlated antioxidant activity. Extraction methods comprised maceration, Soxhlet extraction, and ultrasound assisted extraction (UAE); solvents that were investigated included water, 70\% methanol and 70\% ethanol. The antioxidant activity was measured by the DPPH (diphenyl-2-picrylhydrazyl) method and FRAP (Ferric Reduction Ability of Plasma) method. Based on the amount of polyphenol compounds as well as the antioxidant activity, the experiments showed that Soxhlet extraction with 70\% methanol as solvent worked best for palm bunch waste and sugar cane pulp, resulted in about two times higher values for total phenolic content, flavonoid content and FRAP antioxidant activity as well as extract mass (yield) compared to the results from other extraction methods or solvents used in this experiment. The antioxidant activity of the extracts as measured by DPPH method seemed also to be promising, although the trend among solvent and extraction method was rather inconclusive.
In the present study, a precharacterized oleaginous microalgal species (Chlorella vulgaris) was exploited for its biomass productivity, lipid yield, and fatty acid analysis under mixotrophic and photoautotrophic conditions. For the purpose, the microalgal biomass was raised mixotrophically as well photoautotrophically. For mixotrophic cultivation, molasses was used as additional source of carbon and energy, while for photoautotrophic cultivation, atmospheric CO2 was the sole source of carbon and energy. The microalgal biomass raised thus was then harvested following 5 days of nitrogen starvation. Mixotrophic cultivation depicted remarkably higher biomass productivity (137.43 +/- 13.3 mg L-1 day(-1)) than that of photoautotrophic cultivation (91.57 +/- 7.9 mg L-1 day(-1)). About 39\% (w/w) of total lipid content was obtained from the dried biomass raised mixotrophically. Lipidomic analysis of the extracted oil depicted higher concentrations of polyunsaturated fatty acids (palmitic and oleic acids). The significant availability of polyunsaturated fatty acids (60 mg g(-1) of dried algal biomass) ensured the production of high quality biofuel.
The present study investigated the possibility of valorizing rape straw through anaerobic digestion and the possibility of improving biomethane yield by pretreatment with H2SO4, combined H2SO4 with steam explosion (SE) and SE combined with superfine grinding (SFG). To evaluate the pretreatment method efficiency, several analytical techniques were applied. Additionally, the performance of co-digesting of cattle manure (CM) with pretreated rape straw (PRS) at different ratios was evaluated. The results showed that combined pretreatment could dissolve the lignocellulosic fiber structure, which positively stimulated methane yield. The highest cumulative CH4 yield (CMY) of 305.7 mLg(-1)VS was achieved by combined SE at 180 degrees C for 5 min with SFG, which was 77.84\% higher than the untreated. The CMY was further improved by 11.4-59\% higher than the control (CM) using co-digestion. This study confirmed that, under optimal parameters of AD, pretreatment with SEG180 could significantly boost the CMY from co-digestion of CM and PRS.
Supercritical carbon dioxide (SCCO2) was employed as pretreatment of blue agave bagasse (BAB) to enhance enzymatic hydrolysis (EH) to simple sugars in preparation for bioethanol fermentation. Processing time (10-120 min), temperature (24-120 degrees C), and pressure (80-350 bar) were evaluated to obtain maximum total reducing sugar (TRS) after EH with commercial cellulase. Effect of water activity (a(w)) (0.082-0.973) of BAB was evaluated after optimum pretreatment conditions for maximum TRS (100 degrees C, 280 bar, and 10 min) were established. Higher values of temperature or pressure degraded simple sugars as determined by relative furan analysis. Treated samples were also characterized by scanning electronic microscopy and porosimetry, showing structural and morphological modifications that enhance enzymatic digestibility as compared to untreated controls. Processing with SCCO2 results in 40\% increment in TRS compared with untreated BAB. Hydration level defined by a(w) resulted in the main variable affecting sugar yields, with lowest a(w) of pretreated BAB generating the highest TRS valued. It is proposed that at low hydration levels, diffusivity of CO2 is greater facilitating infiltration into the matrix and a more extensive deconstruction of the tight lignocellulosic matrix by explosion when pressure is released.
The low-cost production of cellulolytic complexes that present high action at mild conditions is one of the major bottlenecks for the economic viability of the production of cellulosic ethanol. The influence of agro-industrial residues was assessed to enhance endoglucanase production by Aspergillus niger 426 grown in solid state fermentation. The highest percentage of lignin degradation was found on soybean hulls (56\%) followed by sugarcane bagasse (36\%) and rice straw (8.5\%). The cellulose degradation, around 90\%, was observed on soybean hulls and sugarcane bagasse, but only 50\% on rice straw, and maximum production of endoglucanase (112.34 +/- 0.984 U mL(-1)) was observed for soybean hulls. The best Experimental Mixture Design condition was under cultivation of 2.5 g of sugarcane bagasse, 2.3 g of rice straw and 5.2 g of soybean hulls, leading to a maximum activity of 138.92 +/- 0.02 U mL(-1). The statistical methodology enabled an increase of over 20\% in the production of endoglucanase using agro-industrial waste. These data demonstrate that A. niger 426 is a potential source of cellulases which can be obtained by solid state fermentation using agro-industrial waste.
Polyvinylidene fluoride (PVDF) based, Cellulose acetate (CA), and Graphene oxide (GO) doped membrane acts as a superior cost-effective cation exchange membrane (CEM) for the energy extraction application using microbial fuel cells (MFCs). In this study, the waste sugarcane bagasse was used to prepare CA, and the Tour method was used to prepare GO. CA and GO compositions were varied to prepare CEMs WCA-1, WCA-2, WCA-3, and WCA-4. Doping the functionalized GO material in the hydrophilic membranes enhances the contribution of conducting phase concerning its hydrophilic nature and facilitates its functional characteristics at the surface. Further, adding an adequate amount of GO improves the physicochemical properties of the membrane and its mechanical stability. Also, with the fusion of GO in the membrane, the trend for water uptake ability significantly increases. Post sulfonating the prepared membranes the enhancement in the attained proton conductivity values from 0.025 Scm(-1) for WCA-1 to 0.4 Scm(-1) for WCA-4 was observed, which may be attributed to the increase in the GO content in the prepared membranes. Among various prepared membranes, WCA-3 was considered for MFC application. The WCA-3 membrane outperformed several membranes for wastewater treatment and energy extraction using MFC. Columbic efficiency (CE) of 7.1\%, chemical oxygen demand (COD) removal efficiency of 97.5 +/- 0.8\%, and power density of more than 150.22 mW m(-2) were achieved without any electrode modification. Thus, the prepared low-cost novel PVDF-based, GO and CA membrane (WCA-3) elucidated its appropriateness for proliferating the efficacy of MFC and is recommended for scaling up of MFCs.
Biomass resources are gaining increasing importance world over due to their ease of conversion to various energy product in the face of depleting fossil fuel store and increasing environmental concerns over their use. The present work elucidates different physico-chemical properties of three biomasses, paddy straw (PS)- an agricultural residue, spent paddy straw obtained after mushroom cultivation (SS), and a noxious weed (Parthenium hysterophorus; PR) to understand their properties and to explore the feasibility of using them as feedstocks in different biomass to bioenergy conversion routes. In addition to physico-chemical analysis, biochemical analysis of these biomasses along with XRD, thermogravimetric analysis, FTIR and SEM analysis have been carried out. Present study suggests that PS is a better choice as feedstock compared to both PR and SS. The calorific value to ash content ratio is more in PS (1.13) as compared to PR (1.06) and SS (0.84). Thus, it may be inferred that the biomasses in question are at par with commonly used bio-energy feedstocks like sugarcane bagasse and corn cob. (C) 2019. CBIORE-IJRED. All rights reserved
In this study, a lichen-like structure was obtained through the production of a unique biomass, formed by algae cells of Scenedesmus obliquus adhering to the mycelium of filamentous fungal Mucor circinelloides. This structure was composed in two steps; in the first one, microalgal cells and spores were incubated separately, and in the second one, after 72 h of growth, isolated, mature mycelium was harvested and added to cell culture. For spores' incubation, a culture medium containing only 2 g center dot L-1 of glucose and minerals was used. This culture medium, with low sugar content, provided a fungal biomass to the anchorage of microalgae cells. WC medium was used without and with sugarcane molasses supplementation for microalgae cells' incubation. The lichen-type structure that was formed resulted in 99.7\% efficiency in the recovery of microalgae cells and in up to 80\% efficiency in the recovery of algae biomass in the lichen biomass composition. In addition, the resulting consortium attained a satisfactory lipid accumulation value (38.2 wt\%) with a balanced fatty acid composition of 52.7\% saturated plus monounsaturated fatty acids and 47.4\% polyunsaturated fatty acids. Since fungal species are easy to recover, unlike microalgae, the lichen-like structure produced indicates an efficient low-cost bioremediation and harvesting alternative; in addition, it provides an oleaginous biomass for various industrial applications.
Lignocellulosic biomass is the most abundant renewable resource existing, and presently it is considered as a promising feedstock for the synthesis of green chemicals and biofuels for reducing transportation emissions and dependence on fossil fuels. In this research, a TCR (thermo-catalytic reforming) reactor is used to transform lignocellulosic biomass into high quality bio-oils, biochar and syngas. Sugarcane bagasse (SB) and oat hulls (OHS) were processed in the TCR (2 kg/h) at 450 degrees C in the intermediate pyrolysis reactor (kept constant) and varying reforming temperature between 500 and 700 degrees C. This paper studies the conversion potential of SB and OHS into sustainable bioproducts at different reforming temperatures. TCR oils contained the highest calorific value of 34.9 MJ/kg from SB and 35.0 MJ/kg from OHS at 700 degrees C which makes the bio-oil suitable to be applied as fuel for engines when compared to bio-oils produced from other pyrolysis technologies. SB and OHS pyrolysis gas at 700 degrees C contained higher H-2 yield 30.9 vol\% and 31.6 vol\%, respectively. The highest gas caloric values of SB and OHS were 18.4 MJ/kg and 18.8 MJ/kg at the same reforming temperatures, respectively. Overall, the TCR results of SB and OHS are promising for waste conversion into sustainable fuels.
The aim of this study was to evaluate the stocks, and quality of the soil organic matter (SOM) through the use of solid state C-13 nuclear magnetic resonance (C-13 NMR), electronic paramagnetic resonance (EPR) and fluorescence spectroscopy of a fine clay fluventic Eutrichrept after long-term sugarcane cultivation. In one area, sugarcane has been grown for 55 years no field burning before harvest. In another area managed under the traditional system the crop field has been burned before harvest for 35 years; vinasse has been applied on onepart (at a rate of 120 m(3) ha(-1) yr(-1)), but not on another. The increases of 157 and 57\% in C stocks of humic acids in the area cultivated without field burning for 55 years were related with the increase in the aromaticity degree as well as lower acidity of the SOM, as shown by C-13 NMR spectroscopy. The serniquinone-type free radical concentration, as observed by EPR, and intensity of fluorescence emission were higher in the humic acid extracted from soils under management system without field burning before harvest. Significant changes in the humification process were observed in the areas with crop trash preservation. However, in areas where sugar-cane fields were burnt at harvest, vinasse application for 35 years resulted in only minor changes in the organic matter quality and C stocks. These data indicate a rapid evolution of the soluble organic matter added to the soil through uinasse application.
The synchronized transformation of molasses, sugarcane juice, glucose, fructose, and sucrose into water insoluble platform chemicals, has stand up as a resourceful exercise to eradicate the expensive separation steps. On the other hand, the existing processes involve both acid-catalyzed and hydrogenation processes. We report herein, new green approaches for sequential conversion of sugarcane biorefinery products into biofuels using metal free carboxyl acid functionalized ionic liquid entangled porphyrin (CAFILP) photo-catalyst. Both levulinic acid (LA) and hydroxymethyl furfural (HMF) are water soluble and difficult to separate from the reaction mixture. Remarkably, the reaction of mixture containing LA and HMF easily converted to ethyl levulinate that considerably increases the yield of levulinate by affording another transformation technique excluding the hydrogenation step. The photo-catalytic activity of CAFILP affords ethyl levulinate (94\%) and HMF (70\%) yield that matches the acidic strength articulated by the Hammett acidity function. Photo-catalyst CAFILP exhibited intense absorptions in the visible regions with low band gap (1.49 eV) for visible light absorption is a key step of photocatalytic performance to convert sugarcane bio-refinery products into biofuels. The yield of HMF/LA was the highest from molasses, comprising more fructose that facilitates faster conversion compare to other biomass sources. Other products of sugarcane bio-refinery like sugarcane juice, sucrose, glucose, and fructose also have potential to add value in the bioenergy chain, affording HMF as the main product using optimized reaction conditions in presence of CAFILP photo-catalyst. The reusability of photocatalyst (up to 5 runs) was confirmed by easy filtration with good photo-catalytic activity.
Enzymatic hydrolysis at high solids loading has the potential to reduce both capital and operational expenditures. Here, pretreatment of rice straw (PRS) with dilute acid was carried out at a pilot scale (250 kg per day) at 162 degrees C for 10 min and 0.35\% acid concentration, followed by enzymatic hydrolysis at different total solids loadings. It showed that although the total sugar concentration increased from 48 to 132 g/l, glucan conversion reduced by 27\% (84-66.2\%) with increasing solids from 5 to 20\% in batch mode. Therefore, two different fed-batch approaches were evaluated to improve the glucan conversion by the sequential addition of a substrate and/or enzyme. At 20\% solid loadings and a 3 filter paper units/g enzyme dosage, the highest glucan conversion obtained was 66\% after 30 h of hydrolysis in batch mode. However, in an optimized fed-batch approach, the glucan yield was improved to 70\% by simply dividing the substrate feeding into three batches, that is, 50\% at 0 h, 25\% each after 4 h, and 8 h of hydrolysis reaction. The addition of surfactant (Ecosurf E6) further improved the conversion to 72\% after 30 h. The role of critical factors, that is, inhibitors, enzyme-lignin binding, and viscosity, was investigated during the course of hydrolysis in the batch and fed-batch approaches. This study suggests a sustainable approach for improved hydrolysis at high solids loadings by fine-tuning a simple process.
The use of agro-industrial by-products as feedstock for selenium-enriched yeast biomass production is an innovative and low-cost method. Thus, the present study aims for the utilization of sugarcane bagasse and corn bran hydrolysates for the production of selenium-enriched yeast and the evaluation of the effect of selenium in growth and cell composition. The hydrolysates were obtained using acid pretreatment, and yeasts were evaluated in different medium compositions. All evaluated yeasts were able to grow in the presence of 15 mg/L selenium.S. cerevisiaestrains presented the major tolerance to selenium and better relation between selenium uptake and cell growth, with maximum cell biomass production of 7.97 +/- 0.24 g/L and maximum selenium uptake of 1193 +/- 336 ppm and 99\% cell viability. Selenium also enhanced the lipid and protein concentration in cell extracts obtained after mechanical disruption. Regarding agro-industrial hydrolysates, corn bran hydrolysate allowed a better growth, with the production of 4.25 +/- 0.49 g/L of biomass enriched with 167 +/- 18 ppm selenium and 100\% of viability. Starchy and lignocellulosic biomasses presented potential as low-cost alternatives for single-cell protein contributing to the development of sustainable and economically viable technologies.
Two field experiments were conducted at CCS HAU Regional Research Station, Karnal, Haryana, India during 2004-2007 on the plant-ratoon-plant sequence of sugarcane crops in and during 2008-2010 on plant-ratoon in sequence. In both the experiments, the application of NPK fertilizer increased the cane yield of plant (3.8-7.9 \%) and ratoon crops (4.9-6.2 \%) of sugarcane, over NP treatment. Cane yields produced with the application of farm yard manure (FYM) + N 1/2 P, press-mud (PM)/press-mud compost (PMC) + N 1/2 P, FYM + NP, PM/PMC + NP, green manure (GM) + NP were at par with application of NPK, respectively (cane yields produced with NPK were 83.0, 77.9 and 85.7 t/ha for plant-ratoon-plant crops, respectively and 76.3 and 90.4 t/ha for plant-ratoon crop, respectively). These treatments produced higher cane yield of plant and ratoon crop than NP fertilizers alone. The application of FYM + NPK or PM/PMC + NPK or GM + NPK produced significantly higher cane yield (3-5 \% of plant and 5-8 \% of ratoon crops) than the application of NPK alone. In both the experiments, the application of NPK fertilizer increased the CCS\% of plant and ratoon crops of sugarcane over NP treatment. The application of organic manure (FYM or PM/PMC or GM) + N 1/2 P or NP or NPK increased the soil organic carbon (OC\%) over NPK (from 0.39 up to 0.52 \% in first experiment and 0.44 up to 0.48 \% in second experiment). The application of NPK increased the available K in the soil over NP (from 180 up to 194 kg/ha in the first experiment and 142 to 150 kg/ha in second experiment). The application of organic manure (FYM or PM at 12.5 t/ha) + NPK substantially increased the available K in the soil (from 180 up to 200 kg/ha in the first experiment and 142 up to 154 kg/ha in second experiment).
Investigating the dynamic changes in bacterial community composition during sugarcane top silage production starting in late March and finishing in late June (storage temperature: 20 to 35 degrees C) will advance our understanding of ensilage in hot ambient temperatures. The results showed that, the fermentation process was dominated by Leuconostocaceae (until d 5), followed by Lactobacillaceae (from d 5 to d 30), and finally Lactobacillaceae and Clostridium (from d 60 to d 90). As the fermentation process progressed, there was a significant increase in Lactobacillaceae abundance, and on d 60 there was a sharp increase in Clostridiaceae abundance. Spearman's correlation showed that, Lactococcus and Leuconostoc abundance were negatively correlated with acetate, propionate, butyrate, and ammonia-N levels. Clostridiaceae and Lactobacillaceae abundance were positively correlated with acetate, propionate, butyrate, and ammonia-N levels. The high moisture content (DM 24.31\%) of sugarcane tops stored in hot ambient temperatures may result in butyric acid fermentation.
Sugar cane bagasse ash (SCBA) is an abundant byproduct of the sugar and ethanol industry. SCBA is generally used as a fertilizer or is disposed of in landfills, which has led to intensified environmental concerns. In recent years, SCBA research has mainly been focused on utilization in construction materials due to the abundance and pozzolanic characteristics of SCBA. In this paper, a comprehensive review of the state-of-the-art morphology, physical properties, chemical composition, and mineralogical composition of SCBA is presented. Studies indicate that SCBA is a potentially promising construction material. The applications of SCBA as a pozzolanic material, a new source for preparing alkali-activated binders, aggregates, and fillers in construction materials, are summarized. The impacts of SCBA on fresh and hardened concrete properties are highlighted, including the physical properties, mechanical strength, microstructure, and durability. Key factors that govern pozzolanic activity are discussed in detail, including calcination and recalcination temperatures, and durations, fineness, loss on ignition (LOI), and crystal silicon dioxide. Finally, further research on the optimal and broad utilization of SCBA in construction materials is recommended.
Biosurfactants are amphipathic molecules, biodegradable, with reduced toxicity. They can be synthesized by fermentative processes from oleaginous compounds and agro-industrial by-products. In this context, the present study describes the production and the physical, chemical, and structural characterization of the bioemulsifier secreted by the yeast Scheffersomyces shehatae 16-BR6-2AI in a medium containing hemicellulosic sugarcane bagasse hydrolysate combined with soybean oil. The bioemulsifier was produced in Erlenmeyer flasks and isolated; then, the physicochemical and structural characterization of the formed molecule was carried out. The following fermentation parameters were obtained: Y-X/S = 0.45, Y-P/S = 0.083, and productivity of 0.076 g/L/h. The bioemulsifier was found to be a polymer containing 53\% of carbohydrates, 40.92\% of proteins, and 6.08\% of lipids, respectively. The FTIR spectrum confirmed the presence of functional groups such as amides, amines, and carbonyls. The bioemulsifier was stable over a range of temperature (-20 degrees C to 120 degrees C), salinity (1-15\%), and pH (2-12). It was observed that the biomolecule has a better emulsifying action in organic solvents with a non-polar character. Therefore, this biomolecule is a potential substitute for synthetic surfactants and can be used in different applications.
Despite being characterized as a renewable energy source, burning biomass is an environmental problem regarding the disposal of generated by-products. The present work aimed to determine the main properties of Rice Husk Ash, Sugarcane Bagasse Ash and Eucalyptus Chip Ash to evaluate their impacts on the production of ecological mortars with lower cement consumption levels. Therefore, the physicalchemical characterization of biomass ashes and flexural and compressive strength tests, dynamic elastic modulus and capillary water absorption of the mortars produced with 10, 20 and 30\% substitution, by mass, of Portland cement were carried out for each of the biomass ashes. It was found that the chemical and mineralogical characteristics presented by the biomass ashes had a significant impact on the results obtained. Considering the high levels of amorphous silica, RHA allowed high levels of substitution without affecting the mortar's physical and mechanical parameters. Although not very reactive, SCBA and ECA maintained the performance of mortars at low levels of incorporation, acting as filling materials (fillers). The results are encouraging for paving the way in terms of using different biomass ashes in rendering mortars. (c) 2021 Elsevier Ltd. All rights reserved.
Antibiotic pollution has drawn considerable attention and the removal of antibiotic from water is crucial. In the present study, biochars were produced from rice straw under different pyrolytic temperatures of 300 degrees C, 500 degrees C, and 700 degrees C (RSBC300, RSBC500, and RSBC700, respectively). The biochars were used to remove tetracycline (TC) from aqueous solution and the influence of different experimental conditions on TC removal was investigated. The results showed that the order of adsorption was as follows: RSBC700 > RSBC500 > RSBC300. A pseudo-second-order model and Langmuir isotherm model described the adsorption process of TC on biochars. Maximum adsorption capacity could reach 50.72 mg g(-1) at 35 degrees C based on Langmuir fitting. Initial pH of the solution had little influence on TC removal. The inhibitory effect of Ca2+ on TC removal was greater than that of Na+. High system temperature was beneficial for TC removal. Minerals in RSBC500 affected TC removal and minerals in RSBC300 and RSBC700 had little influence on TC removal. TC removal rate decreased from 58.86 to 27.84\% when the minerals were removed from RSBC500. The main mechanism involved in high-temperature biochar and TC adsorption included EDA pi-pi interactions and electrostatic interactions. Therefore, high-temperature biochar derived from rice straw has the potential to act as an adsorbent to remove tetracycline from aqueous solution.
Lignocellulosic biomass is the most abundant renewable resource on the earth. With the development of related fields, the high value utilization of lignocellulosic biomass has gradually become a new avenue for research. In this study, unbleached bagasse pulp was pretreated with xylanase and cold alkali to partially remove hemicellulose and convert to some cellulose I into cellulose II. Cellulose nanofibrils (CNF) were then obtained through ultra-micro grinding and high-pressure homogenization. The prepared CNF were characterized by TEM, Zeta potential, ATR-FTIR and XRD, and a thermogravimetric analyzer was used to analyze the thermal stability of CNF. The results show that xylanase pretreatment can improve the dispersion of fibers during mechanical treatment and can enhance the crystallinity of CNF. With an increase in alkali concentrations, the proportion of cellulose II structures increased, while cellulose crystallinity levels decreased due to the folding of cellulose chains. tinder the common influence of crystallinity and crystal structures, the thermal stability of the CNF prepared after cold alkali pretreatment underwent an increasing trend. This shows that the influence of crystal structures on the thermal stability of CNF gradually plays a dominant role as alkali concentrations increase.
In the sugarcane and sugar industry, there is a waste produced from the manufacturing process called ``Filter cake{''
An analytical investigation on different alkaline extraction methods to extract ``Type A{''
Short-chain fructooligosaccharides (sc-FOS) are prebiotics beneficial to human health, which can be synthesized from raw material containing a high sucrose content. Sugarcane syrup (SS) without molasses removal contains sucrose as a major sugar and is a rich source of several bioactive compounds. The aim of this study is to investigate factors affecting sc-FOS synthesis from SS using commercial enzyme preparations containing fructosyltransferase activity as biocatalysts. sc-FOS content increased significantly as the sucrose concentration of SS in the reaction mixture increased up to 40\% (w/v). Changes in carbohydrate compositions during the transfructosylating reaction of a pure sucrose solution and SS prepared from the two sugarcane cultivars Khon Kaen 3 and Suphanburi 50, catalyzed by Pectinex Ultra SP-L and Viscozyme L, showed similar profiles. Both enzymes showed a high ability to transfer fructosyl moieties to produce sc-FOS and a plateau of the total sc-FOS concentration was observed after 4 h of reaction time. For the pure sucrose solution and SS (Suphanburi 50), Viscozyme showed a superior ability to convert sucrose to Pectinex, with a higher sc-FOS yield (g FOS/100 g of initial sucrose), GF2 or 1-kestose yield (g GF2/g of initial sucrose) and GF3 or nystose yield (g GF3/g of initial sucrose). sc-FOS syrup (FOS SS) and the foam-mat-dried syrup powder prepared from SS and FOS SS, respectively, contained a high total phenolic content and possessed higher antioxidant activities than those prepared from pure sucrose, but contained lower calories.
The Present work emphasizes preparing ternary blended geopolymer mortar by partial replacement of Ground Granulated Blast Furnace Slag (GGBS) with a precursor such as Sugarcane Bagasse Ash (SCBA) and Sewage Sludge Ash (SSA) with two different sodium silicate to sodium hydroxide (SS/SH) ratios to prepare an alkaline activating solution. The replacement of GGBS with SCBA and SSA varied from 0-30\% by weight. Binary and ternary mortar mixes were tested for compressive strength and their morphological characters, it was found that 10\% of SCBA and 20\% of SSA incorporation in the binary mix resulted in a drop in strength which is less significant than other replacements for SS/SH ratio of 2.5. The ternary mix consisting of GGBS, SCBA, and SSA in the ratio of 70:10:20 respectively produced a compressive strength that is comparable with the control mortar having 100\% GGBS after 28 days of ambient curing. X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FTIR) studies showed the presence of C-A-S-H gel and participation of precursor in the geopolymer reaction which resulted in enhancement of strength. The Toxicity Characteristic Leaching Procedure (TCLP) results for SSA-incorporated mortar proved the leachability of heavy metals is within the limits. The application of geopolymer mortar proved to be vital in the sustainable production of building materials such as pre-cast elements, masonry units, etc.
A new precipitation method has been developed for improving the production of nanosilica that is faster and more environmentally friendly. The study investigates the effects of different acid types and concentrations, as well as aging times, to determine the optimal conditions for preparing nanosilica from sugarcane bagasse ash (SCBA). Nanosilica synthesised with citric acid exhibits a higher specific surface area (554.01 m2 g-1) and yield (88.54\%) compared to those synthesised with sulfuric, oxalic, and acetic acids. X-ray diffraction (XRD) patterns and transmission electron microscope (TEM) images show that the synthesised nanosilica has an amorphous silica phase with a particle diameter of approximately 5.6 nm. The applicability of the synthesised nanosilica as an adsorbent for methylene blue (MB) is studied. Various conditions such as adsorbent dosage, contact time, and initial concentration of MB are evaluated. The results reveal that the synthesised nanosilica has a high adsorption capacity (232.29 mg g-1) and removal efficiency (R\%) of 90\% for MB. The experimental results align with the Freundlich model and can be used for effective dye removal. The development of a simple and environmentally friendly method for synthesising nanosilica with superior adsorption properties is an important contribution to the field of waste management and provides a useful tool for tackling environmental pollution caused by organic dyes.
High productivity and enzyme stability are desirable characteristics of bioprocesses for production of the (hemi) cellulolytic enzymes needed for biomass conversion. This paper reports a comparative study of different cultivation systems, investigating production efficiency and the thermostability of the (hemi) cellulolytic enzymatic cocktails. A selected strain of Aspergiilus niger was cultivated using a novel sequential fermentation (SF) technique as well as the conventional submerged (SmF) and solid-state fermentation (SSF) methods. Enzyme production and thermostability were evaluated considering the effects of pretreatment (using steam-explosion and liquid hot water) of the sugarcane bagasse used as carbon source and inducer. For endoglucanase and xylanase enzymes, cultivation under SSF favored production when using washed steam-exploded bagasse and liquid hot water-pretreated bagasse as the solid substrates. However, removal of inhibitors from the pretreated biomass employed in the cultivation media was necessary, because the presence of phenolic compounds restricted fungal growth. It was concluded that the cultivation conditions should be conducted in conjunction with characterization of the thermostability of the enzymes, due to the inverse relation that can exist between these two process criteria. The findings revealed that endoglucanase and beta-glucosidase produced under SSF were less prone to deactivation by the phenolics in the medium. The residual activities of such enzymes after 24 h of incubation at 50 degrees C were between 80 and 100\%, indicating that they are highly thermostable. The results emphasize the potential of SSF for the production of (hemi) cellulolytic enzymes that are more stable. (C) 2015 Elsevier Ltd. All rights reserved.
Heavy metal pollution is a common environmental problem all over the world. The purpose of the research is to examine the applicability of bagasse fly ash (BFA)-an agricultural waste of sugar industry used for the synthesis of zeolitic material. The zeolitic material are used for the uptake of Pb(II) and Cd(II) heavy metal. Bagasse fly ash is used as a native material for the synthesis of zeolitic materials by conventional hydrothermal treatment without (conventional zeolitic bagasse fly ash (CZBFA)) and with electrolyte (conventional zeolitic bagasse fly ash in electrolyte media (ECZBFA)) media. Heavy metal ions Pb(II) and Cd(II) were successfully seized from aqueous media using these synthesized zeolitic materials. In this study, the zeolitic materials were well characterized by different instrumental methods such as Brunauer-Emmett-Teller, XRF, Fourier transform infrared spectroscopy, powder X-ray diffraction, and scanning electron microscopic microphotographs. The presence of analcime, phillipsite, and zeolite P in adsorbents confirms successful conversion of native BFA into zeolitic materials. Seizure modeling of Pb(II) and Cd(II) was achieved by batch sorption experiments, isotherms, and kinetic studies. These data were used to compare and evaluate the zeolitic materials as potential sorbents for the uptake of heavy metal ions from an aqueous media. The Langmuir isotherm correlation coefficient parameters best fit the equilibrium data which indicate the physical sorption. Pseudo-second-order and intra-particle diffusion model matches best which indicates that the rate of sorption was controlled by film diffusion. The column studies were performed for the practical function of sorbents, and breakthrough curves were obtained, which revealed higher sorption capacity as compared to batch method. Synthesized zeolitic material (CZBFA and ECZBFA), a low-cost sorbent, was proven as potential sorbent for the uptake of Pb(II) and Cd(II) heavy metal ions.
Pretreatment is essential in the production of alcohol from lignocellulosic material. In order to increase enzymatic sugar release and bioethanol production, thermal, dilute acid, dilute basic and alkaline peroxide pretreatments were applied to wheat straw. Compositional changes in pretreated solid fractions and sugars and possible inhibitory compounds released in liquid fractions were analysed. SEM analysis showed structural changes after pretreatments. Enzymatic hydrolysis and fermentation by Pichia stipitis of unwashed and washed samples from each pretreatment were performed so as to compare sugar and ethanol yields. The effect of the main inhibitors found in hydrolysates (formic acid, acetic acid, 5-hydroxymethylfurfural and furfural) was first studied through ethanol fermentations of model media and then compared to real hydrolysates. Hydrolysates of washed alkaline peroxide pretreated biomass provided the highest sugar concentrations, 31.82 g/L glucose, and 13.75 g/L xylose, their fermentation yielding promising results, with ethanol concentrations reaching 17.37 g/L. (C) 2014 Elsevier Ltd. All rights reserved.
Two Streptomyces strains were grown on sugarcane bagasse and groundnut hulls lignocelluloses in semi-solid state culture at 37-degrees-C for 12 weeks. Best results gave a 45\% depletion of sugarcane bagasse lignocellulose with a 21\% crude protein content of final material. The possibility of using S. viridosporus to improve the protein content of both lignocelluloses for use as an animal feedstock supplement is discussed.
This paper investigates the non-isothermal thermokinetics of the co-pyrolysis of sugarcane bagasse and corn residue blended with coal. The individual devolatilization behaviour of each of the fuels obtained separately was compared with the behaviour of the biomass blends with coal at various mix ratios. Possible synergistic behaviour that points to the existence of chemical interactions during pyrolysis between the coal and biomass fractions of the blends could thus be quantified. Synergistic interactions in the blends resulted in higher than expected volatile yields. The interactions occurred between 300 degrees C and 500 degrees C, corresponding to the end of biomass devolatilization and the start of coal decomposition. Isoconversional kinetic analysis revealed that apparent activation energy values varied between 165-180, 162-190, 160-175, and 225-260 kJ mol(-1) for sugarcane bagasse, corn cobs, corn stover, and coal in the 0.1 to 0.8 conversion range. A comparison of E(alpha) for single fuels and coal-biomass blends gave further evidence of synergistic behaviour as demonstrated by larger variation in E(alpha) during the decomposition of the blends, compared to the individual fuels. (C) 2012 Elsevier B.V. All rights reserved.
Residual lignin affects the physical and chemical performance of lignin-containing cellulose nanofibers (LCNFs). In this work, LCNFs were prepared from sugarcane bagasse powder (SBP) through p-toluenesulfonic acid (p-TsOH) hydrolysis and the subsequent homogenization treatment. By adjusting the concentration of p-TsOH and hydrolysis temperature, LCNFs with lignin content of 4.69-17.53\% were obtained, and the effects of lignin content on the chemical structure, crystallinity, size, hydrophobicity and thermal stability of LCNFs were systematically studied. With the increase of lignin content, the diameters and average water contact angles of LCNFs were increased (from 169.65 to 781.56 nm and 39.74-86.16 degrees, respectively), while the crystallinities were decreased. The thermal stabilities of LCNFs were decided both by lignin content and the crystallinity. The by-product lignin nanoparticles (LNPs) with an average diameter of 50-500 nm were generated with LCNFs, further improving the resource utilization value of SBP. This study provides theoretical and experimental basis for the subsequent processing of films with different hydrophobic properties and materials with higher mechanical properties and thermal stability.
Production of second-generation bioethanol uses lignocellulose from agricultural by-products such as sugarcane bagasse (SCB). A lignocellulose pre-treatment is required to degrade lignin, ensuring further efficient saccharification. Two experimental designs were set up to define culture conditions of Pycnoporus sanguineus in mesocosms to increase laccase activities and thus delignification. The first experimental design tested the effect of phenolic complementation (via coffee pulp) and the use of urea as a simple nitrogen source and the second defined more precisely the percentages of coffee pulp and urea to enhance delignification. The responses measured were: lignocellulolytic activities, laccase isoform profiles by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the chemical transformation of the substrate using solid-state NMR of 13C. Adding 10\% of coffee pulp increased laccase activities and fungal biomass (32.5\% and 16\% respectively), enhanced two constitutive isoforms (R-f 0.23 and 0.27), induced a new isoform (R-f 0.19) and led to a decrease in total aromatics. However, higher concentrations of coffee pulp (25\%) decreased laccase and cellulase activities but no decrease in aromaticity was observed, potentially due to the toxic effect of phenols from coffee pulp. Moreover, laccase production was still inhibited even for lower concentrations of urea (0-5\%). Our findings revealed that an agricultural by-product like coffee pulp can enhance laccase activity-though to a threshold- and that urea limited this process, indicating that other N-sources should be tested for the biological delignification of SCB.
Hydrophobic modification of bagasse fibers (BFs) through a green approach can promote its reuse in asphalt and enhance the utilization value of agricultural and forestry waste in road engineering. In contrast to traditional chemical modification, this study reports a new method for the hydrophobic modification of BFs using tannic acid (TA) and the in situ growth of FeOOH nanoparticles (NPs), resulting in FeOOH-TA-BF, which is used to prepare styrene-butadiene styrene (SBS)-modified asphalt. The experimental results show that the surface roughness, specific surface area, thermal stability, and hydrophobicity of the modified BF are improved, which is beneficial for enhancing the interface compatibility with asphalt. Specifically, compared with BF/SBS-modified asphalt, FeOOH-TA-BF/SBS-modified asphalt exhibits 39.21\% and 23.26\% increase in the elastic modulus G' and viscous modulus G?, respectively, at the optimal dosage of 2.5\%, corresponding to 6.15-fold and 7.13-fold increase in the fatigue life at 2.5\% and 5.0\% strain respectively, and 22.0\% improvement in shear resistance performance. In the meantime, 2.5-fold enhancement of the storage stability. Therefore, this study provides a simple, environmentally friendly, and efficient hydrophobic modification method that is of great significance for promoting the resource utilization of solid waste BF.
The performance of two laboratory-scale biofilters packed with pressmud (BF1) and sugarcane bagasse (BF2) was evaluated for gas-phase xylene removal under various operating conditions. Biofilter was inoculated with a mixed culture obtained from pharmaceutical sludge. Experiments were carried out at different flow rates (0.03, 0.06, 0.09 and 0.12 m(3) h(-1)) and inlet xylene concentrations (0.2, 0.4, 0.6 and 1.2 g m(-3)). A maximum removal efficiency of 99 and 95 \% were achieved at an inlet concentration of 0.2 g m(-3) and gas flow rate of 0.03 m(3) h(-1) for BF1 and BF2, respectively. The dynamic behaviour of the biofilter was tested at different process conditions through vigorous short, medium and long-term shock loads. The biofilter was found to respond apace to rapid changes in loading conditions. The stability of the biomass within the reactor was apparent from the fast response of the biofilter to recuperate and handle intermittent shutdown and restart operations.
This study aimed to establish the optimal operational conditions for hydrogen production using vermicomposting-tea and sugarcane molasses as substrate. The experiments were carried out by triplicate in 110 ml serological bottles, a Box-Behnken design of experiments was performed in anaerobic dark conditions. The maximal hydrogen production (HP), hydrogen production rate (HPR), and hydrogen yield (HY) attained were 1021.0 mlL(-1), 5.32 mlL(-1)h(-1), and 60.3 mlL(H2)(-1) /g(TCC), respectively. The statistical model showed that the optimal operational conditions for pH, molasses concentration, and temperature were 6.5; 30 \% (v/v) and 25 ?. The bioreactor run showed 17.202 L of hydrogen, 0.58 Lh(-1), and 77.2 ml(H2)g(TCC)(-1) For HP, HPR, and HY. Chemometric analysis for the volatile fatty acids obtained at the fermentation showed that only two principal components are required to explain 90 \% of the variance. The representative pathways for hydrogen production were acetic and butyric acids. This study established the operational conditions for the upstream processing amenable to pilot and industrial-scale operations. Our results add value to molasses within the circular economy for hydrogen production using a novel consortium from vermicompost.
The permanence of sugarcane straw on the soil surface, in systems without the pre-harvest straw burning practice, directly affects the soil organic matter dynamics. The objective of this work was to evaluate the changes in total organic carbon (TOC), carbon in the light organic matter (CLOM) and particulate organic carbon (POC), and their carbon stocks in a typic Quartzipsamment cultivated for nine years with sugarcane crops, which were conducted without the pre-harvest straw burning practice, in Paraipaba, State of Ceara, Brazil. Disturbed and undisturbed soil samples were collected at depths of 0.0-0.025, 0.025-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.30 m, in the sugarcane crop area and in an adjacent native forest area, in order to quantify the TOC, CLOM and POC, as well as the carbon stocks accumulated in the layer 0.0-0.30 m related to these fractions (TOCSt, CLOMSt and POCSt). TOC content changes after nine years of sugarcane crops, conducted without pre-harvest straw burning, were found only in the layers 0.10-0.20 and 0.20-0.30 m. The CLOM varied only in the layer 0.025-0.05 m. The POC content changes were more noticeable than the changes in TOC and CMOL. The CLOM of the sugarcane crop area presented high similarity with TOC, which may affect their quantification in studies related to the soil organic matter dynamics. The sugarcane crop increased the TOCSt, POCSt and CLOMSt in the layer 0.0-0.30 m, compared with the adjacent native forest area.
The cellulolytic system of Clostridium cellulovorans mainly consisting of a cellulosome that synergistically collaborates with non-complexed enzymes was investigated using cellulosic biomass. The cellulosomes were isolated from the culture supernatants with shredded paper, rice straw and sugarcane bagasse using crystalline cellulose. Enzyme solutions, including the cellulosome fractions, were analyzed by SDS-PAGE and Western blot using an anti-CbpA antibody. As a result, C. cellulovorans was able to completely degrade shredded paper for 9 days and to be continuously cultivated by the addition of new culture medium containing shredded paper, indicating, through TLC analysis, that its degradative products were glucose and cellobiose. Regarding the rice straw and sugarcane bagasse, while the degradative activity of rice straw was most active using the cellulosome in the culture supernatant of rice straw medium, that of sugarcane bagasse was most active using the cellulosome from the supernatant of cellobiose medium. Based on these results, no alcohols were found when C. acetobutylicum was cultivated in the absence of C. cellulovorans as it cannot degrade the cellulose. While 1.5 mM of ethanol was produced with C. cellulovorans cultivation, both n-butanol (1.67 mM) and ethanol (1.89 mM) were detected with the cocultivation of C. cellulovorans and C. acetobutylicum. Regarding the enzymatic activity evaluation against rice straw and sugarcane bagasse, the rice straw cellulosome fraction was the most active when compared against rice straw. Furthermore, since we attempted to choose reaction conditions more efficiently for the degradation of sugarcane bagasse, a wet jet milling device together with L-cysteine as a reducing agent was used. As a result, we found that the degradation activity was almost twice as high with 10 mM L-cysteine compared with without it. These results will provide new insights for biomass utilization.
The aim of the study was to evaluate the effect of P sources and filter cake, enriched or not with biofertilizers and liquid peat, on the microbial population and the soil available P levels and shoot dry matter and P accumulation by sugarcane. The experiment was conducted in a greenhouse in a completely randomized design with factorial arrangement 4 x 3 + 1 and three replications. The treatments consisted in four sources of P: simple superphosphate, triple superphosphate, monoammonium phosphate and reactive natural phosphate combined with three levels of organic compound: without filter cake, decomposed filter cake (30 t ha(-1), dry basis) and decomposed filter cake enriched with liquid peat (4 mL kg(-1)of filter cake) and biofertilizers (480 mL kg(-1)of filter cake) and a control treatment without organic compound and without phosphorus. At 45 and 110 days after planting the total population of bacteria and fungi, phosphate-solubilizing microorganisms and total microorganisms were evaluated. After 60 and 110 days, the soil available P, plants' P and dry matter and P accumulation were evaluated. The organic compound increased the population of soil microorganism, the soil P levels, the accumulation of P and dry matter by the plants, regardless of the source of P, although the enrichment with biofertilizer and liquid peat did not enhance this effect. In conclusion, the presence of organic compost enhances the effects of phosphate fertilization.
A consolidated bioprocessing (CBP) using Clostridium thermocellum DSM 1237 for bioethanol production in anaerobic bottles and a 3-L fermenter from biomass was investigated. The effects of key operational parameters including different carbon sources, temperature, and substrates on the metabolic performance of the strain were firstly evaluated. It was found that ethanol yield reached 0.60 g/L with a cell biomass of 0.80 g/g at the optimal temperature of 60 degrees C with 0.5\% (w/v) cellobiose. Further experiments indicated that sugarcane bagasse (SCB) could be utilized to efficiently culture this strain. Ethanol yield reached 0.68 g/L (65.8\% of theoretical yield) from alkali-pretreated SCB. In the subsequent 3-L fermenter trial, the maximum ethanol 0.86 g/L (83.3\% of theoretical yield) was achieved, with enzymes enriched in both cellulase and xylanase. The CBP provided enzymes on-site and integrated hydrolysis and fermentation in one-step, which might be an effective approach for economic bioethanol production.
To achieve sucrose-metabolizing capability, different sucrose utilization operons have been introduced into E. con that cannot utilize sucrose. However, these engineered strains still suffer from low growth rates and low sucrose uptake rates. In this study, cell surface display system was adopted in engineered E. coli AFP111 for succinic acid production from sucrose and molasses directly. Invertase (CscA) from E. coli W was successfully anchored to outer membrane by fusion with OmpC anchoring motif, and the displayed CscA showed high extracellular activity. Compared with the sucrose permease system, the cell surface display system consumed less ATP during sucrose metabolism. When less ATP was consumed by AFP111/pTrcC-cscA, the succinic acid productivity from sucrose was 23\% higher than that by AFP111/pCR2.1-cscBKA that having the sucrose permease system. As a result, 41 g L-1 and 36.3 g L-1 succinic acid were produced by AFP111/pTrcC-cscA from sucrose and sugarcane molasses respectively at 34 h in 3-L fermentor during dual-phase fermentation. In addition, 79 g L-1 succinic acid was accumulated with recovered AFP111/pTrcC-cscA cells at the end of dual-phase fermentation in 3-L fermentor, and the overall yield was 1.19 mol mol(-1) hexose. (C) 2014 Elsevier B.V. All rights reserved.
BACKGROUNDA number of pretreatments have been reported in the literature aiming to improve yields with increases in degree of digestibility of the cellulose-enriched fractions, in reducing the process time recalcitrance and costs of a variety of chemicals reagents and physical processes were used. Nevertheless, none of them was considered completely satisfactory. RESULTSModifications and simplifications were made in pretreatments to increase gravimetric yields and to decrease the losses of mass. The highest gravimetric yields and the lowest loss of mass were obtained for cellulose-enriched fractions resulting from microwave pretreatments. Loss of mass during treatments with sulfuric acid were due to dehydration of sugars forming furan aldehydes. Cellulose-enriched fractions PT6 and PT7 are certainly more easily by commercial enzymes as indicated by loss of mass. CONCLUSIONSPretreatments with sulfuric acid resulted in less recalcitrant cellulose-enriched fractions that will give enzymatic hydrolysates containing less inhibitors of yeast cells. FeCl3 greatly modified the yields of total reducing sugars, glucose, furan aldehydes and phenolic compounds released from the cellulose-enriched fractions by sulfuric acid. However, the co-catalytic effect on the sulfuric acid hydrolysis was dependent on the pretreatment used and acid concentration. (c) 2014 Society of Chemical Industry
Cellulose nanocrystals (CNC) and succinic anhydride-modified CNC from bleached soda bagasse pulp under different parameters were used to remove Cd+2 and Pb+2 heavy metal ions from aqueous solution. The aim was to modify the chemical structure of cellulose nanocrystal using succinic anhydride and to investigate the effect of CNC and succinic anhydride-modified CNC on the adsorption capacity of heavy metal ions. The adsorption parameters included pH (3, 5, 6, and 8), contact time (30, 60, and 90 min), and initial metal ion concentration (40, 120, 200, and 280 ppm). It was found at all pHs that the adsorption capacity of the succinic anhydride-modified CNC adsorbent was much higher than that of the default CNC adsorbent, and this difference was greater at higher pHs. The results showed that the maximum metal ion adsorption was obtained at pH 6 for Pb+2 and Cd+2 ions. Both types of CNC had a higher adsorption capacity for lead ions than cadmium ions. To investigate the kinetic models of adsorption, the pseudo-first-order and pseudo-second-order kinetics model were used. Adsorption on unmodified adsorbent gave a better fit to the Langmuir model than the Freundlich model for both Pb+2 and Cd+2 metals. In addition, the adsorption mechanism was changed by modifying the adsorbent, and then it had better fit to the Freundlich adsorption model. Adsorption of cadmium and lead metals by adsorbents fit better to the pseudo-first-order kinetics model.
The sugarcane industry represents one of the most important economic activities in Brazil producing sugar and ethanol for the internal and external markets. Most of the sugarcane plants in Brazil have been projected to produce both sugar and ethanol, prioritizing one over the other according to market prices. There are also plants dedicated only to ethanol production. Nevertheless, this change in the production pattern affects parameters in their production such as water consumption, steam demands, bagasse surplus and electricity production. Thus, the aim of this study is to evaluate the production parameters for different configurations of sugarcane plant: (a) all sugarcane juice is destined to produce ethanol without sugar production and (b) distribution of 50 \%/50 \% of total recoverable sugars in sugar and ethanol production. Simulations in ASPEN PLUS (R) software were performed in order to evaluate the mass and energy balances and thermal integration using the Pinch Method was applied in order to minimize the utilities consumption.
This study was aimed at exergetically analyzing a lignocellulosic biorefinery annexed to a sugar mill for simultaneous lactic acid and electricity production using sugarcane bagasse and brown leaves as feed-stock. The main goal was to reveal the reasons and sources of thermodynamic inefficiencies associated with the biorefinery under investigation. After presenting the exergy balance equations for all the subunits of the biorefinery, their exergetic performance parameters were computed and consequently exergetic performance parameters were measured for the whole system. The exergetic values of the net electricity and steam were found to be 20.66 MW and 50.41 MW, respectively, while the chemical exergy content of the produced lactic acid was determined at 112.84 MW. The overall exergy destruction of the system stood at 207.69 MW. The contribution of the steam generation, as the main subunit wasting exergy, to the overall exergy destruction of the system was found to be 6331\%. Furthermore, lactic acid production subunit stood in the next rank in terms of exergy destruction, contributing 1630\% of the overall exergy destruction of the biorefinery. The universal and functional exergetic efficiencies of the system were determined as 52.71\% and 44.73\%, respectively, while the normalized exergy destruction was calculated as 1.13. (C) 2018 Elsevier Ltd. All rights reserved.
Thirty two Santa Gertrudis bulls with ten months of age and 245 kg average live weight were fed 88\% concentrate diets with corn silage or sugarcane bagasse and dry corn or high moisture corn. Four animals were slaughtered in the beginning of the experiment for initial body composition determination. Other 28 animals were distributed on four treatments. The experimental design was randomized blocks in 2 X 2 factorial (two roughage X two corn sources) with seven replicates. Regression equation of log body energy content as a function of log empty body weight (EBW) provided estimation of body energy content at any EBW range included in this research: for weight gain of 1 kg, an animal of 300 kg requires 3.64 Mcal/day of energy and 129.5 g of protein.
Energy cane is a genotype derived from species of sugarcane (Saccharum officinarum and Saccharum spontaneum) with a lower sucrose content and higher fiber content for bioenergy purposes. It is a rustic plant that demands less fertile soils that do not compete with food crops. In this work, an analysis of energy cane bagasse pyrolysis products was performed, assessing the effect of reaction temperature and kinetic and thermodynamic parameters. Anhydrosugars, such as D-allose, were the primary compounds derived from the decomposition of energy cane at 500 \& DEG;C. Methyl vinyl ketone and acetic acid were favored at 550 and 600 \& DEG;C. At 650 \& DEG;C, methyl glyoxal, acetaldehyde and hydrocarbons were favored. Among the hydrocarbons observed, butane, toluene and olefins such as 1-decene, 1-undecene, 1-tridecene and 1-tetradecene were the most produced. The Friedman isoconversional method was able to determine the average activation energies in the ranges 113.7-149.4, 119.9-168.0, 149.3-196.4 and 170.1-2913.9 kJ mol(-1) for the decomposition of, respectively, pseudo-extractives, pseudo-hemicellulose, pseudo-cellulose and pseudo-lignin. The thermodynamic parameters of activation were determined within the ranges of 131.0 to 507.6 kJ mol(-1) for \& UDelta;H, 153.7 to 215.2 kJ mol(-1) for \& UDelta;G and -35.5 to 508.8 J mol(-1) K-1 for \& UDelta;S. This study is very encouraging for the cultivation and use of high-fiber-content energy cane bagasse, after sucrose extraction, to produce biofuels as an alternative to the current method of conversion into electricity by low-efficiency burning.
This work created, characterized, and used a magnetic biochar catalyst that is both eco-friendly and very effective. Sugarcane bagasse was selected as primary raw material for catalyst preparation, because it is renewable and ecofriendly biomass. Catalyst created by doping sugarcane bagasse biochar with magnetic material in the form of (FeSO4 \& BULL;7H(2)O). Thermogravimetric Analysis (TGA) and Fourier Transform Infrared spectroscopy (FTIR) were used to characterize the catalyst. In addition, physical and textural characteristics of the catalyst were identified and interpreted. The characterization outcome showed that the catalyst has good catalytic qualities. For the manufacturing of biodiesel, discarded cooking oil served as the primary feedstock. The experiment was created utilizing the Box-Behnken Design (BBD) technique. There are four variables with the following three levels each: temperature, methanol to oil ratio, catalyst concentration, and reaction time. 29 experiments in total were carried out. Using the RSM function, optimization was done. The optimal conditions for obtaining biodiesel yield-temperature, methanol to oil ratio, reaction time, and catalyst weight-were 43.597 \& DEG;C, 9.975 mol/L, 49.945 min, and 1.758 wt\%. A study of the produced biodiesel using a FTIR showed that the conventional biodiesel IR spectra were confirmed. All physiochemical characteristics found suggested the biodiesel complied with ASTM and EN norms. Overall, the synthesized catalyst had conducted simultaneous reactions in a single batch reactor and had demonstrated suitability for converting used cooking oil to biodiesel.
A novel hybrid nanocomposite (HNC) was prepared by in situ microwave-mediated polymerization of 2-hydroxyethylmethacrylate with microfibrillated sugarcane bagasse, microfibrillated chitin and Fullers' earth. N,N `-Methylenebisacrylamide as a cross-linker and potassium persulfate as initiator were used as additives. Structural characterization of HNC was performed by FTIR spectroscopy, scanning electron microscopy and powder X-ray diffractometry. Water absorption experiments revealed the superabsorbent behaviour of HNC, and it can absorb water over a long period of time. The results of swelling-deswelling cycles revealed that HNC exhibits high recyclability with increased percent swelling after each cycle. Swelling percent reached 2000\% in 24 h and 9000\% in 10 d. However, equilibrium was not attained even after this duration. Antimicrobial studies were conducted to evaluate the microbial decomposition behaviour of HNC. While HNC is based on biopolymers (microfibrillated sugarcane bagasse and chitin), it was found to exhibit resistance towards microbial decomposition even after exposure for several months under ambient conditions. However, it was found to undergo degradation in moist garden soil in 2 months. Adsorption performance of HNC for Pb(II) ions was investigated in aqueous solutions at 291, 296 and 303 K at pH 7 using Langmuir, Freundlich, Temkin and Dubinin-Kaganer-Radushkevich models of adsorption. Data were found to fit well with the Langmuir model indicating the primarily physical nature of adsorption. The results of adsorption kinetics were found to be in good agreement with the pseudo-second-order model. Overall, HNC was found to exhibit high adsorption capacity for Pb(II) ions in aqueous solutions with a maximum adsorption capacity of 500 mg/g at 303 K. More than 90\% Pb(II) ions could be readily recovered by soaking the Pb(II)-loaded HNC in dilute acetic acid.
The use of natural additives in elastomeric compounds is gaining the special attention of researchers and industry due to their potential applications as environmentally friendly compounds and lower cost-related. Another important issue is the use of powerful mathematical tools to predict experimental results, which is crucial for saving cost and time. Artificial neural network (ANN) combined with other mathematical methods, such as surface response methodology (SRM), can guarantee reliability and faster response of the predicted data for similar materials or properties. The great advantage of the present method is the fast prediction of the analyzed property, in the present case, thermal degradation curves, at heating rates not experimentally tested. In this study, a modified activator from sugarcane bagasse was incorporated in different concentrations in natural rubber compounds, and the degradation behavior was simulated by ANN and SRM based on the experimental thermal degradation curves at different heating rates from the thermogravimetric analysis. The simulated results showed an outstanding agreement with the experimental ones, evidencing the importance of using ANN and SRM tools in the prediction of properties of elastomeric compounds.
This work compares the technical, economic and environmental (GHG emissions mitigation) performance of power generation and ethanol production from sugarcane residual biomass, considering conversion plants adjacent to a sugarcane mill in Brazil. Systems performances were simulated for a projected enzymatic saccharification co-fermentation plant (Ethanol option) and for a commercial steam-Rankine power plant (Electricity option). Surplus bagasse from the mill would be used as fuel/raw material for conversion, while cane trash collected from the field would be used as supplementary fuel at the mill. For the Electricity option, the sugarcane biorefinery (mill + adjacent plant) would produce 91 L of ethanol per tonne of cane and export 130 kWh/t of cane, while for the Ethanol option the total ethanol production would be 124 L/t of cane with an electricity surplus of 50 kWh/t cane. The return on investment (ROI) related to the biochemical conversion route was 15.9\%, compared with 23.2\% for the power plant, for the conditions in Brazil. Considering the GHG emissions mitigation, the environmentally preferred option is the biochemical conversion route: the net avoided emissions associated to the adjacent plants are estimated to be 493 and 781 kgCO(2)eq/t of dry bagasse for the Electricity and Ethanol options, respectively. (C) 2010 Elsevier Ltd. All rights reserved.
Background: Obtaining high-value products from lignocellulosic biomass is central for the realization of industrial biorefinery. Acid pretreatment has been reported to yield xylooligosaccharides (XOS) and improve enzymatic hydrolysis. Moreover, xylose, an inevitable byproduct, can be upgraded to xylonic acid (XA). The aim of this study was to valorize sugarcane bagasse (SB) by starting with XA pretreatment for XOS and glucose production within a multiproduct biorefinery framework. Results: SB was primarily subjected to XA pretreatment to maximize the XOS yield by the response surface method (RSM). A maximum XOS yield of 44.5\% was achieved by acid pretreatment using 0.64 M XA for 42 min at 154 degrees C. Furthermore, XA pretreatment can efficiently improve enzymatic digestibility, and achieved a 90.8\% cellulose conversion. In addition, xylose, the inevitable byproduct of the acid-hydrolysis of xylan, can be completely converted to XA via bio-oxidation of Gluconobacter oxydans (G. oxydans). Subsequently, XA and XOS can be simultaneously separated by electrodialysis. Conclusions: XA pretreatment was explored and exhibited a promising ability to depolymerize xylan into XOS. Mass balance analysis showed that the maximum XOS and fermentable sugars yields reached 10.5 g and 30.9 g per 100 g raw SB, respectively. In summary, by concurrently producing XOS and fermentable sugars with high yields, SB was thus valorized as a promising feedstock of lignocellulosic biorefinery for value-added products.
In recent years, the demand for energy is increasing due to increase in population, industrial and agricultural activities. India has most resources of renewable energy and a number of technologies have been developed to harness the energy resources. There is a huge potential to separate energy from agricultural waste using a suitable technology. The organic waste from various forms can be treated either by a biochemical or thermo chemical route. Biochemical conversion through anaerobic digestion results in the energy degradation. Thermo chemical conversion involves in the burning of waste to produce energy. The treatment method depends on factors such as quality, quantity, works and local requirement. Coconut shell and sugarcane bagasse are naturally occurring and abundant biomass which offers an economical solution for heavy metal removal. Heavy metals like nickel and chromium are main toxins which affects lives severely. The adsorption potential of activated carbon derived from a mixture of coconut shell and sugarcane bagasse has been studied for the removal of chromium from the tannery waste water collected from the Common Effluent Treatment Plant (CETP) at Pallavaram, Chennai. The activated charcoal is prepared by designing a prototype furnace which accommodates large quantity of biomass and burnt in an inert atmosphere to produce activated carbon. This carbon material was collected and made into energy blocks as briquettes. These briquettes have been used as a filter bed to remove the heavy metals by developing a packed bed column experiment. Thus the experiment indicates that mixture of sugarcane bagasse and coconut shell works out as an effective adsorbent for the removal of chromium from tannery waste water. (c) 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Mechanical, Electronics and Computer Engineering 2020: Materials Science.
Recent oil spills causing pollution in oceans and other bodies of water require sorbents that are both cost-effective and eco-friendly. Novel magnetic silica sorbent materials (MSS) have been synthesized using ash from rice husks or sugarcane bagasse and red dust, a waste generated in the steel industry. The designed MSS exhibited a definite response to external magnetic fields. The MSS, based on rice husk ash and bagasse ash, showed oil loading capacities of 1.93 and 2.09 times their weight, respectively, and also exhibited recyclability. The MSS were also functionalized to make them oleophilic and hydrophobic using sodium oleate. These functionalized rice husk ash and bagasse ash-based MSS showed oil loading capacities of 3.22 and 2.69 times their weight, respectively. Magnetic separation provided a convenient method for the removal of magnetizable particles by applying an appropriate external magnetic field. The MSS at the end of their utilization cycles were successfully incorporated into geopolymeric material, enabling the process to be zero waste and to achieve the overall goal of finding a green approach to use these wastes after oil spillage cleanup.
Sugarcane bagasse, a waste product of the sugarcane industry can be used as a precursor for the preparation of carbon. In this study, a composite consisting of hierarchically functionalized porous carbon (FPC) and beta-FeOOH was synthesized via a simple and effective hydrolysis method. The hydrothermal process before the carbonization and activation of the bagasse maintained the hierarchical interconnected porous structure of the sugarcane bagasse. A nitric acid (HNO3) functionalization treatment enabled an in-situ growth of beta-FeOOH on the hierarchically structured bagasse. When tested as an anode for lithium-ion batteries, the obtained FPC/beta-FeOOH composite showed a high discharge capacity of 898.8 mAh g(-1) at 0.2 A g(-1) after 350 cycles and achieved a specific capacity of 446.1 mAh g(-1) at a current rate of 1 Ag-1 after 1000 cycles together with a remarkable coulombic efficiency of 99.9\%. This excellent electrochemical performance of the FPC/beta-FeOOH composite can be attributed to the synergistic effect of the interconnected porous structure of porous carbon and the electrochemically active tunnel type beta-FeOOH nanorods. The strategy developed here is promising in design and fabrication of other composites having interconnected porous structures with high performance. (C) 2018 Elsevier Ltd. All rights reserved.
Identifying new uses for residues of industries that process large quantities of biomass, as in bioethanol production, is essential for a sustainable development with reduced impact on the environment, which is the reason why many efforts have been devoted to find noble uses for lignins. in this study, a lignin obtained from sugarcane bagasse in a bioethanol producing plant was carboxymethylated to yield the water-soluble carboxymethyl lignin (CML), which was then used as stabilizing agent in aqueous alumina (Al2O3) suspensions. CML had a degree of substitution 0.46 +/- 0.01, in relation to the C9 unit of lignin, and behaved as a polyelectrolyte in a large pH range owing to the dissociation of carboxylic groups. The action of CML as stabilizing agent of alumina aqueous suspensions was investigated using viscometry, zeta potential, and photon correlation spectroscopy (PCS) measurements, mainly as a function of pH and time. Overall, the results showed that CML had a good performance as a deflocculating agent, because it led to dispersions with low viscosity and small change in particle size as a function of time. The positive effect from the addition of CML was confirmed in the morphological features of the material obtained from the alumina suspensions after elimination of water, as indicated by scanning electron microscopy. The stabilization of alumina suspensions afforded by CML opens the way for similar applications of modified lignins, whose electrical and structural properties may be tuned for specific uses in various industries, including the ceramic industry. (C) 2011 Elsevier B.V. All rights reserved.
Sugarcane rind contains some functional phenolic acids. The separation of these compounds from sugarcane rind is able to realize the integrated utilization of the crop and reduce environment pollution. In this paper, a novel protocol based on interfacing online solid-phase extraction with high-speed countercurrent chromatography (HSCCC) was established, aiming at improving and simplifying the process of phenolic acids separation from sugarcane rind. The conditions of online solid-phase extraction with HSCCC involving solvent system, flow rate of mobile phase as well as saturated extent of absorption of solid-phase extraction were optimized to improve extraction efficiency and reduce separation time. The separation of phenolic acids was performed with a two-phase solvent system composed of butanol/acetic acid/water at a volume ratio of 4:1:5, and the developed online solid-phase extraction with HSCCC method was validated and successfully applied for sugarcane rind, and three phenolic acids including 6.73 mg of gallic acid, 10.85 mg of p-coumaric acid, and 2.78 mg of ferulic acid with purities of 60.2, 95.4, and 84\%, respectively, were obtained from 150 mg sugarcane rind crude extracts. In addition, the three different elution methods of phenolic acids purification including HSCCC, elution-extrusion counter-current chromatography and back-extrusion counter-current chromatography were compared.
Sugarcane is one of the crops of greatest interest in the search for efficient biomass for the production of bioenergy. In addition to the production of sugar and ethanol from sugarcane juice, the industrialization process obtains the biomass, a lignocellulosic material with high energy content, which can be converted into biofuels. Recognized this importance, the objective of this study was to indicate crosses between potential sugarcane genotypes, aiming at the production of sugar and ethanol, and at the use of biomass for the production of bioelectricity or cellulosic ethanol. Ninety sugarcane genotypes of the Active Germplasm Bank of the Federal University of Vicosa were evaluated for 15 chemical and technological variables that characterize the juice and the bagasse. Crosses were defined by the genotypes which presented the best means using the simultaneous selection index, excluding the crosses between the most similar genotypes based on genetic dissimilarity verified by the analyses of diversity. Thus, it was possible to indicate 40 crosses between potential parents with high quality for production of sugar and ethanol and with efficient biomass for production of bioenergy, 19 crosses being for production of bioelectricity, 15 for production of cellulosic ethanol, and 6 for both purposes.
In this study, a comprehensive approach considering the operational performance, kinetic analysis and microbial ecology was employed to investigate the fermentative biohydrogen (bioH(2)) production from tequila vinasse. Batch fermentations were conducted in a 3-L stirred tank reactor at 35 degrees C and pH 6.5-5.8. The bioH(2) yield of 124 +/- 9 NmL/g VSadded and a peak bioH(2) production rate of 159 +/- 33 NmL/L-h were obtained. Thus, the energy yield and energy production rate were estimated as 1.5 kJ/g VSadded and 48.7 +/- 10.2 kJ/L-d, respectively. The metabolic profile and correlation analysis reflected that bioH(2) was associated with the consumption of lactate and acetate. The lactate-acetate pathway was consistent with the modeling of substrate consumption, product formation and biomass growth accurately described by the modified Gompertz model. Illumina MiSeq high-throughput sequencing revealed that Clostridium beijerinckii, Streptococcus sp. and Acetobacter lovaniensis were the main species at the highest bioH(2) production activity. The results obtained suggested that the lactate-acetate pathway can potentially be used to produce bioH(2) from tequila vinasse.
Lignin can negatively impose on the enzymatic hydrolysis of pretreated lignocellulose through non-productive enzyme adsorption and/or steric hindrance. The effect of the residual lignin on enzymatic hydrolysis was evaluated with sugarcane bagasse (SCB) samples containing different lignin contents and their milled and enzymolytic lignins (MELs) retaining the intact protolignins. The results showed that the improvement of enzymatic hydrolysis of SCB would become insignificant when the lignin removal achieved above 64.0\%, and the changes in chemical groups of lignin had slight impact on adsorbing enzymes. When the lignin retention in the pretreated SCB was less than 36.0\%, the residual lignin would not significantly influence the enzymatic hydrolysis via enzyme adsorption and steric hindrance. The contributions of the residual lignins in pretreated SCB samples to the total enzyme adsorptions of pretreated SCB samples were only in the range of 9.6\% to 15.5\%, which were not predominant for the total enzyme adsorptions.
This study evaluates the integration of supercritical fluid extraction process to obtain sugarcane wax extract from the sugarcane filter cake residue. This cake is eliminated from the decantation process of sugarcane juice in the sugarcane biorefinery and it is generally used as a fertilizer. From this cake a lipophilic material, containing long-chain fatty alcohols and phytosterols, can be selectively recovered by means of the use of supercritical CO2 as extracting solvent. Aspen Plus (R) software was used to simulate the sugarcane biorefinery producing electricity, conventional and cellulosic ethanol and wax extract. A thermal-economic model was developed in Matlab software to perform energy integration and the economic analysis of this novel biorefinery concept. The results showed that by increasing temperature and pressure of the extraction process it is possible to produce more wax extract at an overall lower investment as lower extraction time is necessary, decreasing the number of extractors working in parallel. The integration of the extraction process to the sugarcane biorefinery had no impact on the overall ethanol production and had small impact on the electricity available for sale to the grid, decreasing only around 3\% the net electricity. Payback time is strongly reduced by this integration strategy, decreasing 74\% when the best configuration for SFE is adopted. The selling price for the wax extract strongly influences on the economic viability of this process, indicating that the integration of this extraction process to the sugarcane biorefinery is only economic attractive if the wax extract selling price is higher than 26.5 USD/kg.
Sugarcane bagasse ash sand (SBAS) can be used as a bioadditive in concrete. However, little is known about its effects on the steel corrosion process. This paper reports the evaluation of the corrosion susceptibilities of steel immersed in simulate concrete pore solutions, with addition of SBAS, to understand the corrosion process in reinforced structure. The open-circuit potential profiles and polarisation curves suggested the favourable formation of a passive film on the steel immersed in the SBAS-containing medium. Electrochemical impedance spectroscopy confirmed that the SBAS-containing medium presents better passivating properties, showing that this recycled material can be used as corrosion inhibitor for reinforced concrete, encouraging its use in the civil industry. (C) 2020 Elsevier Ltd. All rights reserved.
Two xylanases from Aspergillus nidulans, XInB and XInC, were expressed in Pichia pastoris, purified and characterized. XInB and XInC achieved maximal activities at 60 degrees C and pH 7.5 and at 50 degrees C and pH 6.0, respectively. XInB showed to be very thermostable by maintaining 50\% of its original activity after 49 h incubated at 50 degrees C. XInB had its highest activity against wheat arabinoxylan while XInC had the best activity against beechwood xylan. Both enzymes were completely inhibited by SDS and HgCl2. Xylotriose at 1 mg/m1 also totally inibited XInB activity. TLC analysis showed that the main product of beechwood xylan hydrolysis by XInB and XInC was xylotetraose. An additive effect was shown between XInB and XInC and the xylanases of two tested commercial cocktails. Sugarcane bagasse saccharification results showed that these two commercial enzymatic cocktails were able to release more glucose and xylose after supplementation with XInB and XInC. (C) 2016 Elsevier B.V. All rights reserved.
The aim of this work was to study ethanol fermentation properties of the robust mutant Candida glycerinogenes UG21 from non-detoxified lignocellulose hydrolysate. C. glycerinogenes UG21 with high tolerance to elevated temperature, acetic acid, and furfural was obtained and applied in lignocellulose-based ethanol production. C. glycerinogenes UG21 exhibited highly-efficient degradation ability to furfural. High levels of acetic acid and furfural inhibited cell growths and ethanol production of Saccharomyces cerevisiae ZWA46 and industrial Angel yeast but had a slight impact on biomass and ethanol titer of C. glycerinogenes UG21. Using non-detoxified sugarcane bagasse hydrolysate, C. glycerinogenes UG21 reached 1.24 g/L/h of ethanol productivity at 40 degrees C but ethanol production of S. cerevisiae ZWA46 and Angel yeast was inhibited. Further, C. glycerinogenes UG-21 exhibited 2.42-fold and 1.58-fold higher productivity than S. cerevisiae ZWA46 and Angel yeast under low-toxicity hydrolysate. Therefore, C. glycerinogenes UG-21 could be an excellent candidate for low-cost lignocelluloses ethanol production.
Rational use of vinasse as a fertilizer in sugarcane cultivation is a good option to increase crop development and yield due to its nutritional support, properly dispose of the by-product, and reduce costs of mineral nutrition. However, in the field, controlling the amount of vinasse can be difficult, interfering in sugarcane development. In this sense, this study aimed to evaluate high doses of vinasse related to biometric responses in the initial growth phase of sugarcane plants. The experimental design was completely randomized, and the treatments consisted of five vinasse doses (0, 150, 300, 600, and 1200 m3 ha-1), with six replicates, except D0, three replicates, and one dose of mineral fertilizer with 70 kg ha-1 of N, 120 kg ha-1 of P2O5 and 90 kg ha-1 of K2O, with three replications. The biometric variables were evaluated in the following sequence: number of tillers per pot from 60 to 150 days after planting (DAP), plant height, number of green and dry leaves from 90 to 210 DAP, stem diameter, leaf area, and fresh and dry biomasses of roots and shoots at 210 DAP. Vinasse increased the biomass production through the number of tillers and the number of leaves compared to mineral fertilizer, promoting greater growth up to the dose of 600 m3 ha-1. The vinasse dose of 1200 m3 ha-1 decreased the plant height.
During the second-generation ethanol production, wastes from the hydrothermal pretreatment process are generated. Such rich organic matter residues should be treated. An alternative for that waste is methane production via the anaerobic digestion process. The characterization and the evaluation of the biochemical methane potential (BMP) and hydrolysis rates from the wasted hydrothermally pretreated wheat straw, corn straw, sugarcane, and agave bagasse was investigated. The liquid extracted lixiviates, and the solid fraction of each waste was evaluated. Diauxic methane production was observed for sugarcane and corn liquid fractions and for all the solids fractions. BMP varied from 369 mL CH4/g COD (sugarcane bagasse) to 178 mL CH4/g COD (agave bagasse). The biodegradability percentage was decreasing from sugarcane bagasse (100\%), corn straw (65\%), wheat straw (55\%) and agave bagasse (51\%). The liquid fraction produced higher BMP values than the BMP obtained for the solid fraction. The relatively low biodegradability of the hydrothermally pretreated wastes, considering the carbohydrate-rich nature of the substrate, was associated with an inhibitory effect. A double effect caused by the presence of furfural was observed. At lower concentrations, there was an inhibitory effect, while for the high concentration a stimulatory effect was detected.
Sugarcane, as one of the most important crops in the world, plays an important role in the economy around the world. However, huge waste and low treatment efficiency put forward new requirements for bagasse treatment. Herein, a wearable eco-friendly cellulose-based hybrid membrane was fabricated with a view to recycling bagasse. Specifically, the bagasse cellulose was extracted from waste bagasse, and the CNT/cellulose@Ag nanoparticles (CCAgNP) hybrid membrane was obtained by magnetron sputtering and blending method. The CNT/cellulose membrane obtained by doping CNTs in cellulose dispersion suspension is abbreviated as CCM. The results indicated that benefiting from the high infrared reflectance (0.82) of the AgNP side and the fast absorbance (1.5) of the CCM side, the CCAgNP can achieve a dual thermal insulation due to the synergistic effect of two sides of the membrane. In addition, the asymmetric wettability of both sides of the hybrid membrane enables sweat to be transported unidirectionally, keeps the skin on the surface of the human body dry, and achieves wearing comfort. More importantly, the hybrid membrane also shows the excellent antibacterial property, air permeability, mechanical property and thermal stability, providing good support for the practical application of the hybrid membrane. This study shows that the fabrication of hybrid membranes with integrated functionalities can be extended for the fabrication of other wearable materials from agricultural wastes for various applications.
The aim of this work was to produce ethanol using the acid hydrolysis of soybean molasses followed by alcoholic fermentation via submerged Saccharomyces cerevisiae. The influence of the acid type, pH, and absolute pressure of the hydrolysis on the ethanol yield and the total residual sugar concentration was evaluated using a factorial design (FD). The absolute pressure ranged from 1 to 2 atm; the pH ranged from 3 to 5; and three different acids were studied in the hydrolysis process: sulfuric, hydrochloric, and nitric acids. The experiments were conducted in an Applicon batch reactor with a useful volume of 1.5 L at a stirring speed of 230 rpm and with an inoculum concentration of 30 g/L. The inoculum volume used was 30\% of the total volume. The best results, as determined by FD, were obtained at pH 4 and an absolute pressure of 1.5 atm for all of the acids studied. The highest ethanol yield was 46\% for sulfuric acid, 48\% for hydrochloric acid, and 54\% for nitric acid. After the concentration of inoculum and the fermentation kinetics profiles were investigated, a 62\% yield relative to the initial sugar content was obtained under optimum conditions after 14 h of fermentation and an inoculum concentration of 35 g/L.
Using Yarrowia lipolytica (DS-1), secretion of citric acid is studied as a function of carbon sources such as glucose, fructose. hydrol, sucrose, cane sugar molasses, kerosene (all available commercially) and tapioca starch hydrolysate, invert sucrose and invert cane sugar molasses (all prepared in laboratory). On the basis of their acceptability by DS-1 for citric and isocitric acid secretion, it is concluded that (a) sucrose and cane sugar molasses (with/without inversion) served as poor carbon sources, (b) fructose, hydrol, impure tapioca starch hydrolysate (96 DE w/w) and invert sucrose served as relatively better carbon sources and (c) purified tapioca starch hydrolysate (96 DE w/w) was the best carbon source to substitute glucose by giving comparable (75\%) efficiency of conversion and economical advantage.
Non-toxic mesoporous magnetic carbon composite was synthesised from hydrothermal carbonization of sugarcane bagasse with Iron (III) nitrate nonahydrate in two steps along with thermo-chemical oxidation process using sodium hydroxide. IR spectrum exposed the presence of oxygenated functional groups and FeO whereas XRD analysis revealed the availability of Fe-0/Fe3C/gamma-Fe2O3 at varying intensities. SEM analysis showed the spherical shaped carbon is well encapsulated with iron particles. Textural studies showed that after thermo-chemical activation intensified the surface area on composites to about 491.474 m(2) g(-1) thereby, promoting improved porosity on the carbon matrix. The fabricated composite showed magnetization of 32.84 emu g(-1) and SMX adsorption capacity as 169.49 mg g(-1). Kinetics and isotherm studies revealed that removal of SMX fitted well in Pseudo-second order and Langmuir models. The mode of interaction of SMX on magnetic carbon composites with respect to different pH was studied showing that pi-pi electron donor interaction (EDA), hydrophobic interaction, charge assisted hydrogen bond formation were responsible for SMX removal. The selectivity nature of magnetic composite with respect to SMX was studied in the presence of multiple pollutant. Use of magnetic carbon helps in industrialising the material to high level due to their unique property in separation and recycling. Application of hydrothermal carbonization is found to be applicable for wet solid substance thereby evolving structural carbon compound.
Ethanol tolerance is one of the important characteristics of ethanol-producing yeast. This study focused on the improvement of ethanol tolerance of Saccharomyces cerevisiae NR1 for enhancing ethanol production by random UV-C mutagenesis. One ethanol-tolerant mutant, UVNR56, displayed a significantly improved ethanol tolerance in the presence of 15\% (v/v) ethanol and showed a considerably higher viability during ethanol fermentation from sugarcane molasses and sugarcane molasses with initial ethanol supplementation. A maximum ethanol concentration produced from molasses medium at 37 degrees C by UVNR56 was 10.3\% (v/v), productivity of 1.7 g/l/h and a theoretical yield of 98.7\%, while the corresponding values for the wild-type were 8.6\% (v/v), 1.4 g/l/h and 83.3\%, respectively. In addition, during molasses fermentation under initial supplementation of 5\% (v/v) ethanol, the maximum ethanol concentration and productivity of UVNR56 was 25.7\% and 42.9\% higher than the wild-type, respectively.
The harvest of sugarcane is still traditionally done manually with the burning of straw in most cultivated areas in Brazil. However, burning has been gradually eliminated with the relatively recent use of mechanical harvesting. This will result in significant changes in the agroecosystem, as the straw will remain in the field. No investigation on Formicidae found in sugarcane plantations in Southeastern Brazil harvested by this new system has been done yet. Because of their feeding habits, many species of this family may act as predators of several sugarcane pests. In this study, the sampling efficacy of pitfall traps, baits, and underground traps with two types of attractants were evaluated. Pitfall traps gave the largest richness, while abundance was the highest from baiting. Community composition and structure differed in relation to the sampling methods used. The myrmecofauna collected with the same method with different baits was similar. Pitfall trapping was the most efficient method in this type of ecosystem; and sardine, the best attractant, due to its easy handing in the field.
In the present study adsorption of Cr(VI) from aqueous solutions onto different agricultural wastes, viz., sugarcane bagasse, maize corn cob and Jatropha oil cake under various experimental conditions has been studied. Effects of adsorbent dosage, Cr(VI) concentration, pH and contact time on the adsorption of hexavalent chromium were investigated. The concentration of chromium in the test solution was determined spectrophotometrically. FT-IR spectra of the adsorbents (before use and after exhaustion) were recorded to explore number and position of the functional groups available for the binding of chromium ions on to studied adsorbents. SEMs of the adsorbents were recorded to explore the morphology of the studied adsorbents. Maximum adsorption was observed in the acidic medium at pH 2 with a contact time of 60 min at 250 rpm stirring speed. Jatropha oil cake had better adsorption capacity than sugarcane bagasse and maize corn cob under identical experimental conditions. The applicability of the Langmuir and Freundlich adsorption isotherms was tested. The results showed that studied adsorbents can be an attractive low cost alternative for the treatment of wastewaters in hatched or stirred mode reactors containing lower concentrations of chromium. (c) 2006 Elsevier B.V. All rights reserved.
Sugarcane harvest implies in the movement of very large amounts of biomass and, therefore, demands careful planning of logistics. Accurate pre-harvest estimation of sugarcane field productivity provides useful data to plan harvest, transportation, selling and industrial processing activities. Currently, the estimation of sugarcane biomass in the field is based on destructive techniques. The use of allometric equations is an adequate, nondestructive tool to provide this information, but these equations are scarcely available for sugarcane. We created regression models to estimate stem fresh (SFB, kg) and total aboveground dry biomass (AB, kg) based on plant height (H, cm) and diameter (D, cm), for different Brazilian sugarcane varieties. The models adequately estimated biomass for all sugarcane varieties. Based on that, we developed two general equations valid for all varieties: SFB = 0.046 H x D-1.5647 and AB = 0.4001 H x D-1.0743. To calculate biomass per hectare, SFB and AB must be multiplied by the average number of stems in the row (N) and divided by row spacing (S). In our study site, N was adequately estimated counting stems in four 100-m row segments. Overall, precise estimates of stem and whole plant biomass for sugarcane can be obtained using the general equations and the number of stems per area. We believe these equations are also useful to estimate biomass for other sugarcane varieties around the world, considering the simplicity of sugarcane plant structure.
A novel strategy for the low-cost, high-yield co-production of xylose and xylooligosaccharides together with no xylose inhibition was developed using a novel heterologous expression of XYN10Ks\_480 endo-1,4-beta-xylanase with a ricin-type beta-trefoil type of domain and XYN11Ks\_480 endo-1,4-beta-xylanase with a CBM 2 superfamily from the Kitasatospora sp in an actinomycetes expression system. Xylose is the main building block for hemicellulose xylan. Our findings demonstrated high levels of expression and catalytic activity for XYN10Ks\_480 during hydrolysis of the extracted xylan of bagasse, and three types of xylan-based substrates were used to produce xylose and xylooligosaccharides. However, hydrolysis by XYN11Ks\_480 produced xylooligosaccharides without xylose formation. This study demonstrated how integrating sodium hypochlorite-extracted xylan and enzymatic hydrolysis could provide an alternative strategy for the generation of XOS from lignocellulosic material.
To investigate the indoor temperature variations of buildings constructed with different masonry materials, the small scale modelling technique was used. Two small scale models were designed and built as per the standards (SP: 41), one with sugarcane bagasse ash (SBA) bricks and another with commercially available fly ash bricks. In order to assess the indoor temperature of the built model houses, the room temperature recordings were monitored for the period of a year over the study area (Nagpur, Maharashtra, India), which has a composite type of climatic condition. The thermal conduction of the exposed wall assembly was estimated by the surface temperature readings of the built houses. The techno-economic viability for the developed model houses was also carried out. The detailed analysis revealed that the developed SBA brick model house (M-1) was thermally more resistant and economic than the fly ash brick model house (M-2). The study revealed that the SBA bricks are novel, and were found to be a better thermally insulated masonry construction material than the commercially available fly ash bricks.
The sugarcane green harvest system, characterized by mechanized harvesting and the absence of crop burning, affects soil quality by increasing crop residue on the soil surface after harvest; thus, it contributes to improving the physical, chemical, and microbiological properties and influences the soil carbon content and CO2 flux (FCO2). This study aimed to evaluate the spatial and temporal variability of soil FCO2 in sugarcane green harvest systems. The experiment was conducted in two areas of sugarcane in Sao Paulo, Brazil: the first had a 5-year history of sugarcane green harvest (SG-5) and the second had a longer history of 10 years (SG-10). The temporal FCO2 were evaluated in the dry and rainy periods, and spatial variability in the dry period, and related to soil chemical and physical properties, including organic C porosity, bulk density, soil penetration resistance, mean weight diameter of soil aggregates, clay, P, S, Ca, Mg and Fe. The temporal variability indicated no differences between the dry and rainy periods in SG-10, while in SG-5 soil moisture was increased by 33 \% in the rainy period. The spatial variability indicated a different pattern from the temporal one, where FCO2 in SG-10 was correlated with soil temperature, air-filled pore space, total porosity, soil moisture, and the Ca and Mg contents; in the SG-5 area, FCO2 was correlated with soil mean weight diameter of soil aggregates and the sulfur content.
Considering that plasmid conjugation is a major driver for the dissemination of antimicrobial resistance in bacteria, this study aimed to investigate the effects of residual concentrations of antimicrobial growth promoters (AGPs) in poultry litter on the frequencies of IncFII-FIB plasmid conjugation among Escherichia coli organisms. A 2 x 5 factorial trial was performed in vitro, using two types of litter materials (sugarcane bagasse and wood shavings) and five treatments of litter: non-treated (CON), herbal alkaloid sanguinarine (SANG), AGPs monensin (MON), lincomycin (LCM) and virginiamycin (VIR). E. coli H2332 and E. coli J62 were used as donor and recipient strains, respectively. The presence of residues of monensin, lincomycin and virginiamycin increased the frequency of plasmid conjugation among E. coli in both types of litter materials. On the contrary, sanguinarine significantly reduced the frequency of conjugation among E. coli in sugarcane bagasse litter. The conjugation frequencies were significantly higher in wood shavings compared with sugarcane bagasse only in the presence of AGPs. Considering that the presence of AGPs in the litter can increase the conjugation of IncFII-FIB plasmids carrying antimicrobial resistance genes, the real impact of this phenomenon on the dissemination of antimicrobial resistant bacteria in the poultry production chain must be investigated.
Non-degradable plastics are a global crisis that has a detrimental effect on human life and all living systems. Normally, extraction of nanocellulose passes through several tedious processing including a number of steam explosions. This paper is demonstrating an easy method for the extraction of nanocellulose by using a cheaper, effective and modified acid hydrolysis route from sugarcane bagasse. The films were characterised using FT-IR, XRD, FESEM and DLS techniques. The effects of acid, alkali and salt on the thin films and the various hydro-dynamic and tensile properties were also analysed. The degradation of nanocellulose thin films in three types of soils having different moisture-holding capacities using soil burial method (ASTM D 2216) was studied. This study revealed that degradation has a direct correlation to water retention capacity of soils. Also, these thin films could be effectively degradable in soils, salt, acidic and alkaline environments. So, these fall under the category of bio-based, biodegradable and compostable bag class.
Superior inbred clones selected in S-1 families can integrate an individual reciprocal recurrent selection program in sugarcane by eliminating the genetic load of the population and exploring superior hybrid combinations. Molecular markers can be used for reliable identification of the true selfing-derived clones in these S-1 populations. The objective of this study was to confirm true self-fertilized individuals in sugarcane families using microsatellite markers aimed at the use of self-fertilized plants in an individual reciprocal recurrent selection strategy. Self-fertilized individuals from five cultivars were genotyped with eight simple sequence repeat (SSR) markers. The markers generated 62 polymorphic markers, with an average of seven polymorphic alleles across the cultivars tested. Three loci revealed highly informative bands and were used to assess the level of selfing in five S-1 families. Selfing in these families ranged from 71.7 to 97.6\%. The SSR loci provide a reliable and accurate method to identify S-1 progenies in sugarcane crosses and can be used as a tool to assist selection strategies in sugarcane breeding programs.
The effect of the ultrasonic/mechanical stirring method (physical treatment) and 3-glycidoxypropyltrimethoxy silane (GPS, chemical treatment) modifications on the sugarcane fiber (SGF)/epoxy composites was investigated to improve the interfacial interaction between fiber and epoxy resin. An optimum concentration GPS at 2 wt\% was found for the best improvement in tensile strength at 40 wt\% SGF content based on the evaluation of GPS content, indicating the role of GPS as an effective coupling agent. Overall, the best improvement in tensile strength was observed for GPS-modified cases, and particularly tensile strength reached up to 32.9 MPa at 50 wt\% of fiber content. In addition, three types of Polyurethane (PU)-modified epoxy with different polyols at various SGFs contents were investigated. In all cases, the tensile strength of SGF/PU-epoxy cases was higher than that of SGF/epoxy cases due to the relatively lower viscosity of PU-epoxy to easily wet the SGF surface. In general, impact strength for samples without physical or chemical treatment also ranked the lowest value in most cases. The enhanced interfacial interaction between SGF and epoxy for surface-modified cases was suggested through the morphology observation, dynamical mechanical analysis, and the onset degradation improvement in thermal stability.
Biphasic organosolv treatment for soft- and hardwood using water/1-butanol was unique based on the correlation between liquid-phase states and solubility of the co-solvents when compared with a monophasic water/ethanol system. First, Pro II process simulator showed that water/1-butanol exhibited a biphasic system in the range of 1.6-19.0 mol/mol at a treatment temperature of 473 K. In addition, solubility of the co-solvents was evaluated using the Hildebrand solubility parameter (delta), which indicated that the biphasic system could simultaneously provide 28.5 and 42.0 MPa1/2 for the 1-butanol and water phase, respectively. Each delta value appeared appropriate for lignin and hemicellulose dissolution because they were similar to those reported for lignin and a typical sugar. While hemicellulose could be removed by increasing water content in an organosolv of Japanese cedar sawdust, high lignin removal was achieved only under biphasic conditions. Carbon yield of each fraction (solid, 1-butanol-, and water-soluble fraction) and Py-GC/MS analysis revealed that lignin and hemicellulose could be recovered in the 1-butanol and water fractions, respectively. The organosolv using Japanese cedar and willow was compared to the results when using monophasic water/ethanol. The results indicated that the co-solvent could not efficiently remove hemicellulose and lignin simultaneously because the monophasic system did not produce the level of solubility needed under the same conditions. In contrast, the biphasic water/1-butanol system achieved greater removal of hemicellulose and lignin compared to water/ethanol. The biphasic system was also applicable to separation of an industrial agricultural waste; sugarcane bagasse. Finally, the 2D-NMR spectra of 1-butanol-soluble lignin showed a trace amount of beta-O-4 linkages in the lignin, indicating beta-O-4 was cleaved via hydrolysis in the water phase during biphasic treatment.
Researchers are increasingly focusing on natural, biodegradable materials because of environmental concerns. Although natural fibers give less strength than synthetic fibers, but they still contain some specific properties. In this paper, we studied the fire and water resistance, density, and swelling behavior of sugarcane bagasse fiber and chicken feather fiber composites using polylactic acid (E-3051D) as a matrix for different weighing fractions of fiber viz. 03\%, 06\%, 09\%, (03 + 05)\%, (06 + 05)\%, (09 + 05)\% and for 3 mm thickness. The 300 mm x 300 mm panels were made using the compression molding. According to ASTM standards, an investigation was carried out on several physical characteristics, including density, moisture content, water absorption, linear swelling, and a flammability test. It was observed that 3\% sugarcane bagasse and 5\% chicken feather fiber are better for various applications, as further increments will affect the mechanical properties. It is a combination of natural fibers and biodegradable matrix material, which makes it ecofriendly with various applications such as in automobile interiors, packaging materials, wall panels, window and door frames, and roof sheets, but limited use in bathroom and kitchen areas.
Reducing greenhouse gas (GHG) emissions by substituting fossil fuels depends on how biofuels are produced and how emissions are calculated. Nitrous oxide (N2O) emissions from synthetic and organic N fertilizers are important sources of GHG from sugarcane ethanol. This study aimed to synthesize the literature information and derive regional N2O emissions factors (EFs) for N fertilizers according to Tier 2 approach. This study also evaluated how the use of Tier 2 affects emissions compared with those obtained by the IPCC Tier 1. Moreover, this study examined how N fertilizers can affect GHG emissions and the earning of decarbonization certificates (CBIOs) by ethanol producers. For an ethanol distillery producing 339 million liters annually, the use of Tier 1 and Tier 2 resulted in emissions of 176.5 and 145.2 Gg CO2eq, whereas for the same amount of energy, gasoline would emit 661.8 Gg CO2eq. The addition of nitrification inhibitors (NIs) to N fertilizers and improvements in vinasse/fertilizer management further reduced emissions compared with Tier 2. In Tier 1, the GHG emission savings would result 485,270 CBIOs, worth 4.85 million US\$ at US\$10 per CBIO. But if the IPCC Tier 2 is considered, the annual CBIOs would be worth 5.17 million US\$. Using NIs and improving vinasse/fertilizer management may bring an additional US\$ 31,700 and US\$ 48,000 revenue above that of Tier 2. Public and sectorial policies behind decarbonization certificates can encourage farmers and decision-makers to pursue more efficient and economical solutions to further decrease GHG emissions and improve the sustainability of ethanol.
This work investigates the potentiality of application of spent waste biomass (yeast Saccharomyces cerevisiae, rice straw, and sugarcane bagasse) from bioethanol production process as low-cost biosorbents for removal of phenol from petroleum refinery wastewater. Batch adsorption studies were carried out under varying experimental conditions of contact time, initial phenol concentration, and operational temperature. Rice straw showed better affinity towards phenol than sugarcane bagasse, while S. cerevisiae did not express any biosorption capacity. The biosorption process on rice straw or sugarcane bagasse was fast and the time to reach equilibrium was found to be 150 min. Kinetic studies showed that biosorption follows the pseudo-second order rate expression. The results were better described by the Langmuir isotherm model than the Freundlich and Temkin isotherm models. The calculated heat of adsorption indicated that the biosorption process is taking place by chemical adsorption and has an endothermic nature.
Indonesia is one of the largest sugarcane producing countries in the world. At present, the use of bagasse is only as compost, electricity generation, etc. In the oil industry, bagasse can use as a base material in making surfactants that function as fluid reservoir oil injection to improve oil recovery factors, so it is good to develop a type of plant-based local surfactant with a lot of raw materials in Indonesia. The purpose of this study was to see that bagasse can increase the oil recovery factor at low salinity. The methods used is a laboratory study using a concentration of 1\%; 1.5\%; 2\%; 2.5\% and 3\% NaLS and salinity of 4000 ppm, 5000 ppm, and 15000 ppm NaCl. The Surfactant first conducted a compatibility test then core flooding was carried out to obtain the recovery factor value. The results obtained were surfactants with variations of 1.5\% 4000 ppm; 1.0\% 15000 ppm; and 1.5\% 15000 ppm which passes the compatibility test with the recovery factor value sequentially is 3.24\%; 3.62\%; and 5.34\%. It shows that NaLS surfactant can increase the oil recovery factor at low salinity by 5.34\% by optimizing 1.5\% NaLS 15000 ppm concentration.
Recently, cost-effective production of high value-added furan chemicals from abundant and renewable bioresources has attracted much attention via a chemoenzymatic approach in an environmentally friendly reaction system. In this work, a chemoenzymatic cascade reaction for bridging tandem chemocatalysis and biocatalysis was constructed to valorize biomass into furfurylamine in a deep eutectic solvent (DES)-water system. Waste shrimp shell (SS) was used as a biobased carrier to prepare sulfonated tin-based solid acid (Sn-SS) for catalyzing sugarcane bagasse (SB) into furfural in DES-water. The prepared Sn-SS was characterized by XRD, SEM, FTIR spectroscopy and BET. Furfural (113.2 mM) was obtained in 62.3\% yield from xylan in SB by Sn-SS (0.6 wt\% dose) within 20 min at 170 degrees C in {[
The Brazilian Energy Matrix is characterised by the presence of Renewables, whose participation reached 46.1\% in 2019, equivalent to 133.8 Mtoe, of which 18.0\% represented the sugarcane biomass share, 12.4\% the hy-draulic, 8.7\% the wood and charcoal, and 7.0\% corresponded to other renewables. The sugarcane industry produces sugar, ethanol, and electricity as main products and, considering the total primary energy produced, 52.861 Mtoe comes from sugarcane products (BEN, 2020). Another aspect of this industry is that it is energy self-sufficient, that being so, the energy used in the production process is also produced (from bagasse) in the same process. The aforementioned data show the significance of the sugarcane industry for the country and being this an energy industry, there is no doubt that the energy management holds importance to its industrial process. The present work will address different alternatives to improve the industrial process of sugarcane, aiming at opti-mising the energy management. Among the proposals to be presented, the following can be mentioned: increasing of electric energy in cogeneration, thermal integration of process streams using the Pinch Point method, second-generation ethanol production, water use in the process, integration with biodiesel production, vinasse disposition aiming at increasing energy production and reducing pollution. The main objective is to identify each proposal's influence on and contribution to the improvement of the performance and efficiency in the production process from sugarcane.
Background The composition of biomass determines its suitability for different applications within a biorefinery system. The proportion of the major biomass fractions (sugar, cellulose, hemicellulose and lignin) may vary in different sugarcane genotypes and growth environments and different parts of the plant. This study investigated the composition of mature and immature internodes, roots and mature leaves of sugarcane. Results Internodes were found to have a significantly larger alcohol-soluble component than leaves and roots. The primary difference between the immature and mature internodes was the ratio of soluble sugars. In mature tissues, sucrose content was significantly higher, whereas in immature internodal tissues there was lower sucrose and heightened concentrations of reducing sugars. Carbon (C) partitioning in leaf tissues was characterised by low levels of soluble components and high ``other{''
A method to pretreatment of biomasses using glycerol as a green solvent was developed. Optimization of organosolv pretreatment was performed using a 2(3) factorial design, investigating synergism among the variables particle size (from 0.85 to 2.0 mm), FeCl3 concentration (0.025-0.175 mol L-1), and temperature (160-220 degrees C). Although the effects of the variables differed according to the type of lignocellulose, it was nonetheless possible to find an optimal condition in common (< 0.85 mm; 0.025 mol L-1; 220 degrees C), which was economically and environmentally sustainable, employing a small amount of catalyst. The biomasses pretreated using this combination of factors exhibited enzymatic digestibility exceeding 93\% after 48 h, reflecting efficient reduction of recalcitrance as a result of high removal of hemicellulose (ca. 90\%), provided by the use of FeCl3, together with substantial delignification. There was low formation of inhibitors in the hydrolysate, indicating that it could be directly fermented. The lignin removed to liquors could be easily recovered by centrifugation. Tests carried out under the optimal condition revealed that after the pretreatment the biomass could be directly used in enzymatic hydrolysis, without washing and wet. Furthermore, after simple treatment, crude glycerol was as effective as commercial glycerol.
This study investigated the possibility of using the mixing bagasse and sengon wood (Paraserianthes fal-cataria (L.) Nielsen) wastes combined with urea formaldehyde (UF) and polyester (PE) as binders for par-ticleboards application. The tested composite materials included the baggase-sengon powder mixed with two kinds of polymers separately, UF and polyester. One-UF composite were examined the volume frac-tion by comparison of sugarcane baggase (SCB), sengon wood (SW), and UF with 8:0:2, 6:2:2, 4:4:2, 2:6:2, and 0:8:2, respectively. While another one, polyester composites were manufactured by ratio of volume fraction of SCB, SW, and PE with 6:0:4; 4:2:4; 3:3:4; 2:4:4; 0:6:4, respectively. Those lignocellulosic materials were treated with 5\% alkalization (NaOH) for 2 h then mixed with a specified binder before con-duction hot press compression molding at 100 degrees C and 40 bar was carried out. The boards were tested for their modulus of rupture (MOR), modulus of elasticity (MOE), internal bond, and Scanning Electron Microscopy (SEM) after being subjected to the bending test. The results showed that in specific tests, all lignocellulosic mixed powders may serve as partial substitutes for wood-based composites in the par-ticleboards. The presence of these materials was particularly favourable for the internal bond. SCB was the useful part of mixing powder, as the boards supplemented with the material met the requirements of the Indonesian Standard SNI 03-2105-2006 in terms of the internal bond and therefore it can be poten-tially used for non-structural boards such as furniture. Copyright (c) 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 2nd International Con-ference on Sustainable Environmental Technology (ISET2021).
The prevailing approach of total clearing to contain the spread of invasive plants (IP) in South Africa is generating enormous lignocellulosic wastes. This study examined the possibility of utilizing these wastes in the production of geopolymer composites for use in outdoor environments. Untreated wood particles from Acacia mearnsii and A. longifolia, as well as sugarcane bagasse residues, were incorporated into a geopolymer matrix developed from a binary precursor system of 75\% fly ash and 25\% metakaolin. The variables considered included precursor-activator ratio (PA), curing pattern (CP), lignocellulosic material (LM), and alkali concentration (Mcon). The production process was established using a mixed factorial experimental design. PA and CP were considered at 2 levels, while LM and MCon were considered at 3 levels. The density of the boards exceeded 1 g cm(-3) and are classified as high-density boards. The boards have comparable sorption properties to the cement-bonded particleboard according to the EN 632-2: 2007 standard. However, only A. longifolia boards produced with 12 M NaOH and PA ratio of 2:1 met the mechanical strength requirements. Thermogravimetric analysis revealed that the boards are thermally stable. These results have shown that South African woody IPs are suitable for geopolymer wood composites, but there is still concern about their durability in the alkaline matrix. Scanning electron microscopy micrographs indicated mineralization of the particles and a partial degradation of hemicellulose was confirmed by Fourier transform infrared spectroscopy. Although the degraded components did not prevent geopolymer setting, there is need to further investigate the extent and means of preventing degradation as this can derail the intended use of the product.
Lignocellulose is a prominent source of carbohydrates to be used in biorefineries. One of the main challenges associated with its use is the low yields obtained during enzymatic hydrolysis, as well as the high cost associate with enzyme acquisition. Despite the great attention in using the fraction composed by hexoses, nowadays, there is a growing interest in enzymatic blends to deconstruct the pentose-rich fraction. Among the organisms studied as a source of enzymes to lignocellulose deconstruction, the anaerobic bacterium Clostridium thermocellum stands out. Most of the remarkable performance of C. thermocellum in degrading cellulose is related to its capacity to assemble enzymes into well-organized enzymatic complexes, cellulosomes. A mini-version of a cellulosome was designed in the present study, using the xylanase XynA and the N-terminus portion of scaffolding protein, mCipA, harboring one CBM3 and two cohesin I domains. The formed mini-xylanosome displayed maximum activity between 60 and 70 degrees C in a pH range from 6 to 8. Although biochemical properties of complexed/non-complexed enzymes were similar, the formed xylanosome displayed higher hydrolysis at 60 and 70 degrees C for alkali-treated sugarcane bagasse. Lignocellulose deconstruction using fungal secretome and the mini-xylanosome resulted in higher D-glucose yield, and the addition of the mCipA scaffolding protein enhanced cellulose deconstruction when coupled with fungal enzymes. Results obtained in this study demonstrated that the assembling of xylanases into mini-xylanosomes could improve sugarcane deconstruction, and the mCipA protein can work as a cellulose degradation enhancer.
Sugarcane, as one of the most important crops in the world, plays an important role in the economy around the world. However, huge waste and low treatment efficiency put forward new requirements for bagasse treatment. Herein, a wearable eco-friendly cellulose-based hybrid membrane was fabricated with a view to recycling bagasse. Specifically, the bagasse cellulose was extracted from waste bagasse, and the CNT/cellulose@Ag nanoparticles (CCAgNP) hybrid membrane was obtained by magnetron sputtering and blending method. The CNT/cellulose membrane obtained by doping CNTs in cellulose dispersion suspension is abbreviated as CCM. The results indicated that benefiting from the high infrared reflectance (0.82) of the AgNP side and the fast absorbance (1.5) of the CCM side, the CCAgNP can achieve a dual thermal insulation due to the synergistic effect of two sides of the membrane. In addition, the asymmetric wettability of both sides of the hybrid membrane enables sweat to be transported unidirectionally, keeps the skin on the surface of the human body dry, and achieves wearing comfort. More importantly, the hybrid membrane also shows the excellent antibacterial property, air permeability, mechanical property and thermal stability, providing good support for the practical application of the hybrid membrane. This study shows that the fabrication of hybrid membranes with integrated functionalities can be extended for the fabrication of other wearable materials from agricultural wastes for various applications.
Optimizing soil health through soil amendments is a promising strategy for enhancing rainwater efficiency for stabilizing crop production. Biochar, obtained by torrefaction of sugarcane bagasse, a byproduct from sugar mills, has a high potential for its use as a soil amendment, which can boost crop yields, but needs further field trials for its adoption in farming systems. A field study was conducted during 2019-2021 at Stoneville, Mississippi, to assess rainfed cotton (Gossypium hirsutum L.) production under four biochar levels (0, 10, 20, and 40 t ha(-1)) on Dundee silt loam soil. The effects of biochar on cotton growth and lint yield and quality were examined. Biochar levels had no significant impact on cotton lint and seed yield for the first two years. Still, in the third year, a significant increase in lint yield by 13 and 21.7\% was recorded at 20 and 40 t ha(-1) biochar levels, respectively. In the third year, lint yields were 1523, 1586, 1721, and 1854 kg ha(-1) at 0, 10, 20 and 40 t ha(-1) biochar levels, respectively. Similarly, cotton seed yield increased by 10.8\% and 13.4\% in 20 and 40 t ha(-1) biochar plots. This study demonstrated that successive biochar applications at 20 or 40 t ha(-1) can enhance cotton lint and seed yields under rainfed conditions. These improved yields with biochar did not produce increased net returns due to the increased production costs. Many lint quality parameters were unaffected except for micronaire, fiber strength and fiber length. However, potential long-term benefits of enhanced cotton production from biochar application beyond the length of the study merit further investigation. Additionally, biochar application is more relevant when accrued carbon credits through carbon sequestration outweigh the increased production costs due to biochar application.
Hydrogen bond donor (HBD) in ChCl-based deep eutectic solvent (DESs) had significant influence on the Sorghum straw (SS) pretreatment. Lactic acid (LAC) was chosen as the appropriate HBD for preparing ChCl-based DES to pretreat Sorghum straw (SS). Furthermore, sequential pretreatment with dilute sodium hydroxide (0.75 wt\%) for 1 h at 121 degrees C and ChCl:LAC soaking at 140 degrees C for 40 min was applied to pretreat SS for removing lignin (78.4\%) and xylan (67.6\%). Hydrolysis for 72 h, the reducing sugar yield reached 94.9\%. Moreover, relationships of delignification and xylan removal with saccharification were explored after pretreatment. Finally, the fermentability of SS-hydrolysates was verified by bioethanol fermentation by S. cerevissiae with the yield of 0.45 g ethanol/g glucose. No significant inhibition was observed on ethanol fermentation. Obviously, establishment of high-efficient combination pretreatment with alkali extraction and ChCl:LAC soaking was successfully demonstrated for enhancing enzymatic saccharification of SS.
Produced water is a waste generated in the units of petroleum production having as main characteristics the high salinity with presence of emulsified oil, suspended solids, chemical additives, heavy metals and other contaminants. Considering that the inadequate disposal of this water causes environmental contamination, this work aimed to investigate the adsorption of emulsified oil present in the produced water, using sugarcane bagasse (an abundant by-product from sugar/ethanol production) as adsorbent, reducing the pollutant of the effluent according to the parameters accepted by the Brazilian environmental legislation. The adsorption reached equilibrium within 5 minutes of contact and more than 90\% of the emulsified oil present in the mixture was removed when 0.1\% adsorbent (w/v) was used at 30 degrees C and 110 rpm. Pseudo first-order and pseudo second-order models were applied to adjust the kinetic data. The best correlation was provided by the pseudo first-order kinetic model demonstrating that chemical sorption was the rate-limiting step, although intraparticle diffusion can not be neglected. From these results, it can be stated that the use of sugarcane residues as an adsorbent agent is an alternative for the efficient removal of the oil present in the produced water. Thus. two partial problems can be solved: wastewater treatment and versatility of agroindustrial waste application.
Biomass gasification is the thermochemical conversion of biomass mainly into syngas, and sugarcane bagasse (SCB) is its main feedstock in Brazil. However, the seasonal production of SCB influences biomass supply. This paper analyzed, via multivariate analysis, gasification datasets of 12 Brazilian feedstocks obtained from simu-lation to determine possible substitutes for SCB, optimal gasification conditions for all biomasses aiming at FT synthesis downstream, and key parameters for several syngas applications. A validated simulation in Aspen PlusTM of a fluidized bed gasifier generated one dataset with fixed gasification conditions used in hierarchical cluster analysis (HCA) and principal component analysis (PCA), and another with varying temperatures and S/B to obtain regression models via partial least squares (PLS) for optimization and Monte Carlo simulations. HCA and optimization using PLS models showed that sugarcane straw, energy cane, energy cane bagasse, and corn straw have similar gasification performances as SCB, being possible substitutes. Independent thermochemical plants based on eucalyptus, or corn and soybean straws are also suggested. Lignin is mostly useful for heat and power applications. PCA and HCA highlighted important correlations between inputs and outputs. Monte Carlo simulations suggested biomasses of lower C and higher O contents to obtain syngas suitable for FT synthesis and the opposite for applications of higher syngas heating values.
For second-generation (2 G) cellulosic ethanol production to be sustainable and viable, there is the need to value-add to the stillage. Here, pilot plant-derived 2G ethanol sugarcane bagasse stillage (BS) and eucalyptus stillage (ES) was transformed into valuable products using hydrothermal liquefaction (HTL) at 300 degrees C and 20 bar with Pd/C and K2CO3. BS produced oil, phenolic monomers, and organic acid yields of 32 \%, 49 \% and 25 \% respectively, while yields for ES were lower. Catechol constituted 43 \% of the total phenolic content for BS. Recycling the aqueous phase (containing acetic, formic, lactic, and propionic acids) improved phenol, guaiacol and catechol yields. Oil stability tests indicated a significant drop in oil yield with aging, but there was no significant change in higher heating value. A preliminary techno-economic analysis suggests that the potential value of producing 2G ethanol and products (including fertilizer) from BS is three times that of depithed sugarcane bagasse. This study demonstrated a potential technology to convert 2G cellulosic ethanol stillage to value-added chemicals, which not only improved the efficiency and profitability of 2G ethanol production but reduced organic contaminants synthesis.
Sugar industry is the second largest agro-based industry in India and contributes significantly to the socioeconomic development of rural population. It supports 50 million farmers and their families and provides direct employment to over 0.5 million skilled and semi-skilled persons in sugar mills and integrated industries. The Indian sugar industry plays a leading role in global sugar market being the world's second largest producer after Brazil, producing nearly 15 and 25\% of global sugar and sugarcane, respectively. The sugar industry which encompasses 599 operating sugar mills, 309 distilleries and 180 cogeneration plant and numerous pulp, paper and chemical making units is supported by four leading sugarcane research institutions, twenty-two state sugarcane research stations, world class sugar machinery manufacturers, suppliers and technical experts. Currently, the industry produces around 300-350 million tonnes (Mt) cane, 20-22 Mt white sugar and 6-8 Mt jaggery and khandsari to meet the domestic consumption of sweeteners. Besides, about 2.7 billion liters of alcohol and 2,300 MW power and many chemicals are also produced. The industry is able to export around 1,300 MW of power to the grid. Indian sugar industry is fully capable of meeting demand of potable alcohol as well as 10\% blending in gasoline. Industry is gradually transforming into sugar complexes by producing sugar, bio-electricity, bio-ethanol, bio-manure and chemicals; these contribute about 1\% to the National GDP. Emerging businesses like fuel ethanol, raw sugar and structural changes in global market have provided new horizons for the Indian sugar industry. The sector today has transformational opportunities that would enable it not only to continue to service the largest domestic markets but has also emerged as a significant carbon credit and green power producer and has the potential to support an ethanol blending programme of E10 and beyond.
Sugarcane is the second largest export crop in Australia. Industrial production of sugar, from sugarcane, results in bagasse fly ash (BFA), a by-product from the cogeneration in sugar milling operations that generate electricity by steam. The chemical and physical properties of BFA highlight its potential as a promising pozzolan for the stabilization of expansive soils, due primarily to a high content and surface area of the amorphous silicate found in BFA. Silicate in bagasse fly ash reacts extensively with calcium hydrate in lime to produce hydrated products via pozzolanic reactions, this results in a hardening of the material to which BFA and lime have been added. This reaction has been studied to be a function of the size of BFA particles and conditions of the curing process. This study explored the variables that influence the reaction and evaluated shrinkage and compressive strength of the mixtures to which bagasse fly ash, in the form of different particle size distributions, and hydrated lime are added. The maximum BFA particles sizes considered within this study include 75, 150 and 425 mu m; curing times of 7 and 28 days are also explored. A suite of testing, including Atterberg limits, linear shrinkage (LS), and unconfined compressive strength (UCS) tests were completed on the prepared mixtures. The findings indicate that bagasse fly ash with a maximum size of 425 mu m yields a higher UCS and lower LS, compared to finer BFA particle mixtures. The ash with a maximum particle size of 425-mu m also improves the ductility of treated soils and accelerates their strength gain, compared to soillime stabilized samples. The results of the study build towards a better understanding of BFA, and the ways in which such a material maybe engineered to replace concrete in road work projects and other applications involving expansive soils.
Renewable, cost-effective and eco-friendly electrode materials have attracted much attention in the energy conversion and storage fields. Bagasse, the waste product from sugarcane that mainly contains cellulose derivatives, can be a promising candidate to manufacture supercapacitor electrode materials. This study demonstrates the fabrication and characterization of highly porous carbon aerogels by using bagasse as a raw material. Macro and mesoporous carbon was first prepared by carbonizing the freeze-dried bagasse aerogel; consequently, microporous structure was created on the walls of the mesoporous carbon by chemical activation. Interestingly, it was observed that the specific surface area, the pore size and distribution of the hierarchical porous carbon were affected by the activation temperature. In order to evaluate the ability of the hierarchical porous carbon towards the supercapacitor electrode performance, solid state symmetric supercapacitors were assembled, and a comparable high specific capacitance of 142.1 F g(-1) at a discharge current density of 0.5 A g(-1) was demonstrated. The fabricated solid state supercapacitor displayed excellent capacitance retention of 93.9\% over 5000 cycles. The high energy storage ability of the hierarchical porous carbon was attributed to the specially designed pore structures, i.e., co-existence of the micropores and mesopores. This research has demonstrated that utilization of sustainable biopolymers as the raw materials for high performance supercapacitor electrode materials is an effective way to fabricate low-cost energy storage devices.
Pervious concrete has newly undertaken to escalate for its demand. As urban areas develop, the difficulties related to runoff management have become more herculean and pervious concrete can provide a sustainable solution. Sustainable development in the field of concrete structures can be achieved by minimizing the usage of cement in concrete as it releases a large amount of CO2 leading to various hazards. The reduction of Portland cement is attained by replacing by-product from various industries. Sugarcane bagasse ash (SCBA) is obtained by burning sugarcane after the extraction of all efficient sugar from it. Disposal of the ash material causes various environmental hazards. Strength is improved by using SCBA as a supplementary material and thus makes the resultant concrete eco-friendlier and economical. The bagasse ash which passes 150 lm and retained on 90 lm similar to that of OPC is used in this study. The samples are prepared by replacement of bagasse ash with cement in different percentages and the strength parameters and permeability of concrete is tested. Six different concrete mixes with the bagasse ash replacing 0\%, 5\%, 10\%, 15\%, 20\% and 25\% of the OPC were prepared with water to cement ratio of 0.34 and 202.83 kg/m3 cement content. It is found that at 15\% replacement, the optimum strength is obtained. Since the aggregate sizes used for all the percentage replacements remains same, the permeability ranges from 0.2 cm/s to 0.4 cm/s. (c) 2020 Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the International Conference on Advances in Materials and Manufacturing Applications.
Presently, sugarcane bagasse (SB) and oat hulls (OH) have a distinctive potential as a renewable source of biomass, due to its global availability, which is advantageous for producing liquid and gaseous fuels by thermochemical processes. Thermo-Catalytic Reforming (TCR) is a pyrolysis based technology for generating energy vectors (char, bio-oil and syngas) from biomass wastes. This work aims to study the conversion of SB and OH into fuels, using TCR in a 2 kg/h continuous pilot-scale reactor at different pyrolysis temperatures. The pyrolysis temperatures were studied at 400, 450 and 500 degrees C, while the subsequent reforming temperature remained constant at 500 degrees C. The bio-oil contained the highest calorific value of 33.4 and 33.5 MJ/kg for SB and OH, respectively at 500 degrees C pyrolysis temperature, which represented a notable increase compared to the raw material calorific value of SB and OH (16.4 and 16.0 MJ/kg, respectively), this was the result of deoxygenation reactions occurring. Furthermore, the increment of the pyrolysis temperature improved the water content, total acid number (TAN), viscosity and density of the bio-oil. The syngas and the biochar properties did not change significantly with the increase of the pyrolysis temperature. In order to use TCR bio-oil as an engine fuel, it is necessary to carry out some upgrading treatments; or blend it with fossil fuels if it is to be used as a transportation fuel. Overall, TCR is a promising future route for the valorisation of lignocellulosic residues to produce energy vectors. (C) 2020 Energy Institute. Published by Elsevier Ltd. All rights reserved.
In this study, the biomass wastes of sugarcane bagasse and coconut endocarp were used for the adsorption of basic blue 3 and reactive blue 19 dyes from aqueous solutions. DFT calculations and Response Surface Models (RSM) were used to analyze the adsorbent-adsorbate interactions and to propose an adsorption mechanism. These adsorbents were characterized by FTIR, DRX, SEM and EDX. RSM allowed the evaluation of the effects of temperature and pH on the dye adsorption. DFT modeling was used to analyze the dye - biomass interactions using six representative model molecules for the composition of lignocellulosic biomass. The experimental and modeling results showed that the best experimental conditions to remove BB3 dye were 40 degrees C and pH 4, while the best conditions for RB19 dye adsorption were 40 degrees C and pH 6. RSM models satisfactorily correlated the experimental data with R2 values of 0.90 - 0.98 and modeling errors of 0.30- 1.53\%. The adsorption of these dye molecules was endothermic and governed by physical interaction forces. The adsorption capacity for BB3 increased with increasing pH, whereas that of RB19 showed the opposite trend. DFT calculations indicated that BB3 and RB19 molecules interact via the nitrogen located in the phenoxazine and the sulfonate group, respec-tively, with the hydroxyl and oxygenated groups of monomers that compose the natural polymers of these lignocellulosic materials.
The consumption of dietary fibres can affect glycemic power and control diabetes. Sugarcane fibre (SCF) is known as insoluble dietary fibre, the properties of which can be affected by physical, chemical, and enzymatic treatments. In this study, alkaline hydrogen peroxide (AHP) treatments were conducted over time (0.5, 1, 3, and 5 h) at 12.6\% (w/v) SCF and the effects on the physicochemical and structural properties of the SCF were evaluated. After making dough and bread with the SCF, with and without AHP treatments, the glycemic responses of the bread samples were evaluated. Shorter durations of AHP treatment (0.5 and 1 h) reduced lignin effectively (37.3 and 40.4\%, respectively), whereas AHP treatment at 1 and 3 h duration was more effective in increasing particle sizes (50.9 and 50.1 mu m, respectively). The sugar binding capacity, water holding capacity (from 2.98 to 3.86 g water/g SCF), and oil holding capacity (from 2.47 to 3.66 g oil/g SCF) increased in all AHP samples. Results from Fourier-transform infrared spectroscopy (FTIR) confirmed the polymorphism transition of cellulose (cellulose I to cellulose II). The morphology of SCF detected under scanning electron microscopy (SEM) indicated the conversion of the surface to a more porous, rough structure due to the AHP treatment. Adding SCF decreased dough extensibility but increased bread hardness and chewiness. All SCF-incorporated bread samples have reduced glycemic response. Incorporation of 1, 3, and 5 h AHP-treated SCF was effective in reducing the glycemic potency than 0.5 h AHP-treated SCF, but not significantly different from the untreated SCF. Overall, this study aims to valorize biomass as AHP is commonly applied to bagasse to produce value-added chemicals and fuels.
Background: The filamentous fungus Trichoderma reesei is used on an industrial scale to produce enzymes of biotechnological interest. This fungus has a complex cellulolytic system involved in the degradation of lignocellulosic biomass. However, several aspects related to the regulation of the expression of holocellulolytic genes and the production of cellulases by this fungus are still understood. Methods: Here, we constructed a null mutant strain for the xyloglucanase cel74a gene and performed the characterization of the Delta cel74a strain to evaluate the genetic regulation of the holocellulases during sugarcane bagasse (SCB) cultivation. Results: Our results demonstrate that the deletion of xyloglucanase cel74a may impact the regulation of holocellulase expression during SCB cultivation. The expression of cellulases cel7a, cel7b, and cel6a was reduced in Delta cel74a strain, while the hemicellulases xyn1 and xyn2 were increased in the presence of SCB. The cel74a mutation also affected the xyloglucan hydrolysis patterns. In addition, CEL74A activity was modulated in the presence of calcium, suggesting that this ion may be required for efficient degradation of xyloglucan. Conclusions: CEL74A affects the regulation of holocellulolytic genes and the efficient degradation of SCB in T. reesei. This data makes a significant contribution to our understanding of the carbon utilization of fungal strains as a whole.
Several pretreatment strategies focus on the removal of a significant part of lignin from plant cell walls, as it is considered the main barrier to the process of deconstructing biomass to simple sugars by hydrolytic enzymes. The ability to chemically differentiate and spatially locate lignins across cell walls provides an important contribution to the effort to improve these processes. Here, we present a novel approach using synchrotron phase contrast tomography to probe the physicochemical features of plant cell walls. In addition to the 3D cellular architecture, the distribution of dense packed lignin carbohydrate complexes (or, simply dense lignin) over larger regions and within cell walls has been successfully provided. We examined in particular the effect of the sequential H2SO4 and NaOH pretreatment on sugacane bagasse. Our results revealed that aggregates of dense lignin form elongated 3D structures in cell corners (CC) following the orientation of the sclerenchyma fibers; a remarkable result in the light of the conventional perception that lignin particles are discrete and roughly spherical. After the acid pretreatment, a considerable fraction of the dense lignin primarily located in CCs was removed; and it was further dissolved with the subsequent alkali treatment. Unexpectedly, the two-step pretreatment did not contribute to the cellulose accessibility in terms of available surface area and porosity. This study provides new insights into the underlying mechanisms of biomass deconstruction by pretreatments; and the approach established here can be extended to other systems relevant to the bioenergy and biotechnology arenas.
Ethanol at high concentration was produced from rice straw pretreated with sodium carbonate through dry simultaneous saccharification and fermentation (DSSF). A high concentration of ethanol was obtained without mechanical mixing, an increase in fermentation time, and pre-hydrolysis. The most important influencing factors, including pretreatment time (3-10 h), enzyme loading (5-40 FPU/g substrate), solid loading (15-30 wt \%), and DSSF reaction time (48-120 h), were investigated on dry hydrolysis and DSSF. An increase in pretreatment time from 3 to 10 h improved ethanol concentration from 55.1 to 67.7 g/L, obtained through DSSF at 20\% solid loading and 10 FPU/g substrate. A glucose concentration as high as 124.6 was obtained from the hydrolysis of the straw treated for 5 h. The highest total sugar and ethanol concentration were 137.3 and 83.1 g/L for the treated straw, while they were 65.2 g/L and 38.6 g/L for the untreated ones, respectively, obtained by hydrolysis and DSSF at 30\% solid loading. Changes associated with pretreatment, i.e., composition, crystallinity, and microscopic structure of untreated and treated straws, were investigated to find the reason for the improved hydrolysis and DSSF. (C) 2018 Elsevier Ltd. All rights reserved.
The present study demonstrates a cost-effective process for liquid biofuel production (butanol and ethanol) from non-acetone forming strain C. sporogenes NCIM 2918. The cost-effectiveness was achieved by culturing the organism on cheaper raw materials such as sugar hydrolysate from lignocellulosic biomass and crude glycerol, a waste from the biodiesel industry. Three types of biomass namely rice straw, sugarcane bagasse, and areca nut husk were explored. The maximum amount of glucose was obtained from hydrolysis of rice straw and optimization of enzymatic hydrolysis conditions was carried out for the same. The hydrolysate thus obtained was used to replace pure glucose in dual substrate blend while pure glycerol was replaced with hexane washed crude glycerol. Batch fermentation resulted in a total alcohol titer and productivity of 23.5 g L-1 and 0.52 g L-1 h(-1) respectively. An improvement in total alcohol titer (26.4 g L-1) and productivity (0.69 g L-1 h(-1)) was observed when batch fermentation was coupled with an in situ product recovery via gas stripping. To extend the cultivation period, the mode of fermentation was changed from batch to fed-batch. Fed-batch fermentation, with intermittent feeding of sugar hydrolysate and crude glycerol, coupled with gas stripping resulted in improved total alcohol titer of 44.4 g L-1 (butanol 21.5 g L-1 and ethanol 22.9 g L-1) with a productivity and yield of 0.62 g L-1 h(-1) and 0.37 alcohol per gram of sugar (glucose + glycerol) respectively.
In this work, we have tested individual and combination of applications of ozonolysis and liquid hot water (LHW) to pretreat sugarcane bagasse (SCB) for the removal of enzyme and/or microbial inhibitors and generation of potential value-added chemicals. A solid content with 80\% cellulose and a liquid phase (liquor) rich in phenolic derived compounds (3 g(.)L(-1)) from lignin, sugars (>20 g(.)L(-1)), and other compounds, such as furfural and hydroxymethylfurfural (HMF), were generated. Maximal (59\%) glucan conversion occurred in the presence of double-pretreated bagasse, which had 32-50\% more glucan available than the samples that were individually LHW or ozone-pretreated, resulting in maximal ethanol production (92\% after 42 h) from double-pretreated SCB enzyme hydrolyzate. In summary, this work showed that ozone reacts effectively with lignin without the use of any other chemical reagent, and LHW pretreatment, followed by a washing step, was effective in solubilizing and cleaning up the fiber enzyme and microbial inhibitory compounds with ozone being effective against phenolics. Moreover, the generated cellulose-rich substrate is readily fermentable. The acidic liquor fraction removed by sequential washings and containing mainly sugars and phenolic compounds may be evaluated for use in green chemistry bioconversions processes.
This paper presents results on the features of bagasse pretreatment with peroxide and acetic acid (peroxide-HAc) aiming at selective removal of lignin to enhance enzymatic hydrolysis. Surface response methodology was employed to study the effects of major process parameters on delignification and to establish a model for the prediction of lignin removal in the process. Enzymatic hydrolysis following the pretreatment was conducted to evaluate the enhancement of biohydrolysis by the pretreatment. Results revealed that peroxide-HAc pretreatment of bagasse retained most of the carbohydrate constituents, although the delignification rate was low. Peroxide-HAc concentration, temperature, and time demonstrated significant effects on bagasse lignin removal. The relationship between lignin removal and the process parameters could be well described by a mathematical model derived from the experimental data. After treatment with 69.1\% peroxide-HAc at 80 degrees C for 26.5 h, 97.08\% of lignin could be removed while keeping 68.24\% hemicelluloses intact. Over 93.58\% of carbohydrate in treated bagasse could be hydrolyzed with exoglucanase in a dosage of 138 FPU/g carbohydrates at 35 degrees C within 48 h. It was thus demonstrated that treated bagasse has a much higher response toward enzymatic hydrolysis than its untreated counterpart.
The water absorbent polymer effect on vegetative growth and production of Theoretical Recovery Sugar (TRS) of sugarcane cv. RB 86 7515 was evaluated on two field tests installed in randomized blocks, with four treatments and five repetitions. The polymer doses were 0; 4; 8 and 12 g m(-1) of furrow (test 1) and 0; 1.4; 2.8 and 4.2 g m(-1) of furrow (test 2). Test 1 (dec/2007 to may/2009) was implanted in a Distroferric Red Argisol soil in Presidente Prudente - State of Sao Paulo (SP), Brazil; and the test 2 (Aug/2008 to Aug/2009) was implanted in a Red Yellow Argisol soil in Lucelia - State of Sao Paulo (SP), Brazil. In test 2, there were no significant differences for any evaluated parameters. In both tests the polymer doses equal to or less than 4 g m(-1) of furrow showed no significant effect on the evaluated parameters. In test 1, the polymer doses of 8 and 12 g m(-1) of the conditioning polymer increased the number of tillers in stage II of development and led to the largest amount of straw. The gross income per hectare has positive relation with the polymer doses. The polymer had no significant effect on the sugarcane stems productivity and technological parameters.
Organic vinasse, a residue produced during bioethanol production, increases nitrous oxide (N2O) emissions when applied with inorganic nitrogen (N) fertilizer in soil. The present study investigated the role of the ammonia-oxidizing bacteria (AOB) community on the N2O emissions in soils amended with organic vinasse (CV: concentrated and V: non-concentrated) plus inorganic N fertilizer. Soil samples and N2O emissions were evaluated at 11, 19, and 45 days after fertilizer application, and the bacterial and archaea gene (amoA) encoding the ammonia monooxygenase enzyme, bacterial denitrifier (nirK, nirS, and nosZ) genes and total bacteria were quantified by real time PCR. We also employed a deep amoA amplicon sequencing approach to evaluate the effect of treatment on the community structure and diversity of the soil AOB community. Both vinasse types applied with inorganic N application increased the total N2O emissions and the abundance of AOB. Nitrosospira sp. was the dominant AOB in the soil and was correlated with N2O emissions. However, the diversity and the community structure of AOB did not change with vinasse and inorganic N fertilizer amendment. The results highlight the importance of residues and fertilizer management in sustainable agriculture and can be used as a reference and an input tool to determine good management practices for organic fertilization.
Using chemical ripeners in the sugarcane favors the increase of sucrose productivity, regulates the effects of adverse weather conditions for ripening, and promotes the anticipation of harvest. However, it can also modify the nutrient absorption, translocation, and accumulation process and, consequently, affect the nutrient cycling of the straw maintained on the soil surface. Thus, this research aimed to evaluate ripeners' effects (glyphosate - 0.5 L ha(-1); sulfometuron-methyl - 0.02 kg ha(-1), and trinexapac-ethyl - 0.8 L ha(-1)) on the nutritional status of the sugarcane leaf canopy. Natural ripening maintained the highest levels of P and Zn throughout the time. The highest levels of N, P, and K were provided by trinexapac-ethyl in most of the evaluated periods, as well as contributing to the highest levels of Ca, Mg, and S, along with sulfometuron methyl, from 30 to 60 days after application (DAA). The highest levels of B and Zn were observed under sulfometuron methyl. On the other hand, glyphosate was the ripener responsible for the lowest nutrient concentrations in the leaf canopy, including N, Ca, Mg, and S at 45 DAA and B and Mn at 30 and 45 DAA. Considering the importance of maintaining the straw for nutrient cycling, in addition to being a ripener, trinexapac-ethyl contributed to the maintenance of high levels of nutrients in the leaf canopy in relation to the other ripeners, which suggests a greater possibility of availability of these nutrients for the ratoon development in the upcoming cycles.
In this study, organosolv pre-extraction of wheat straw (WS) was conducted to extract lignin for understanding the effect of silica on enzymatic hydrolysis of carbohydrates. The results showed that the presence of silica in the WS substrate was associated with a decreased conversion of carbohydrates into monomeric sugars during enzymatic hydrolysis. Then, a sequential two-stage pretreatment process comprising ethanol pre-extraction and alkaline pretreatment was investigated to convert WS carbohydrates into bioethanol and recover lignin and silica. The results demonstrated that the pre-extraction with ethanol at 160 degrees C for 50 min followed by alkaline treatment with 11\% sodium carbonate (Na2CO3) was sufficient to generate a highly digestible substrate. 85.7\% of the original sugars in the raw feedstock was recovered by two-stage pretreatment followed by enzymatic hydrolysis with an enzyme loading of 12 FPU/g glucan. Fermentation with Saccharomyces cerevisiae SR8 u strain consumed 97.8\% sugars in the hydrolysate to reach 6.5\% w/v ethanol titer. With this proposed process, about 89.1\% silica and 62.5\% lignin were recovered at high levels of purity.
The capacity of Phanerochaete chrysosporium grown on soil with added sugarcane baggase (BP) and pine sawdust (PS) to remove benzo(a)pyrene (BaP) was studied. A half factorial two-level experiment 2(4-1) was designed to determine the effect of: type of lignocellulosic material (BP and PS) for fungus growth, age of fungus (5 and 10d), amount of lignocellulosic material (10\% and 15\% w/w) and soil moisture content (water holding capacity of 45\% and 56\% w/w). Inoculum obtained at different ages showed that the capacity of P. chrysosporium to remove BaP depends on the lignocellulosic used and on inoculum age. Abiotic BaP removal was affected significantly (p < 0.05) by inoculum age, type of lignocellulosic added and soil moisture content. The removal of BaP by lignocellulosic material was more effective by young inocula (71.97 mg BaP kg(-1) dry soil), with high percentage of added lignocellulosic (71.57 mg BaP kg(-1) dry soil) and at low soil moisture content (73.07mg BaP kg(-1) dry soil). When fungus was grown on BP, maximum BaP removal rate was obtained at 5d of incubation (10.85 mg BaPd-1 1(-1) and 50.12 mg BaP kg(-1) dry soil), while in PS maximum BaP removal was obtained at 10 d of incubation (12.06 mg BaP d(-1) 1(-1) and 39.94 mg BaP kg(-1) dry soil). (C) 2004 Elsevier Ltd. All rights reserved.
The biorefinery of the future will be an integrated complex that makes a variety of products (e.g., biofuels, chemicals, power and protein) from a variety of feedstocks. The objective of this work was to evaluate the environmental benefits, compared to the traditional sugarcane ethanol system, of the integrated production of ethanol and biodiesel through a sugarcane-soybean biorefinery concept in Brazil. The environmental aspects considered here were the fossil energy use and the greenhouse gases (GHGs) emissions associated with ethanol production. In the Integrated System, soybean would be cultivated in part of the sugarcane reforming areas, which represents similar to 17\% of the total sugarcane area. Sugarcane and soybean oil would be processed in a combined ethanol-biodiesel plant, which would use only bagasse as fuel. All the demand for utilities of the biodiesel plant would be provided by the distillery. The output products of the combined plant would comprise sugarcane ethanol, soybean biodiesel (which would be used as diesel (B5) substitute in the sugarcane cultivation), bioelectricity and glycerin. The results indicate that the Integrated System can reduce the fossil energy consumption from 75 to 37 kJ/MJ of ethanol, when compared to the traditional system. For GHG emissions, the value would drop from 22.5 to 19.7 g CO(2)eq/MJ of ethanol. This analysis shows that the Integrated System is an important option to contribute to ethanol's life cycle independence from fossil resources. This is an attractive environmental aspect, but socio-economic (as well as other environmental) aspects should also be analyzed in order to assess the sustainability of such systems in a broader perspective. (C) 2012 Elsevier Ltd. All rights reserved.
Sucrose has been the major commercial product of the sugar industry for decades. Sugarcane is a C4 photosynthetic crop and has great diversification potential. It can be used to produce dozens of bioproducts, apart from ethanol, electricity, paper, vinasse, and other green products of commercial importance already being generated. The optimal processing of sugarcane can yield food, feed, biofertilizers, bioplastics, and biomolecules, apart from sucrose of several applications as sucrochemistry. The diversification of the sugar industry would not only enhance the commercial competitiveness of this sector but will also limit the wastes production from sugar mills, offering environmental benefits. Nevertheless, despite the exceptional possibilities of the biorefinery concept of the sugar industry, the industrial adoption of this strategy has remained limited in most of the sugarcane growing countries for some reasons. In the current scenario of sugarcane agroindustry in many areas of the world, sugarcane diversification is crucial for improving the sugarcane value chain, ensuring the efficient exploitation of sugarcane agriculture, and contributing to the 2030 sustainable development goals. The purpose of this review was to carry out an analysis of the factors and constraints that determine the potential of sugarcane supply areas and sugar mills to establish diversification projects. The analysis presented in this study would serve as a useful guide to formulate strategies for optimal utilization of sugarcane crop and sugar industry wastes, by maximizing its benefits through modifying/converting the sugar mills to so-called bio-refineries.
This study was conducted to examine feasibility of using some agricultural residues and their biochars as substitutes for commercial horticultural growing media as cocopeat, sand, perlite, zeolite, pumice, vermiculite and rockwool. Biochars of wheat straw, sawdust, rice hull, sugarcane bagasse and date palm bunches were produced at 300 and 500 degrees C. Following substrate properties were determined: easily available water (EAW) defined by the difference between water contents (theta) at absolute matric potentials (h) of 10 and 50 hPa (EAW = theta(10) - theta(50)), air after irrigation (AIR = theta(0) - theta(10)), water holding capacity (WHC = theta(10)), water buffering capacity (WBC = theta(50) - theta(100)), saturated water content (theta(s)), bulk density (BD), total porosity (TP), water drop penetration time (WDPT), pH and electrical conductivity (EC). A classification system was developed to evaluate the substrates as horticultural growing media. Higher pyrolysis temperature produced biochars with higher pH, EC, TP, theta(s), WHC, EAW, and WBC and lower biochar yield, AIR, BD and WDPT. Sugarcane bagasse biochars had higher theta(s), TP and WBC and lower BD than other biochars. Comparison among organic residues and inorganic substrates showed that highest TP, theta(s) and EAW were observed in rockwool, whereas, among organic residues, maximum values of these properties were achieved for sugarcane bagasse, wheat straw and sawdust, respectively. Considering pH, EC, BD, TP, EAW, AIR, WBC and WDPT, wheat straw and sawdust were classified as very good substrates similar to cocopeat and rockwool. Other organic residues were placed in good class. Wheat straw and date palm bunches biochars produced at 500 degrees C and sugarcane bagasse and rice hull biochars were good growing media and can be suitable candidates for amendments or replacements of commercial growing media. (C) 2019 Elsevier Ltd. All rights reserved.
The present paper evaluated a sugarcane biorefinery producing ethanol, through the conventional process by sugars fermentation and methanol through bagasse and leaves gasification, hot cleaning and synthesis. The sugarcane biorefinery was modelled using flowsheet modelling software and thermal integration. A thermo-economic model was developed in order to analyze the energy efficiency of the system as well as the total investment. Different configurations are analyzed for the methanol production process. Multi-objective optimization using a genetic algorithm solver is performed, allowing the analysis of several process configurations in terms of conflictive objectives energy efficiency and investment cost. The sugarcane biorefinery is self-sufficient in energy demand after thermal integration with a system energy efficiency increasing when the methanol production is higher, although it also leads to an increase in the total investment. Both Entrained Flow and Circulated Fluidized Bed gasification technologies are modelled and compared for sugarcane residues conversion, showing similar impacts in the system efficiency that can reach more than 55 \% (dry biomass input low heating value basis), which is almost two fold higher than the one obtained in the traditional sugarcane ethanol plants currently in use.
In this study, bagasse was pretreated with ionic liquid (IL) 1-butyl-3-methylimidazolium chloride ({[
Naturally abundant lignocellulosic material recovered from sugarcane industry has revealed a potential adsorbent for a textile dye uptake. In this work, bagasse is soaked with alkali then treated with sulphuric acid to produce cellulose fibres. X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) were used to characterise such adsorbent. SEM pictures explained that the chemically treated bagasse adsorbent has a micro-fibrous structure that increases the adsorption capacity. The experimental adsorption results and the characterisation data explore the prepared adsorbents from pure sugarcane bagasse (BG), chemically treated (BGT) or chemically and thermally treated (BGT500) are successfully used to remove Procion Blue (PB) dye from aqueous media. The highest dye removal was corresponding to 98.5\% when BGT adsorbent was applied. Freundlich isotherm and pseudo-second order models are well described Procion Blue adsorption onto bagasse. The thermodynamic data, i.e. Delta G degrees, Delta H degrees and Delta S degrees illustrated the spontaneous and exothermic nature of the physical adsorption process. This investigation suggested that bagasse residue could be proposed as a low-cost adsorbent with a high adsorption capacity value for textile dye effluent removal.
The production of extracellular xylanase by a locally isolated strain of Aspergillus tubingensis JP-1 was studied under solid-state fermentation. Among the various agro residues used wheat straw was found to be the best for high yield of xylanase with poor cellulase production. The influence of various parameters such as initial pH, moisture, moistening agents, nitrogen sources, additives, surfactants and pretreatment of substrates were investigated. The production of the xylanase reached a peak in 8 days using untreated wheat straw with modified MS medium, pH 6.0 at 1:5 moisture level at 30 A degrees C. Under optimized conditions yield as high as 6,887 +/- A 16 U/g of untreated wheat straw was achieved. Crude xylanase was used for enzymatic saccharification of agro-residues like wheat straw, rice bran, wheat bran, sugarcane bagasse and industrial paper pulp. Dilute alkali (1 N NaOH) and acid (1 N H2SO4) pretreatment were found to be beneficial for the efficient enzymatic hydrolysis of wheat straw. Dilute alkali and acid-pretreated wheat straw yielded 688 and 543 mg/g reducing sugar, respectively. Yield of 726 mg/g reducing sugar was obtained from paper pulp after 48 h of incubation.
A novel consolidated bioprocess for hyper-production of butyric acid from delignified rice straw without exogenous enzymes involved was developed by co-fermentation of Clostridium thermocellum ATCC 27405 and C. thermobutyricum ATCC 49875. Feasibility of the consolidated bioprocess was approved by batch fermentations, with the optimum pH of 6.5. Fed-batch fermentation with a constant pH of 6.5 at 55 degrees C could enhance the butyric acid yield to a remarkable 33.9 g/L with a selectivity as high as 78\%. Metabolic analysis of the co-culture indicated that sugars liberated by C. thermocellum ATCC 27405 were effectively converted to butyric acid by C. thermobutyricum ATCC 49875. Secondary metabolism of C. thermobutyricum ATCC 49875 also contributed to the hyper-production of butyric acid, resulting in the re-assimilation of by-products such as acetic acid and ethanol. This work provides a more effective fermentation process for butyric acid production from lignocellulosic bio-mass for future applications.
The optimizations of enzymatic hydrolysis to produce of xylo-oligosaccharides (XOs) from three different lignocellulosic biomasses were investigated. Sugarcane bagasse, oil palm empty fruit bunch, and rice straw contain rich hemicelluloses especially hetero-xylan which can be hydrolyzes by endo-xylanase enzyme. Enzymatic hydrolysis of sugarcane bagasse by endo-xylanase from Kitasatospora sp. was optimum at temperature hydrolysis 30 degrees C using 16 U of enzyme concentrations and4 \% substrate concentrations, while oil palm empty fruit bunchwas optimum at temperature hydrolysis 30 degrees C using 16 U of enzyme concentrations and 5 \% substrate concentrations, and rice straw was optimum at 40 degrees C temperature hydrolysis using 16 U of enzyme concentrations and 4 \% substrate concentrations. The hydrolysis products were analyzed by TLC and HPLC. The main product hydrolysis for sugarcane bagasse, oil palm empty fruit bunch and rice straw are xylobiose.
The sugarcane industry represents one of the most important economic activities in Brazil, producing sugar and ethanol for the internal and external markets. Moreover, thermal and electric energy is produced for self-consumption, using sugarcane bagasse as fuel in cogeneration plants. Almost all the sugarcane plants in Brazil are self-sufficient in terms of energy supply and in the last few years some of them have been selling their surplus electricity for the grid. The reduction of process steam requirements and the use of more efficient cogeneration systems are new alternatives to increase the surplus electricity generation. The purpose of this paper is to analyze the steam demand reduction on sugar and ethanol process and alternatives for cogeneration systems in sugarcane plants, aiming at the surplus electricity generation increase. (c) 2007 Elsevier Ltd. All rights reserved.
The current work presents a relatively simple, cost-effective, and environmentally friendly solution for the removal of dye effluents from wastewater. The work demonstrated the treatment of MB dye effluents using varying contents of SBA. The performance of SBA contents in MB dye solution was evaluated via absorbance values of the supernatant measured under dark and UV environments at different time intervals varying from 0.5 to 120 h. The obtained result shows that after 6 h of contact between the MB dye (5 ppm) and SBA (20 mg), the removal efficiency of SBA in a dark environment was found to be 44.6\% in comparison to 55.2\% under a UV environment. The data suggests the greater removal efficiency of UV-irradiated dye samples in comparison to the samples kept in dark. Further, the concentration of dye decreased to 2.7 mg/L from the initial concentration (5 mg/L) after 6 h of addition of 20 mg of SBA, while it decreased to 2 mg/L after exposure to the UV environment. Adsorption kinetic models such as pseudo-first and pseudo-second-order were applied to find the rate of adsorption on SBA. The practical feasibility of SBA as a dye removal agent was checked using an unknown yellowish-green colored dye. The results confirmed the removal of dye from the wastewater to a significant extent in about 15 min, which proves its importance for industrial applications. The experiments for the desorption of dye molecules from SBA were performed in an acidic medium (0.1 M HNO3) of pH = 1. This provision resulted in the desorption of the MB dye from the SBA into the solution through electrostatic forces of repulsion. The desorption results confirmed the recovery of SBA. The obtained SBA at the end of the process can be reused again for the removal of dye molecules and hence provides an additional advantage in large-scale industrial applications in terms of the cost-effectiveness of the approach.
Experiments were conducted in an attempt to study the impact of using different organic residues as fertilizers on grain yield, magnitude of nitrous oxide (N2O) emissions, and soil characteristics. Five fertilizer treatments including conventional nitrogen (N) fertilizer, cow manure, rice straw, poultry manure, and sugarcane bagasse were applied in the rice field in 2012. The maximum reduction in seasonal N2O emissions (10-27\%) was observed under the influence of rice straw application over conventional N fertilizer. The experiment was repeated for a second season in 2013 with the same treatments for further confirmation of the results obtained during the first year of experimentation. The application of rice straw also showed a slight advantage by increasing grain yield (4.38 t ha(-1)) compared to control. Important soil properties and plant growth parameters were studied and their relationships with N2O emission were worked out. The incorporation of organic residues helped in restoring and improving the soil health and effectively enhancing grain yield with reduced N2O emission from rice fields.
This work investigates the isolation of cellulose nanocrystals (CNC) from sugarcane bagasse (SCB) waste and the evaluation of their mechanical reinforcement capability for k-carrageenan biopolymer. The results from Atomic Force Microscopy and Transmission Electron Microscopy indicated the successful extraction of CNC from SCB following alkali, bleaching and acid hydrolysis treatments. The CNC displayed a needle-like structure with an average aspect ratio of 55. The surface functionality of the CNC was evaluated by Fourier Transform Infrared Spectroscopy and X-ray Photoelectron Spectroscopy measurements. X-ray diffraction studies showed that the as-extracted CNC exhibit cellulose I crystalline structure, with a crystallinity index of 80\%. The obtained CNC were dispersed into k-carrageenan biopolymer matrix at various CNC contents (1, 3, 5 and 8 wt\%) and the prepared films were further characterized. The incorporation of CNC decreased the light transmittance values but enhanced the mechanical properties compared with the neat k-carrageenan film. Empirical Halpin-Tsai model was used to predict the CNC dispersion within k-carrageenan matrix. The obtained nanocomposite films have the potential to be used as food packaging material. (C) 2018 Elsevier B.V. All rights reserved.
PURPOSE: To evaluate the benefit of using carriers such as the biopolymer gel (hidrogel of polysaccharide of sugarcane molasses) associated with the bone morphogenetic proteins (BMP's) in the repair of critical bone defects in calvaria of Wistar rats. METHODS: Forty-two rats were submitted to a surgical calvaria bone defects. These animals were divided into two experimental groups, positive control group and negative control group. The Group I the calvaria defect was filled up with biopolymer gel, biological membrane, BMP and lyophilized graft. The Group II was treated with biopolymer gel, BMP and lyophilized graft. And the group III (positive control group) was treated with BMP, lyophilized graft and biological membrane. In the negative control group (Group IV) a defect was made in the rat calvaria and the animals were sacrificed immediately after the surgery. The animals of experimental groups and positive control group were slaughtered after subsequent periods of 90 and 180 days. In these periods, the histological analysis and image assessment by cone bean tomographic imaging were obtained. RESULTS: There was highest bone tissue formation with statistically significant results in the groups that associated biopolymer gel and membrane (Group I), followed by the group III (BMP, lyophilized graft and biological membrane). The lower bone formation occurred in the group not using the sugarcane biopolymer gel (Group II). The radiolucent areas of the analyzes of 180 days among the groups studied were respectively, 14.98 mm(2), 26.65 mm(2) and 35.81 mm(2). CONCLUSION: The biopolymer gel showed to be an excellent bone morphogenetic protein carrier, probably by facilitating the controlled release of these proteins in the process of bone repair.
Microbial fuel cells (MFC) generate clean energy from organic wastes. This study reports the development and application of novel lab-scale MFC with granular activated carbon-modified electrode fed with synthetic sugarcane vinasse. Biological activity involving nitrogen in the cathode chamber was assessed as a strategy to improve cathode performance under different temperatures (similar to 25, 35 and 55 degrees C) and external resistance (13 and 300 Omega). High organic matter removal (>90\%) was obtained regardless of the condition applied. Nitrification occurred in the cathode chamber at temperature up to 35 degrees C; this resulted in a decrease in pH to <7, which favored the cathode performance. The anode, applied at 35 degrees C and 55 degrees C, presented lower internal resistance and more negative potentials; this shows that the temperature reduced the anode overpotentials. The application of 13 Omega external resistance promoted higher electrogen activity, which resulted in coulombic efficiency up to 12.6 +/- 2.4\% against 1.9 +/- 0.2\% at 300 Omega. The combination of the proposed configuration, operation and electrode materials yielded maximum power density of 41.3 W m(-3), which is higher than values reported by other studies with similar electrode materials, reactor configuration (not stacked) and substrate composition (diversified). The findings contribute to the development of scalable renewable energy generation systems based on combination of biochemical and bioelectrochemical processes in wastewater treatment.
Plant straw resources are rich, and the annual yield of crop straw is large. To reduce environmental pollution caused by the burning of plant straw and realize maximum resource utilization of straw, the published literature data are analyzed in depth. It was found that the carbon element content in the straw was about 40\% and the ash content was low. The straw activated carbon can meet the adsorption standard requirements of wooden activated carbon, which was a good material for the sustainable utilization of activated carbon. The activated carbons prepared from cotton straw and hemp straw have large specific surface area, and the total pore volumes of activated carbon from sunflower straw and hemp straw are obviously higher than that of other straw activated carbon. In order to improve the quality of activated carbon, the effects of various activators are better than that of single activator in the preparation of straw activated carbon. The study found that when the ratio of the initial concentration of pollutants to the adsorbent concentration is 30, the removal efficiencies of heavy metals (Cu(II), Cr(VI) and Fe(III)) aren't less than 90\%. This review will be of great significance to optimize the preparation conditions of straw activated carbon, improve the quality of straw activated carbon and expand the application range of straw activated carbon. (C) 2020 Elsevier Ltd. All rights reserved.
The valorization of lignocellulosic feedstocks into biofuels and biochemicals has received much attention due to its environmental friendliness and sustainability. However, engineering an ideal microorganism that can both produce sufficient cellulases and ferment ethanol is highly challenging. In this study, we have tested seven different genes that are involved in glycosylphosphatidylinositol (GPI) biosynthesis and remodeling for the improvement of cellulase activity tethered on the S. cerevisiae cell surface. It was found that the overexpression of LAS21 can improve beta-glucosidase activity by 48.8\% compared to the original strain. Then, the three cellulase genes (cellobiohydrolase, endoglucanase, and beta-glucosidase) and the LAS21 gene were co-introduced into a diploid thermotolerant S. cerevisiae strain by a multiple-round transformation approach, resulting in the cellulolytic ECBLCCE5 strain. Further optimization of the bioprocess parameters was found to enhance the ethanol yield of the ECBLCCE5 strain. Scaling up the valorization of pretreated sugarcane bagasses in a 1 L bioreactor resulted in a maximum ethanol concentration of 28.0 g/L (86.5\% of theoretical yield). Our study provides a promising way to improve the economic viability of second-generation ethanol production. Moreover, the engineering of genes involved in GPI biosynthesis and remodeling can be applied to other yeast cell surface display applications.
In Mexico, sugarcane (Saccharum spp.) is one of the most notable agrifood crops, due to the economic importance it represents, sucrose and ethanol are systematically produced from it. However, a modernization scheme is currently required through productive diversification, valorizing and taking advantage of the generated co-products. In this scheme, the production of lactic acid is proposed, which generates added value and has potential demand in different industries such as food and pharmaceuticals. Therefore, the objective of this research was to evaluate factors that determine potential supply of lactic acid, if it were produced using bagasse and molasses generated in 18 sugar mills located in four sugarcane regions in Veracruz, Mexico. Statistical methods of panel data analysis were applied by estimating five econometric models, using the factors that can determine such supply. Analysis results indicated that the four sugarcane regions have lactic acid production potential, highlighting the Papaloapan-Gulf (2.6 million t) and Cordoba-Gulf (1.6 million t) regions. Factors that influenced or determined supply were: harvest duration, lactic acid import price, the number of co-products and by-products, the harvested area and the average of schooling level. In conclusion, the sugar agroindustry in Veracruz has the potential to diversify its production through the co-production of lactic acid in the context of a deficit trade balance.
This study tested the hypothesis that enhanced-efficiency fertilizers, such as urea treated with NBPT, are a feasible substitute for ammonium nitrate-based fertilizers for green sugarcane cultivation. The experimental design included six N sources applied over sugarcane straw at two sites in Central-South Brazil. Treatments included ammonium nitrate, urea, and four urea-based fertilizers treated with different rates of the urease inhibitor N-(n-butyl)thiophosphoric triamide (NBPT) at two rates of N (50 and 100 kg ha(-1)), plus an additional control. Nitrogen status in the plant, the activity of glutamine synthetase (GS) and nitrate reductase (NR) in the leaves, and sugarcane stalk yield and quality were evaluated. At site 1, N rates increased the SPAD index, stalk yield, N uptake, and sugar yield. At site 2, N rates increased GS activity, N content, the SPAD index, and N uptake, but stalk and sugar yield were not increased due to large variability in these parameters. All N sources resulted in similar yields at both sites. These results were compared with those in the literature. Among 27 studies surveyed, the average sugarcane yield was 97.8 or 97.4 Mg ha(-1) under ammonium nitrate or urea fertilization, respectively, and these averages did not differ by the Kruskal-Wallis test. The results of this study demonstrate that enhanced-efficiency fertilizers have the potential to reduce NH3 emissions from urea-based fertilizers in green sugarcane fields without affecting sugarcane yield.
Steam pre-treatment has been examined to sugarcane bagasse fibers (BF). Steam pressure plays an important role in the fibrillation process that is capable in dissolving fibers up to micron scale. Values of fiber diameter with steam pre-treatment (BFP) significantly decreased by 57\%. Decrease of the size of fiber can increase the active area of bonding interaction between the fiber surface and the composite matrix. The investigation resulted in mechanical characteristics of unsaturated polyester composite matrix (UP) containing a filler of spent coffee grounds (SCG). When compared between UP-SCG-BF composites to UP-SCG-BF8, it has an increase in tensile strength and flexural strength by 53.57\% respectively.
Hydrochar washed (1.0, 2.5, 5.0 and 10.0 \%) and not washed (10.0\%) produced by hydrothermal carbonization using vinasse and sugarcane bagasse was applied in sand, ultisol and oxisol columns, and the release of NO3-, Orthophosphate, SO42-, Total Organic Carbon (TOC), H+ were evaluated for 30 days. These results were compared with the release of these parameters from experiments conducted with anthropogenic soils. The results demonstrated that higher amounts of nutrients were released for the experiments conducted with hydrochar not washed. With higher rates of hydrochar washed, higher the amount of nutrients released. TOC and SO42- were released throughout the experiment, which is beneficial from the agricultural point of view. Low values of orthophosphate and nitrate release in the leachates were observed for ultisol and oxisol due to the clay and iron and manganese oxides contents. Principal components analysis confirmed the observations and demonstrated that SO42- and TOC preferentially influence the oxisol, being that nitrate and pH influenced the columns containing Terra Mulata and sand. The results allow to conclude that it is possible to adjust the application rate of hydrochar in soils with lower fertility in order to increase it as observed for anthropogenic soils.
``Nanoplastics-the emerging contaminants{''
This work aims to present an alternative detector for the determination of arabinose, galactose, glucose and xylose in hydrolyzed sugarcane bagasse. The detector was developed using an electrode modified with multi-walled carbon nanotubes containing cobalt oxide nanoparticles (GCE/MWCNT/CoOOH) applied in high-performance liquid chromatography (HPLC) with reverse pulsed amperomehric detection (RPAD). The limits of detection obtained were 3.4 x 10(-6), 4.4 x 10(-6), 3.6 x 10(-6) and 5.0 x 10(-6) mol L-1 for arabinose, galactose, glucose and xylose, respectively. The standard addition method was used to determine the concentration of sugars in the hydrolyzed sugarcane. The determined concentrations for arabinose, galactose, glucose, and xylose were 1.0 x 10(-3), 7.2 x 10(-5), 3.0 x 10(-3) and 2.4 x 10(-3) mol L-1. respectively. The results demonstrate that this new method can be used for the detection of sugars without the interference of other electroactive species.
The biofloc technology (BFT) system has been widely applied in the shrimp and fish culture industry for its advantages in water-saving, growth improvement, and water quality purification. However, The BFT system usually takes a long time to establish, and the extra carbon source input increases the maintenance cost of the system. In this study, we aimed to develop a low-cost and high-efficient BFT system for Litopenaeus vannamei by applying bacteria that could promote the formation of BFT and utilize cheap carbon sources. Three bioflocculant-producing bacteria strains (M13, M15, and M17) have been screened from a cellulolytic strain collection. All three strains have been identified as Bacillus spp. and can use sugarcane bagasse (SB) as a carbon source, which is a cheap byproduct of the sucrose industry in the tropic area of China. Compared to sucrose, the addition of SB and the three strains could improve the biofloc formation rate, biofloc size distribution, ammonia removal rate, and the growth performance of the shrimps. These results suggest that the bioflocculant and cellulase-producing bacteria strains could promote the biofloc formation and the growth of shrimps by using SB as an economic substitute carbon source in the BFT shrimp culture system.
The energy demand, which is expected to increase more worldwide, has sparked the interest of researchers to find sustainable and inexpensive sources of energy. This study aims to integrate an energy recovering step into municipal wastewater treatment plants (MWWTPS) through anaerobic digestion. The anaerobic digestion of municipal wastewater (MWW), and then co-digestion with sugar cane molasses (SCM) to improve its organic content, was conducted at 25 degrees C and 37 degrees C. The results showed a substrate mixture containing 6\% of SCM and total solids (TS) of 7.52\% yielded a higher amount of biogas (9.73 L/L of modified substrate). However, chemical oxygen demand (COD) of the resulting digestate was high (10.1 g/L) and pH was not stable, and hence needed careful adjustment using 2 M of NaOH solution. This study recommends a substrate mixture containing SCM (2\%) and TS (4.34\%) having biogas production (4.97 L/L of modified substrate) for energy recovery from MWWTPS, since it was found to have more stable pH and low COD residue (1.8 g/L), which will not hold back the MWW treatment process. The annual generation of modified substrate (662,973 m(3)) is anticipated to generate about 16,241 m(3)of methane, which produces up to 1.8 GWh and 8,193 GJ per annum.
In this paper, dilute acid pretreatment of bagasse pith was investigated at low temperature. Process parameters varied including mass ratio of liquid to solid (r = 6:1-12:1 l/kg), reaction temperature (T = 100 degrees C-130 degrees C), and acid concentration (c = 0.75wt.\%-1.5 wt.\%) in order to effectively transform hemicellulose to fermentable sugar to improve the utilization of bagasse pith. The effects of dilute acid pretreatment were evaluated by fermentable sugar yield and decomposition products concentration. The optimum pretreatment conditions for depolymerization of hemicellulose bagasse pith was obtained at r = 10:1 l/kg, T = 120 degrees C, c = 1.0 wt. \%, t = 16 min. From this paper, it could be concluded that dilute acid pretreatment can be successfully applied to bagasse pith to achieve high yield of xylose (84.41\%) with acceptable levels of fermentation inhibitors formation. (C) 2013 AIP Publishing LLC.
In the present study, a CFD model was developed for the biomass gasification process in a downdraft fixed-bed gasifier. Sugarcane bagasse was used as feedstock in gasification experiments and simulation studies. Several operating parameters, including the velocity and preheating temperature of the inlet air/steam mixture, steam to air ratio (S/A), and biomass moisture content (MC), were investigated to achieve the maximum syngas yield (CO2, H-2, CH4, and CO) and conversion efficiency. Results proposed that the syngas yield and conversion efficiency were maximized at S/A of 0.67 and inlet velocity of 20 m/s. In addition, increasing the preheating temperature of air/steam and decreasing the MC of bagasse had positive impacts on the gasification process. The maximum conversion efficiency was 69.14\% at the optimum operating conditions. This study offers an advanced tool for the simulation of gasification process that can be used in primary-stage engineering designs. (C) 2020 Elsevier Ltd. All rights reserved.
The major interest of the paper deals with the extraction of silica from four natural sources such as rice husk, bamboo leaves, sugarcane bagasse and groundnut shell. These waste materials in large quantities can create a serious environmental problem. Hence, there is a need to adopt proper strategy to reduce the waste. In the present investigation, all the waste materials are subjected to moisture removal in a hot plate and sintered at 900 degrees C for 7 h. The sintered powder was treated with 1 M NaOH to form sodium silicate and then with 6 M H2SO4 to precipitate silica. The prepared silica powders were characterized by FT-IR, XRD and SEM-EDAX analysis. The silica recovered from different sources was found to vary between 52\% and 78\%. Magnesium substituted silica was formed from the groundnut waste and further treatment is required to precipitate silica. (C) 2014 Elsevier B.V. All rights reserved.
Silica nanoparticles have rapidly found applications in medicine, supercapacitors, batteries, optical fibers and concrete materials, because silica nanoparticles have tunable physical, chemical, optical and mechanical properties. In most applications, high-purity silica comes from synthetic organic precursors, yet this approach could be costly, polluting and non-biocompatible. Alternatively, natural silica sources from biomass are often cheap and abundant, yet they contain impurities. Silica can be extracted from corn cob, coffee husk, rice husk, sugarcane bagasse and wheat husk wastes, which are often disposed of in rivers, lands and ponds. These wastes can be used to prepare homogenous silica nanoparticles. Here we review properties, preparation and applications of silica nanoparticles. Preparation includes chemical and biomass methods. Applications include biosensors, bioimaging, drug delivery and supercapacitors. In particular, to fight the COVID-19 pandemic, recent research has shown that silver nanocluster/silica deposited on a mask reduces SARS-Cov-2 infectivity to zero.
This study investigated the composition and phase of major biomasses fly ash in Thailand at different sintering temperatures by X-rays fluorescence spectrometer (XRF) and X-Rays Diffractometer (XRD). All biomasses were sintered at different temperature (400 degrees C, 600 degrees C, 800 degrees C, and 1,000 degrees C) under same condition. The result found that Rice husk ash, Sugarcane leaves ash, Straw ash and Plam petiole ash at all sintering temperatures and Bagasse ash at 800 and 1,000 degrees C have silica content of >50 wt.\%. The main phase of Rice husk ash, Sugarcane leaves ash, Straw ash, Plam petiole and Bagasse ash was found to be SiO2 form. Theses result indicate that Rice husk ash, Sugarcane leaves ash, Straw ash, Palm petiole ash and Bagasse ash may be use substituted or additive for a silica source in the glass manufacturing process. (C) 2011 Published by Elsevier Ltd.
Nitrate removal in submerged membrane bioreactors (MBRs) is limited as intensive aeration (for maintaining adequate dissolved oxygen levels and for membrane scouring) deters the formation of anoxic zones essential for biological denitrification. The present study employs baffled membrane bioreactor (BMBR) to overcome this constraint. Treatment of nitrate rich water (synthetic and real groundwater) was investigated. Sludge separation was achieved using ceramic membrane filters prepared from waste sugarcane bagasse ash. A complex external carbon source (leachate from anaerobic digestion of food waste) was used to maintain an appropriate C/N ratio. Over 90\% COD and 95\% NO3-N reduction was obtained. The bagasse ash filters produced a clear permeate, free of suspended solids. Sludge aggregates were observed in the reactor and were linked to the high extracellular polymeric substances (EPS) content. Lower sludge volume index (40 mL/g compared to 150 mL/g for seed sludge), higher settling velocity (47 m/h compared to 10 m/h for seed sludge) and sludge aggregates (0.7 mm aggregates compared to <0.2 mm for seed sludge) was observed. The results demonstrate the potential of waste-derived materials viz, food waste leachate and bagasse ash filters in water treatment. (C) 2014 Elsevier Ltd. All rights reserved.
Techno-economic analysis of first- and second-generation (1G2G) integrated sugarcane biorefinery producing ethanol and electricity was performed, exploring the virtues and limitations of dilute acid pretreatment. Process variables such as solid content in the pretreatment reactor, enzymatic hydrolysis time, and the possibility of pentose fermentation were pondered using computational tools and simulation platforms to assess the impacts of the variables overall production chain. Previously published data reporting optimal pretreatment conditions applied to a leading sugarcane hybrid were considered in the simulation studies. Better economic returns were obtained using the lowest solids content in the pretreatment reactor, the shortest incubation time in the enzymatic hydrolysis step, as well as the use of the pentose stream to produce additional ethanol. Process profitability was mostly affected by sugarcane cost, followed by capital costs associated with investment, and input chemicals costs. Finally, this study indicates that the economic benefits do not only depend on achievement of high final product yields, but also on a set of industrial factors, demonstrating the suitability of process simulation to point out industrial bottlenecks deserving future research. (C) 2020 Elsevier Ltd. All rights reserved.
Xylan is the major hemicellulose present in sugarcane stem secondary cell walls. Xylan is composed of xylose backbone with a high degree of substitutions, which affects its properties. In the present study, the xylan from sugarcane tops (SCT) was extracted and characterized. Compositional analysis of xylan extracted from SCT (SCTx) displayed the presence of 74\% of D-xylose residues, 16\% of D-glucuronic acid residues and 10\% of L-arabinose. High performance size exclusion chromatographic analysis of SCTx displayed a single peak corresponding to a molecular mass of similar to 57 kDa. The Fourier transform infrared spectroscopic analysis of SCTx displayed the peaks corresponding to those obtained from commercial xylan. FESEM analysis of SCTx showed the granular and porous surface structure. Differential thermogravimetric analysis (DTG) of SCTx displayed two thermal degradation temperatures (T-d) of 228 degrees C, due to breakdown of the side chains of glucuronic acid and arabinose and 275 degrees C, due to breakdown of xylan back bone. The presence of arabinose and glucuronic acid as a side chains was confirmed by the DTG and thermogravimetric analysis. The CHNS analysis of SCTx showed the presence of only carbon and hydrogen supporting its purity. The recombinant xylanase (CtXyn11A) from Clostridium thermocellum displayed a specific activity of 1394 +/- 51 U/mg with SCTx, which was higher than those with commercial xylans. The thin layer chromatography and electrospray ionization mass spectroscopy analyses of CtXyn11A hydrolysed SCTx contained a series of linear xylo-oligosaccharides ranging from degree of polymerization 2-6 and no substituted xylo-oligosaccharides because of the endolytic activity of enzyme. The extracted xylan from SCT can be used as an alternative commercial substrate and for oligo-saccharide production. (C) 2021, The Society for Biotechnology, Japan. All rights reserved.
Cellulases are essential for the hydrolysis of lignocellulosic materials in the production of second generation ethanol. Solid-state cultivation is a process that provides high concentrations of enzymes that can be used in this hydrolysis. The objectives of this work were to produce cellulases by cultivating the fungus Myceliophthora thermophila I-1D3b in a packed bed bioreactor with sugarcane bagasse (SCB) and wheat bran (WB) as substrate and to evaluate the efficiency of the enzymatic extract in the hydrolysis of SCB in natura (BIN) and pretreated with ozone, alkali and ultrasound (BOU). The conditions for enzyme production in the bioreactor were SCB:WB at a ratio of 2.3:1 (w/w), 75 \% moisture content; 45 degrees C; aeration rate 240 L h(-1) and 96 h. The enzyme production was evaluated by endoglucanase, xylanase, filter paper (FPU) and beta-glycosidase activities. For the application of the enzymes, a central composed response surface design with 5 repetitions of the central point was used, taking enzyme volume and hydrolysis time as factors. Such cultivation yielded the following enzymatic activities: 723 U gss(-1) of endoglucanases, 2024 U gss-1 of xylanase, 12.6 U gss(-1) of FPU and 41 U gss-1 of beta-glucosidase. The results of the application tests indicated the best conditions as 7.0 mL of the enzyme extract (4.2 FPU) and 6 hours for BIN and BOU. The best cellulose-glucose conversions were obtained for BOU, reaching 32.1 \% at 65 degrees C. In conclusion, the enzyme production in the packed bed bioreactor was efficient and BOU pretreatment improved the hydrolysis of biomass, increasing the efficiency of conversion of cellulose to glucose.
Various technological options for recycling of sugar processing by-products and residuals are discussed making use of field data from five sugar factories in the State of Veracruz in Mexico and information from the literature. It is emphasized that diversification is urgently required in developing sugar exporting countries but that the feasibility of each technological option has to be assessed within each national and regional scenario. Bagasse is already recycled towards energy generation or sold to paper and pulp industries, It is recommended that the use of this by-product as a fuel should be optimized through various actions in such a way that a large saving of fossil fuel could be achieved. In the case of molasses, a strategy to increase ethanol production in the short, medium and long term is discussed. For the short term, the introduction of highly productive yeast strains and use of well trained personnel is recommended, For the medium and long term, development and adaptation of innovative technologies such as those involving continuous reactors and the use of Zymomonas mobilis are suggested, The strategy could be promoted through a National Programme aimed at increasing ethanol exportations, contributing to the benefit of the imports/exports balance. As stillage is the most important residual due to its high BOD and COD values, a discussion of at least five different alternative technologies for the recovery of the minerals or organic matter contained in it is presented. Such alternatives range from low to medium and high capital costs. Some of their advantages and disadvantages are discussed. Anaerobic digestion seems to be the best option whenever capital is available, although a secondary polishing treatment of the anaerobic effluents is required. In this case, an integrated system with recuperation of a multiproduct microalgae biomass (Spirulina sp.) appears to be a feasible option.
Brazil's agriculture and livestock annually generates enormous amounts of biomass, which varies in its biochemical composition. Many studies have pointed out the benefits of using this biomass as a substrate for biogas production through anaerobic digestion (AD), mostly via the co-digestion (co-AD) pathway. The agriculture and livestock of southeastern Brazil - sugarcane, orange, corn, soybean, coffee, cattle, swine, and poultry - have together demonstrated their potential for producing biomass that can be used for maximizing methane production. Filter cake, vinasse, straws, bagasse, mucilage, pulp, washing water, thin stillage, and manures also have specific organic matter and nutrient content that can be evaluated from an economic perspective as co-products of biorefineries. Some are costless but others have acquisition costs in the agricultural market. Comparing the recent biochemical compositions cited in scientific literature (technical parameter) and to know the costs (valuation parameter) is crucial for farmers and investors make decisions in large-scale. This study conducted a bibliographical survey of biomass generated in Brazilian agroindustry as a co-substrate for energy production. The analysis summarized two tables: 1- a compilation of biochemical composition of the main co-substrates, and 2- the acquisition or opportunity costs, discussing innovative aspects in the context of biogas production. (c) 2022 Society of Chemical Industry and John Wiley \& Sons, Ltd.
In this experimental work, the geopolymer blends were synthesized from metakaolin, fly ash, and sugarcane bagasse ash based on their low cost and easy availability to improve the strength and durability of the newly developed product. In this research, a multilevel investigation has been carried out in two phases i.e., initially at the laboratory-scale which was then upscaled to pilotscale. In the laboratory-scale study, the precursors namely, metakaolin, fly ash, and sugarcane bagasse ash were used in the multilevel materials investigation i.e., these materials were tested at mono level, binary level, and ternary level. Cylindrical specimens with 500 mm diameter and 100 mm height in size were cast by applying a constant pressure of 10-MPa. The samples were prepared with 10 M solution of NaOH and a Na2SiO3/NaOH ratio of 1.5 and were cured under normal room temperature. Upscaling of the optimized mixes, as revealed from the laboratoryscale investigation, was carried out at the pilot-scale by simulating the laboratory conditions for casting the full-sized brick specimens. The mechanical properties and durability aspects of the upscaled-brick specimens were investigated and compared with the standard codes of practice for conventional burnt clay bricks, leading to satisfactory results overall. The strength and durability of the developed product were enhanced due to the formation of the sodium- and calcium-based aluminosilicate hydrates i.e., N-A-S-H and C-A-S-H, which were validated through FTIR and SEM analysis. Interestingly, multilevel investigation of the blends helped in identification of the geopolymerization potential of these materials at different levels (mono, binary, and ternary level in this study).
This work investigates the evolution of cellulose crystals from sugarcane lignocellulose (bagasse and leaves) submitted to prehydrolysis (hydrothermal, dilute acid, or steam explosion) and soda delignifications. Raw and treated materials are characterized by X-ray diffraction with modeling of area-detector patterns. Three treatment effects are correlated: increase in cellulose content, quantified by strong acid hydrolysis; increase in average cellulose crystallite width, inferred from sharper 200 diffraction peaks; and decrease in crystallite distortion, evidenced by d(200)-spacing approaching reference values. Crystal contents measured according to recent developments (in Driemeier and Calligaris, J Appl Cryst 44: 184-192, 2011) are compared to cellulose contents. Limitations for this comparison are discussed. Results are consistent with minimum non-crystalline cellulose in raw lignocellulose, and with partial cellulose decrystallization or more defective crystallites in treated materials.
This study presented a recent progress in the application of a novel cetylpyridinium chloride modified sugarcane bagasse (SB-CPC) as adsorbent with multiple functionalities for the remediation of micropollutant 2,4-Dichlorophenoxyacetic acid (2,4-D, herbicide) and bacteria from aqueous matrices. Antibacterial potential of SB-CPC was assessed on Staphylococcus aureus and Escherichia coli (as nominated bacteria) using spread plate technique. In addition, a batch mode was employed to conduct adsorption and regeneration experiments. Brunauer-Emmett-Teller (BET) methods, X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy were used to study the morphology, surface chemistry and functional groups of SBCPC. SB-CPC possessed higher antibacterial activity to such an extent that it decreased (inhibited) the number of colonies of S. aureus and E. coli in the suspensions by 84.8 +/- 1.2 and 89.5 +/- 1.9\%, respectively. A novel SB-CPC had a maximum uptake of 66.5 +/- 3.5 mg g(-1) at lower temperature (293 K). Electrostatic interaction, pi-pi electron donor/acceptor (EDA) interaction and pore filling effect could be the primary mechanisms governed the removal of 2,4-D. Equilibrium isotherms were better fit to Langmuir and Koble-Corrigan models, while adsorption kinetics to pseudo-second order reaction. Thermodynamic analysis has confirmed the spontaneous, exothermic and physisorption characters of adsorption process. Moreover, a novel SB-CPC had showed a better regeneration efficiency on 2,4-D using 0.1 mol L-1 HCl solution; consequently substantiates its practical application for remediation of water and wastewater contaminated with 2,4-D and its derivatives.
Enzymatic kinetic studies of celulignin material obtained from acid-catalyzed hydrothermally pretreated sugarcane bagasse at high-solids loading (S/25\%), acid concentration (A) equal to 1.0; 2.0 and 3.0\% w/v and pretreatment time (t(P)) equal to 30; 90 and 150 min were carried out using the synergistic action of cellulase from T. reesei and cellobiase from Aspergillus niger. The kinetic experiments were carried out at 50 degrees C, 150 rpm and 3 h with substrate (water insoluble solids after pretreatment-WIS) loading range between 30 gsubstrate/L-sol and 100 gsubstrate/L-sol, and mixed with cellulase (at 5.0; 15.0; 30.0 and 60.0 FPU cellulase/(gsubstrate)) and beta-glucosidase (at 33.0 IU beta-glucosidase/gsubstrate) enzymes. A Michaelis-Menten dependence on the cellulase from T. reesei concentration and substrate concentration plots were obtained based on experimental data. The rate constant, K-m and maximum reaction rate attainable, V-max were determined to characterize the cellulase-catalyzed reaction. Results showed that the cellulase from T. reesei behavior was highly specific for each WIS fraction obtained under a combination of {[
The present study was designed to model the adsorption of geosmin from water under laboratory conditions using the Freundlich isotherm model. This model was used to compare the efficiency of sugarcane bagasse and pecan shell-based powdered activated carbon to the efficiency of a coal-based commercial activated carbon (Calgon Filtrasorb 400). When data were generated from Freundlich isotherms, Calgon Filtrasorb 400 had greater geosmin adsorption at all geosmin concentrations studied than the laboratory produced steam-activated pecan shell carbon, steam-activated bagasse carbon, and the CO(-)activated pecan shell carbon. At geosmin concentrations < 0.07 mug/l for the phosphoric acid-activated pecan shell carbon and below 0.08 mug/l for a commercially produced steam-activated pecan shell carbon obtained from Scientific Carbons, these two carbons had a higher calculated geosmin adsorption than Filtrasorb 400. While the commercial carbon was more efficient than some laboratory prepared carbons at most geosmin concentrations, the results indicate that when the amount of geosmin was below the threshold level of human taste (about 0.1 mug/l), the phosphoric acid-activated pecan shell carbon and the Scientific Carbons sample were more efficient than Filtrasorb 400 at geosmin removal. (C) 2002 Elsevier Science Ltd. All rights reserved.
In this study, adsorbent materials were prepared from sugarcane bagasse and modified with thermal treatment and chemical activation through activating agents (ZnCl2 and H3PO4). The modified adsorbents were then used to remove mercury (Hg(II)) from aqueous solutions. Batch adsorption experiments were performed to explore the influence of the kinetics, isotherm, and pH, on Hg(II) adsorption. The results demonstrated their high potential for Hg(II) adsorption (more than 90\%) owing to the various functional groups generated via the thermochemical treatment. The adsorption process was best described by the pseudo-second-order kinetics model, the adsorption phenomenon is contemplated as a mechanism mixture due to the complex surface of the studied adsorbents, and the maximum adsorption capabilities in this study exceeded 11.47 mg g(-1). Hg(II) removal is related to the existence of functional groups, such as -COO-, -O-, C=C, and C=O, on the material surface that selectively bind the Hg(II) through complexation, electrostatic interaction, and complexation with electrons pi. Based on these results, the adsorbent materials are determined to be effective for eliminating Hg(II) and a valuable alternative for treating water contaminated with mercury.
Textile wastewaters (TW) contain contaminants such as organic matter, dyes, sulfate, and many salts. Many methods have been used to remove these pollutants and to reduce the environmental impact associated with their release into water bodies. In the present study, physically activated carbon made of sugar cane bagasse was used as an adsorbent to remove color and chemical oxygen demand (COD) from textile effluent. The experiments were carried out with a real effluent from a textile jeans laundry. The effect of the variables, such as adsorbent amount, pH, contact time, temperature, and particle size of the adsorbent, was tested. The most efficient results were obtained for the adsorbent mass of 0.25 g, pH 6.0, contact time of 60 min, and adsorbent size smaller than 0.42 mm. The adsorbent performed well for color removal of textile effluent, removing up to 93\% and 55\% of color and COD, respectively. The Brunauer-Emmett-Teller (BET) surface area and total pore volume were 188.2 m(2) g(-1) and 0.13 cm(3) g(-1), respectively, and average sizes of pore diameter of 2.7 nm and 3.6 nm. This indicates the ability of agro-industrial waste for application in the process of textile wastewater treatment.
Sugarcane bagasse (SCB) and beet pulp (BP) are promising low cost natural wastes with cellulose-lignin polymeric structure. Their adsorption properties for the removal of Pb(II) and Na(I) under variable conditions of solution pH, time of equilibrium, weight of adsorbent, and metal ion concentration were investigated. These two adsorbents were characterized using Fourier transform infrared spectra, Scanning electron microscope (SEM), and X-ray diffraction. SCB and BP showed high percentage of extraction of Pb(II) (100.0 +/- 1.0\% and 100.0 +/- 0.5\%) and Na(I) (97.5 +/- 0.1\% and 98.9 +/- 0.1\%), respectively. The adsorption isotherm data for Pb(II) and Na(I) ions by the two adsorbents were modeled using Langmuir and Freundlich equations. Furthermore, the adsorption kinetics data were best fitted with the pseudo-second-order type. Finally, the proposed method has been successfully applied for removal of Pb(II) from environmental water samples. Adapting batch condition, this application revealed high efficiency and good precision as indicated by recovery values 95.2-103.2\% and RSD\%=0.339-1.333\%. Moreover, SCB and BP were used to reduce sodium ion concentrations from irrigation water for improvement of plants production.
Cellulolytic bacteria that produce cellulases, which are active over a range of pH and temperatures, can be used to catalyze hydrolysis of pretreated lignocellulosic material. This is important in the production of second generation biofuels among other biotechnological applications. In this investigation, bacteria isolated from sugarcane bagasse were identified as strains of Enterobacter xiangfangensis, Serratia rubidaea, Klebsiella pneumoniae and a novel species of Citrobacter designated Citrobacter sp. UWIBGS10. The glucose production potential of these strains was studied on thermally and solvent pretreated sugarcane bagasse. This was performed at 24-hour intervals up to 168 hours in the range of pH 5-9 and temperature range 25-40 degrees C. Maximal concentrations of glucose for Citrobacter sp. UWIBGS10 occurred at pH 6 and 25 degrees C. For E. xiangfangensis, S. rubidaea, K. pneumoniae glucose concentrations were consistent across the pH and temperature ranges examined. From these results it could be concluded that the bacteria demonstrated ability for lignocellulolytic hydrolysis for the production of glucose and could be further explored for the characterization of commercial cellulolytic enzymes.
In this work, the sugarcane bagasse fiber was used as a filler to make a new type of biodegradable composite, using the cardanol resin, as a fully biodegradable thermosetting polymer matrix. Biocomposite performance was improved by chemically modified bagasse fiber using alkaline treatment. Two sets of composites were prepared with a fiber length of 10 and 20 mm with various weight percentages viz., 0, 5, 10, 15, and 20 of cardanol resin using a compression molding machine. The mechanical properties were studied using some tests and the morphological study in flexural fractured specimens was carried out using SEM. The thermal properties of biodegradable polymer composites were evaluated using TGA. The chemical formation of the new biocomposites was also examined by the FT-IR spectroscopy technique. The result proved that the morphology of the composites has improved the bonding between the fiber and resin, thus leading to enhancement of the mechanical properties. The result had shown the tensile and flexural strength with an increase in the range of bagasse fiber up to 15 wt\% in both the sets. The TGA results showed that biocomposites of 15 wt\% in both sets had the highest thermal stability. This investigation recommended the possibility of introducing bio-fiber obtained from waste agricultural residues in polymer matrix composites.
In this work, alkaline hydrogen peroxide pretreatment (AHP), at low concentrations of chemical reagents and mild temperature, on sugarcane bagasse was evaluated for production of bioethanol via enzymatic hydrolysis using Cellic (R) CTec3 from Novozymes (R) and fermentation using Saccharomyces cerevisiae wild-type strain AR5. Sodium hydroxide NaOH and calcium hydroxide Ca(OH)(2) as alkaline reagents were used and combined with hydrogen peroxide (H2O2) as oxidant reagent. AHP pretreatment with NaOH increased cellulose content up to 78\% and holocellulose content up to 90\%, resulting in 35\% more of cellulose and holocellulose contents compared with AHP pretreatment with Ca(OH)(2). Results of enzymatic hydrolysis of substrate coming from pretreatment with NaOH achieved high holocellulose-to-reducing sugar yield up to 81\% in 7 h of reaction time, 30\% higher production than using Ca(OH)(2). Besides, for the fermentation process, the necessity and effectiveness of removing remaining solids after enzymatic hydrolysis are not reported in the open literature. Finally, the maximum theoretical yield (95\%) was obtained using bothalkaline reagents for the fermentation experiments, producing a maximum ethanol concentration of 39 g/L when AHP pretreatment with NaOH was used, as well the ethanol production balances of 28.9\% and 19.1\%, were achieved according to the pretreatments with NaOH and Ca(OH)(2), respectively.
The use of natural fiber residues as reinforcement in biodegradable composites has been performed; however, the incompatible interface limits the applications. In this work, the use of starch coating as a natural coupling agent was studied in three different natural residues: sugarcane bagasse, macaranduba, and pinus wastes, aiming biodegradable composites. The coating in bagasse showed low efficiency, with low thickness and failures, due to residue intrinsic higher surface area; while the wood residues showed shorter fibers with uniform starch deposition. These results affected the compatibility between filler and matrix; while the bagasse composite showed voids and decrease in the mechanical properties; however, the macaranduba and pinus showed an increase in the stiffness and strength. All the coated fiber composites showed stable thermal properties and an increase in the crystallinity in the coated samples. The addition of the natural filler resulted in a high water absorption with coated samples absorbing six times more water than neat PLA and without stabilization in a short time. This characteristic may favor the initial abiotic hydrolysis in the biodegradation, showing that the material could be an option to produce short-life packaging in dry environments.
Lipases with unique characteristics are of value in industrial applications, especially those targeting cost-effectiveness and less downstream processes. The aims of this research were to: (i) optimize the fermentation parameters via solid state fermentation (SSF); and (ii) study the performance in hydrolysis and esterification processes of the one-step partially purified Schizophyllum commune UTARA1 lipases. Lipase was produced by cultivating S. commune UTARA1 on sugarcane bagasse (SB) with used cooking oil (UCO) via SSF and its production was optimized using Design-Expert (R) 7.0.0. Fractions 30\% (ScLipA) and 70\% (ScLipB) which contained high lipase activity were obtained by stepwise (NH4)(2)SO4 precipitation. Crude fish oil, coconut oil and butter were used to investigate the lipase hydrolysis capabilities by a free glycerol assay. Results showed that ScLipA has affinities for long, medium and short chain triglycerides, as all the oils investigated were degraded, whereas ScLipB has affinities for long chain triglycerides as it only degrades crude fish oil. During esterification, ScLipA was able to synthesize trilaurin and triacetin. Conversely, ScLipB was specific towards the formation of 2-mono-olein and triacetin. From the results obtained, it was determined that ScLipA and ScLipB are sn-2 regioselective lipases. Hence, the one-step partial purification strategy proved to be feasible for partial purification of S. commune UTARA1 lipases that has potential use in industrial applications.
The nanocatalyst impregnation onto the biomass matrix has gained importance in enhancing the H-2 yield and overcoming the catalyst deactivation problems. In-situ catalytic gasification of Ru/Fe-impregnated sugarcane bagasse and citrus limetta (mosambi peels) were examined and compared with their raw biomass at subcritical and supercritical water conditions. Bagasse having a higher amount of lignocellulosic content produces a maximum yield of H-2 over moambi peels. Besides, Ru and Fe nano-metal carbon hybrids with crystalline sizes between 10 and 25 nm were formed during in-situ hydrothermal gasification. The performance of hydrothermal gasification based on hydrogen yield was studied, and it relatively follows the order as temperature, nanoparticle composed, metal loading onto biomass matrix, type of catalyst, and biomass used. At the maximum operating temperature of 600 degrees C, B: W ratio 1:10 for the resident time of 60 min, highest H-2 yield of 12.75 +/- 0.17 and 11.20 +/- 0.13 mmol/g attained for Ru and Fe impregnated bagasse with the CGE of 72.28 +/- 2.17\% and 67.08 +/- 1.97\% respectively. At similar operating conditions, H-2 yields of 8.75 +/- 0.18 and 8.13 +/- 0.16 mmol/g were achieved with the CGE of 62.4 +/- 1.91\% and 53.7 +/- 1.66\% for Ru and Fe impregnated mosambi peels, respectively. Based on the H-2 and CH4 production, Ru shows the highest performance than Fe catalyst.
Since the usage of hair dyes has increased in recent time, the removal of residual dye from environment is also an emerging issue. Hair dye contains mixture of chemicals including genotoxic chemical, p-phenylenediamine (p-PD or PPD). The present study reports bioremediation of hair dye using bacteria isolated from saloon effluent. Sugarcane bagasse powder (SBP) was used as a source of nutrient and surface for bacterial growth. The 16S rDNA sequencing confirmed the isolate as Enterobacter cloacae which was designated as DDB I. The decolourization of dye was studied using UV-vis spectrophotometer. The detoxification study was conducted on microbes isolated from fresh ponds using well diffusion assay. The 1 mg/ml of dye was effectively decolourised within 18 h of DDB I treatment in the minimal medium containing 30 mg/ml of SBP. (C) 2017 Elsevier B.V. All rights reserved.
Agave bagasse is a lignocellulosic agroindustrial waste suitable for biofuel production. This study aimed to compare biological, enzymatic, chemical, and hydrothermal pretreatments applied to Agave bagasse in terms of solubilization of carbohydrates (CHO) and chemical oxygen demand (COD), as well as the biochemical methane potential (BMP) from hydrolyzates. Most pretreatments behave similarly, with an average yield of 0.16 +/- 0.02 g(COD)/g, only the chemical pretreatment overcame this yield by a factor of 2.6 with a CHO/COD ratio of 0.95. The concentrations of inhibitors - furfural, hydroxymethylfurfural, and phenols - were higher in the chemical hydrolyzates than in the biological and enzymatic hydrolyzates. BMP from most hydrolyzates was the same, on average 219 +/- 15 mL/g(CODin), hydrolyzates differentiate only in terms of lag phase and the methane production rates.
The present study verified an applicable technology of xylitol bioconversion as part of the integration of co-product generation within second-generation bioethanol processes. A newly isolated yeast strain, Candida tropicalis JH030, was shown to have a capacity for xylitol production from hemicellulosic hydrolysate without detoxification. The yeast gives a promising xylitol yield of 0.71 g(p) g(s)(-1) from non-detoxified rice straw hydrolysate that had been prepared by the dilute acid pretreatment under severe conditions. The yeast's capacity was also found to be practicable with various other raw materials, such as sugarcane bagasse, silvergrass, napiergrass and pineapple peel. The lack of a need to hydrolysate detoxification enhances the potential of this newly isolated yeast for xylitol production and this, in turn, has the capacity to improve economics of lignocellulosic ethanol production. (C) 2010 Elsevier Ltd. All rights reserved.
Saccharification of lignocellulosic biomass might contribute to the bioethanol production, positively impacting energy security and sustainability. Lignin reduces polysaccharide saccharification and needs to be depolymerized and separated to improve fermentable sugar yield. Here, we report a substantial increase in lignocellulose saccharification after treating plants with the natural compounds: 3,4-(methylenedioxy)cinnamic acid (MDCA), a competitive inhibitor of 4-coenzyme A ligase (4CL); piperonylic acid (PIP), a quasi-irreversible inhibitor of cinnamyl 4-hydroxylase (C4H); and daidzin (DZN) a competitive inhibitor of coniferaldehyde dehydrogenase (CALDH). A single treatment with these inhibitors on different young developmental stages significantly increased lignocellulosic saccharification of crops at maturity stage. Field trial experiments with sugarcane (Saccharum spp), soybean (Glycine max), and brachiaria (Urochloa decumbens), showed that 12-month-old sug-arcane bagasse increased saccharification up to 120\%, 90-days-old soybean residues increased saccharification up to 36\%, and 40-days-old brachiaria straw increased saccharification up to 21\%. Treatments did not affect biomass productivity, lignin content or its monomeric composition. In contrast, anatomic assessment by UV microscopy revealed that MDCA affected tissue formation, increasing the lignification in fibers and vessels, but not in parenchyma. The tissue-specific and developmental persistent phenomena allowed a substantial increase in saccharification, while preserving the mechanical strength necessary for plant growth and development, suggesting that natural compounds are opportune for bioenergy applications.
This study analyzes the use of lime and sugar cane bagasse ash (SCBA) as chemical stabilizers in compacted soil blocks. The blocks were tested for flexure and compression in a dry and a saturated state. The tests were performed at 7, 14 and 28 days of age in order to evaluate the effects of the addition of lime and SCBA on the mechanical properties of the compacted soil blocks: The results indicate that blocks manufactured with 10\% of lime in combination with 10\% of SCBA showed better performance than those containing only lime. Nevertheless, the addition of lime improved the strength of the blocks when compared with blocks fabricated with plain soil. According to SEM and DRX analyses, considerable improvement of the matrix was observed due to the formation of strong phases, such as CSH and CAH for the mixtures with additives. It was also concluded that the combination of SCBA and lime as a replacement for cement in the stabilization of compacted soil blocks seems to be a promising alternative when considering issues of energy consumption and pollution. (C) 2012 Elsevier Ltd. All rights reserved.
The cogeneration process from sugarcane bagasse is an alternative way to reduce fossil fuels consumption. In the environmental assessment of products, processes and services the methodology of Life Cycle Analysis (LCA) is commonly used. This study aimed to evaluate and compare the environmental impacts of the life cycle of different cogeneration technologies currently used in the Cuban sugar industry. For doing this, a combination of nine steam generators models with eight turbogenerators was analyzed, for a total of 72 alternatives, using the Eco-indicator 99 and the software SimaPro. The electricity generated daily (1000 kWh) was the functional unit used for the analysis. The results showed that the reduction of this process emissions to the air, water and soil had a favorable effect on the categories of carcinogenesis, radiation, ecotoxicity and land use. The category of Human Health damages reached higher impacts in the cogeneration stage, which represented about 80\% of the total environmental impact of the process. It was evidenced that the largest contribution to this category was the emissions of particulate material from bagasse combustion. The combination of the steam generator German Modified EKE 80 with the Russian turbogenerator 2500 was the alternative that involved a reduction of the total impact compared to the rest of alternatives. (C) 2012 Published by Elsevier Ltd.
Gluconacetobacter diazotrophicus is a plant-growth promoting endophytic bacterium used as a microbial inoculant for different crops. The objective of this work was to apply different mathematical models to represent its growth in a batch submerged culture employing a 3-L bioreactor and using sugarcane molasses and sucrose as energy sources. The time profile of pH, cell biomass, and total sugars was obtained. Models studied were compared considering their fit quality and complexity, and a parametric sensitivity analysis was performed. Four- and five-parameter models with expressions involving substrate and biomass inhibition effects were considered. The Herbert-Pirt-Contois model achieved the highest fit quality with determination coefficients of 0.888 and 0.425 for biomass and substrate, respectively. These values indicate a higher correspondence between the experimental data of biomass concentration and the data calculated by the model, compared to results obtained for total sugars for which this correspondence was lower. This model reached the best combination considering the fit quality and complexity according to the Akaike's information criterion. The kinetic study performed enabled to observe a bi-phasic behavior in the growth stage of the bacterium when grown on molasses, and a growth limitation effect due to biomass concentration. The outcomes obtained provide a mathematical description useful for design, scale-up, and operation of a future process for the production of a microbial inoculant based on G. diazotrophicus.
With the ordinance that prohibits sugarcane harvesting with prior burning of plantations in Brazil, sugarcane crops absorbs barely 20 \% of the N-fertilizer applied. This low recovery is attributed, in part, to nitrogen (N) mineralization in plant straw, high microbial immobilization, and N losses in the soil-plant system, mainly, when sources containing urea are applied to the soil surface. To evaluate N contribution from fertilizer in the sugarcane compartments and total N extracted by plants during the first ratoon cycle, microplots were installed inside plots of sugarcane ratoons. We applied isotope N-15-labelled urea, ammonium sulfate and ammonium chloride (3 \% N-15 atoms) at the dose of 100 kg N ha(-1). The soil in the study was classified as a Typic-Hapludox and the experimental design consisted of randomized complete block with four replicates. In addition nitrogen immobilization and mineralization rates was evaluated estimated by aerobic incubation during 20 weeks. Sugarcane residue was incorporated to soil and nitrogenous fertilizers applied to the surface as ammoniacal or amidic-N at 100 mg N kg(-1). N sources showed the same efficiency as the results showed no difference for N contents in plant shoots obtained from treatment with N fertilization. The use of ammonium chloride resulted in greater accumulation of N fertilizer in stalks at 218 days after fertilization. The percentage of N fertilizer was approximately 60 \% in the early developmental stages, decreasing to 20 \% near the harvesting stage. The addition of N-fertilizer in soils covered by sugarcane residue leads to immobilization of available-N in the soil.
Nanocomposites from poly(vinyl alcohol) {[
Aconitic acid (propene-1,2,3-tricarboxylic acid) is the most prevalent 6-carbon organic acid that accumulates in sugarcane and sweet sorghum. As a top value-added chemical, aconitic acid may function as a chemical precursor or intermediate for high-value downstream industrial and biological applications. These downstream applications include use as a bio-based plasticizer, cross-linker, and the formation of valuable and multi-functional polyesters that have also been used in tissue engineering. Aconitic acid also plays various biological roles within cells as an intermediate in the tricarboxylic acid cycle and in conferring unique survival advantages to some plants as an antifeedant, antifungal, and means of storing fixed pools of carbon. Aconitic acid has also been reported as a fermentation inhibitor, anti-inflammatory, and a potential nematicide. Since aconitic acid can be sustainably sourced from renewable, inexpensive sources such as sugarcane, molasses, and sweet sorghum syrup, there is enormous potential to provide multiple streams of additional income to the sugar industry through downstream industrial and biological applications that we discuss in this review.
Sludge is the solids recovered from wastewater treatment. Its high content of organic matter makes it a potential biomass resource for renewable energy production. In this study, batch and continuous countercurrent fermentations were performed with a 60: 40 mixture (dry weight basis) of lime-treated bagasse: sludge. This combination provides an optimal C/N ratio and therefore enhances yield. Two trains of continuous fermentations were performed using different volatile solids loading rates (VSLR) and liquid retention times (LRT). The highest total carboxylic acids concentration obtained was 60.8 g L-1 with a total acid yield of 420 g kg(-1) of VS added and an acid productivity of 2.31 g L-1 d(-1). In studies on co-fermentation of lignocellulosic biomass, this acid concentration is the highest reported in MixAlco (TM) (a patented process that converts biomass to a mixture of alcohols). This study shows that wastewater sludge is a valuable resource for liquid transportation fuels, and provides an attractive replacement for fossil fuels. (C) 2017 Elsevier Ltd. All rights reserved.
Maize stover, rice straw, oil palm fronds and sugarcane bagasse were treated with the white-rot fungi Ceriporiopsis subvermispora, Lentinula edodes, Pleurotus eryngii, or Pleurotus ostreatus at 24 degrees C for 0-6 weeks. The fungi increased total gas production from oil palm fronds by 68-132\%, but none of the fungi improved the in vitro rumen fermentability of maize stover. C. subvermispora and L. edodes increased total gas production of sugarcane bagasse by 65-71\%, but P. eryngii and P. ostreatus decreased it by 22-50\%. There was a linear relationship (P < 0.05) between the proportion of lignin in the original substrate and the increase in in vitro gas production observed for C. subvermispora and L edodes treatments (R-2 = 0.92 and 0.96, respectively). It is concluded that C subvermispora and L. edodes have a particularly high potential to improve the nutritive value of highly lignified ruminant feeds. (C) 2012 Elsevier Ltd. All rights reserved.
The co-production of bio-char and upgraded bio-oil by fast pyrolysis of raw and sulfuric-acid pretreated agro-industrial wastes (corn cob, sugarcane bagasse and sunflower seed hull) was investigated to valorize wastes as sources of value-added products (VAPs) following the circular bio-economy system. To this end, proximate and elemental analyses were performed, and adsorption properties were determined in pyrolysis products. Bio-char and bio-oil yields from raw wastes ranged 28-33\% and 30-35\%, respectively. For all wastes, acid pretreatment increased the solid fraction and caused a reduction of the liquid one, compared to untreated wastes. Pyrolysis of raw wastes led to the co-production of bio-chars and bio-oils with different applications. Bio-chars could be put in for soil amendment, primarily due to high ashes concentration, mesoporosity, and elevated cation exchange capacity; whereas, bio-oils could be upgraded by water addition, leading to a source for carrying out reforming reactions in the context of hydrogen production. Properties of bio-chars from acid washed biomasses enabled them for pollutant remediation, due to their high specific surface and microporosity features. The corresponding bio-liquid was a stable-to-storage material, being a practical source of furfural. These findings emphasize that lignocellulosic wastes can be envisaged as starting materials for producing VAPs via pyrolysis.
The feasibility of the pulping technology depends on the efficiency of by-products and solvent recovery. In this regard, the development of an environmentally friendly peracetic method of delignification should be accompanied by the development of an effective method of lignin disposal. Usually, delignification methods are characterized without a detailed study of the by-products. Herein, let's describe the structural and chemical characteristics of lignin, as well as its sorption properties. Pulping liquors after peracetic delignification of rapeseed straw were used in this work. The application of sodium tungstate and sodium molybdate as catalysts gave a significant effect on the dissolution of lignin during pulping. The composition, structure and functional groups of lignins were investigated. Application of catalysts in organosolv pulping resulted in small amounts of carbohydrates in lignins if compare to lignins after non-catalytic pulping. As catalysts, Na2WO4 and Na2MoO4 exhibited no obvious differences in carbohydrate contents and in molecular weights of organosolv lignin (M-w = 4910-5640 g/mol, M-n = 2350-2500 g/mol). The obtained lignin was successfully used for Methylene Blue adsorption due to high content of functional groups (R-OH = 1.72 mmol/g, Ph-OH = 5.72 mmol/g, R-COOH = 0.88 mmol/g) despite the poorly developed porous structure (11.03 +/- 0.35 m(2)/g). Lignin has potential applicability as a biosorbent for wastewater treatment to solve environmental problems of water pollution.
In this study naturally occurring biodegradable polysaccharides i.e., chitosan and cellulose are used to formulate the composite membrane. Sugarcane bagasse was used as raw material for the extraction of nanocellulose by adopting acid hydrolysis method followed by delignification process. The composite membrane was evaluated to eliminate chromium ion from the aqueous solution (100 ppm) by using vaccum filtration unit. During study total ten cycle was run to analyze the potential of the chitosan/nanocellulose composite membrane against removal of chromium ions. Observed data showed that first four cycles significantly remove the chromium ions concentration ranging from 87 to 29 PPM. The prepared composite membrane was structurally characterized by FTIR and XRD analysis. Results showed the characteristics peaks of cellulose structure and XRD confirms crystalline order respectively. The contact angle of 60.70 observed showing the hydrophilic behavior of the nano composite membrane. The swelling study (5 min) and the chemical stability (24 hrs) were also assessed; observed results showed that maximum swelling ratio of 1.8 was attained within 5 mins whereas the membrane is totally dissolved in acidic medium and swells in basic medium respectively. (C) 2021 Elsevier Ltd. All rights reserved.
Nano-hematite bagasse composite (n-HBC) was synthesized, characterized and tested for the removal of Pb(II) from dilute aqueous solutions. The particle size of ferric oxide was in the range of 100-300 nm. The composite surface, both internal and external, was occupied by abundant oxygen-containing functional groups. The optimum Pb(II) adsorption density occurred in the pH range from 4.0 to 5.5. Adsorption reached equilibrium rapidly in 480, 600, 720 min at initial Pb(II) concentration of 20, 30, and 40 mg/L, respectively, at 25 degrees C and pH 5.0. The maximum Pb(II) adsorption capacity, calculated from the Langmuir adsorption isotherm, was 16.57 mg/g at 25 degrees C. Furthermore, surface complexation model was also applied to describe the adsorption reaction between aqueous Pb(II) and n-HBC. The Gibbs free energy of adsorption, Delta G(ads)(0), was -39.49 kJ/mol (9.44 kcal/mol) at 25 degrees C, which indicated spontaneous Pb(II) ion adsorption on n-HBC. Results of XPS studies demonstrated the presence of surface oxygen-containing functional groups, which were involved in the adsorption of Pb(II) and that hematite played a key role in Pb (II) uptake.
The macroalgae surface allows specific bacterial communities to colonize, resulting in complex biological interactions. In recent years, several researchers have studied the diversity and function of the epiphytic bacteria associated with algal host, but largely these interactions remain underexplored. In the present study we analysed the cultivable diversity and polymer degradation potential of epiphytic bacteria associated with five different marine macroalgae (Sargassum, Ulva, Padina, Dictyota and Pterocladia sp.) sampled from the central west coast of India. Out of the total 360 strains isolated, purified and preserved, about 238 strains were identified through 16S rRNA gene sequence analysis and processed for polymer (cellulose, pectin, xylan and starch) degrading activities. Phylogeny placed the strains within the classes Actinobacteria, Bacilli, Alpha-proteobacteria, and Gamma-proteobacteria and clustered them into 45 genera, wherein Vibrio, Bacillus, Pseudoalteromonas, Alteromonas, Staphylococcus and Kocuria spp. were the most abundant with 20 strains identified as potentially novel taxa within the genera Bacillus, Cellulosimicrobium, Gordonia, Marinomonas, Vibrio, Luteimonas and Pseudoalteromonas. In terms of polymer hydrolysis potential, 61.3\% had xylanase activity, while 59.7\%, 58.8\%, and 52.2\% had amylase, cellulase, and pectinase activity, respectively. Overall, 75.6\% of the strains degraded more than one polysaccharide, 24\% degraded all polymers, while nine strains (3.8\%) degraded raw sugarcane bagasse. This study showed great potential for seaweed-associated bacteria in the bio-remediation of agro-waste based raw materials, which can be employed in the form of green technology.
In this work, oil mill wastewater (OMW), a residue generated during olive oil extraction, was evaluated as an inducer of rhamnolipid production. Using a medium containing as sole ingredients corn steep liquor (10\%, v/v), sugarcane molasses (10\%, w/v) and OMW (25\%, v/v), Pseudomonas aeruginosa \#112 produced 4.5 and 5.1 g of rhamnolipid per liter in flasks and reactor, respectively, with critical micelle concentrations as low as 13 mg/l. Furthermore, in the medium supplemented with OMW, a higher proportion of more hydrophobic rhamnolipid congeners was observed comparing with the same medium without OMW. OMW is a hazardous waste which disposal represents a serious environmental problem; therefore, its valorization as a substrate for the production of added-value compounds such as rhamnolipids is of great interest. This is the first report of rhamnolipid production using a mixture of these three agro-industrial by-products, which can be useful for the sustainable production of rhamnolipids. (C) 2016 Elsevier Ltd. All rights reserved.
Background: Structural component of plant biomass, lignocellulose, is the most abundant renewable resource in nature. Lignin is the most recalcitrant natural aromatic polymer and its degradation presents great challenge. Nowadays, the special attention is given to biological delignification, the process where white-rot fungi take the crucial place owing to strong ligninolytic enzyme system. However, fungal species, even strains, differ in potential to produce high active ligninolytic enzymes and consequently to delignify plant biomass. Therefore, the goals of the study were characterization of Mn-oxidizing peroxidases and laccases of numerous mushrooms as well as determination of their potential to delignify wheat straw, the plant raw material that, according to annual yield, takes the first place in Europe and the second one in the world. Results: During wheat straw fermentation, Lentinus edodes HAI 858 produced the most active Mn-dependent and Mn-independent peroxidases (1443.2 U L-1 and 1045.5 U L-1, respectively), while Pleurotus eryngii HAI 711 was the best laccase producer (7804.3 U L-1). Visualized bends on zymogram confirmed these activities and demonstrated that laccases were the dominant ligninolytic enzymes in the studied species. Ganoderma lucidum BEOFB 435 showed considerable ability to degrade lignin (58.5\%) and especially hemicellulose (74.8\%), while the cellulose remained almost intact (0.7\%). Remarkable selectivity in lignocellulose degradation was also noted in Pleurotus pulmonarius HAI 573 where degraded amounts of lignin, hemicellulose and cellulose were in ratio of 50.4\%:15.3\%:3.8\%. Conclusions: According to the presented results, it can be concluded that white-rot fungi, due to ligninolytic enzymes features and degradation potential, could be important participants in various biotechnological processes including biotransformation of lignocellulose residues/wastes in food, feed, paper and biofuels.
The objectives of this work were to develop biodegradable trays from cassava starch, sugarcane fibers and Na-montmorillonite (Na-MMT) using a baking process and to study the effects of these components on the physical properties, photo- and bio-degradation of the trays. The sample F20 (produced with 20 g fiber/100 g formulation) showed the maximum yield production (100 \%). All formulations resulted in well-shaped trays with densities between 0.1941 and 0.2966 g/cm(3). The addition of fibers and Na-MMT resulted in less dense and less rigid trays compared to control samples (only starch). The studied processing conditions resulted in good nanoclay dispersion, leading to the formation of an exfoliated structure. The evaluation of the photo-degradation stability of the trays under UV exposure for 336 h showed that a sample produced with a specific combination of fiber and nanoclay (20 g fiber and 5 g nanoclay/100 g formulation) had the highest loss in stress at break (91 \%). Biodegradation assays showed that Control trays (starch) and F20 (20 g fiber/100 g formulation) lost a greater percentage of their weight after 90 days of incubation in soil, with losses of up to 85.50 and 82.70 \%, respectively.
Cellulosic biomass is a potentially inexpensive renewable feedstock for the biorefineries of fuels, chemicals and materials. Sugarcane bagasse was pretreated in dilute acid solution under moderately severe conditions, releasing sugars and other hydrolysates including volatile organic acids, furfurals and acid soluble lignin. Utilization of the hydrolysates by an aerobic bacterium, Ralstonia eutropha, was investigated to determine if the organic inhibitors can be removed for potential recycling and reuse of the process water. Simultaneous biosynthesis of polyhydroxyalkanoates (PHAs) for the production of value-added bioplastics was also investigated. An inhibitory effect of hydrolysates on microbial activity was observed, but it Could be effectively relieved by using (a) a large inoculum, (b) a diluted hydrolysate solution, and (c) a tolerant strain, or a combination of the three. The major organic inhibitors including formic acid, acetic acid, furfural and acid soluble lignin were effectively utilized and removed to low concentration levels (less than 100 ppm) while at the same time, PHA biopolyesters were synthesized and accumulated to 57 wt\% of cell mass under appropriate C/N ratios. Poly(3-hydroxybutyrate) was the predominant biopolyester formed on the hydrolysates, but the cells could also synthesize co-polyesters that exhibit high ductility. (C) 2008 Elsevier Ltd. All rights reserved.
The present work reports the development of an electrochemical sensor based on molecularly imprinted polymer for the determination of D-xylose. This is the first report of its kind in the literature. The sensor was prepared through the modification of a glassy carbon electrode with reduced graphene oxide and molecularly imprinted poly(phenol) film. The use of graphene oxide and molecularly imprinted poly(phenol) film led to remarkable improvements in the sensor sensitivity and selectivity, respectively. The electrode was characterized by several techniques, including cyclic voltammetry, differential pulse voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy, atomic force microscopy and RAMAN spectroscopy. The proposed sensor presented linear responses ranging from 1.0 x 10(-13) to 1.0 x 10(-11) mol L-1. The amperometric sensitivity, limit of detection, and limit of quantification obtained were 6.7 x 10(5) A L mol(-1); 8.0 x 10(-14) mol L-1 and 2.7 x 10(-13) mol L-1 (n = 3), respectively. The proposed analytical method was successfully applied in sugarcane bagasse, which is known to contain large amounts of D-xylose and other structurally similar molecules in its composition. The chemical composition of sugarcane bagasse makes this biomass suitable for evaluating the ability of the sensor to specifically detect the target molecule. Mean recoveries obtained in the analysis ranged from 95.4 to 105.0\%; this indicates that the proposed method has good accuracy when applied toward the determination of D-xylose.
The carbon sources such as molasses cane sugar, dextrose and rice bran were tested in growing Pacific white shrimp, Litopenaeus vannamei, using the Biofloc Technology System, and the reduction in the concentration of total ammonia nitrogen in the experimental nursery and grow-out phases were assessed in tanks with a volume of 800 L at 35 and 70 days, respectively. In the nursery experiment, postlarvae with an average weight of 0.024 +/- A 0.01 g were stocked at 1200 m(-2) and shrimp with an average weight of 4.09 +/- A 0.51 g and stocking density of 300 m(-2) was used in the grow-out. The carbon sources used in the nursery were molasses (M) and rice bran (R) and in the grow-out were dextrose (D) and rice bran (R). In the nursery experiment, using molasses, the ammonia concentration was significantly lower (p < 0.05). In the grow-out experiment with dextrose, the ammonia concentration was significantly lower (p < 0.05), but performance data were significantly better (p < 0.05) in the rice bran treatment. The faster degradation of dextrose and molasses sources may have provided higher levels of carbon as a substrate for heterotrophic bacteria to use in metabolizing ammonia, thereby improving the water quality.
Liquid phase esterification of carboxylic acids with alcohols is an important organic synthesis process in the petrochemical and fine chemical industries. These reactions required mineral acid catalysts, which are corrosive and difficult to be separated from the reaction mixture. Therefore, the use of solid acid catalysts is economically viable, reusable, and environmentally amicable. In this study, sugarcane bagasse ash (SCBA) was impregnated with 1-10 wt\% of sulfuric acid (H2SO4) or perchloric acid (HClO4) for the liquid-phase esterification of acetic acid with n-amyl, benzyl, and n-butyl alcohols under various reaction conditions. The catalysts were characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier-transform infrared (FTIR), N-2 sorption, and scanning electron microscopy (SEM). Their acidities were measured through the dehydration of isopropyl alcohol and pyridine adsorption FTIR. The effects of the acid activation of SCBA on its texture properties (such as surface area and the nature of the surface functional groups), acidity, and catalytic activity were studied in detail. FTIR of the pre-saturated catalysts with pyridine reflected the presence of Bronsted and Lewis acid sites. The concentrations of the acid sites were improved by increasing the percentages of acid loading. All the catalysts showed high catalytic activity with 100\% selectivity to ester formation. The catalyst pretreated with H2SO4 showed the higher ester yields compared to that of treated with HClO4. The optimum reaction conditions were a reaction time of 2 h, an alcohol-to-acid molar ratio of 1:3, and catalyst loading of 0.5 g. The highest yields of n amyl acetate, benzyl acetate, and n-butyl acetate of 98, 90.8, and 70.5\%, respectively, were achieved over the SCBA pretreated with 10 wt\% H2SO4 catalyst. The high catalytic performance of this catalyst is due to the high surface acidity generated by the inductive effect of the S=O bond.
Advantages in biomass pretreatment could be reached by improving lignin removal. In this study, the antioxidant butylated hydroxytoluene (BHT) was evaluated for lignin removal from biomass. In pretreatments performed at 121 degrees C with 50\% (v/v) ethanol as solvent, the presence of BHT resulted in 45.28\% and 72.45\% lignin and hemicellulose removal, against its absence that resulted in 35.09\% and 56.31\%, respectively. The use of BHT in lignin removal under these conditions represents an improvement in the pretreatment reducing the biomass recalcitrance. FTIR analyses showed that organosolv pretreatment with BHT influenced band intensity of the pseudo-lignin, while in acid medium similarity was observed among the spectra. The enzymatic hydrolysis of pretreated biomass suffered the influence of hemicellulose and lignin removal. Pretreatments at 121 degrees C resulted in the highest cellulose conversion with 75\% ethanol (58.67\%), while pretreated biomass at 160 degrees C with 0.3\% BHT resulted in a 59.04\% of glucose yield. The use of BHT increased the lignin solubilization from the biomass in the organosolv pretreatment, increasing the effectiveness of the process, collaboration for further use of lignin.
Alkaline peroxide pretreatment of rapeseed straw was evaluated for conversion of cellulose and hemicellulose to fermentable sugars. After pretreatment, a liquid phase called pretreatment liquid and a solid phase were separated by filtration. The neutralized pretreatment liquids were used in a co-fermentation process, with Saccharomyces cerevisiae and Pichia stipitis. The solid fraction was used for simultaneous saccharification and co-fermentation process in the same vessel. The effects of various operating variables were investigated. Pretreatment with 5\% (v/v) H2O2 at 50 degrees C for 1 h was found to be the optimal pretreatment combination with respect to overall ethanol production. At this condition, 5.73 g ethanol was obtained from pretreatment liquid and 14.07 g ethanol was produced by co-fermentation of solid fraction with P. stipitis. Optimum delignification was observed when 0.5 M MgSO4 was included in the pretreatment mixture, and it resulted in 0.92\% increase in ethanol production efficiency. (C) 2011 Elsevier Ltd. All rights reserved.
Pigment was extracted to decolor the sugarcane juice alcohol wastewater and its antioxidant activities were evaluated. The pigment was extracted using ion exchange fiber along with macroporous resin D-101 as the absorbent and an ethanol-water mixture (6:4, v/v) as the eluent. Total flavonoid and phenolic contents of the pigment were determined. DPPH radical scavenging ability and reducing power of 1.0 mg/mL of the pigment were approximately 78.5 and 16.8\%, respectively, compared to 1.0 mg/mL of the tea polyphenol (positive control). The hydroxyl radical scavenging ability of 10.0 mg/mL of the pigment was about 92.5\% compared to that of positive control. The DPPH radical scavenging ability of the pigment was enhanced significantly with thermal treatment at 70 and 100A degrees C. The result shows the proposed procedure can be effective to decolor such wastewater and to get antioxidative pigment.
Pycnoporus sanguineus (Ps) and Candida tropicalis (Ct) can selectively degrade the lignin and hemicellulose in lignocellulosic cells respectively; Ps-Ct mixed fermentation may improve the multiphase reaction performance of lignin in the cell walls. Alkaline nitrobenzene oxidation, ozonation and infrared spectroscopy, which are the in-situ analytical techniques of lignin in the cells, were used to characterize the delignification kinetics, the reactions of the non-condensed, beta-O-4 structures and their stereochemistry of lignin in wheat straw in Ps and Ps-Ct fermentations. Results indicated that the biodelignification processes in Ps and Ps-Ct fermentations of wheat straw, being divided into a fast phase and a following slow phase, had the characteristics of a pseudo-first-order reaction in both the phases. The lignin reaction pathways in Ps and Ps-Ct mainly included the cleavage of ring, C alpha-C beta, beta-O-4, and the cleavage and polymerization of 5-5'. Compared with Ps fermentation, Ps-Ct fermentation enhanced the biodegradation of condensed, beta-O-4 structures and threo beta-O-4 structures in the lignin in the fast phase. A proposal scheme of biodelignification by Ps and Ps-Ct is outlined for the first time. These results will be helpful for the understanding and application of lignocellulosic biomass by mixed fermentations. (C) 2016 Elsevier B.V. All rights reserved.
Dietary fiber (DF) was extracted from plant byproducts (date seed and sugarcane bagasse) by alkaline hydrogen peroxide extraction and their chemical composition, technological properties, antioxidant activity, and prebiotic activity were evaluated. Bagasse had a significantly higher DF content (48.34\%) than date seed (39.89\%). Bagasse dietary fiber (BDF) had a significantly higher Fe, K, Mg, Na, and Zn (1343 ppm, 274.69 ppm, 640.08 ppm, 643.08 ppm, and 31.74 ppm, respectively) than date seed dietary fiber (DSDF) with 186.84 ppm, 185.88 ppm, 505.64 ppm, 506.72 ppm, and 13.28 ppm, respectively. The results showed that BDF had significantly higher values for oil binding capacity, water-holding capacity, and swelling capacity which equaled 2.73 g/g, 7.12 ml/g, and 12.50 ml/g, respectively, compared to DSDF (0.81 g/g, 4.06 ml/g, and 8.88 ml/g, respectively). The samples containing 5\% DSDF and 5\% BDF had the highest stimulating effect on Lactobacillus acidophilus growth, respectively. Also, pH reduction in the studied media depended on the type of DF and its concentration and the trend of decrease in pH was variable. Evaluation of the antioxidant activity of the studied DFs indicated that, at a 500 ppm concentration, DSDF with 89.12\% had a significantly higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) inhibition rate than ascorbic acid (85.4\%), and with increasing the DF concentration, antioxidant activity increased. The findings confirmed that the studied DFs have prebiotic effects. Due to their technological, physicochemical, and antioxidant properties, they can be used as inexpensive DF sources in the food and pharmaceutical industries.
One of the waste products of the industrial process of the sugar and alcohol agribusiness is filter cake (FC). This waste product has high levels of organic matter, mainly proteins and lipids, and is rich in calcium, nitrogen, potassium and phosphorous. In this work we characterized samples of FC from sugar and alcohol industries located in sugarcane-producing regions in Brazil and assessed the adsorption of potentially toxic metals (Cu(II), Cd(II), Pb(II), Ni(II) and Cr(III)) by this waste in mono- and multi-elemental systems, seeking to use FC as an adsorbent in contaminated environments. The characterization of FCs showed significant differences between the samples and the adsorption studies showed retention of over 90\% of potentially toxic metals. In a competitive environment (multi-metallic solution), the FC was effective in adsorbing all metals except lead, but less effective compared to the mono-metallic solution. These results show the potential for use of this residue as an adsorbent in contaminated environments.
A composite of cellulose extracted from bagasse with Nb2O5 center dot nH(2)O in three different proportions (16.67, 37.5 and 50.0 wt\%) was prepared using the co-precipitation method. The materials were characterized by X-ray diffractometry (XRD), Fourier transform infra-red spectroscopy (FTIR), thermogravimetric analysis (TG/DTG), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). TG data obtained show that the presence of inorganic material influenced slightly the stability of the hybrid material. The precipitation of 16.67 wt.\% of oxide was sufficient to inhibit the combustion peaks present in the DSC curve of cellulose. This work will help find new applications for these materials. Published by Elsevier Ltd.
An integrated membrane process for green sugarcane juice purification is promising but its application is limited by serious membrane fouling, especially biofouling. For the first time, this work investigated the effect of pH, temperature and sugar concentration on the growth of L. mesenteroides subsp. dextranicum, which is a main bacterium consisting in cane juice leading to serious biofouling during decoloration of cane juice by nanofiltration (NF). It was found that acidic pH, lower temperature and sucrose concentration increased bacterial growth, and more dextran was produced at faster bacterial growth, resulting in severer fouling during membrane filtration. Biofouling behavior and enzymatic/chemical cleaning efficiency were compared in dead-end and cross-flow filtrations of synthetic solution or cane juice (in virtue of membrane fouling resistance, permeate flux decline, permeability recovery, surface morphology and chemistry characterizations), showing that dextran was not only the main foulant but also the adhesive among the other foulants as well as between foulants and membrane. Moreover, a compact dextran layer would cover or enwrap other foulants such as protein, pigments, cell debris and bacteria, protecting them from chemical cleaning. Therefore, the dextranase degradation followed by an alkaline cleaning with surfactant was the most effective strategy to remove the biofouling layer and recover the membrane permeability. This work not only elucidated the fouling mechanisms during decoloration of cane juice by NF, but also offered an effective cleaning strategy for biofouling control in the practical application.
Brazil is a country with extensive agricultural production and a prolific exporter of agricultural commodities. Massive harvests lead to considerable biomass waste generation, all of which represents a significant energy generating potential that could be better utilized. Currently, most bioelectricity production in Brazil is derived from sugar cane bagasse. With the aim of contributing to Brazilian bioenergy initiatives and development, this study assesses the potential for electrical energy generation from three agricultural byproducts generated in large quantities: rice straw, sugar cane straw, and coffee husks. The investigation for bioenergy potential determination was carried out considering the direct combustion of 100\% of these materials in every Brazilian municipality that registers rice, sugar cane or coffee cultures. Statistical analysis and potential maps were constructed using these data. The results revealed a total generated potential of 15 GW (105.1 TWh/y) from these three residues, with around 90\% originating from sugar cane. The southeast region showed the greatest potential for sugar cane and coffee cultivation, while the most significant potential for rice cultivation is mainly located throughout the South and Central-West regions of the country.
The effects of harvesting methods were evaluated on losses and damage in sugarcane after harvesting. The IAC86-2480 cultivar was evaluated, in its third cut, in November, 2006. Three herbage harvesting methods were evaluated: manual cutting, mechanical cutting using a harvester and mechanical followed by manual cutting. After harvesting, the material was weighed and separated into fractions of stalks, green leaves and straw. The damage under sugarcane ratoons was evaluated by counting of the number of damaged stalks, uprooted stalks and whole plants left on the central lines of the plot. Treatments were assigned to experimental units (136.5 m(2)) according to a complete randomized block design, with six replications. The harvested yield and total biomass available were 80.7 t/ha and 90.3 t, respectively (average data). The total losses were higher for the mechanical followed by manual cutting as herbage harvesting method, representing 18.5\% of the total harvested biomass. However, when compared on a DM basis, there were no differences among herbage harvesting methods. The quantitative and relative losses of green leaves and straw were similar among herbage harvesting methods. There was difference among herbage harvesting methods for stalk fraction, showing relative loss values of 1.5\% for manual cutting, 7.6\% for mechanical cutting, and 12.7\% for mechanical followed by manual cutting, in relation to the harvested yield. The number of damaged and uprooted stalks was higher for mechanical followed by manual cutting as herbage harvesting method. The mechanical method significantly increased the number of plants left in the field. Due to the lower losses generated by the mechanical cutting using a harvester followed by manual cutting (up to 8\% on DM basis) than the manual method, the performance of the mechanical harvesting method ( with or without manual cutting after arvesting) is considered satisfactory.
The effects of straw retention on soil bacterial community structure, microbial function, and biochemical properties were assessed. Terminal restriction fragment length polymorphism (T-RFLP) and community-level physiological profile (CLPP) assays were used to assess the bacteria community structure and microbial function respectively. Treatments included straw removal with conventional tillage (CT), straw retention with conventional tillage (SRCT) and straw retention with no tillage (SRNT). SRCT and SRNT significantly (p < 0.05) increased soil organic carbon by 8.9\% and 9.7\%, and microbial biomass carbon by 44.7\% and 330.8\%, respectively, compared with CT. T-RFLP analysis indicated that straw retention had no favourable effect on soil bacterial diversity, and SRCT significantly (p < 0.05) decreased bacterial diversity compared to CT. Among the three treatments, SRNT had the highest activity of urease, invertase, cellulase, and beta-glucosidase. SRCT significantly (p < 0.05) increased the activity of invertase and beta-glucosidase compared to CT treatment. CLPP analysis showed that microbial functional diversity was significantly (p < 0.05) increased by straw retention. Enzyme activity and microbial functional diversity were not correlated with bacterial diversity. Therefore, according to this study, SRNT is a better farming practice because it improves soil fertility and biological quality.
In the growing polymer industry, the interest of researchers is captivated by bioplastics production with biodegradable and biocompatible properties. This study examines the polyhydroxyalkanoates (PHA) production performance of individual Lysinibacillus sp. RGS and Ralstonia eutropha ATCC 17699 and their co-culture by utilizing sugarcane bagasse (SCB) hydrolysates. Initially, acidic (H2SO4) and acidified sodium chlorite pretreatment was employed for the hydrolysis of SCB. The effects of chemical pretreatment on the SCB biomass assembly and its chemical constituents were studied by employing numerous analytical methods. Acidic pretreatment under optimal conditions showed effective delignification (60\%) of the SCB biomass, leading to a maximum hydrolysis yield of 74.9 +/- 1.65\% and a saccharification yield of 569.0 +/- 5.65 mg/g of SCB after enzymatic hydrolysis. The resulting SCB enzymatic hydrolysates were harnessed for PHA synthesis using individual microbial culture and their defined co-culture. Co-culture strategy was found to be effective in sugar assimilation, bacterial growth, and PHA production kinetic parameters relative to the individual strains. Furthermore, the effects of increasing acid pretreated SCB hydrolysates (20, 30, and 40 g/L) on cell density and PHA synthesis were studied. The effects of different cost-effective nutrient supplements and volatile fatty acids (VFAs) with acid pretreated SCB hydrolysates on cell growth and PHA production were studied. By employing optimal conditions and supplementation of corn steep liquor (CSL) and spent coffee waste extracted oil (SCGO), the co-culture produced maximum cell growth (DCW: 11.68 and 11.0 g/L), PHA accumulation (76\% and 76\%), and PHA titer (8.87 and 8.36 g/L), respectively. The findings collectively suggest that the development of a microbial co-culture strategy is a promising route for the efficient production of high-value bioplastics using different agricultural waste biomass.
Addition of 1.5\% propionic/formic acid (1:1) prevented degradation of crab-processing waste for up to 14 days. The preserved waste was ensiled with wheat straw, sugarcane molasses, and water (32:32:16:20, wet basis) with or without 0.1\% microbial inoculant. Reductions in pH and water soluble carbohydrates (WSC) and an increase in lactic acid were achieved in silages made with or without inoculant. Preserving crab waste with either 0.2\% sodium hypochlorite (NaOCl) or 0.4\% hydrogen peroxide (H2O2) prevented deterioration for up to 7 days. The concentration of trimethylamine (TMA), which indicates offensive odor in marine products, increased (P < 0.05) from 3.70 to 12.85 mg of N/100 g in NaOCl-treated waste, compared to no change (2.66 vs 2.71 mg of N/100 g) for H2O2-treated waste. The use of 1\% sodium nitrite (NaNO2) and a combination of 0.2\% NaOCl/0.2\% calcium hypochlorite {[
Three green solvents were tested for lipid extraction based on the Bligh and Dyer method. Lipids from the microalgae Chlorella pyrenoidosa were extracted through the tertiary systems 2-methyltetrahydrofuran:isoamylalcohol:water (1:3, 1:2, 1:1, 2:1, 3:1 v/v) and 2-methyltetrahydrofuran:ethanol:water (3:1 v/v). For comparative effect, extractions with chloroform:methanol:water (3:1, 2:1, 1:1, 1:2, 1:3 v/v), with binary systems 2-methyltetrahydrofuran:water, isoamyl alcohol:water, chloroform:water, n-hexane:water, and monophasic systems 2-methyltetrahydrofuran (2-MeTHF), isoamyl alcohol, chloroform and n-hexane were used. The Bligh and Dyer method using green solvents was highly efficient, although some undesirable components were extracted, especially when larger volumes of isoamyl alcohol were used. System 2-MeTHF:ethanol:water formed only a biphasic system when it was used in a 3:1 (v/v) proportion, obtaining 64\% of fatty acids. The chloroform:methanol (1:2 v/v) system extracted 122.2 +/- 1.9 mg g(-1), in which 92.4\% consisted of fatty acids. In systems using green solvents, the extractions with the system 2-MeTHF:isoamyl alcohol (2:1 v/v) achieved a 78\% selectivity (99.6 +/- 7.6 mg g(-1) of fatty acids) and an 88.2\% efficiency when compared with the reference system chloroform:methanol 1:2 (v/v).The fatty acids profile showed that extractions with 2-MeTHF:isoamyl alcohol had higher percentages of fatty acids with low degree of unsaturation, which is ideal for the production of better quality biodiesel. The results obtained suggest that 2-MeTHF:isoamyl alcohol (2:1 v/v) can replace the chloroform:methanol system currently used. M an industrial level, this system still requires some technical improvements related to the energy expenditure for solvent evaporation, and at an economic level, the high price of the 2-MeTHF makes the process impracticable compared with hexane.
Profiling the transcriptome that underlies biomass degradation by the fungus Trichoderma harzianum allows the identification of gene sequences with potential application in enzymatic hydrolysis processing. In the present study, the transcriptome of T. harzianum IOC-3844 was analyzed using RNA-seq technology. The sequencing generated 14.7 Gbp for downstream analyses. De novo assembly resulted in 32,396 contigs, which were submitted for identification and classified according to their identities. This analysis allowed us to define a principal set of T. harzianum genes that are involved in the degradation of cellulose and hemicellulose and the accessory genes that are involved in the depolymerization of biomass. An additional analysis of expression levels identified a set of carbohydrate-active enzymes that are upregulated under different conditions. The present study provides valuable information for future studies on biomass degradation and contributes to a better understanding of the role of the genes that are involved in this process.
Lentinus crinitus is a basidiomycete with the ability to produce laccase and other enzymes of biotechnological interest. Laccase production depends on cultivation conditions and can be induced by metallic, phenolic or aromatic compounds. This study aimed to evaluate the laccase production of L. crinitus cultivated in sugarcane vinasse and urea with addition of laccase inducers. L. crinitus was cultivated in sugarcane vinasse with urea and supplemented with copper sulfate (0, 50, 150, 250, 350 and 450 mu M) and aromatic compounds (guaiacol, veratryl alcohol, or 2,5-xylidine) added alone or combined to the cultivation medium. Cooper (150 or 250 mu M) increased laccase activity in 14.5 (49,000 U/L) and 28.5\% (55,000 U/L), respectively. Guaiacol had no significant effect, but veratryl alcohol (similar to 46000 U/L) and xylidine (similar to 75000 U/L) increased laccase activity. Copper with other inducers had the most relevant effects on laccase production. Simultaneous guaiacol addition with 150 or 250 mu M copper increased 108\% and 151\% laccase activity, respectively, when compared with only copper addition to vinasse-urea medium. Veratryl alcohol and 150 or 250 mu M copper addition increased 100\% and 138\% laccase activity, respectively, when compared to only copper addition. Interaction analysis of the variables guaiacol or veratryl alcohol and copper (250 mu M) added to cultivation medium demonstrated synergistic effects resulting in laccase activity increase. These results highlight the importance of L. crinitus as a laccase producer and emphasize the relevance of studies using a combination of inducers to increase laccase production.
This study evaluated a novel three-stage process devoted to the cascade production of lactate, biohydrogen and methane from tequila vinasse (TV), with emphasis on attaining a high and stable biohydrogen production rate (HPR) by utilizing lactate as biohydrogen precursor. In the first stage, tailored operating conditions applied to a sequencing batch reactor were effective in sustaining a lactate concentration of 12.4 g/L, corresponding to 89\% of the total organic acids produced. In the second stage, the stimulation of lactate-centered dark fermentation which entails the decoupling of biohydrogen production from carbohydrates utilization was an effective approach enabling stable biohydrogen production, having HPR fluctuations less than 10\% with a maximum HPR of 12.3 L/L-d and a biohydrogen yield of 3.1 L/L-TV. Finally, 1.6 L CH4/L-d and 6.5 L CH4/L-TV were obtained when feeding the biohydrogen fermentation effluent to a third methanogenic stage, yielding a global energy recovery of 267.5 kJ/L-TV.
In this study, the potential integration of steam explosion (StEx) and ammonia fiber expansion (AFEX) with existing sugar/ethanol mills to form decentralized pre-processing depots was explored. Both StEx and AFEX pretreatment facilitated the production of sugarcane bagasse (SCB) and cane leaf matter (CLM) pellets with significantly higher bulk density, mechanical durability, and hydrophobicity relative to their untreated biomass pellet controls. However, ethanol production from standalone StEx and AFEX-treated SCB and CLM pellets required enzyme dosages greater than 21 mg/g glucan to achieve enzymatic hydrolysis sugar yields of 75\% and ethanol titres greater than 40 g.L-1. Coupling AFEX-treated SCB or CLM pellets with a room temperature CIIIIactivation step using liquid ammonia lowered enzyme dosage requirements by more than 50\% without affecting ethanol titers and production yields (greater than300 L per Mg residual dry matter raw dry biomass (RDM)). In contrast, treating StEx-treated pellets with CIIII-activation using liquid ammonia did not result in similar enzyme dosage reductions, due to pseudo-lignin formation, leading to enzyme deactivation and/or lignin blockage that retarded enzymatic hydrolysis at low enzyme dosages. A gross energy conversion assessment revealed that low enzyme dosage (3-4 mg enzyme/g RDM) ethanol and electricity co-production from AFEX and CIIII-activated SCB and CLM can recover up to 73\% of the energy in the untreated biomass, compared to 54\% recovered by StEx and CIIII-activation. The results from this work suggest that StEx or AFEX based pre-processing depots can produce dense and mechanically durable biomass pellets. The AFEX-treated pellets can be easily upgraded using a room temperature CIIII-activation step at the biorefinery to significantly reduce bioconversion enzymes.
The balance between sunscreen performance and color is a main obstacle in the preparation of high-quality lignin-based sunscreens. In this study, five lignin samples (i.e., NaOH-L, EG-L, G-L, 1,3-PDO-L, and 1,4-BDO-L) are extracted from sugarcane bagasse by using five different solvent systems. The lignin extracted by organic solvents clearly shows light color and excellent UV-shielding performance, and the 1,3-PDO-L sample reveals the lowest total color difference (Delta E is 30.4) and highest sun protection factor (SPF 3.99) among the samples obtained. The SPF of commercial facial creams significantly increases after addition of 5 wt\% lignin samples, and the colors of these creams are lighter than that of 10 wt\% lignin-modified cream samples. Moreover, the lignin-modified creams exhibit excellent broad-spectrum UV absorbency. The synergistic effects of lignin and the active substances of commercial sunscreen dramatically enhance the UV shielding effect of the commercial sunscreen. The aging test confirms that the lignin-based sunscreens have good photostability. This study provides a reliable reference for the development of lignin-based sunscreens and high-value utilization of lignin.
The Streptomyces spp. are notorious plant biomass decomposers in soil environments, but only few strains were biochemically and genetically characterized. Here, we employed functional screening along with genomic sequencing for identification of novel lignocellulolytic Streptomyces strains. Streptomyces strains isolated from soil were functional screened based on their cellulolytic and hemicellulolytic capacities by enzymatic plate assays containing carboxymethylcellulose (CMC) and beechwood xylan as sole carbon source. Subsequently, genomes of Streptomyces strains were sequenced, annotated, and interpreted to correlate their genetic contents with biochemical properties. Among the 80 bacterial isolatesthat werescreened forenzymatic activity, two Streptomyces strains (named asF1 and F7) exhiting higher endoglucanase and endoxylanase activities were selected for biochemical and genomic characterization. After cultivation on steam-pretreated sugarcane bagasse-based medium, the supernatant of the strains F1 and F7 exhibited enzymatic activity against different substrates, such asarabinan, rye arabinoxylan, -glucan, starch, CMC, xylan, and chitin. Furthermore, strain F7 was able to degrade pectin, mannan, and lichenan. The genomic analysis of both strains revealed a diversity of carbohydrate-active enzymes. The F1 and F7 genomes encode 33 and 44 different types of glycosyl hydrolases families, respectively. Moreover, the genomic analysis also identified genes related to degradation of lignin-derived aromatic compounds. Collectively, the study revealed two novel Streptomyces strains and further insights on the degradation capability of lignocellulolytic bacteria, from which a number of technologies can arise, such as saccharification processes.
To obtain high-yield production of 2,3-butanediol (2,3-BD) from glucose, we optimized the culture conditions for a lactate dehydrogenase-deficient mutant (Delta ldhA) of Klebsiella pneumoniae using response surface methodology. 2,3-BD production was successfully improved by optimizing pH (5.6), aeration (3.50 vvm) and concentration of corn steep liquor (45.0 mL/L) as a nitrogen source, resulting in a maximum level of 2,3-BD production of 148.8 g/L and productivity of 2.48 g/L/h. 2,3-BD was also obtained with high concentration (76.24 g/L) and productivity (2.31 g/L/h) from the K. pneumoniae mutant strain using sugarcane molasses as a carbon source.
To meet the increasing needs of fuels, especially non-fossil fuels, the production of ``bio-oil{''
The pyrolysis of sugarcane bagasse derived-humins (H-SCB) was evaluated in this work by considering inde-pendent, overlapping, or competing multistep reactions. An eight-stage parallel reaction model was used in the thermokinetic analysis. The most appropriate kinetic mechanism determined by the master-plot method showed that the second sub-stage proceeds via a 4th-order chemical reaction and the other steps are controlled by nucleation. Based on mathematical calculations, six consecutive-competitive reactions were studied and the modified Kilzer-Broido model was the most relevant to represent the pyrolysis of H-SCB. The kinetics is influ-enced by the reactivity of H-SCB in two parallel n-order reactions (n = 6.28 to volatile compounds and n = 1.35 to intermediate product). Diffusion-controlled reaction governed the secondary stage in the conversion to bio-char. Competitively, nuclei growth occurs and the intermediate product decomposes into volatile products. By using multistep reactions to account for pyrolysis products, the predicted kinetic profiles agreed well with the experimental data.
Sugarcane silage (SS) is generally susceptible to yeast action, resulting in dry matter losses due to high soluble carbohydrate concentration. We evaluated the effects of adding corn grain and microbial inoculant at ensiling on fermentative profile, losses, chemical composition and degradation of silages. Forty experimental silos (PVC tubing) were assigned at random to a 5 x 2 factorial arrangement with: (1) 5 corn additions at ensiling: CONT - straight sugarcane silage; GC2 - sugarcane with ground corn (processed through a 2 mm sieve) added at ensiling; GC8 - sugarcane with ground corn (processed through an 8 mm sieve) added at ensiling; WC - sugarcane with whole corn grain added at ensiling; and RCS - rehydrated corn ensiled without sugarcane; and (2) 2 microbial inoculant additions at ensiling : 0 and 8 mg of commercial inoculant per kg of feed. Corn grain was added at the rate of 100 g per kg of fresh sugarcane. Adding corn grain to sugarcane at ensiling improved SS fermentation and silage chemical composition. There was no benefit from grinding the grain before adding it to sugarcane. Microbial inoculant had little effect on SS fermentation. Studies comparing corn grain with other energy sources, e.g. molasses or cassava, for addition at ensiling sugarcane seem warranted along with feeding studies with livestock to assess intake and subsequent performance. The overall benefits of adding the energy sources at ensiling versus feeding them directly to animals with untreated sugarcane silage should be determined.
The objective of this work was to assess the lethal concentration and lethal time (LC and LT) of spinosad and spinetoram, combined with different food lures, and their residual effects on South American fruit fly (Anastrepha fraterculus). The toxic baits were offered in eight concentrations (2, 6, 14, 35, 84, 204, 495, and 1,200 mg L-1), combined with the following food lures: 7\% sugarcane molasses, 3\% Biofruit, 1.5\% CeraTrap, 1.25\% Flyral, 3\% Samarita Bait, and 3\% Samarita Tradicional; diluted food lures in water were used as controls. The residual effect of the formulations at 96 mg L-1 concentration were evaluated for 21 days and were compared with that of the commercial bait Success 0.02 CB. Both insecticides were toxic to adults of A. fraterculus, and mortality varied with the food lure used. The LC50 and LT50 ranged from 15.19 to 318.86 mg L-1 and from 11.43 to 85.93 hours, respectively. Spinosad was 2 to 36 times as toxic as spinetoram when combined with different hydrolyzed proteins. Toxic baits formulated with spinosad and spinetoram (96 mg L-1) caused mortality equivalent to the one by Success 0.02 CB (90.2\%), when assessed on the day of application. Toxic baits formulated with 3\% Biofruit + spinosad and 3\% Samarita Bait + spinetoram are effective for managing A. fraterculus and provide up to seven days of residual effect in the absence of rain; however, only Success 0.02 CB caused more than 80\% mortality for up to 21 days.
Brazil is one of the world's largest producers of alcohol from biomass at low cost and is responsible for more than 1 million direct jobs. In 1973, the Brazilian Program of Alcohol (Proalcool) stimulated the creation of a bioethanol industry that has led to large economic, social, and scientific improvements. In the year 1984, 94.5\% of Brazil's cars used bioethanol as fuel. In 2003/2004, 350.3 million of sugarcane produced 24.2 million t of sugar and 14.4 billion L of ethanol for an average 4.3 million cars using ethanol. Since its inception, cumulative investment in Proalcool totals US\$11 billion, and Brazil has saved US\$27 billion in oil imports. The ethanol production industry from sugarcane generates 152 times more jobs than would have been the case if the same amount of fuel was produced from petroleum, and the use of ethanol as a fuel is advantageous for environmental reasons. In 2003, one of the biggest Brazilian ethanol industries started consuming 50\% of the residual sugarcane bagasse to produce electrical energy (60 MW), a new alternative use of bioenergy for the Brazilian market. Other technologies for commercial uses of bagasse are in development, such as in the production of natural fibers, sweeteners (glucose and xylitol), single-cell proteins, lactic acid, microbial enzymes, and many other products based on fermentations (submerged and semisolid). Furthermore, studies aimed at the increase in the biosynthesis of sucrose and, consequently, ethanol productivity are being conducted to understand the genetics of sugarcane. Although, at present, there remain technical obstacles to the economic use of some ethanol industry residues, several research projects have been carried out and useful data generated. Efficient utilization of ethanol industry residues has created new opportunities for new value-added products, especially in Brazil, where they are produced in high quantities.
The distribution of products from the slow heating rate pyrolysis of coal, corn residues (cobs and stover), sugarcane bagasse and their blends were investigated by slow pressurized pyrolysis in a packed bed reactor. A factorial experimental design was implemented to establish the relative significance of coal-biomass mix ratio, temperature and pressure on product distribution. Results showed that the yield and composition of tar and other volatile products were mostly influenced by mix ratio, while temperature and pressure had a low to negligible significance under the range of conditions investigated. Analysis of the composition of condensates and gas products obtained showed that there was significant synergy or chemical interactions in the vapor phase during co-pyrolysis of coal and biomass. However, the interactions did not significantly affect the relative distribution of the lumped solid, liquid and gas products obtained from the blends, beyond what would be expected assuming additive behavior from the contributing fuels. (C) 2012 Elsevier Ltd. All rights reserved.
Cellulose-based materials are the most widely used green materials because of their abundance, sustainability, biodegradability, and functionalizability. The capability of cellulosic materials as adsorbents and coagulants to remove negatively charged contaminants from water requires the possession of a positively charged functionality. In this study, cationic dialdehyde cellulose (c-DAC) nanofibers with three different degrees of oxidation were created by preparing metaperiodate-oxidized cellulose followed by cationization using Girard's reagent T. The resulting c-DAC was applied for the removal of hexavalent chromium (Cr(VI)) ions from water, where the efficiency was evaluated as functions of the initial chromium concentration, adsorption time, pH value, and co-existing anions. It was found that all c-DAC samples showed excellent adsorption efficiencies against Cr(VI), where the c-DAC with the highest charge density exhibited the maximum adsorption capacity of 80.5 mg/g. The Cr(VI) adsorption mechanism is found to be dominated by the electrostatic interactions between the quaternary ammonium cations on the c-DAC surface and Cr(VI) ions and can be best described using the Langmuir model. These samples also exhibited stable adsorption capacity in a wide pH range, where the c-DAC surface could remain positively charged.
PurposePoor structure, nutrient deficiency, and acidification are core factors restricting the reclamation of rare earth mining wasteland soil (REMWS). Sewage sludge, bagasse, and molybdenum tailings, all of which need proper disposal, have great potentials in REMWS reclamation. The goal of this study was to explore the remediation effect on rare earth mining wasteland soil with the combined application of sewage sludge compost (SSC), bagasse, and modified molybdenum tailings (MMT).Materials and methodsSSC (T1), SSC + bagasse (T2), and SSC + bagasse + MMT (T3) were applied in REMWS as amendments in a 4-month pot experiment, and their effects on REMWS properties and heavy metals (HMs) toxicity were tested with Eucalyptus urophylla, which grows fast, resists environment stress, and is a promising plant in REMWS reclamation.ResultsThe application of SSC (T1) improved REMWS fertility, but increased Cu, Zn, Cd, and Ni contents in soil and E. urophylla seedlings, and inhibited E. urophylla growth. Bagasse application (T2) alleviated growth inhibition and further addition of bagasse + MMT (T3) significantly improved E. urophylla growth. Moreover, T3 improved soil physical properties, organic carbon content, pH, and reduced soil HMs bioavailability and plant HMs content as compared to T1 and T2. Structural equation modeling results revealed that plant nutrient accumulation increased plant HMs accumulation, the latter inhibited plant nutrient accumulation in turn, and soil pH played a key role in retarding HMs uptake and improving E. urophylla growth and nutrients uptake.ConclusionThese results suggested that the combined application of SSC, bagasse, and MMT is an effective approach for REMWS amelioration and land disposal of solid waste resources.
Replacing fossil fuels with an economically viable green alternative at scale has proved most challenging in the aviation sector. Recently sugarcane, the most productive crop on the planet, has been engineered to accumulate lipids. This opens the way for production of far more industrial vegetable oil per acre than previously possible. This study performs techno-economic feasibility analysis of jet fuel production from this new cost efficient and high yield feedstock. A comprehensive process model for biorefinery producing hydrotreated jet fuel (from lipids) and ethanol (from sugars), with 1 600 000 MT yr(-1) lipid-cane processing capacity, was developed in SuperPro Designer. Considering lipid-cane development is continuing for higher oil concentrations, analysis was performed with lipid-cane containing 5\%, 10\%, 15\%, and 20\% lipids. Capital investments for the biorefinery ranged from 238.1 to 351.2 million USD, with jet fuel capacities of 12.6-50.5 million liters (correspondingly ethanol production of nil to 102.6 million liters). The production cost of jet fuel for different scenarios was estimated \$0.73 to \$1.79 per liter (\$2.74 to \$6.76 per gal) of jet fuel. In all cases, the cost of raw materials accounted for more than 70\% of total operational cost. Biorefinery was observed self-sustainable for steam and electricity requirement, because of in-house steam and electricity generation from burning of bagasse. Minimum fuel selling prices with a 10\% discount rate for 20\% lipid case was estimated \$1.40/L (\$5.31/gal), which was lower than most of the reported prices of renewable jet fuel produced from other oil crops and algae. Along with lower production costs, lipid-cane could produce as high as 16 times the jet fuel (6307 L ha(-1)) per unit land than that of other oil crops and do so using low-value land unsuited to most other crops, while being highly water and nitrogen use efficient.
The extracted sugarcane molasses-melanoidins showed the presence of Mn (8.20), Cr (2.97), Zn (16.61), Cu (2.55), Fe (373.95), Pb (2.59), and Ni (4.18 mg L-1) along with mixture of other organic compounds which have endocrine-disrupting chemicals (EDCs) properties. A consortium of aerobic bacteria comprising Klebsiella pneumoniae (KU321273), Salmonella enteric (KU726954), Enterobacter aerogenes (KU726955), and Enterobacter cloacae (KU726957) showed the optimum decolourisation of molasses-melanoidins up to 81\% through co-metabolism in the presence of glucose (1.0\%) and peptone (0.2\%) as a carbon and nitrogen source, respectively. The absorption spectrum scanning by UV-visible spectrophotometer between 200 and 700 nm revealed reductions of absorption spectrum of organic compounds present in bacterial degraded sample of melanoidins in range of 200-450 nm compared to control. The degradation and decolourisation of melanoidins by bacterial consortium was noted by induction of manganese peroxidase and laccase activities in sample supernatant. Furthermore, the TLC and HPLC analysis of bacterial decolourised melanoidins also showed degradation and reduction of absorption peak at (295 nm), respectively. Furthermore, FT-IR and GC-MS analysis also showed the change of functional group and disappearance of ion peaks. This indicated the degradation and depolymerisation of melanoidins and cleavage of C=C, C=O and C N conjugated bonds which resulted in reduction of colour. The metabolic analysis also showed the disappearance of some organic compounds and generation of new metabolites. Furthermore, the seed germination test using Phaseolus mungo L. showed toxicity reduction in decolourized effluent.
The production of n-butanol from sugarcane juice by metabolically engineered Clostridium tyrobutyricum Ct(Delta ack)-pscrBAK overexpressing scr operon genes (scrB, scrA, and scrK) for sucrose catabolism and an aldehyde/alcohol dehydrogenase gene (adhE2) for butanol biosynthesis was studied with corn steep liquor (CSL) as a low-cost nitrogen source. In free cell fermentation, butanol production of similar to 16 g/L at a yield of 0.31 +/- 0.02 g/g and productivity of 0.33 +/- 0.02 g/L.h was obtained from sucrose and yield of 0.24 +/- 0.02 g/g and productivity of 0.30 +/- 0.01 g/L.h from sugarcane juice containing sucrose, glucose and fructose. The fermentation was also studied in a fibrous bed bioreactor (FBB) operated in a repeated batch mode for 10 consecutive cycles in 10 days, achieving an average butanol yield of 0.21 +/- 0.02 g/g and productivity of 0.53 +/- 0.05 g/L.h from sugarcane juice, demonstrating its long-term stability without applying the antibiotic selection pressure. (C) 2017 Elsevier Ltd. All rights reserved.
The sugarcane bagasse is a heterogeneous material and needs a pretreatment to breakdown its complex structure to make cellulose accessible to enzyme action. This study aimed to evaluate pseudo-lignin formation, enzymatic hydrolysis of sugarcane fractions (leaf, external fraction, internode, and node), and bagasse after partial delignification and acid pretreatment. The leaf and external fraction presented the highest content of lignin, and external fraction was the most recalcitrant material resulting in lower glucose release. Pretreatment with diluted sulfuric acid (20\% m/m or 2\% m/v) generated 5 g/L of acetic acid and 2.07 g/L of 5-hydroxymethylfurfural (external fraction in natura and leaf extractive-free, respectively). Furfural ranged between 0.11 g/L (node delignified) and 0.06 g/L (leaf, external fraction, and node in natura). A decrease was observed in pseudo-lignin formed with extractive-free and delignified biomasses, with different structure compared with non-delignified samples. The biomass partial delignification and subsequent pretreatment with dilute acid generate a material with fragmented anatomical structure, with improved cellulose accessibility, favoring enzymatic hydrolysis achieving more than 90\% of glucose yield (up to 12 g/L). This study has shown strategies to decrease material heterogeneity and avoid pseudo-lignin formation as it results in lower recalcitrance and better efficiency of the enzymatic hydrolysis.
The aim of the present study was to develop a suitable pretreatment method to enhance the microbial degradation of lignocellulosic biomass and to maximize the overall energy recovery by using biohythane process. An efficient and eco-friendly biological pretreatment was used. Maximum lignin removal using biological pretreatment of sugarcane top was 60.4\% w/w after 21 d incubation at 28 degrees C in static condition. Confocal microscopy observation and FTIR analysis confirmed the removal of lignin from sugarcane top. The maximum hydrogen production rate (R-m), hydrogen production potential (P) and lag time (lambda) using pretreated sugarcane top were 16.76 mL/g-VS/h, 87.40 mL/g-VS and 3.38 h respectively. The maximum methane production potential using spent medium of dark fermentation was 180.86 mL/g-VS with the lag time of 2.9 d. The overall gaseous energy recovery was 37.7\% which is 54\% higher than that of the untreated one. (C) 2016 Elsevier Ltd. All rights reserved.
The significant physical, economic and environmental properties of some agricultural wastes have made them viable alternatives for the conventional sound-absorbing materials. Therefore, it is necessary to identify these types of agricultural wastes and investigate the acoustic behavior and applicability of mathematical predictive models for sound absorption of the samples fabricated from such wastes. In this regard, this study was conducted to investigate the sound absorption coefficient (SAC) values of the samples made from sugarcane and corn husk wastes using experimental and empirical methods. The morphological examination of sugarcane and corn husk fibers was performed by Field emission scanning electron microscopy (FESEM). Having prepared the fibers, several cylindrical samples with a constant density (150 kg/m3) and different thicknesses (20, 30 and 40 mm) were fabricated. The SAC values, porosity and airflow resistivity of these samples were then measured using ISO 10534-2 (impedance tube system), SEM and ASTM C522-03, respectively. The Delany-Bazley (DB) analytical model and the reversed Delany-Bazley model with Nelder-Mead Simplex (DB-NMS) were also used to predict the SAC values. Based on the acoustic performance of the fabricated samples, the SAC values for the thickness of 40 mm and frequency of 500 Hz were, respectively, 0.42 and 0.54 for sugarcane and corn. Increasing the thickness of the samples and creating an air gap behind them were found to be the acceptable approaches for improving the sound absorption. It was found that the DB-NMS model would appropriately follow the experimental results. The purposeful application of agricultural waste and analytical acoustic models because of their outstanding benefits and an effective approach will encourage the usability of natural materials (as eco-friendly, cheap and efficient acoustic products) in indoor and outdoor commercial applications.
Trichoderma atroviride 676 was studied to evaluate its efficiency in the production of some lignocellulolytic enzymes, using lignocellulosic residual biomass. Best results were obtained when 3.0 \% (w/v) untreated sugarcane bagasse was used (61.3 U mL(-1) for xylanase, 1.9 U mL(-1) for endoglucanase, 0.25 U mL(-1) for FPase, and 0.17 U mL(-1) for beta-glucosidase) after 3-4 days fermentation. The maximal enzymatic activity for endoglucanase, FPase, and xylanase were observed at 50-60 A degrees C and pH 4.0-5.0, whereas thermal stability at 50 A degrees C (CMCase and FPase) or 40 A degrees C (xylanase) was obtained after 8 h. Zymograms have shown two bands of 104 and 200 kDa for endoglucanases and three bands for xylanase (23, 36, and 55.7 kDa). The results obtained with T. atroviride strain 676 were comparable to those obtained with the cellulolytic strain Trichoderma reesei RUT-C30, indicating, in the studied conditions, its great potential for biotechnological application, especially lignocellulose biomass hydrolysis.
The implications of bioenergy deployment for sustainable development goals (SDGs) have been gaining importance worldwide, as bioenergy may contribute to other sustainability impacts besides climate change. Decarbonization of the energy sector can promote major co-benefits between Climate Action and other SDGs and lead to important tradeoffs. Life cycle assessment (LCA) methods have been proposed to monitor the SDGs as many of them are closely interconnected but often separately studied. A harmonized application of environmental and social LCA can reveal additional relevant aspects of SDGs. This work proposes an interpretation of combined environmental and socioeconomic LCA impacts by comparing the SDG impacts of electricity from sugarcane biomass with other technological options, which altogether represent 96\% of the Brazilian electricity matrix. Our analysis indicates that sugarcane electricity has a higher SDGs score (58 points) compared to coal and oil electricity (42 and 47 points, respectively); however, it is lower than natural gas (78). Sugarcane SDG internal normalization related to the biosphere is very close to natural gas, varying only 3-4 points. On the Economy and Society SDG score, sugarcane electricity is also lower than natural gas. Key areas in sugarcane electricity production that need to be enhanced to better contribute to achieving the SDGs include improving its awareness levels, increasing wages and women representation on the workforce, and promoting measures to decrease work accidents as well as the use of fertilizers and pesticides. This approach may help design specific measures for different value chains for them to significantly contribute to the achievement of SDGs.
In present work, mustard straw, an abundantly available agricultural residue in various parts of globe, is used to prepare a low-cost activated carbon by chemical activation using phosphoric acid. Response surface methodology is employed for optimization of adsorption of methylene blue dye onto mustard straw-activated carbon (MSAC). Central composite design is employed to evaluate the effect of three production variables namely activation temperature (400-800 degrees C), activation time (60-120 min), and impregnation ratio (2-7), on adsorption capacities of activated carbon to maximize methylene blue dye removal from its aqueous solution. Among the three process variables, activation time showed prominent effect on the response whereas the effect of activation temperature was relatively less significant on adsorption capacity of MB. The optimum conditions obtained for MSAC are activation temperature, 768 degrees C; activation time, 60 min; and impregnation ratio, 4.2, which leads to 198 mg g(-1) adsorption capacity of methylene blue. The model predicted and experimental value for response were highly comparable. Characterization of MSAC was done using several analytical techniques such as Fourier transform infrared spectroscopy and field emission scanning electron microscopy techniques, and reusability up to five adsorption-desorption cycles was tested. The results showed that MSAC obtained has highly porous structure comparable with activated carbon obtained from other biomass feed stocks.
Silicon (Si) could contribute to maintaining nutrient uptake, above-ground and root system biomass, enhancing sugar yield in sugarcane under water deficit at the ripening phase, but results are still scarce. This study aims to determine whether water deficit during the ripening phase causes deleterious effects on the biomass of green leaf, straw, stalk, and root system, nutrient uptake, and sugar accumulation of two drought-contrasting sugarcane cultivars, and whether Si alleviates these effects. An experiment was conducted in pots under greenhouse conditions using a randomized factorial design with two sugarcane cultivars (RB86-7515; RB85-5536), two Si rates (equivalent to 0 and 1000 kg ha(-1) Si) as silicate, and the absence (well-watered, WW) or presence of water deficit (WD) during the ripening phase. There was an independent effect of water deficit, cultivar, and Si in soil on plant results. Water deficit decreased concentrations of Si, Ca, Fe, and B in leaves, leaf biomass by 19\%, and sugar content by 27\%. RB85-5536 showed the highest concentrations of Si, Ca and lower leaf biomass. Si increased soluble Si, base saturation in soil, Si, and Mg in plant, and sugar by 30\%, and reduced Fe, and B in the root, straw by 7.3\%, stalk biomass by 9.8\%. The effects of water deficit were not intense at the ripening phase and caused decreased leaf biomass and enhanced sugar accumulation. Si, in turn, contributed to decreased straw biomass because of Si deposition, maintenance of green leaves, and increased sugar production with or without water deficit.
Background: Xylitol is a five carbons polyol with promising medical applications. It can be obtained from chemical D-xylose reduction or by microbial fermentation of Sugarcane Bagasse Hemicellulosic Hydrolysate. For this last process, some microbial inhibitors, as furfural, constitute severe bottleneck. In this case, the use of strains able to produce xylitol simultaneously to furfural neutralization is an interesting alternative. A wild-type strain of Geotrichum sp. was detected with this ability, and its performance in xylitol production and furfural consumption was evaluated. Furthermore, were analyzed its degradation products. Results: Geotrichum sp. produced xylitol from D-xylose fermentation with a yield of 0.44 g.g(-1). Furfural was fully consumed in fermentation assay and when provided in the medium until concentration of 6 g.L-1. The furfural degradation product is not an identified molecule, presenting a molecular weight of 161 g.mol(-1), an uncommon feature for the microbial metabolism of this product. Conclusion: This strain presents most remarkable potential in performing furfural consumption simultaneous to xylitol production. Subsequent efforts must be employed to establish bioprocess to simultaneous detoxification and xylitol production by Geotrichum sp. (C) 2016 Pontificia Universidad Catolica de Valparaiso. Production and hosting by Elsevier B.V. All rights reserved.
Rice straw was pretreated with sodium hydroxide (NaOH) before subsequent use for succinate production by Escherichia coli KJ122 under simultaneous saccharification and fermentation (SSF). The NaOH pretreated rice straw was significantly enhanced lignin removal up to 95\%. With the optimized enzyme loading of 4\% cellulase complex + 0.5\% xylanase (endo-glucanase 67 CMC-U/g, beta-glucosidase 26 pNG-U/g and xylanase 18 CMC-U/g dry biomass), total sugar conversion reached 91.7 +/- 0.8\% (w/w). The physicochemical analysis of NaOH pretreated rice straw indicated dramatical changes in its structure, thereby favoring enzymatic saccharification. In batch SSF, succinate production of 69.8 +/- 0.3 g/L with yield and productivity of 0.84 g/g pretreated rice straw and 0.76 +/- 0.02 g/L/h, respectively, was obtained. Fed-batch SSF significantly improved succinate concentration and productivity to 103.1 +/- 0.4 g/L and 1.37 +/- 0.07 g/L/h with a comparable yield. The results demonstrated a feasibility of sequential saccharification and fermentation of rice straw as a promising process for succinate production in industrial scale.
Large amounts of agricultural residues are produced annually in the UK alone, which presents a significant biomass energy resource. It has limited availability in briquetted form in the UK but is widely used, particularly in Asia. The aim of this work is to assess the emission from briquetted agricultural residues to wood fuel, including commercial wood briquettes, when utilised in a 5 kW domestic heating stove. Other straw-type materials, sugarcane bagasse, Miscanthus, were also investigated. The combustion behaviour depended on the chemical and physical nature of the briquettes. Results indicate that fuel choice is an important consideration for emission reduction. Fuel-N directly correlates to emitted NOx and all the fuels studied had NOx emissions below the EU regulation limit. While agricultural residues can be relatively high in Cl and S, there is evidence of in-situ capture of HCl and SO2 by calcium salts in the fuel ash. Particulate emissions correlate with the volatile matter in the fuel, but also are influenced by the quality/durability of the briquette. The briquettes performed well compared to wood logs, and while there is a fuel-type influence on emissions, it is also clear that briquettes from optimised manufacture can be lower emitting than wood logs.
The most popular fly ash application as coal combustion energy waste is as a mixing agent for cemented infrastructure and building construction. However, due to its appropriate various mineral content from vegetation fossil, the usage for fertilizer and soil amelioration agent was tested in small pots on the field. The experiment's purpose was to confirm the effectiveness of fly ash granule application using tapioca flour and sugar cane molasses as granule agents for soil ameliorant and fertilizer. Specifically, for the sorghum growth, development, and potential bioethanol yield harvested in the vegetative stage. The granule binding agents' source is from an agricultural product, byproduct, or agricultural waste. Hence, environmental management and the fly ash granules' production system exhibit the advantage of a sustainable production system. The concentration of 10\% of the granule binding agents concentration for the application at a rate of 8 tons ha(-1) was effective enough to improve the soil properties, plant growth, and the doubling of potential bioethanol yield.
The waste sugarcane dry leaves were utilized as the reinforcement with the epoxy matrix to prepare the sugarcane dry leaves reinforced polymer composites (SDLRPCs). The tensile, compressive, impact and flexural tests were conducted following respective ASTM standards. The proportion of SDL in SDLRPCs for the most effective fiber-matrix interaction was determined. The statistical analysis has confirmed that the error in experimental results was within the specified limits. The resistance to natural weathering of SDLRPCs were evaluated following ASTM D5338-11. The effect of weathering on tensile strength was also investigated. The scanning electron microscopy (SEM) micrographs revealed reasons for fracture of SDLRPC samples during mechanical testing. It was noticed that the biodegradability corresponds with resistance to natural weathering; more biodegradable wood plastic composites were having the lesser resistance to natural weathering. The micromechanical finite element (FE) model coupled with the numerical homogenization technique (NHT) was constituted to predict the elastic properties of SDLRPCs. The micro-scale stress analysis revealed that the von Mises stress for SDLRPC was up to 267\% higher than the pure epoxy. The transient/static micro-mechanical models were constituted to predict the tensile, compressive, impact, and flexural behavior of SDLRPCs. The developed models were found in-line with the experimental data. (C) 2020 Elsevier Ltd. All rights reserved.
One of the key issues that must be addressed in the biofuel production based on sugarcane industry is the energy consumption of the process. Process energy demand has direct impact on the amount of lignocellulosic material available for use as feedstock for second generation ethanol production. A significant fraction of the energy consumption in bioethanol production occurs in the purification step, since conventional fermentation systems employed in the industry require low substrate concentration and, consequently, produce wine of low (around 8.5 degrees GL) ethanol content that must be distilled in order to meet product specifications. In this study alternatives to the conventional fermentation processes employed in the industry (low temperature fermentation and vacuum extractive fermentation) were assessed, in the context of a large scale sugarcane autonomous distillery, through computer simulation. Electricity consumption and lignocellulosic material surplus on each case were evaluated. It is shown that the alternative fermentation processes allow a significant reduction on vinasse generation and increases ethanol production when compared with conventional fermentation, but increases electricity consumption (for the extractive fermentation) or steam consumption (for low temperature fermentation); when vinasse concentration is considered in the conventional process, steam consumption in the extractive fermentation is also significantly smaller. (c) 2012 Elsevier Ltd. All rights reserved.
Background: Pretreatment is necessary to reduce biomass recalcitrance and enhance the efficiency of enzymatic saccharification for biofuel production. Ionic liquid (IL) pretreatment has gained a significant interest as a pretreatment process that can reduce cellulose crystallinity and remove lignin, key factors that govern enzyme accessibility. There are several challenges that need to be addressed for IL pretreatment to become viable for commercialization, including IL cost and recyclability. In addition, it is unclear whether ILs can maintain process performance when utilizing low-cost, low-quality biomass feedstocks such as the paper fraction of municipal solid waste (MSW), which are readily available in high quantities. One approach to potentially reduce IL cost is to use a blend of ILs at different concentrations in aqueous mixtures. Herein, we describe 14 IL-water systems with mixtures of 1-ethyl-3-ethylimidazolium acetate ({[
An on-farm field experiment was conducted in northeastern Thailand to assess the effects of different eucalyptus biochar (BC) application rates, in combination with mineral fertilizers, on upland rice and a succeeding crop of sugarcane on sandy soil. Soil mineral N and greenhouse gas emissions were also evaluated. The field experiment consisted of three treatments: no biochar (BC0), 3.1 Mg ha(-1) of biochar (BC1), and 6.2 Mg ha(-1) of biochar (BC2). All treatments received the same recommended fertilizer rate. Soil mineral N, and emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were monitored after BC application. The results revealed that the BC2 treatment caused lower soil mineral N content than that of the BC0 treatment during the upland rice period. During the sugarcane period, the BC2 treatment induced a greater soil mineral N content than the BC1 treatment but had no significant difference from the BC0 treatment. The BC2 treatment resulted in significantly lower cumulative CH4 and N2O emissions than the BC0 treatment during the upland rice period. In conclusion, we found that the BC2 treatment alleviated the global warming potential from CH4 and N2O emissions throughout the experiment, causing slight changes in soil N availability in the upland rice-sugarcane cropping system.
Objective. The objective of the study was to evaluate the effect of the addition of an additive and an inoculum bacterial in the chemical composition and in vitro digestibility dry matter (IVDMD) and organic matter (IVOMD) of sugarcane silage. Materials and methods. Experimental treatments were: a) sugarcane silage with 1\% of bacterial inoculum and 1\% of additive (SCS1); b) sugarcane silage with the bacterial inoculum 3\% and 1\% of additive (SCS3). The bacterial inoculum consists of 10.0\% molasses, 1.0\% of commercial yogurt containing Lactobacillus plantarum, L. bulgaricus, L. casei, L. acidophilus and L. bifidus, 5.0\% poultry manure, 0.5\% urea and 83.0\% of water; the additive is formulated with 1.0\% urea, 0.1\% sulfate of ammonium and 0.25\% phosphorus. Each treatment was determined to its chemical composition and in vitro digestibility of dry and organic matter and the results obtained were analyzed using T Student test. Results. There were differences between treatments (p<0.05) in crude protein, neutral detergent fibre, hemicellulose, ammoniacal nitrogen and pH, as well as on IVDMD, but without changes in the IVOMD, presenting the better values for SCS1. Conclusions. The 1\% concentration of bacterial inoculum and additive added to sugarcane silage showed better values on in vitro digestibility of dry matter, and chemical composition, indicating an adequacy fermentation, but, at concentrations higher than 1\% of additive and an inoculum bacterial decreases the quality and digestibility of the silage.
Three species of Pleurotus, P. sajor-caju, P. platypus and P. citrinopileatus, were cultivated on various agro-residues such as paddy straw, maize stover, sugarcane bagasse, coir pith and a mixture of these wastes. Primordium initiation was observed on 22nd-27th day after spawning. Maximum yield was obtained in P. sajor-caju cultivated on paddy straw. P. platypus yielded its maximum on coir pith and P. citrinopileatus on sugarcane bagasse. The biological efficiency, nutrient composition, energy value and energy recovery of the fruit bodies obtained on these substrates were reported.
Remote sensing has been used in the evaluation of physical and chemical characteristics of soils as a source of rapid, non-destructive, and low cost information, which may assist in management of environmental liabilities. The aim of this study was to investigate the potential for use of hyperspectral data in determining some properties of soil under different levels of application of sugarcane residue (vinasse) using spectral data obtained from samples in field conditions and laboratory oven-dried soil. A randomized block design was used with six treatments and four replications, the treatments being: 1. without vinasse; 2. fertigation with chemicals; 3, 4, 5, and 6 received the application of 150, 300, 600, and 900 m(3) ha(-1) of vinasse, respectively. Models were generated for prediction of chemical and physical soil properties for both types of samples from spectral curves of visible and near-infrared wavelengths. For determination of soil particle size, models classified as acceptable to good (R-2 from 0.7 to 0.9) were generated, and these models were not affected by the type of sample used. In regard to chemical properties, models were generated with capacity only for differentiation between high and low concentrations (R-2 from 0.5 to 0.65) for the properties of pH, organic matter, H+Al and cation exchange capacity. The models generated for laboratory oven-dried soil were in some cases better than those generated for samples in field conditions.
Perennial grasses display several positive attributes as suitable energy crops for use as a solid fuel for direct combustion, such as high annual production of dry matter per unit area, perennity and high harvest flexibility. This study aimed to characterize the chemical composition and calorific value of 18 elephant grass (EG) varieties (Pennisetum purpureum Schum.) and 10 other potential bioenergy feedstocks intended for direct combustion. Samples were obtained from 6-month-old EG and sorghum and 3-year-old eucalyptus, Mimosa caesalpiniaefolia, and bamboo plants. Sugarcane bagasse and straw, rice husk, corn stover, coconut husk, and fiber samples were also evaluated. The elemental composition, lower heating value (LHV), and cellulose (CEL), hemicellulose (HCEL), lignin (LIG) and ash contents (\% dry matter) were analyzed. The results indicated that the EG genotypes showed significant differences when compared with other evaluated biomasses, but showed no differences among themselves. The EG varieties showed a mean LHV (16.7 MJ/kg) superior to that of rice husk, sugarcane bagasse, and sorghum and similar to that of sugarcane straw, coconut fiber, and corn stover. The EG varieties showed a mean ash content (4.74\%) inferior to that of rice husk, sugarcane bagasse, coconut fiber, and sorghum; a mean CEL content (36.0\%) similar to that of sugarcane straw, coconut fiber, corn stover, sorghum, and Mimosa caesalpinifolia; HCEL; a mean HCEL content (30.3\%) superior to that of rice husk, bamboo, eucalyptus, M. caesalpinifolia, coconut husk, and fiber; and a mean LIG content (8.80\%) superior to that of corn stover and similar to that of sorghum, sugarcane bagasse, and straw biomass. The significant capacity of EG to accumulate dry matter was associated with the biomass quality attributes (LHV and CEL, HCEL, LIG, and ash contents), thereby making it an excellent alternative to lignocellulosic feedstock for direct combustion.
A new method named the production of aryl oxygen-containing compounds via catalytic pyrolysis of bagasse lignin (BL) over perovskites, La0.8M0.2FeO3 (M = La, Ca, Sr, Ba) was proposed. La0.8M0.2FeO3 (M = La, Ca, Sr, Ba) samples were synthesized by the sol-gel method (SG) and characterized by XRD, SEM, BET and XPS, and their catalytic pyrolysis performances were evaluated by the test of TG and the evaluation of the fixed bed microreactor. Under the action of perovskites, the pyrolysis of BL was promoted, the yields of gaseous and solid products decreased while the yield of liquid products increased by 10-20\%; decarboxylation and decarbonylation could be inhibited, and it was conducive to the fracture of aliphatic hydrocarbon side chains on aromatic rings, as a result, the selectivity of CO2/CO decreased while the selectivity of hydrocarbons in gaseous products increased; the total selectivity of aryl oxygen-containing compounds increased from 56 wt.\% in the liquid product obtained from pure BL pyrolysis to more than 69 wt.\% in that of catalytic pyrolysis of BL. The spent catalyst was regenerated after controlled combustion of solid product - char, and it showed good structural and catalytic stabilities after 5 successful redox cycles.
This paper provides a comprehensive review of literature on the properties of sugar industry waste, their varied uses in energy and construction sector, performance and limitations. An efficient upcycling of sugar industry waste in energy production would help the energy sector to reduce its dependency on non-renewable fossil fuels. Literature demonstrates that in the recent years there has been an increased research interest in thermochemical conversion of sugarcane bagasse to produce cleaner energy, rather than its landfilling or combustion. On the other hand, utilisation of secondary by-products from sugar industry in the production of cement, bricks, paver blocks, activated binder and other construction products helps to cut down the carbon footprint of the construction industry, while improving the properties of the final products. From the perspective of the sugar industry, such an arrangement eliminates disposal problems and creates additional revenue. Although independent research studies investigating the use of sugar industry by-products exist, few studies consider these valorisation options together to minimise waste and to create an efficient material flow chain. This study identifies various material and energy recovery pathways from published literature and connects the materials and processes to form a continuous material supply chain with minimum wastage. From the findings, a symbiotic framework has been developed with primary and secondary by-products from the sugar industry serving as source materials for energy production and sustainable construction products. (C) 2018 Elsevier Ltd. All rights reserved.
This study assesses the socio-economic impacts in terms of value added, imports and employment of sugarcane-derived bioethanol production in Northeast (NE) Brazil. An extended inter-regional Input-Output (10) model has been developed and is used to analyse three scenarios, all projected for 2020: a business-as-usual scenario (BaU) which projects current practices, and two scenarios that consider more efficient agricultural practices and processing efficiency (scenario A) and in addition an expansion of the sector into new areas (scenario B). By 2020 in all scenarios, value added and imports increase compared to the current situation. The value added by the sugarcane-ethanol sector in the NE region is 2.8 billion US\$ in the BaU scenario, almost 4 billion US\$ in scenario A, and 9.4 billion US\$ in scenario B. The imports in the region will grow with 4\% (BaU scenario), 38\% (scenario A) and 262\% (scenario B). This study shows that the large reduction of employment (114,000 jobs) due to the replacement of manual harvesting by mechanical harvesting can be offset by additional production and indirect effects. The total employment in the region by 2020 grows with 10\% in scenario A (around 12,500 jobs) and 126\% in scenario B (around 160,000 jobs). The indirect effects of sugarcane production in the NE are large in the rest of Brazil due to the import of inputs from these regions. The use of an extended inter-regional 10 model can quantify direct and indirect socio-economic effects at regional level and can provide insight in the linkages between regions. The application of the model to NE Brazil has demonstrated significant positive socioeconomic impacts that can be achieved when developing and expanding the sugarcane-ethanol sector in the region under the conditions studied here, not only for the NE region itself but also for the economy of the rest of Brazil. (C) 2013 Elsevier Ltd. All rights reserved.
This study aims to produce a biodegradable active packaging film that is pH sensitive, and has a good antioxidant and antimicrobial activity. To do this, a novel phenolic extract was interfacially assembled onto a cellulose film, resulting in a film with a pH-triggered release mechanism of the active polyphenol agent. First, an aqueous extraction of cashew nut testa (CTE) was performed and subsequently, the CTE was characterized. The disc diffusion assay showed that CTE exhibited antimicrobial activity towards the food pathogens Escherichia coli (6 mm) and Staphylcoccus aureus (12 mm). CTE was also cytotoxic against cancer HepG2 and HEK293 cells, reducing the viability to 52\% and 47\%, respectively. It was incorporated into a cellulose-based packaging film, prepared from the by-product, sugarcane bagasse (SC) through interfacial assembly. The incorporation of CTE resulted in a film with good antimicrobial activity, excellent antioxidant content (91\%), and has extremely high thermal stability (290 degrees C). FTIR indicated the formation of hydrogen bond between the SC cellulose-based film and CTE. The hydrogen bonds formed between the cellulose film and CTE became the driving force behind the pH-triggered release mechanism. It was found that the active agent, tannic acid, could be controllably released from the film, depending on the pH of the environment. Our strategy to produce a cellulose-based film impregnated with a phenolic extract, using interfacial assembly, resulted in an active packaging film with pH-triggered release mechanism. This film could be useful to extend the shelf life of perishable food items.
BACKGROUND: Although cells recycling has been recognized as an important technology in obtaining first generation ethanol, there are few studies using this technology to obtain second generation ethanol, limited only to the fermentation of lignocellulosic hydrolysate and molasses mixture. The present work evaluated the use of cell recycle batch fermentation to validate a setup for cellulosic ethanol production. Setup considered a diluted phosphoric acid pretreatment followed by alkaline delignification, enzymatic hydrolysis, hexoses concentration, and finally, cell recycle batch fermentations. After the concentration step of cellulosic hydrolysate, performance of Saccharomyces cerevisiae recycling was evaluated from parameters related to the alcoholic fermentation, such as productivity and ethanol yield. RESULTS: Global productivity values of 1.94, 4.19, 5.62, 5.68 and 5.81 g L-1 h(-1) were obtained for all batch fermentations, respectively. Fermentation reaction was performed for 8 h in the 3rd, 4th and 5th batches. The medium yield of 87.4\% and ethanol titer of 47.0 g L-1 were obtained in nearly all batches. CONCLUSIONS: The results showed good performance of the yeast with consumption of almost all glucose present in cellulosic hydrolysate without sterilization and supplied with molasses. In this context, the setup proposed can be a possible design for second generation ethanol production. (C) 2015 Society of Chemical Industry
Anaerobic co- digestion (co-AD) of agro-industrial waste, namely, palm oil mill effluent (POME) and sugarcane vinasse (Vn), with water hyacinth (WH) as co-substrate was carried out in two separate Anaerobic Suspended Growth Closed Bioreactors (ASGCBs) under thermophilic (55 degrees C) conditions. The highest chemical oxygen demand (COD) and soluble COD reduction in co-AD of POME-WH (78.61\%, 78.86\%) is slightly higher than co-AD of Vn-WH (75.75\%, 78.24\%). However, VFA reduction in co-AD of POME-WH (96.41\%) is higher compared to co-AD of Vn-WH (85.94\%). Subsequently, biogas production peaked at 13438 mL/day values and 16122 mL/day for co-AD of POME-WH and Vn-WH, respectively. However, the methane content was higher in the co-AD of POME-WH (72.04\%) than in the co-AD of Vn-WH (69.86\%). Growth yield -(Y-G), maximum specific substrate utilization rate -(r(x,max)) and maximum specific biomass growth rate (mu(max)) are higher in co-AD of POME-WH, as supported by the higher mixed liquor volatile suspended solids (MLVSS) and COD reduction efficiency compared to co-AD of Vn-WH. However, methane yield ( Y-CH4) reported in the co-AD of POME-WH and Vn-WH are 0.2748 and 0.3112 L -CH4/g -CODreduction, respectively, which suggests that WH is a more suitable co-substrate for Vn compared to POME.
Cost effective bioprocessing of nutraceuticals in present global scenario is a matter of concern. This study explored Paper mill sludge (PMS) and sugarcane bagasse (SCB) as inexpensive substrate for Planococcus sp. TRC1 mediated valuable beta-carotene production and residual treated biomass as value added crystalline cellulose source simultaneously. Both biomass supported significant bacterial growth reaching highest yield 38.54 +/- 1.4 mg/g on PMS (36 h) and 47.13 +/- 1.9 mg/g (48 h) on SCB in solid state fermentation. Luedeking-Piret model revealed growth associated production with alpha and much lower beta values of 5.18 and 0.24 for PMS and 4.5 and 0.165 for SCB. Cost analysis exhibited decrementation of pigment cost/mg by 84 \% compared to synthetic media. Optimum production conditions were 30 degrees C temperature, pH 7, 10 \% inoculum and initial moisture content 80 \% (PMS) and 85 \% (SCB). TLC (R-f = 0.9), HPLC (RT = 7.646) and lambda max (465 nm) confirmed pigment's beta-carotene nature with significant antioxidant and antimicrobial activity. It showed stability at varied temperature, pH and light conditions along with negligible phytotoxicity on Vigna radiata. Planococcus sp. TRC1 delignified PMS (41 \%) and SCB (38 \%) and FT-IR, FESEM and XRD suggested crystalline nature of residual cellulose rich fraction shedding light on a biorefinery approach for valorization of industrial solid wastes.
The aim of this study was to examine the effect of lindane-degrading yeast on the growth and lindane uptake by Saccharum sp., in doped garden soils. The rhizosphere of Saccharum plant was amended with yeast Candida VITJzN04 by root-inoculation. The bio-augment yeast was applied in two different forms viz, planktonic form and cells immobilized on sugarcane-bagasse, in the pot experiments. Garden soils (lindane-100 mg/kg) exposed to various treatments were monitored for a period of 30 days, for residual lindane by gas-chromatography analysis. The lindane-removal rates in soil were expressed in terms of half-life period and were recorded as 13.3 days (yeast), 43.3 days (Saccharum), 9.8 days (free yeast-plant) and 7.1 days (immobilized yeast-plant). Additionally, Candida sp., was also identified as a plant growth promoting yeast due to its ability to produce growth hormone and solubilize insoluble phosphates in the soil for better uptake by the plant species. Bio-stimulation of the soil with yeast immobilized on sugarcane bagasse further enhanced the total yeast activity in the soil which in turn had a positive influence on lindane-removal. Combined treatment with bagasse immobilized yeast and plant showed the best lindane degradation. Results suggested that the synergistic activity of plant and yeast resulted in fast and efficient degradation of lindane. Thus, it can be concluded that Saccharum plant in combination with Candida VITJzN04 is an effective alternative for the conventional remediation strategies. (C) 2017 Elsevier Ltd. All rights reserved.
An easy one-step co-precipitation method was adopted to prepare chitosan/Fe3O4 composite microparticles (MCTS). Scanning electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometer, and X-ray diffraction were utilized to examine the features of the microparticles. The results showed that the microparticles had a honeycomb-like porous framework with superparamagnetic properties and a saturation magnetization of 43.4emug(-1). The adsorption performance of polyphenols in sugarcane juice with using MCTS as adsorbent was also investigated. The adsorption kinetics indicated that the polyphenol adsorption process was suitable for the pseudo-second-order mode, while the Langmuir isotherm mode could be employed to best show the adsorption behavior. According to the thermodynamic parameter values, this adsorption process is endothermic and spontaneous. Recycling experiments indicated that the MCTS adsorbent had considerable reusability.
Given that the glycerol organosolv pretreatment (GOP) can effectively improve the hydrolyzability of various lignocellulosic substrates, physicochemical changes of the substrate before and after the pretreatment was characterized to elucidate what is responsible for it. The effect of GOP on the main components and hydrolyzability of wheat straw was revisited. Results demonstrate that the GOP should be a promising candidate for the current pretreatment. Then the composition and structure of substrates was measured at multi-dimensional scales by using various analytic equipment such as TGA, SEM, AFM, CLSM, FTIR, XRD and solid-state CP/MAS C-13 NMR. This paper reports some new insights on the mechanism behind that, which can be beneficial for further development, optimization, and scale-up of the GOP process. (C) 2015 Elsevier Ltd. All rights reserved.
This paper describes a preliminary analysis of two technological routes (based on hydrolysis and on gasification + Fischer-Tropsch conversion process) of biofuels production from cellulosic materials. in this paper it was considered the integration of the two alternative routes to a conventional distillery of ethanol production based on fermentation of sugarcane juice. Sugarcane bagasse is the biomass considered as input in both second-generation routes. Results show that the integration of gasification + FT process to a conventional distillery is slightly more efficient (from an energetic point of view) and also offers the advantage of products diversification (ethanol from the conventional plant, plus diesel, gasoline and more surplus electricity regarding the hydrolysis route). Considering typical Brazilian conditions, at this stage it is not possible to foresee any significant advantage of any of the alternatives, but potentially the gasification route would have an advantage regarding avoided GHG emissions depending on the emission factor of the electric sector in which cogeneration units will be installed. (C) 2009 Published by Elsevier Ltd.
Symbiotic cellulolytic microcosms represent a promising microbial agent for enhancing degradation of cellulosic materials in biotechnological processes. In this study, structurally stable lignocellulose-degrading microbial communities were constructed from cellulolytic seed culture from sugarcane bagasse compost using swine manure and Napier grass as co-digested carbon sources under static aerobic condition at 55 A degrees C. The lignocellulolytic microbial consortium enriched in peptone and yeast extract-based medium (PLMC) showed higher cellulose-degrading activity compared to lignocellulolytic microbial consortium isolated in the water-based medium (WLMC). The composite microbes in both consortia were originated from the seed culture and the co-digested substrates according to denaturing gradient gel electrophoresis profile. PLMC exhibited higher CMCase, xylanase, FPase, and avicelase activities in the supernatant than those of WLMC and was capable of degrading 70 \% of filter paper within 1 week. PLMC was capable of degrading substrate with higher efficiency than the control by 11.7, 9.2, 15.5, and 11.9 \% of total solid, suspended solid, volatile solid, and volatile suspended solid, respectively. The work demonstrated the potential of cellulolytic microcosms enriched by this approach on enhancing conversion efficiency in biogas production from cellulosic wastes.
Porous hydroxyapatite-biochar composites with layered microstructures (SC-HA/C) were prepared by carbonizing sugarcane stem nodes and then soaking them in lime water and (NH4)(2)HPO4 solutions in rotation. The surface area of SC-HA/C ranges from 8.52 to 28.44 m(2)/g, and its microstructure inherits various macro-, meso-, and micro-pores in the cell walls of sugarcane and in the pits of the vessel walls. The maximum removal capacities were 11.50, 14.65, and 19.81 mg/g for the Cu (II) immobilization at 25 degrees C, 35 degrees C, and 45 degrees C with the solution Cu (II) concentration of 10-320 mg/L, respectively, which were in accordance with the copper sorption capacities of synthesized nano-hydroxylapatites. The Cu (II)-removal kinetics and isotherm followed the pseudo-second-order equation and the Langmuir equation very well. The formation of the Cu-containing hydroxylapatite solid solutions ((CuxCa(1)(-x))(5)(PO4)(3)(OH)) through adsorption, ion exchange (x = 0.01-0.04), and dissolution-coprecipitation (x = 0.13-0.35) was the dominant process for the Cu (II) removal by the SC-HA/C composite.
Aims To reduce the cost of biodiesel, the utilization of rice straw hydrolysate and restaurant oil wastes as the substrates for biodiesel production in a recombinant strain by a one-step method was investigated. Methods and Results A recombinant Escherichia coli pET28a (+)-PAW, which encodes enzymes for the ethanol pathway and acyltransferase, was constructed. Fermentation results in Luria-Bertani medium revealed that xylose was favourable for fatty acid ethyl esters (FAEEs) production (2.79 g l-1) by E. coli pET28a (+)-PAW. When rice straw hydrolysate and restaurant oil wastes were utilized as the monosaccharide substituent and the fatty acids substituent, 0.27 g l-1 FAEEs and 0.249 g l-1 FAEEs were obtained, respectively. 1.27 g l-1 FAEEs was obtained in the restaurant oil wastes medium supplemented by 2\% sodium oleate. Conclusions The fermentation results indicated that the strain was effective in biodiesel production. The rice straw hydrolysate and restaurant oil wastes could be utilized by E. coli as the substrates for FAEE production. Significance and Impact of the Study This novel exploration might pave the way for biodiesel production from waste materials by genetically engineered microorganism.
The objective of this study was to evaluate the association of forage cactus with different fiber sources (elephant grass hay - EGH; corn straw - CS, hay of cassava shoots - HCS; fresh sugarcane bagasse - FSB; and hydrolyzed sugarcane bagasse - HSB) on the milk yield and composition and the feeding behavior of lactating Sindhi cows. Five cows with average body weight, average daily milk yield, and average daily 4\%-fat-corrected milk yield of 265, 4.95 and 5.22 kg, respectively, were used in a 5 x 5 Latin square design. The effect of experimental diets on milk yield and composition, feeding time (FT), rumination time (RT), idle time, mean values of total chewing time (TCT), number of ruminal boli (NRB), number of rumination chews (NRC), and feed efficiency (FE) and rumination efficiency (RE) expressed as a function of DM and NDF were analyzed. Milk yield in kg/day and corrected to 4.0\% fat from the animals that received cactus associated with CS were higher as compared with the treatment with hydrolyzed sugarcane bagasse. The milk composition variables were not influenced by the treatments, and nor were FT, RT, TCT, NRB and NC. Two patterns were observed for FE and RE, with higher efficiency of the diets with EGH, CS and HCS and lower efficiency for diets containing sugarcane bagasse. In this context, Sindhi cows fed forage cactus associated with corn straw, elephant grass hay, and hay of cassava shoots present better performance, feeding efficiency, and rumination responses than those fed forage cactus associated with fresh sugarcane bagasse and hydrolyzed sugarcane bagasse.
Use of inferior yeast cultures represents one of the reasons for low fermentation efficiencies in Sri Lankan alcohol distilleries that use sugarcane molasses. The present study isolated and characterised yeast strains found in natural environments in Sri Lanka and evaluated their performance under laboratory conditions in an effort to select superior strains for industrial fermentations. Yeasts were characterised based on morphological and physiological features such as sugar fermentation and nitrate assimilation. Ethanol production, alcohol tolerance and growth rate of the most promising strains were monitored following laboratory fermentations of molasses. Over a thousand yeast cultures were collected and screened for fermentative activity and a total of 83 yeast isolates were characterised as higher ethanol producers. Most of these belonged to the genus Saccharomyces. Certain strains produced over 10\% (v/v) alcohol in molasses media during 72 h laboratory fermentations. Only two strains, SL-SRI-C-102 and 111, showed an appreciable fermentation efficiency of about 90\%. The latter strain produced the highest level of ethanol, 11\% (v/v) within a 48 h fermentation and exhibited improved alcohol tolerance when compared with the baker's yeast strains currently used in Sri Lankan alcohol distilleries. This study highlights the benefits of exploiting indigenous yeasts for industrial fermentation processes.
Rice husk ash (RHA) and bagasse ash (BA) are available in large quantities in South Asian countries growing rice and sugarcane. Land application of RHA and BA is likely to influence chemistry of soil phosphorus (P) and thereby P adsorption and desorption. Laboratory studies were carried out to investigate the short-term and long-term effects of RHA and BA application on P adsorption and desorption in an alkaline soil under a wheat-rice system. Addition of RHA or BA (10 Mg ha(-1)) resulted in a significant decrease in P adsorption compared to the control. The decrease in P adsorption was lower when RHA and BA were applied to either rice or wheat as compared with when applied to both the crops. The BA was more effective in reducing P adsorption than RHA because of its greater P concentration. Fresh addition of RHA and BA at 1\% (dry-weight basis) showed a small effect on P adsorption as compared to their long-term application. The Frendulich isotherm equation gave better fit with the experimental data than the Langmuir equation and is reliable to describe the P quantity/intensity relationships of this soil as affected by the additions of RHA and BA. The P-adsorption capacities (revealed from the Langmuir isotherms) of the unamended control, RHA, and BA (applied to both wheat and rice) were 256, 313, and 385 mg kg(-1), respectively; the corresponding bonding energies for the three treatments are 0.0085, 0.0041, and 0.0026 L kg(-1), respectively. Desorption of P was minimum in the control plots and maximum with BA followed by RHA, especially when applied to both the crops.
The presence of melanoidins in molasses wastewater leads to water pollution both due to its dark brown color and its COD contents. In this study, a bacterial consortium isolated from waterfall sediment was tested for its decolorization. The identification of culturable bacteria by 16S rDNA based approach showed that the consortium composed of Klebsiella oxytoca, Serratia mercescens, Citrobacter sp. and unknown bacterium. In the context of academic study, prevention on the difficulties of providing effluent as well as its variations in compositions, several synthetic media prepared with respect to color and COD contents based on analysis of molasses wastewater, i.e., Viandox sauce (13.5\% v/v), caramel (30\% w/v), beet molasses wastewater (41.5\% v/v) and sugarcane molasses wastewater (20\% v/v) were used for decolorization using consortium with color removal 9.5, 1.13, 8.02 and 17.5\%, respectively, within 2 days. However, Viandox sauce was retained for further study. The effect of initial pH and Viandox concentration on decolorization and growth of bacterial consortium were further determined. The highest decolorization of 18.3\% was achieved at pH 4 after 2 day of incubation. Experiments on fresh or used medium and used or fresh bacterial cells, led to conclusion that the limitation of decolorization was due to nutritional deficiency. The effect of aeration on decolorization was also carried out in 2 L laboratory-scale suspended cell bioreactor. The maximum decolorization was 19.3\% with aeration at KLa = 2.5836 h(-1) (0.1 vvm).
Bagasse is an underutilized agro-industrial residue with great potential as raw material for the production of cellulose nanofibrils (CNF) for a range of applications. In this study, we have assessed the suitability of bagasse for production of CNF for three-dimensional (3D) printing. First, pulp fibers were obtained from the bagasse raw material using two fractionation methods, i.e. soda and hydrothermal treatment combined with soda. Second, the pulp fibers were pretreated by TEMPO-mediated oxidation using two levels of oxidation for comparison purposes. Finally, the CNF were characterized in detail and assessed as inks for 3D printing. The results show that CNF produced from fibers obtained by hydrothermal and soda pulping were less nanofibrillated than the corresponding material produced by soda pulping. However, the CNF sample obtained from soda pulp was cytotoxic, apparently due to a larger content of silica particles. All the CNF materials were 3D conclude that the noncytotoxic CNF produced from hydrothermally and soda treated pulp can potentially be used printing of biomedical devices.
Xylanases from the pathogen fungus Chrysoporthe cubensis were produced under solid state fermentation (SSF) using wheat bran as carbon source. The enzymatic extracts were submitted to ion exchange (Q Sepharose) and gel filtration chromatography methods (Sephadex S-200) for purification. The xylanases were divided into three groups: P1 showed better performance at 60 A degrees C and pH 4.0, P2 at 55 degrees C and pH 3.0, and P3 at 80 degrees C and pH 3.0. Oat spelt xylan was the best substrate hydrolyzed by P1 and P3, while beechwood xylan was better degraded by P2. Carboxymethyl cellulose (CMC) and p-nitrophenyl-beta-d-xylopyranoside (p-NP beta Xyl) were not hydrolyzed by any of the xylanases. The K-M (') or K-M values, using oat spelt xylan as substrate, were 2.65 mg/mL for P1, 1.81 mg/mL for P2, and 1.18 mg/mL for P3. Xylobiose and xylotriose were the main xylooligosaccharides of oat spelt xylan degradation, indicating that the xylanases act as endo-beta-1,4-xylanases. Xylanases also proved to be efficient for hydrolysis of sugarcane bagasse when used as supplement of a commercial cocktail due to the increase of the reducing sugar release.
This study reports the technical and economic feasibilities of converting sugar cane residue (bagasse) into biofuel by using novel zeolite (P) catalyst. Using silica gel, aluminum powder, and sodium hydroxide as a precursor material, zeolite (P) has been successfully fabricated by template free hydrothermal synthesis. The as-prepared catalyst is used for the conversion of sugarcane residue into valuable hydrocarbons by an autoclaving process. The effect of various parameters on catalytic and conventional (noncatalytic) pyrolysis was scrutinized and compared. It has been recognized that conventional pyrolysis (without catalyst) and catalytic pyrolysis (with Cat (I) and Cat (II)) produced 25.06\%, 80.31\%, and 55.26\% of combustible liquid. The facial synthesis, high thermal stability, and economic and environmental feasibilities of the as-synthesized zeolite (P) makes it a promising catalyst for biofuel production from biomass.
In order to increase the biogas production from sugarcane rind (SCR), microwave coupled Ca(OH)(2) (MCC) pretreatment was applied to pretreat the SCR before batched mesophilic anaerobic digestion. The synthetic biogas was injected into the pretreatment effluent to decrease the inhibition on biogas production caused by calcium, phenols and over-high pH. The results showed that MCC pretreatment can effectively improve both of the rate and methane production when considering both of pretreated SCR and the effluent. The maximum methane production from pretreated SCR was 271.67 NmL CH4/g VS, which was 41.13\% higher than the untreated SCR. Total methane production from pretreated SCR and the effluent was 25.7\% more than untreated SCR based on 100 g of dry SCR. This work will provide a theoretical reference for the resource utilization of SCR for clean industrial application in future.
The kinetic pyrolysis is often studied as a global process (single-step mechanism), but this method is inadequate since it does not adequately describe the biomass pyrolysis. In this context, the purpose of this study is to present a simple pathway to describe the kinetic parameters of pyrolysis properly. Sugarcane bagasse waste and cashew nut shell waste were chosen because each presented high bioenergetic potential, based on preliminary physicochemical characterizations. Pyrolysis was performed at a range from room temperature to 1073 K under heating rates of 5, 10, 20, and 30 K min(-1). The activation energy, frequency factor and reaction model were obtained from isoconversional methods, compensation effect and master plot, respectively. For the study of the single-step mechanism, a temperature range of 408-723 K and 398-873 K was used for sugarcane bagasse waste and cashew nut shell waste, respectively. For study of the multi-step mechanism study, the algorithm process of deconvolution was used as a simple pathway. The results obtained for single-step mechanism suggest that the kinetic parameters are only applied for decomposition processes with only one decomposition stage. Overlap curves reduce the accuracy between the simulated and experimental curves for sing-step mechanism and unable to describe the biomass pyrolysis process. On the other hand, the multi-step mechanism using deconvolution associated with isoconversional methods can provide a good approximation of the experimental data independent of the thermal behavior of the biomass. In addition, the algorithm provides suitable values of kinetic parameters, which do not require advanced programming or software.
During the beer brewing process, some compounds are formed in the primary fermentation step and may affect the final quality of beer. These compounds, called off flavors, such as diacetyl, are produced during fermentation and are related to a buttery taste. The use of acetolactate decarboxylase (ALDC) in the traditional beer brewing process may significantly increase productivity since it allows for a faster decrease in the adverse flavor caused by diacetyl. However, production costs directly impact its application. For this reason, we analyzed the effect of different cultivation media on ALDC production by Bacillus subtilis ICA 56 and process economics. Different carbon and nitrogen sources, including agro-industrial residues, were evaluated. The best result was obtained using sugarcane molasses and corn steep solids (CSS), allowing a 74\% reduction in ALDC production cost and an enzyme activity of 4.43 +/- 0.12 U center dot mL(-1). The enzymatic extract was then characterized, showing an optimum temperature at 40 degrees C and stability at different pH levels, being able to maintain more than 80\% of its catalytic capacity between pH values of 3.6 and 7.0, with higher enzymatic activity at pH 6.0 (50 mM MES Buffer), reaching an ALDC activity of 5.30 +/- 0.06 U center dot mL(-1).
Sugarcane bagasse is a recalcitrance lignocellulosic material with difficult to structure disorganize and it has low cellulose accessibility, negatively influencing the enzymatic saccharification. This study identified the minor particle size that resulted in the efficient diluted acid pretreatment (10 \% m/m, 121 degrees C/30 min) of sugarcane bagasse and a more recalcitrant material, that is external fraction (2 to 3 mm from the extremity, containing epidermis). Particle sizes were obtained by sieving sugarcane bagasse at 16 (1 mm), 24 (0.710 mm), 35 (0.425 mm), 60 (0.250 mm) and <60 mesh (<0.250 mm) on a sieve agitator. The decrease of the particle sizes led to an increase of cellulose accessibility. Both of the samples showed high accessibility after the pretreatment due to the particle size decrease. Accordingly, there was a better enzyme action, what increased the glucose yield with samples lower than 0.425 mm (35 mesh).
Condensed molasses soluble (CMS) has been reported to be rich in mineral nutrients and organic matter. However, the potential of CMS as a new organic fertilizer for crops is poorly understood. In this study, we explored the effects of CMS on seed germination, plant growth and field production ofBrassica napusthrough seed germination, hydroponics and field trials. The results demonstrated that a small amount of CMS (0.05 g L-1) on the basis of normal nutrient supply significantly increased plant biomass, root vigor and root development, and improved the superoxide dismutase (SOD) activity of shoot at the seedling growth stage. Nevertheless, a high concentration of CMS (0.2 g L-1) inhibited plant growth, root development, the activities of peroxidase (POD) and catalase (CAT), and elevated accumulation of malondialdehyde (MDA) in the shoot at the same stage. In the field, exogenous application of CMS as well as chemical fertilizers increased seed yield up to 20\% compared with chemical fertilization only. Collectively, our results conclude that the appropriate amount of CMS could promote the growth and development of rapeseed at both seedling and mature stages. Hence, CMS may be used as a new potential organic fertilizer for crop production in the future.
The sugarcane borer Diatraea saccharalis is an important pest of sugarcane and ants are one of its main predators. The practice of burning sugarcane straw in situ after harvest has been gradually replaced in Brazil by other practices. However, it is unknown whether ants can control the abundance of this borer in the presence of straw. In this study, we assessed the diversity and species composition of ants attacking different stages of the pest's life cycle. Specifically, we asked whether the species richness and abundance of ants varies during the course of day and a year. We established one-hectare plots at random locations in a sugarcane plantation. Once a month, we collected 20 samples of each stage of the D. saccharalis life cycle and randomly distributed these samples as bait on plants spaced 20 m apart within a plot. Ants were collected daily in the morning and afternoon over a period of 12 months. We identified several aspects of ant feeding behaviour that may affect their biological control of the borer: (1) the greatest number of ants were collected from baits consisting of the immature stages of the sugarcane borer, (2) ants were most active in the morning and (3) their activity varied from month to month. Solenopsis saevissima and morphotypes of Crematogaster sp.7 and Pheidole sp.35 are potentially important predators of borers in sugarcane crops in which the straw is not burnt.
The gradual increase in organic loading is a strategy that has been used in reactor operation of wastewater treatment to adapt the microbial community and its metabolic activities. Within this context, the aim of this research was to investigate the microbial community present in an anaerobic chambered reactor (ACR) operating for 270 days treating ethanol distillery stillage. The operation the ACR reactor started with low feed rate which was increased gradually so that the organic load rate (OLR) ranged from 0.5 to 2.5 g COD m(-3) day(-1). Performance monitoring included physicochemical analyses, methane production, microscopy, and biomolecular analyses. The operational data shows satisfactory performance in terms of COD removal, averaging over 92.5\%. DGGE analyses revealed that the structure of the microbial community of Bacteria domain is more sensitive to reactor operational conditions than that of the Archaea domain, when the OLR increased. A clear relationship was observed between the microbial diversity and the dominance for Bacteria and Archaea domains to different OLR, indicating adaptation of communities to the operating conditions imposed on the ACR.
Graphene oxide (GO) treated thermostable crude cellulase has been obtained via fungal co-cultivation of strain Cladosporium cladosporioides NS2 and Emericella variecolor NS3 using mix substrate of orange peel and rice straw under solid state fermentation (SSF). Enzyme activity of 60 IU/gds FP, 300 IU/gds EG and 400 IU/gds BGL are recorded in the presence of 1.0\% GO in 96 h. This crude enzyme showed 50 degrees C as optimum incubation temperature, thermally stable at 55 degrees C for 600 min and stability in the pH range 4.5-8.0. Further, 70.04 g/L of sugar hydrolyzate is obtained from enzymatic conversion of 3.0\% alkali pre-treated baggase using GO treated crude cellulase. Finally, 2870 ml/L cumulative biohydrogen production having bacterial biomass similar to 2.2 g/L and the complimentary initial pH 7.0 is recorded from sugar hydrolyzate via dark fermentation using co-culture of Clostridium pasteurianum (MTCC116) and a newly isolated Bacillus subtilis PF\_1.
Lignocellulosic jute waste products, viz. leaves, stick and caddis, generated in large quantities from jute cultivation and industry were used as separate substrates and in admixture with rice straw in a 1:1 ratio for the production of the edible mushroom Pleurotus sajor-caju (Fr.) Singer. While growth of mushroom mycelia was hindered on jute leaves, jute stick and caddis separately, and as mixed substrates with rice straw, were found to produce a good yield of the mushroom. The chemical and mineral analyses and neutral sugar composition of the mushroom fruit bodies are reported. It was found that the efficiency of jute wastes as substrates for the production of P. sajor-caju is better than other lignocellulosic substrates, such as sugarcane bagasse and paper wastes, but more or less similar to sorghum stalk and cotton wastes.
The objective of the extraction process in the ethanol production from sugarcane is to separate the sucrose-containing juice from the remainder of the cane, mainly fibre. The two currents, products of this process, are the juice and the bagasse. The juice is used to produce ethanol and the bagasse is the fuel for the boilers. Two types of devices are employed to perform this operation: mills and diffusers. Each one of them consumes different types of energy: mills consume mechanical energy, diffusers consume basically thermal energy. As both devices utilize an important quantity of energy, their effect in the energy balance of the factory needs to be taken into account. Aiming to discuss and characterize these effects, simulations of the complete ethanol production process, including the cogeneration system, were carried out using the Aspen Plus software, considering both devices. Process integration was also performed targeting to reduce the energy consumption. These results are presented and compared. Considering the integrated ethanol production process, with extraction -condensing steam turbines in cogeneration system, working with mills, it can produce an electricity surplus of 83.4 kWh/t of sugarcane, however, for the same conditions, working with the diffusion extraction process a production of 91.3 kWh/t of cane can be obtained, including also a small increase of 2 \% in the ethanol production.
Induction motors, acting as work house of industries, are affected by winding temperature due to poor insulation. In producing a sustainable polymer composite electrical insulator, this article gets into the investigative study of tensile strength, hydrophobicity, hardness and the electrical breakdown properties of silicone rubber (SR) reinforced with sugarcane bagasse ash (SCBA). In order to identify optimal proportion, various filler proportions are studied for mechanical, physical, tensile and electrical properties. For 7\% optimal filler composition, the tensile and hardness tests on SR/SCBA composite manifested a maximum value of 78.48 x 10(-3) MPa and 0.91496 MPa, respectively. The electrical breakdown was recorded with the maximum value of 108.65 kV/cm with 7\% filler. For hydrophobicity, the 7\% filler specimens had the lowest rate of rise in weight after the water absorption test. Scanning electron microscopy (SEM) analysis and particle size analysis were carried out to evaluate the molecular interaction and particle dispersion. SEM analysis confirmed the presence of fiber-adhesion in matrix composites. Finally, the superiority of the context is also compared with earlier works. This context investigates the properties of bio-resin composite derived from sugarcane ash and creating its properties with artificial polymers to come out with a reliable electrical insulator application.
The improvement of various pretreatment methods of lignocellulose biomass has been a major concern due to the cost involved, especially in the production of succinic acid which requires high carbohydrate content. Sugarcane trash is lignocellulosic biomass, which is the most abundant renewable carbon source. This study optimized the conditions of organosolv pretreatment of sugarcane trash using sodium hydroxide (NaOH) as a catalyst, to increase alpha-cellulose and decrease lignin content using response surface methodology based on Box-Behnken design with 3 factors (temperature, time, NaOH). Enzyme hydrolysis and fermentation proceeded after the pretreatment to produce succinic acid. The optimized conditions for the pretreatment include 140 degrees C, 60 min, and 20 wt\% NaOH. In the validation experiment under these conditions, the alpha-cellulose content increased to 67.75\% and lignin decreased to 5.41\%. Enzyme hydrolysis of 10\% substrate by Cellic Ctec2 (15 FPU/g substrates) resulted in 70.6 g/L glucose, 14.8 g/L xylose, 2.1 g/L arabinose, and 2.3 g/L cellobiose. Fermentation by Actinobacillus succinogenese TISTR 1994T using the hydrolysate containing glucose (35 g/L), xylose (10 g/L), and arabinose (5 g/L) resulted in 41.39 g/L succinic acid after 48 h of fermentation. The maximum succinic acid produced was 41.39 g/L at 48 h of fermentation. With the potential on obtaining high amount of cellulose, the work demonstrated the potential of the alkaline-catalyzed ethanol-based organosolv process for pretreatment of sugarcane trash in succinic acid production.
Indian sugar mills produce a large volume of agro-waste sugar cane bagasse (SCB), which, due to its improper use, causes environmental issues. Contrastingly, the valorization of SCB by integrating advanced technologies for biochemical production can alleviate waste disposal problems, enhance resource utilization, and promote a circular economy. The present review explores recent advances in SCB-derived valuable biochemicals such as bioethanol, biogas, xylitol, carboxylic acids, 2,3-butanediol, and furfural using advanced pretreatment techniques and engineered strains. Furthermore, it discusses the challenges and opportunities in bio-chemical production, the economic and environmental assessment, and the implications of the Government of India's (GOI) valuable schemes for agro-waste valorization.
In this study, an innovative approach is proposed for the valorization of all sugars (cellulosic and hemicellulosic) contained in a lignocellulosic feedstock, as is rice straw biomass (RSB), for the production of second-generation bioethanol. For this purpose, the whole slurry obtained after dilute sulfuric acid pretreatment at a biomass loading of 5\% (w/v) was subjected to consolidated bioprocessing without previous solid-liquid separation and/or detoxification and the concentrated solution of carbohydrates recovered was fermented to bioethanol by a coculture of thermophilic anaerobic bacteria. To bypass the inhibitory effect of undetoxified whole slurry on the lower fermentability of the co-culture, the concentration of different additives was optimized for improved buffering capacity, enhanced substrate-microbe interaction, and by-product elimination. The individual supplementation of 3 selected additives at optimum concentration; 20 mM calcium carbonate, 0.4\% (v/v) polyethylene glycol, and 1\% (w/v) sodium acetate resulted in enhanced ethanol yield of 130.83 mM, 106.37 mM, and 99.10 mM, respectively, compared to 75.03 mM ethanol yield in control. The combined effect of optimal dosage of these additives was able to improve the ethanol concentration and yield to 142 mM and 48\% of the theoretical maximum respectively, suggesting about 88.58\% increase compared to control medium without additives supplementation. The combined supplementation of additives proved to be an advantageous strategy for bioethanol production using undetoxified whole slurry biomass.
The development of new biomaterials for the remove of organic contaminants from wastewater has attracted much attention over the few past years. One of the most cost-effective approaches is to produce new high value biomaterials from low value solid agricultural biowastes. In this work, sugarcane bagasse and agricultural waste rich in reducing sugars, acted as both a green bioreductant for graphene oxide (GO) and a sustainable supporter for the immobilization of Burkholderia cepacia. Therefore, this new biomaterial which contained both reduced graphene oxide (RGO) and Burkholderia cepacia, was cable of initial adsorption of malachite green (MG) and its subsequent biodegradation. After 60 h, immobilized Burkholderia cepacia degraded more MG (98.5\%) than a cell cultured Burkholderia cepacia (87.7\%) alone. Raman spectroscopy confirmed that GO was successfully reduced by bagasse and that consequently a composite (B-RGO) was prepared. SEM indicated that Burkholderia cepacia was well immobilized and kinetics studies showed that the adsorption of MG onto the developed composite fitted a pseudo-second order kinetics model (R-2 > 0.99). Biodegradation of MG, was confirmed by the detection of appropriate degradation products such as N, N-dimethylaniline and 4-(Dimethylamino) benzophenone using GC-MS, UV and FT-IR, and via best fit first-order biodegration kinetics. Furthermore, a response surface methodology (RSM) was applied to the removal process by varying four independent parameters using a Box-Behnken design (BBD). Optimum MG removal (99.3\%) was achieved at 31.5 degrees C, with an initial MG concentration of 114.5 mg L-1, initial pH of 5.85, and an adsorbent dosage of 0.11 g L-1. The excellent removal efficiency indicated that agricultural waste derived reduced graphene oxide bio-adsorbents have significant potential for the removal of dyes such as MG from industrial wastewaters. (C) 2018 Elsevier Ltd. All rights reserved.
In sugarcane (Saccharum officinarum) plantations, it was common to use fire to facilitate the cutting and harvesting of the sugarcane crop. The largest sugarcane producing state in Brazil is Sao Paulo, which has a planted area of about 4.7 million hectares. In the state of Sao Paulo law 11241/02 provides for the gradual elimination of the burning of sugarcane trash. It is estimated that one hectare produces about 14 tons of trash. The mills are trying to incorporate this trash with bagasse for power generation. The high concentration of mineral impurities is a problem in its use for energy purposes. The aim of the study was to investigate the influence of storage time and particle size on the physicochemical characterization of the sugarcane trash. The treatments were based on: the position of the bale (inner and surface), the storage time (0, 1 and 2 years) and the particle size (> 0.420 mm, 0.250-0.420 mm, < 0.250 mm and mix), totaling 24 treatments. The performed analyses were particle size distribution, proximate analysis, the higher heating value (HHV), the chemical analysis of the components of the ashes by Wavelength Dispersive X-ray Fluorescence (WDXRF) and the Scanning Electron Microscope (SEM) images. There were variations in the results of the ash content with different particle sizes. A higher concentration of mineral impurities in smaller particles (< 0.250 mm) was observed. The HHV varied from 15.9 to 18.3 MJ kg(-1) and showed no statistical difference between the treatments. The results indicate that the sugarcane trash presents problems related to mineral impurities which constrain its use as a solid fuel in industry. The particle size interferes in its physicochemical characteristics. The trash can be stored in the field and did not affect the quality for use as a solid biofuel.
The present study evaluated the natural and synthetic substrate for biofilm formation in in vitro condition and their effect on physico-chemical parameters of water. The four different treatments i.e., control (without substrate), T-1 (sugarcane bagasse), T-2 (PVC), T-3 (coconut husk) and T-4 (bamboo strips) as substrates were used for assessment of biofilm formation and heterotrophic bacterial growth. Physico-chemical parameters of water and total platecolonies were estimated at weekly intervals for five weeks. Results of dissolved oxygen, total alkalinity, as well as nutrients like ammonia-nitrogen, nitrate-nitrogen and nitrite-nitrogen showed significant (p<0.05) difference in the treatment groups compared with control. The total bacterial count of the substrata significantly (p<0.05) high in all the treatment groups during the 3rd week and the highest value was recorded in the treatment T-3(12.42 x 10(3)cfucm(-2)). Based on the present in vitro study, it may be concluded that biodegradable substrates especially sugarcane bagasse significantly enhanced the physico-chemical parameters of waters and optimized the favourable conditions for heterotrophic bacterial growth in biofilm, making it the most suitable substrate which can be used in aquaculture system as production enhancement strategy.
The life cycle of a product depends to a great extent on its reuse and ease of recycling. This work had developed of composite materials of reprocessed polypropylene composites with rice husk ash (RHA) and sugarcane bagasse ash (SBA) through the coextrusion and injection processes as main purpose. The polymeric matrix was reprocesed until six generations by the injection technique. The reprocessed PP was mixed in 80:20 proportions with respect to filler mineral, using maleic anhydride as coupling agent in a coextrusion machine. The new series of composite materials were analyzed thermal, mechanical, theological and morphologically. The incorporation of ashes in the PP matrix achieved characteristics of improved tensile strength, conserving the thermal properties. For this reason, this work presents an alternative for the manufacture of composite materials from post-industrial waste.
A hydroxylapatite-biochar composite material with the hierarchical porous microstructures of sugarcane top internodes (HAP/C-SC) was produced by carbonizing sugarcane top stalks, an agricultural waste residue, and then soaking them in limewater and (NH4)(2)HPO4 solution in turns. The HAP/C-SC with the surface area of 8.52-28.44 m(2)/g inherited various macropores from parallel vessels, thick-walled cells of sclerenchyma, thin-walled cells of storage parenchyma, and pits in cell and vessel walls of sugarcane top stalks. When the initial Zn2+ concentration is 5-400 mg/L, the Zn2+ absorption capacity of HAP/C-SC is 19.91, 22.54, and 25.37 mg/g at 25 degrees C, 35 degrees C, and 45 degrees C, respectively, which is equivalent to the Zn2+ absorption capacity of synthetic nano-hydroxyapatite. The HAP/C-SC showed a good removal performance for Zn cations, and the adsorption followed Langmuir model and pseudo-second-order kinetic model well. The Zn-containing hydroxylapatite solid solutions {[
Lignocellulosic wastes can be potentially converted into several bioproducts such as glucose, xylo-oligosaccharides, and bioethanol. Certain processes, such as enzymatic hydrolysis, are generally needed to convert biomass into bioproducts. The present study investigated the production of xylanases and cellulases by Streptomyces thermocerradoensis I3 under solid-state fermentation (SSF), using wheat bran as a low-cost medium. The activities of xylanase and carboxymethyl cellulase (CMCase) were evaluated until 96 hr of incubation. The highest enzyme activity was observed after 72 hr of incubation. The crude enzyme extract was sequentially filtered, first using a 50 kDa filter, followed by a 30 kDa filter. Fraction 3 (F3) exhibited activities of both xylanase and CMCase. Xylanase and CMCase showed optimum activity at 70 degrees C and pH 6.0 and 55 degrees C and pH 6.0, respectively. The zymogram analysis showed a single activity band with a molecular mass of approximately 17 kDa. These findings provide strong evidence that the enzyme is a bifunctional xylanase/endoglucanase. This enzyme improved the saccharification of sugarcane bagasse by 1.76 times that of commercial cellulase. This enzyme has potential applications in various biotechnological procedures.
Increasing abundance of Stomoxys calcitrans has been observed in organic byproducts resulting from sugar cane alcohol production. This study aimed to evaluate the abundance of S. calcitrans in such byproducts. From January to December 2011, the abundance of S. calcitrans was monitored in four byproducts: sugar cane bagasse, mulch, filter cake (FC) and mulch plus vinasse (MV), in a sugar cane mill located at the municipality of Angelica, state of Mato Grosso do Sul, Brazil. Monthly, 20 emergence traps were placed in each substrate, remaining active for the following four weeks. A total of 4,049 specimens of S. calcitrans was caught during the whole period, representing 9.22\% of total amount of collected flies. The four byproducts studied showed significant differences regarding the abundance of S. calcitrans, being higher in FC (67.20\%) and MV (29.19\%). Abundance peaks were observed in June (PV) and October (PV and TF). The highest productivity of S. calcitrans was observed in TF (55.8 flies/m(2)) and PV (24.2 flies/m(2)) and the average monthly production of S. calcitrans at the mill was estimated at 37,000 and 24 million, respectively. The high capacity of S. calcitrans breeding in sugar cane byproducts explains the recent population explosions of this species reported in cattle ranches around sugarcane mills.
Agave bagasse is one of the most abundant lignocellulosic residues readily available for valorization. The agave bagasse was pretreated by applying high-pressure CO2-H2O mixture at temperatures ranging from 150 to 190 degrees C for a residence time varying from 10 to 50 min. Subsequently, solid phase obtained from pretreatment was subject to enzymatic hydrolysis at high solid loadings. Under optimal conditions, the process integrating pretreatment followed by enzymatic hydrolysis yielded 75.8 mol\% of the polysaccharides present in the biomass converted into oligo- or monosaccharides, providing 110.5 g/L of reducing sugars. The monosaccharides present in the obtained hydrolysate were successfully fermented into ethanol, demonstrating the feasibility of performing its biological conversion to commercial biofuels or biochemicals. Thereby, the present study has demonstrated the proof of concept of use of more sustainable high-pressure CO2-H2O pretreatment in the context of lignocellulosic residual biomass valorization based on the biochemical sugar platform. (C) 2020 Elsevier Ltd. All rights reserved.
A heat pump based Freeze Concentration System (FCS) is proposed to concentrate sugarcane juice from 20 to 40 Brix in a Jaggery making process. Further concentration of the juice is carried out in a boiling pan. Inclusion analysis is carried out to estimate sucrose loss in the ice formed in a layer freezing process. A mathematical model is developed taking in to consideration effect of time varying ice thickness on evaporator temperature, compressor capacity, Coefficient of Performance (COP) of the heat pump. Data on operating parameters for a jaggery unit located at Rahu Pimplgaon in Daund District, Maharashtra was collected through field visits. Using this data, energy consumption of this conventional Jaggery making process is calculated. Energy balance has been carried out and Sankey diagram is drawn. Energy consumption of the FCS is calculated using results of the mathematical model. Total energy consumption of the FCS integrated jaggery making process is calculated. Comparison of the conventional process and FCS integrated process is presented. Bagasse saving of about 1338 kg per day can be achieved using heat pump based FCS along with bagasse fired pan boiling. Further, hot spots are eliminated thereby reducing caramelisation significantly resulting in improved Jaggery color. (c) 2005 Elsevier Ltd. All rights reserved.
Solid-state fermentation was carried out to evaluate three different agro-industrial wastes, sugar cane bagasse, coffee husk and cassava bagasse for their efficiency in production of citric acid by a culture of Aspergillus niger. Cassava bagasse best supported the mould's growth, giving the highest yield of citric acid among the tested substrates. Results showed the fungal strain had good adaptation to the substrate (cassava bagasse) and increased the protein content (23 g/kg) in the fermented matter. Citric acid production reached a maximum (88-g/kg dry matter) when fermentation was carried out with cassava bagasse having initial moisture of 62\% at 26 degrees C for 120 h. (C) 2000 Elsevier Science Ltd. All rights reserved.
Lactobacillus vini is a bacterial contaminant found in industrial environments of winemaking and fuel-ethanol fermentation. However, there has been no standard analysis of its physiology that can pinpoint its adaptive traits to these kinds of environments. In view of this lack of information, the aim of this study is to determine the nutritional factors that lead to the growth of L. vini in the industrial plants of fuel-ethanol. First of all, the limited growth of this bacterium was studied in the industrial substrate, which was improved by nutritional supplementation with amino acids, and its homofermentative status was confirmed. Metabolite analysis showed that citrate is a growth factor of paramount importance for this bacterium in industrial processes through pyruvate metabolization, and increases ATP production and biomass formation. Furthermore,e acetate uptake, either from the medium or generated from citrate metabolism, was assimilated for biomass production. Hence, a metabolic model was designed to describe the role of citrate and acetate in the growth of L. vini that could be tested on other lactobacilli.
Sustainable bioenergy production is required to meet the growing demand and environmental concerns. This study addresses current and advanced options for biomass-based electricity generation integrated to a sugarcane ethanol distillery in Brazil and polices that would foster its deployment. The typical combustion and steam cycle system and the integrated gasification combined cycle are the options considered for lignocellulosic biomass conversion into heat and power, associated with carbon capture and storage technologies. Besides conventional sugarcane, eucalyptus and energy-cane are also examined as promising feedstocks to extend operational days and/or increase biomass yields. The considered biomass-based electricity options are able to mitigate climate change impacts and depletion fossil resources. However, decreasing costs is a challenge to overcome for its broader implementation. The assessed strategies may help to guide policymakers on how to feasibly deploy advanced technologies for electricity production from biomass, meeting the future demands for sustainable electricity. The choice of larger processing scales shows an important effect on reducing costs, as well as choosing energy-cane as feedstock, which is also favorable for reducing climate change and land use impacts. Likewise, government policies that reward climate mitigation, as RenovaBio in Brazil, have a prominent role to foster advanced biomass-based electricity production technologies.
This study evaluates the energy and environmental performance of a cogeneration system operating simultaneously with bagasse and straw in a rankine cycle. Different process conditions, defined in terms of boiler operating pressure, moisture content and straw addition rate, were analyzed. The combination of these parameters led to the elaboration of one hundred and twenty-five analysis scenarios. The energy profile was based on the energy performance indicator, which is the ratio between the exported electricity and the intrinsic energy of biomass consumed for its generation, and the environmental assessment was performed in terms of climate change. Scenario modeling was developed according to the conceptual framework proposed by the life cycle assessment technique with a `from cradle-to-gate' coverage. Results indicate that the best energy and environmental performances (energy performance indicator = 0.193 and 688 kg CO2eq/MWh) were obtained with the highest pressure (100 bar) and addition rate (50\%), and the lowest moisture content (10\%). Moreover, straw moisture has more influence on the system environmental performance than its addition rate.
Kinetics of batch fermentation of sugarcane juice for lactic acid production by Lactobacillus plantarum NCIM 2912 under anaerobic conditions has been analyzed. Lactic acid fermentation with this bacterium is found to be homolactic. Kinetics of cell growth and multiplication fits reasonably into Monod's kinetic model, and the Luedeking-Piret equation has been found to reliably predict kinetics of lactic acid production. The kinetic parameters have been determined on the basis of experimental data using a program developed in Microsoft Excel and matlab. The value of the key kinetic constants estimated is the maximum specific growth rate (max), 0.92/h; substrate limitation constant (Ks), 44.1g/L; growth-associated constant (), 10.08g/g; and nongrowth-associated constant (), 0.92g/gh for lactic acid production. Maximum lactic acid concentration and productivity were found to be 89.5g/L and 1.243g/Lh, respectively. Kinetic analysis thus revealed that lactic acid production is predominantly growth associated. Effect of substrate inhibition has been observed to be relatively small. Stoichiometric parameters have been estimated to be the maximum product yield coefficient YPS, 0.83g, lactic acid/g sucrose and average cell mass yield coefficient Yxs, 0.47. (c) 2014 Curtin University of Technology and John Wiley \& Sons, Ltd.
Soil organic carbon (SOC) largely influences soil quality and sustainability. The effects of no-till (NT) and crop straw return practices (SR) on soil organic carbon sequestration have been well documented. However, the mechanism of soil bacterial community in regulating soil organic carbon under NT and SR remains unclear. In this study, we investigated the impacts of tillage (conventional tillage (CT) and NT) and crop straw return practices (crop straw removal (NS) and SR) on topsoil layer (0-5 cm) bacterial community, CH4 and CO2 emissions and SOC fractions in rice-wheat cropping system. Overall, in the wheat season following the annual rice-wheat rotation in two cycles, NT significantly increased SOC by 4.4\% for 1-2 mm aggregates in the 0-5 cm soil layer, but decreased CO2 emissions by 7.4\%. Compared with NS, SR notably increased the contents of SOC in the topsoil layer by 6.5\% and in macro-aggregate by 17.4\% in 0-5 cm soil layer, and promoted CH4 emissions (by 22.3\%) and CO2 emissions (by 22.4\%). The combination of NT and NS resulted in relatively high SOC and low CH4 emissions along with high bacterial community abundance. The most abundant genus under different treatments was Gp6, which significant impacted SOC and MBC. Bacterial communities like Subdivision3 had the most impact on CH4 emissions. Structural equation modeling further suggested that the soil bacterial community indirectly mediated the SOC through balancing SOC in 1-2 mm aggregates and CH4 emissions. This study provides a new idea to reveal the mechanism of short-term tillage and straw return on SOC.
A lysimeter experiment was carried out with sugarcane aiming to evaluate the leaching of nitrogen derived from either urea (N-15) or the soil/sugarcane crop residues. The leaching of K+, Ca2+, and Mg2+ was also evaluated. The experiment was a factorial 2x4. The influencing factors were: firstly, the differential addition of two kinds of sugarcane remains to the soil, simulating conditions of cane-plantation renewal after the cane crop harvest, with and without previous straw removal by burning; secondly, four doses of N: 0, 30, 60, and 90 kg ha(-1). During the experimental period the total volume of water received by the sugarcane-soil system was 2,015 mm, with 1,255 mm as precipitation and 760 mm as irrigation. The loss of N by leaching from the fertilizer (N-15) was not detected. In the first three weeks the largest losses of N by leaching occurred, originating from the soil/sugarcane remains-N. The mean of leached N during the experimental period of 11 months was of 4.5 kg ha(-1). The mean losses of K+, Ca2+, and Mg2+ were of 13, 320 and 80 kg ha(-1), respectively.
Brazil has become a great producer of bioethanol using sugarcane as the basic raw material. Fed-batch process and continuous process are used. Biogas generation from vinasse, production of dry yeast, and autolyzed bagasse for animal feed are making the ethanol production less polluting and more profitable. Bagasse surplus has also been converted into electrical energy. Another alternative use for bioethanol is its conversion to petrochemical derivatives. Up to the present, however, this conversion has been carried out on only a small scale by the industry.
To better understand the production of enzymes of industrial interest from microorganisms with biotechnological potential using lignocellulosic biomass, we evaluated the production of endoglucanase and xylanase from Aspergillus tamarii. CAZymes domains were evaluated in the genome, and a screening of the enzymatic potential of A. tamarii in various agricultural biomasses was done. The enzymatic profile could be associated with the biomass complexity, with increased biomass recalcitrance yielding higher activity. A time-course profile defined 48 h of cultivation as the best period for cultivating A. tamarii in sugarcane bagasse reached 12.05 IU/mg for endoglucanase and 74.86 IU/mg for xylanase. Using 0.1\% (w/v) tryptone as the only nitrogen source and 12 mu mol/L CuSO4 addition had an overall positive effect on the enzymatic activity and protein production. A 2(2) factorial central composite design was used then to investigate the simultaneous influence of tryptone and CuSO4 on enzyme activity. Tryptone strongly affected enzymatic activity, decreasing endoglucanase activity but increasing xylanase activity. CuSO4 supplementation was advantageous for endoglucanases, increasing their activity, and it had a negative effect on xylanases. But overall, the experimental design increased the enzymatic activity of all biomasses used. For the clean cotton residue, the experimental design was able to reach the highest enzyme activity for endoglucanase and xylanase, with 1.195 IU/mL and 6.353 IU/mL, respectively. More experimental studies are required to investigate how the biomass induction effect impacts enzyme production.
Composite materials are less weighty, stronger or also cheaper. A composite material is usually composed of two or more identical or different metals. It examines the mechanical behaviour, in the production of specimens in different silicon nitride compositions, of Aluminium Alloy 6063 metal matrix composites with controlled (or) bagasse ash (BA) and silicon nitride distribution. The Stir Casting and Friction stir processing (FSP) method is used to fabricating the AMCs. The mechanical behaviour of the entire specimen is examined in comparison to the existing composite materials, such as the modification of the hardness, tensile and compression tests. The work is aimed at producing an absolutely new composite material and at examining its mechanical properties with various reinforcement compositions.Copyright (c) 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference Virtual Conference on Technological Advancements in Mechanical Engineering
In this study, mechanical, thermal and insulating properties of ultra-light thick particleboard (nominal density 250 kg m(-3) and thickness 50 mm) made from sugarcane residues (bagasse) and wood planer shaving as a green building material (mainly based on renewable resources) were investigated. Urea formaldehyde and melamine-urea-formaldehyde resins have been used for board making. The results of insulating properties showed the absorption coefficient of sound for both bagasse and wood planer shaving particleboard increased as frequency increased, and noise reduction coefficient for all treatments was 0.313 and 0.365 for bagasse and wood planer shaving particleboard, respectively. Thermal conductivity for all boards was varying from 0.045 to 0.051 Wm(-1)K(-1), and was in the range of insulation boards from other lignocellulosic materials. The results also showed that the boards from bagasse and melamine-urea-formaldehyde resin had the best mechanical properties. Finally, thermal conductivity and noise reduction coefficient for all treatments met the requirements of IS standard (IS 3129: Amendment No. 4 2006) for low density particleboard as a thermo- acoustic insulating semi- green composite.
Introduction: Allelopathic properties of cane straw arc reported. however. information on the effect on some weed species is incomplete Objective: To evaluate the allelopathic effect of sugarcane straw (Sacchanun spp. Hybrid) on germination and initial growth of weed (Achyranthes aspera var. Indica L.) under controlled conditions. Methodology: An experiment was carried out using a completely randomized design with six treatments including a control, and five ratios of straw 25\%, 50\%, 75\%. 100\%, 125\%, with four repetitions. The doses used corresponded to the proportion of dry straw biomass / m2 in a cane field. Weed seeds were placed at a depth of 1.0 cm, and germination, thy mass, stem length and radicle length were evaluated. Results: It was evidenced that germination was influenced at 10 days by the different treatments, as well as the thy mass, the length of the stem and the length of the radicle at 7 and 10 days after starting the experiment. Conclusions: The results of the study indicate that the sugarcane straw exerts a negative allelopathic effect on the germination and initial growth of Achyranthes aspera, being the 75\% dose the one with the best results.
The study was conducted to assess the effects of whey, molasses and exogenous enzymes on fermentation, aerobic stability and nutrient composition of ensiled maize cobs. Five treatments were ensiled in 1.5 L anaerobic glass jars over 32 days, namely i) control (maize cobs without additives (CON); ii) maize cobs with sugarcane molasses only (MOL); iii) MOL and whey (MOW); iv) MOW and exogenous enzyme at 0.5 g/kg maize cob mixture (ENZ1) and v) MOW and exogenous enzyme at 1 g/kg maize cob mixture (ENZ2). There was a day effect on gross energy (GE) for CON, MOL, ENZ1 and ENZ2 and none for MOW. There was a day effect in ADF for MOL, ENZ1 and ENZ2 and none for CON and MOW. There was lower dry matter (DM) on day 32 compared with day 0 for all treatments. There were treatment effects for GE, crude protein (CP), ash, ether extract, amylase-treated neutral detergent fibre and acid detergent fibre (ADF). On day 32, the neutral detergent fibre (NDF) and ADF concentrations in CON were higher than in MOL, MOW and ENZ2. At day 32, CON silage pH (4.2) was lower than the pH values of ENZ1 (4.5) and ENZ2 (4.6) silages. Acetic acid levels were higher in ENZ1 than ENZ2 silages. Ammonia nitrogen (NH3-N) levels averaged 25 +/- 6.6 g NH3-N/kg total nitrogen, which is indicative of satisfactory ensiling. The MOL, ENZ1 and ENZ2 silages produced more carbon dioxide than CON and MOW silages. The addition of molasses and whey did not improve the nutritive quality of the maize cobs after ensiling. Ensiling maize cobs with molasses, whey and exogenous enzymes resulted in lower DM and fibre levels in the maize cobs, which could enhance intake and digestibility of nutrients when offered to pigs as a component of a balanced diet. Further investigations using higher concentrations of whey and molasses are warranted to improve the energy and protein composition of the maize cobs.
This study investigated the fractionation of biomass using a decomposing mixture of hydrogen peroxideformic acid as a pretreatment for the biorefining of Miscanthus x giganteus and of sugarcane bagasse. The main parameters investigated were the hydrogen peroxide concentration (2.5, 5.0 and 7.5 wt\%) and biomass loading (5.0 and 10.0 wt\%). At the highest hydrogen peroxide concentration used (7.5 wt\%), the energy released by the decomposition of the H2O2 could heat the reaction mixture up to 180 degrees C in a short time (6-16 min). As a result, highly delignified pulps, with lignin removal as high as 92 wt\%, were obtained. This delignification process also solubilised a significant amount of pentosan (82-98 wt\%) from the initial biomass feedstock, and the resulting pulp had a high cellulosic content (92 wt\%). The biomass loading only affected the reaction rate of hydrogen peroxide decomposition. Various analytical methods, including Fourier transform infrared spectroscopy, and thermogravimetric and elemental analyses, characterized the lignin obtained. (C) 2014 Elsevier Ltd. All rights reserved.
Silicon (Si) is one of the most abundant elements found in the earth's crust, but is mostly inert and only slightly soluble. Agriculture activity tends:to remove large quantities of Si from soil. Sugarcane is known to absorb more Si than any other mineral nutrient, accumulating approximately 380 kg ha(-1) of Si, in a 12-month-old crop. Sugarcane (plant growth and development) responses to silicon fertilization have been documented in some areas of the world, and applications on commercial fields are routine in certain areas. The reason for this plant,response or yield increase is not fully understood, but several mechanisms have been proposed. Some studies indicate that sugarcane yield responses to silicon may be associated with induced resistance to biotic:and abiotic stresses, such as disease and pest resistance, Al, Mn, and Fe-toxicity alleviation, increased P availability, reduced lodging, improved leaf and stalk erectness, freeze resistance, and improvement in plant water economy. This review covers the relationship of silicon to sugarcane crop production, including recommendations on how to best manage silicon in soils and plants, silicon interactions with others elements, and laboratory methodology for determining silicon in the soil, plant and fertilizer. In addition, a future research agenda for silicon in sugarcane is proposed.
Sugarcane is one of the biggest sugar-producing commodities in Indonesia and has been established by the government in a national sugar self-sufficiency program. Increasing sugar productivity is one of the keys to achieving sugar self-sufficiency. The use of organic material mixed with Trichoderma sp. believed to be able to increase the productivity of sugar cane, especially those planted in the marginal fields with low fertility. The aim of this study was to evaluate the growth response of Bulu Lawang (BL) sugarcane variety to the application of organic plus material. The design of the experiment used a split plot design. The main plot was anorganic fertilizer with 4 levels while organic matter was added as a subplot with 3 levels. Based on the results of the study, there was no interaction between the main plot and the experimental subplot. Independently, the application of inorganic fertilizer 100\% of the recommendations triggers a better sugarcane stem length. The application of organic rice straw plus endophytic and non-endophytic T. asperellum encourages better leaf number, stem height, segment length and sugarcane stem diameter
Agro-industrial wastes such as sugarcane bagasse, wheat bran, rice bran, corn cob and wheat straw are cheapest and abundantly available natural carbon sources. The present study was aimed to production of amylase and xylanase simultaneously using agro-industrial waste as the sole carbon source. Seven thermophilic strains of actinomycete were isolated from the mushroom compost. Among of these, strain designated MSC702 having high potential to utilize agro-industrial wastes for the production of amylase and xylanase. Strain MSC702 was identified as novel species of Streptomyces through morphological characterization and 16S rRNA gene sequence. Enzyme production was determined using 1\% (w/v) of various agro-industrial waste in production medium containing (g/100mL): K2HPO4 (0.1), (NH4)(2)SO4 (0.1), NaCl (0.1), MgSO4 (0.1) at pH 7.0 after incubation of 48 h at 50 degrees C. The amylase activity (373.89 IU/mL) and xylanase activity (30.15 IU/mL) was maximum in rice bran. The decreasing order of amylase and xylanase activity in different type of agro-industrial wastes were found rice bran (RB) > corn cob (CC) > wheat bran (WB) > wheat straw (WS) > sugarcane bagasse (SB) and rice bran (RB) > wheat bran (WB) > wheat straw (WS) > sugarcane bagasse (SB) > corn cob (CC), respectively. Mixed effect of different agroindustrial wastes was examined in different ratios. Enzyme yield of amylase and xylanase was similar to 1.3 and similar to 2.0 fold higher with RB: WB in 1: 2 ratio.
The main attention of the article deals with the taking out of silica from natural supply such as sugar cane bagasse. These waste materials in large quantities can produce a critical environmental problem. Hence, there is a need to adopt suitable plan to condense the waste. In the present study, all the waste materials are subjected to humidity removal with heating at 200 C-degrees and sintered at 900 C-degrees for 7 h. The obtained powders were examined and described by FT-IR and XRD analysis. The powder obtained from sugar cane bagasse sources was found to 100\% SiO2 in tridymite and crystobalite phases. Crystalline sugarcane bagasse (SCB) was used as an alternative silica source for the synthesis of glass samples. The synthesis was studied as a function of crystalline sugarcane bagasse up to 35 mol\% and the products of glass samples were characterized using a variety of analytical techniques, including X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR), differential thermal analyzes (DTA) and UV/VIS/NIR spectroscopy.
Bioconversion of hemicellulosic hydrolysate into ethanol plays a pivotal role in the overall success of biorefineries. For the efficient fermentative conversion of hemicellulosic hydrolysates into ethanol, the use of immobilized cells system could provide the enhanced ethanol productivities with significant time savings. Here, we investigated the effect of 2 important factors (e.g., cell concentration and stirring) on ethanol production from sugarcane bagasse hydrolysate using the yeast Scheffersomyces stipitis immobilized in calcium alginate matrix. A 2(2) full factorial design of experiment was performed considering the process variables- immobilized cell concentration (3.0, 6.5 and 10.0g/L) and stirring (100, 200 and 300rpm). Statistical analysis showed that stirring has the major influence on ethanol production. Maximum ethanol production (8.90g/l) with ethanol yield (Yp/s) of 0.33g/g and ethanol productivity (Qp) of 0.185g/l/h was obtained under the optimized process conditions (10.0g/L of cells and 100rpm).
In this study the effect of pretreatments, such as hydrothermal (HT) with hydrogen peroxide-alkaline (HP-A), acid-alkaline (AA), or alkaline (AL) pretreatments, on the Carnauba (Copernicia prunifera) straw residue a plant native to Brazil that is used to produce wax as well as the use of the pretreated biomass for the production of lignocellulolytic enzymes (cellulases and xylanases) by Trichoderma reesei CCT2768 using solid state fermentation (SSF) were evaluated. The untreated and pretreated biomasses were characterized by using the Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy assays. A kinetic study was carried out to estimate the best time for producing cellulases (FPase and CMCase) and xylanases. HP -A pretreatment was the only one that simultaneously reduced hemicellulose (removal of 60.72\%), lignin (removal of 50.71\%) and pretreatment yield of 59.28\%. FPase (0.9 U/g) and CMCase (13 U/g) production in the case of this pretreatment was optimum, while AL pretreatment was ideal for xylanase (99.5 U/g). The use of Carnauba (Copernicia prunifera) straw residue coupled with HP -A pretreatment and SSF shows promise for the production of lignocellulolytic enzymes. (C) 2017 Elsevier Ltd. All rights reserved.
This paper introduces a methodological framework for assessing the sustainability of solid biofuels in Mexico. The designed framework comprises 13 normalized indicators and two diagnostic studies, covering the economic, social, environmental, and institutional sustainability dimensions, and their intersections. Indicators are normalized using the concept of load capacity of a system, similarly to the planetary boundaries. Thus, the graphical representation of results facilitates their multidimensional analysis. The framework was applied to three case studies: traditional fuelwood in rural households, charcoal for restaurant grilling, and electricity cogeneration from sugarcane bagasse. This was part of an iterative process of testing and refining the framework and simultaneously demonstrating its application in the Mexican bioenergy context. This led to the conclusion that the resulting framework (a) provides a useful, quantitative, and comprehensive overview of both broad and specific sustainability aspects of the assessed system; (b) requires a balance of accessible but also scattered or sensitive data, similarly to most existing frameworks; (c) is highly flexible and applicable to both modern and traditional solid biofuels; and (d) is simple to communicate and interpret for a wide audience. Key directions for improvement of the framework are also discussed.
Pollution caused by heavy metals has become a serious problem to the environment nowadays. The treatment of wastewater containing heavy metals continues to receive attention because of their toxicity and negative impact on the environment. Recently, various types of adsorbents have been prepared for the uptake of heavy metals from wastewater through the batch adsorption technique. This study focused on the removal of zinc from aqueous solution using microwave incinerated sugarcane bagasse ash (MISCBA). MISCBA was produced using microwave technology. The influence of some parameters such as pH, contact time, initial metal concentration and adsorbent dosage on the removal of zinc was investigated. The competition between H+ and metal ions has affected zinc removal at a low pH value. Optimum conditions for zinc removal were achieved at pH 6.0, contact time 180 min and adsorbent dosage of 10 g/L, respectively. The maximum adsorption capacity for the removal of zinc was found to be 28.6 mg/g. The adsorption process occurred in a multilayered surface of the MISCBA. Chemical reaction was the potential mechanism that regulates the adsorption process. MISCBA can be used as an effective and cheap adsorbent for treatment of wastewater containing zinc metal ions.
Ocular drug delivery is a significantly challenging task due to the presence of various anatomical and physio-logical barriers in the eye. Naturally available polysaccharides, when used as drug vehicles provide increased retention time, bioavailability, and penetration due to their unique mucoadhesive and charge-possessing nature. This review discusses the polysaccharide-based drug delivery system for the eye. Polysaccharides like alginic acid, cellulose derivatives, chitosan, pectin, xanthan gum, gellan gum, and hyaluronic acid are reviewed in this report. Additionally, emphasis is given to some of the recently investigated polymers such as sugarcane bagasse cellulose, a polysaccharide extracted from the seeds of Manilkara zapota, and Tremella fuciformis polysaccharide as drug vehicles for effective ocular drug delivery. This review also provides insight on clinical status and FDA -approved polysaccharides for ophthalmic delivery of therapeutics.
This research was performed to find an alternative, low-cost, competitive, locally available and efficient adsorbent to treat nickel (Ni) containing effluents. For this purpose, several Brazilian agro-wastes like sugarcane bagasse (SCB), passion fruit wastes (PFW), orange peel (OP) and pineapple peel (PP) were compared with an activated carbon (AC). The adsorbents were characterized. Effects of fundamental factors affecting the adsorption were investigated using batch tests. Kinetic and equilibrium studies were performed using conventional models. It was verified that the adsorption was favored at pH of 6.0 for all agro-wastes, being dependent of the Ni speciation, point of zero charge and surface area of the adsorbents. The Ni removal percentage was in the following order: SCB > OP > AC > PFW > PP. From the kinetic viewpoint, the Elovich model was appropriate to fit the Ni adsorption onto SCB, while for the other adsorbents, the pseudo-first-order model was the most suitable. For all adsorbents, the Langmuir model was the more adequate to represent the equilibrium data, being the maximum adsorption capacities of 64.1 mg g(-1), 60.7 mg g(-1), 63.1 mg g(-1), 48.1 mg g(-1) and 64.3 mg g(-1) for SCB, PFW, OP, PP and AC, respectively. These results indicated that mainly SCB and OP can be used as alternative adsorbents to treat Ni containing effluents.
The aim of this work was to propose a new analysis procedure to obtain the kinetic parameters of lignocellulosic biomass pyrolysis assuming first order reactions in independent parallel scheme using sugarcane straw as case study. The thermogravimetric experiments were carried out using heating rates between 1.25 degrees C/min and 10 degrees C/min. Firstly, considering 700 different scenarios were obtained correlations between pre-exponential factor and activation energy from simulations of a first order global reaction. In these correlations only three experimental parameters are strictly necessary such as heating rate, peak temperature and peak conversion rate. Two approaches were proposed to apply the correlations in an independent parallel reactions scheme in order to obtain the kinetic parameters of lignocellulosic biomass pyrolysis. The results obtained with both approaches presented a good agreement between experimental and modeled data. Therefore, the correlations proposed will help in the kinetic parameters determination providing reliable results. (C) 2015 Published by Elsevier B.V.
Southeast Asia currently faces a huge increase in energy consumption and serious environmental issues. A widely underutilized and still unexplored potential of these countries lies in residual biomass. In the present research, the production quantities and energy yields of the most abundant agricultural byproducts in Vietnam, i.e., rice straw, rice husks, sugarcane bagasse and sugarcane trash, were calculated. Total crop yield, residues ratio and net calorific values of the wet basis biomass served as input parameters for the calculations. Moreover, the results were found for individual regions and provinces of the country. The findings show that the production of paddy rice straw is an enormous 97 million tons per year with an energy potential of over 380 TWh, as well as another 9 million tons yearly and 35 TWh in the case of rice husks. More than half of rice biomass production is concentrated in the Mekong River Delta region. Harvesting and processing of sugarcane annually generates about 5 million tons of bagasse and over 3.5 million tons of sugarcane trash with the total energy potential of about 27 TWh, which is primarily available in the central regions of Vietnam. The detailed laboratory determination of fuel-energy properties of studied materials, such as gross and net calorific value, volatile matter, ash and moisture content and contents of chemical elements was also carried out. Based on the research results and literature analysis, the possibilities of biofuel production and energy utilization of the above-mentioned residues are discussed.
Our study was motivated by the large amount of crop residues produced in Brazil, which represent underutilized waste biomass and a serious threat to the environment because of the landfilling. For example, even though the corn crop is not popular in Brazil, it is produced in the area of around 18-20 million hectares with an average production of 5-6 t ha(-1). That is the reason to seek for the crop residues value-added applications as proposed in the present study. Four Brazilian crop waste biomass: orange bagasse, corn husks, sugarcane straw and coffee residues were used for cellulose nanofibers (CNF) production. CNFs were prepared using alkali treatment, followed by bleaching with sodium chlorite and extraction with oxalic acid. All steps were applied under moderate conditions of temperature and pressure, such as temperature of 120 degrees C and below, water solutions with chemicals' concentrations lower that 10\% and short sonication pulses. CNFs with diameters in the range 50-70 nm were obtained and products from orange bagasse and corn husks presented high crystallinity indexes (CI), 0.72 and 0.75, respectively. The highest CNF yield was obtained from corn husks (38.5\%) followed by sugarcane straw (24.0\% with CI of 0.69). CNFs obtained from coffee residues showed a CI value of 0.65 after two bleaching steps. Different CNF morphologies were obtained according to the raw material. The four-crop waste biomass can be considered as excellent starting materials for CNF production in the four-steps process that adds new value to agro-industrial waste and might bring great economical valorization to Brazilian crops production.
Bagasse is an abundant by-product from sugarcane production that can be used for conversion into biofuels. Nonetheless, the recalcitrant structures of lignocellulosic fibers required a pretreatment prior conversion into biofuels. In this study, four mechanical deconstruction methods were compared in terms of energy demand and energy efficiency at lab scale: BM (ball mill), VBM (vibratory ball mill), CM (centrifugal mill) and JM (jet mill). Results indicate that VBM was more effective compared to BM, JM and CM in enzymatic accessibility and sugars solubilization: VBM-3h > BM-72 h > JM-5000 rpm > CM-0.12 mm. However, preliminary energetic assessment showed that at lab scale, the CM (centrifugal mill) as mechanical fractionation process appears to be the most efficient in terms of energy-efficiency (kg glucose/kWh) compared to BM, VBM and JM. A comparison with literature pretreatments data highlighted that fine and/or ultrafine milling process (BM, VBM, CM) are simpler saccharification technologies, which not required any chemical or water inputs, thus minimizing waste generation and treatment. (C) 2016 Elsevier Ltd. All rights reserved.
Sugarcane-bagasse fiber-polymer cement composites were prepared using three lattices namely, styrene butadiene, vinyl ester, and styrene acrylic. The lattices percentages ranged between 3 and 21\% from the weight of the mixture. The pressed samples were irradiated at different irradiation doses by using electron beam (EB) accelerator. Comparative studies have been made for physicomechanical properties of unirradiated and irradiated samples. The results indicated that the flexural strength, modulus of elasticity, and impact toughness of the composites increase with the increasing polymer content up to 9.9 and 15\% of styrene butadiene, vinyl ester, and acrylic styrene, and then decrease. It was also observed that the maximum values of flexural strength and modulus of elasticity obtained at EB-irradiation dose 45, 40, and 25 kGy for styrene butadiene, acrylic ester, and vinyl ester, respectively. The impact strength of the composites did not significantly improve above 10 kGy. The average values of hardness of irradiated composites were higher than that those of unirradiated and control composites. (c) 2007 Wiley Periodicals, Inc.
Sugarcane agricultural residue (RAC) has a high potential as an energy source to fight global warming. No studies have characterized RAC baling, which is needed for the use of this material as an energy source. To fill this void, we studied the effects of particle size and moisture content on energy consumption and bale density during RAC compaction with laboratory and field tests. Using a theoretical model calibrated with the laboratory tests, the components of the energy consumption of the field tests were determined. The energy consumption tended to rise as the particle size increased in field and laboratory tests (9.13 and 0.9 kJ kg(-1)). In the field tests, the energy and density increased with moisture for large and small particle sizes. The energy required for bale production was about 6.5 \% of the available energy of RAC, which provides a wide range of opportunities to use RAC as a source of renewable energy. These findings may be used to optimize bale compaction. They indicate that RAC is a viable alternative for replacing high-contaminating materials such as coal in energy generation.
Biochemical conversion of wheat straw was investigated using hydrothermal pretreatment, enzymatic saccharification, and microbial fermentation. Pretreatment conditions that were compared included autocatalyzed hydrothermal pretreatment at 160, 175, 190, and 205 degrees C and sulfuric-acid-catalyzed hydrothermal pretreatment at 160 and 190 degrees C. The effects of using different pretreatment conditions were investigated with regard to (i) chemical composition and enzymatic digestibility of pretreated solids, (ii) carbohydrate composition of pretreatment liquids, (iii) inhibitory byproducts in pretreatment liquids, (iv) furfural in condensates, and (v) fermentability using yeast. The methods used included two-step analytical acid hydrolysis combined with high-performance anion-exchange chromatography (HPAEC), HPLC, ultra-high performance liquid chromatographyelectrospray ionization-triple quadrupole-mass spectrometry (UHPLC-ESI-QqQ-MS), and pyrolysisgas chromatography/mass spectrometry (Py-GC/MS). Lignin recoveries in the range of 108-119\% for autocatalyzed hydrothermal pretreatment at 205 degrees C and sulfuric-acid-catalyzed hydrothermal pretreatment were attributed to pseudolignin formation. Xylose concentration in the pretreatment liquid increased with temperature up to 190 degrees C and then decreased. Enzymatic digestibility was correlated with the removal of hemicelluloses, which was almost quantitative for the autocatalyzed hydrothermal pretreatment at 205 degrees C. Except for the pretreatment liquid from the autocatalyzed hydrothermal pretreatment at 205 degrees C, the inhibitory effects on Saccharomyces cerevisiae yeast were low. The highest combined yield of glucose and xylose was achieved for autocatalyzed hydrothermal pretreatment at 190 degrees C and the subsequent enzymatic saccharification that resulted in approximately 480 kg/ton (dry weight) raw wheat straw.
Lignin has been suggested as a promising candidate for cosmetic applications due to its remarkable potential to absorb ultraviolet rays and distinctive antioxidant activity. This study aims at evaluating the performance of lignin from sugarcane bagasse (SCB) as natural UV blocker, antioxidant, and pigment. Lignin was extracted from SCB, characterized and incorporated into a blemish balm (BB) cream. The biological potential, concretely, in vitro and in vivo sun protection factor (SPF) and in vitro UVA-PF, and safety were assessed. A high-purity SCB lignin (>92 \%) was obtained by a mild alkaline extraction process. The results of cytotoxicity, mutagenicity, skin sensitization and in vivo acute cutaneous irritation demonstrated that SCB lignin is safe for topical applications. Lignin showed capacity to scavenge both ABTS and DPPH radicals, which were preserved after its incorporation into the cosmetic formulation. Notable results were achieved in terms of in vitro and in vivo SPF of 9.5 +/- 2.9 and 9.6 +/- 0.8, respectively. Furthermore, the tested lignin-based BB cream revealed a broad-spectrum UV protection (critical wavelength of 378 +/- 0.5 nm). These results suggest SCB lignin as multifunctional and safe ingredient for use in cosmetic products.
Disturbances in soil can cause short-term soil changes, consequently changes in microbial community what may result in long-lasting ecological effects. Here, we evaluate how multiple pulse disturbances effect the dynamics and resilience of fungal community, and the co-occurrence of fungal and bacterial communities in a 389 days field experiment. We used soil under sugarcane cultivation as soil ecosystem model, and organic residue (vinasse - by-product of sugarcane ethanol production) combined or not with inorganic (organic residue applied 30 days before or together with mineral N fertilizer) amendments as disturbances. Application of organic residue alone as a single disturbance or 30 days prior to a second disturbance with mineral N resulted in similar changes in the fungal community. The simultaneous application of organic and mineral N as a single pulse disturbance had the greatest impact on the fungal community. Organic amendment increased the abundance of saprotrophs, fungal species capable of denitrification, and fungi described to have copiotrophic and oligotrophic lifestyles. Furthermore, the changes in the fungal community were not correlated with the changes in the bacterial community. The fungal community was neither resistant nor resilient to organic and inorganic disturbances over the one-year sampling period. Our findings provide insights on the immediate and delayed responses of the fungal community over one year to disturbance by organic and inorganic amendments.
Rice straw, a renewable feedstock, is recalcitrant and its degree of polymerization makes pretreatment obligatory for subsequent bioconversion. The present study explores an advanced oxidation process i.e. Alkaline Wet Air Oxidation (AWAO) as a pretreatment for rice straw and scrutinizes the effect of operation parameters on cellulose recovery, hemicellulose solubilization and lignin removal through Response Surface Methodology (RSM). AWAO resulted in 68-90\% cellulose recovery, 67-87\% hemicellulose solubilization and 32-66\% lignin removal while generating limited inhibitors. AWAO caused oxidative delignification, hemicellulose deacetylation and cleavage of carbohydrate-lignin linkages as revealed by FT-IR, thereby improving cellulose accessibility indicated by 42-89\% enzymatic cellulose convertibility (\%ECC) or \% cellulose conversion. The findings of the present study indicate minimization of chemical input and absence of potent inhibitors in the liquor which collectively implies reduction in freshwater requirements, minimization of waste generation and its treatment cost. (C) 2017 Elsevier Ltd. All rights reserved.
Both the excess and deficiency of nutrients in the soil can influence the technological quality of sugarcane stalks, and affect the quality of the juice, the fiber content, and the concentration of sucrose, which directly impact the quality and quantity of products derived from sugarcane. Thus, this study aimed to investigate the effect of nitrogen and zinc fertigation, irrigated by a central pivot, on various parameters that affect the industrial quality of sugarcane (IACSP 95-5000), in the plant and first ratoon crop cycles in a Cerrado Red Latosol soil in Brazil. The experiment was conducted under field conditions at an average altitude of 907 m in an area of the Rio Paraiso II farm of the Raizen Mill, in the municipality of Jatai, Goias (GO). The experiment was conducted in a randomized complete blocks design and analyzed in a scheme of 4 x 5 subdivided plots, with three repetitions. The treatments consisted of four nitrogen doses (0, 60, 120, and 180 kg ha(-1)) and five zinc doses (0, 2.5, 5.0, 7.5, and 10.0 kg ha(-1)), on plant cane and first ratoon cane. Urea served as the source of nitrogen fertilizer and was applied in three dosages (treatments) 60 days after planting. Zn sulfate served as the zinc source and was applied in four dosages (treatments) at a single time in the planting. At harvest, ten stalks were randomly sampled from each plot and sent to the Raizen Mill agro-industrial laboratory in Jatai-GO for analysis and to determine the polarizable amount of sugar per cane (Pol \% cane), polarizable amount of sugar in the juice (Pol \% juice), total soluble solids (Brix \%), apparent purity, wet bagasse weight (WBW), reducing sugars, total recoverable sugar (TRS), and fiber content. The highest doses of zinc (10 kg ha(-1)) and nitrogen (180 kg ha(-1)) had the greatest effects on sugarcane WBW and TRS.
Rice straw lignin was extracted via alkaline hydrolysis and structurally characterized using FT-IR and H-1 NMR spectra. Ethyl acetate extract of acid solubilized lignin was found to contain p-coumaric acid, ferulic acid and caffeic acid as major phenolic acids which were isolated and characterized using spectral data. Amides of isolated phenolic acids were synthesized by their reaction with propyl and butyl amines using microwave irradiation and analysed using spectral studies. Phenolic acids and amides were evaluated for their effect on pollen germination and tube growth in pumpkin. Pollen tube length was significantly increased with N-butyl-3-(3, 4-dihydroxyphenyl) acrylamide and N-butyl-3-(4-hydroxyphenyl) acrylamide at 5 ppm concentration than the control. These results could be utilised in increasing pollen tube length of Cucurbita pepo while making interspecific cross between C. moschata and C. pepo in order to transfer hull-less character of C. pepo to virus resistant C. moschata genotypes.
In the present study, a magnetically separable adsorbent, manganese ferrite (MnFe2O4)/sugarcane bagasse biochar magnetic composites (MFSCBB-MCs), was fabricated through a one-step pyrolysis method. The characterization of the prepared adsorbents indicated that MnFe2O4 nanoparticles were successfully embedded into the biochar matrix, offering magnetic separability and increasing the negative charges on the surface relative to the pristine biochar. Batch adsorption tests indicated that the adsorption of lead on MFSCBB-MCs was pH-and dose-dependent. The experimental results were effectively fitted using the pseudo-second-order kinetic model (R2 > 0.99) and the Langmuir isotherm equation (R2 > 0.99), indicating the main chemisorption pathway and monolayer coverage process. Meanwhile, lead adsorption was found to be spontaneous and endothermic, as shown by the study of thermodynamic parameters. The maximum capacity, qm, calculated from the Langmuir model was 155.21 mg center dot g-1 at 25 degrees C, demonstrating excellent adsorption capability compared with several previously reported bagasse adsorbents. Based on adsorption mechanism analysis, physical adsorption, electrostatic attraction, and complexation were all involved in the lead(II) adsorption process on MFSCBB-MCs. Furthermore, the adsorbent was easily regenerated as indicated by the high magnetic separation and chemical desorption potential after five cycles, so it is a cost-effective and environmentally favorable adsorbent for wastewater lead removal.
First generation ethanol production from two crops, sugarcane and sorghum in four modalities, could be done considering the sustainability level of each modality. We studied two ethanol production modalities from sugarcane, the first from molasses while the second from direct juice; as well as two ethanol production modalities from sorghum, one from a high crop yield and the other from a medium crop yield. To find the modality with the highest sustainability, we developed a sustainability index integrated by six indicators applied in all lifecycle stages of each crop modality considering: greenhouse gas emissions (GHG), land use, water use, energy balance, ethanol production costs and the number of employments generated. We found that sensitivity analysis shows water use is the most sensitive indicator although this sensitivity to the weight factor of each indicator is not large enough to produce significant changes. We also found that production of sugarcane ethanol from direct juice has the highest sustainability index; therefore it would be the most sustainable modality, especially in Mexican regions where abundance of rainwater takes place. It requires 52\% less blue water, involves 10.6 times less land use, has 28\% less Greenhouse Gas emissions, generates 11\% more employments, and its unit costs are 3.5\% lower than sugarcane ethanol from molasses -this last one being the current modality Mexico uses to produce ethanol.
Lasiodiplodan, a (1 -> 6)-beta-d-glucan, is an exopolysaccharide with high commercial value and many applications in food, pharmaceuticals, and cosmetics. Current industrial production of beta-glucans from crops is mostly by chemical routes generating hazardous and toxic waste. Therefore, alternative sustainable and eco-friendly pathways are highly desirable. Here, we have studied the lasiodiplodan production from sugarcane bagasse (SCB), a major lignocellulosic agricultural residue, by Lasiodiplodia theobromae CCT 3966. Lasiodiplodan accumulated on SCB hydrolysate (carbon source) supplemented with soybean bran or rice bran (nitrogen source) was 16.2 {[
This study modeled and optimized the operational parameters for biohydrogen production from waste sugarcane leaves and assessed hydrogen production on a semi-pilot scale. A Box-Behnken design with input variables of substrate concentration (8 to 24 g/L), inoculum concentration (10\% to 50\% v/v), and hydraulic retention time (HRT, 24 to 96 h) was used. A coefficient of determination (R-2) of 0.90 and the predicted optimum operational set-points of 14.2 g/L substrate concentration, 32.7\% inoculum concentration, and 62.8 h HRT were obtained. Experimental validation produced a biohydrogen yield of 12.8 mL H-2/g fermentable sugar (FS). A semi-pilot scale process in a 13-L Infors reactor under optimized conditions gave a cumulative hydrogen volume and yield of 3740 mL and 321 mL H-2 g(-1) FS, respectively, with a peak hydrogen fraction of 37\%. Microbial analysis from the process effluent conducted by Polymerase Chain Reaction cloning indicated the presence of hydrogen-producing bacteria belonging to Clostridium sp., Klebsiella sp., and Enterobacter sp. These findings highlight the feasibility of biohydrogen production from sugarcane waste and provide preliminary knowledge on process scale up.
The production of textiles generates a large amount of liquid residues considered to be environmentally problematic and which, if discarded without due treatment, may cause eutrophication of water sources, the intoxication of living beings, and the blocking of light penetration. Some methods have been applied for the treatment of this type of waste, with the prominence of biological and physicochemical techniques. The combination of two or more techniques enhances the treatment's efficiency. This work investigated the use of bacteria derived from the leachate produced by the textile industry itself, fed with vinasse, a by-product of the alcohol industry, with subsequent application of Fenton's reaction. The biological method, optimized in terms of aeration and quantity of nutrients for the bacteria combined with the physicochemical method optimized in terms of the amount of reagents, was efficient for the discoloration of the effluent in approximately 100 \%, for toxicity reduction, for the degradation of organic matter in 80 \%, and with acceptable acidity for disposal after only eight days of treatment. The method was considered of great efficiency and low application cost, without the production of hazardous waste.
Bioremediation is one of the existing techniques applied for treating oil-contaminated soil, which can be improved by the incorporation of low-cost nutritional materials. This study aimed to assess the addition of two low-cost plant residues, sugarcane bagasse (SCB) and leaf litter (LL) of the forest leguminous Mimosa caesalpiniifolia plant (sabia), either separately or combined, to a contaminated soil from a petroleum refinery area, analyzed after 90 days of treatment. Individually, both amounts of SCB (20 and 40 g kg(-1)) favored the growth of total heterotrophic bacteria and total fungi, while LL at 20 g kg(-1) better stimulated the hydrocarbon-degrading microorganism's activity in the soil. However, no TPH removal was observed under any of these conditions. Higher microbial growth was detected by the application of both plant residues in multicontaminated soil. The maximum TPH removal of 30\% was achieved in amended soil with 20 g kg(-1) SCB and 20 kg(-1) LL. All the experimental conditions revealed changes in the microbial community structure, related to the handling of the soil, with abundance of Alphaproteobacteria. This study demonstrates the effectiveness of the plant residues SCB and LL as low-cost nutritional materials for biodegradation of hydrocarbon in real oil contaminated soil by indigenous populations.
Bagasse fiber is a residue of a sugarcane milling process. In this research, bagasse fiber has been used as reinforcing component for unsaturated polyester resin (USP) to open up further possibilities in waste management. The chemical treatments using sodium hydroxide (NaOH) and acrylic acid (AA) were carried out to modify the fiber properties. The effect of different fiber treatment and the fiber content on the composite properties were investigated. At different fiber loadings, AA treated fiber composites shows better mechanical properties compared to those of NaOH treated fiber composites. SEM investigations show that the surface modifications improve the fiber-matrix interaction. Moreover, the storage modulus of dynamic mechanical analysis (DMA) indicated that NaOH and AA treated fibers based composites enhance the storage modulus of the composites. From water absorption study, it was observed that the treated fiber composites show lower water absorption properties compared to those of untreated fiber based composites. (c) 2007 Elsevier Ltd. All rights reserved.
This study investigated the effects of Lactobacillus hilgardii (LH), alone or in combination with Lactobacillus plantarum (LP), on the aerobic stability, fermentation quality and dynamics of the bacterial and fungal communities of sugarcane top silage. Results demonstrated that LH and LHLP (LH combined with LP) improved the aerobic stability of sugarcane top silages. As the exposure time increased, the pH values and the contents of lactic acid, acetic acid, as well as propionic acid remained stable in silage treated with LH and LHLP. The abundance of L. hilgardii was enriched and the undesirable microorganisms, such as Acetobacter pasteurianus, Paenibacillus amylolyticus and yeasts like Kazachstania humilis, were suppressed in silages treated with LH and LHLP. In conclusion, LH-treated silage, whether with LP or not, positively impacted the fungal and bacterial microbes. This improved the quality of fermentation, the aerobic stability, and reduced aerobic spoilage in sugarcane top silage.
This study describes a two-step alkali/oxidation process to efficiently convert waste sugarcane bagasse (SCB) into cellulose nanofibrils (CNF) whose structures have been characterized using a range of analytical techniques (SRWAXS, IR, TEM and DLS). Increasing the concentration of the NaOH solution from 10 to 16 wt\% in the first step results in a gradual increase in cellulose II content from 0 to >99 \%, which also produces a corresponding increase in fiber crystallinity index from 32 to 61 \%. Varying the concentration of NaClO used in the second oxidative step enables the morphologies of the CNF to be reliably controlled, with fiber lengths decreasing from micrometer to nanometer levels as the amount of NaClO oxidant used is increased. This simple two-step alkaline/ oxidative treatment process enables SCB to be converted into CNF exhibiting different polymorphic and morphological properties, thus enabling their economic and reproducible production as nanostructured materials for numerous applications.
MCM-41 and SBA-15 have many applications in chemical processes. However, the high cost of producing these materials limits their applications to a large-scale. To reduce production costs and promote recycling of industrial waste, this study presents methodologies for the synthesis of MCM-41 and SBA-15 using glass powder, rice husk ash and sugarcane bagasse ash. The methodologies consist of dissolving the raw materials in a sodium hydroxide solution under mild reaction conditions and subsequently using it as reactive silica source, to synthesize the MCM-41 and SBA-15 hybrid silicas. The materials were synthesized in two steps. The first step of SBA-15 occurred at 35 degrees C for 24 h and the hydrothermal synthesis occurred at 100 degrees C for 48 h. For MCM-41, these steps occurred at 28 degrees C for 2 h and 150 degrees C for 96 h, respectively. The samples were characterized using X-ray Diffraction (XRD), Energy-dispersive X-ray Fluorescence (ED-XRF), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR). The results showed that the basic treatment of the raw materials was effective in increasing the reactivity of the alternative silica sources and eliminating the negative effects of impurities. Moreover, the results showed that the syntheses produced highly-ordered materials, free of contaminants.
A novel type of gel-like bioadsorbent was prepared by crosslinking thiourea-modified sugarcane bagasse cellulose with carboxymethyl cellulose, and used for the removal of methylene blue (MB) and crystal violet (CV) in single and binary systems. The resulting bioadsorbent was characterized with FTIR, XRD, SEM and thermogravimetric analysis. The porous structure of hydrogels significantly improved the adsorption capacity towards dyes. The effects of pH, temperature, initial concentration of dyes and adsorbent dosage on the adsorption behavior were systematically investigated. The maximum adsorption capacity for MB and CV reached as high as 632.9 and 574.7 mg/g in single system; and 555.6 and 427.4 mg/g in binary system, respectively. The kinetic data fitted well to the pseudo-second-order model in both systems; and the dye adsorption on bioadsorbent was mainly governed by intraparticle diffusion. Meanwhile, the isotherm data fitted well to Langmuir models. Moreover, the bioadsorbent showed excellent recycling ability over the desorption tests, thus leading to a promising and green-based adsorbent for the removal of dyes.
In this study, an environmentally benign strategy was used to fabricate hierarchically ordered mesoporous carbons (HOMCs) using sugarcane bagasse as the scaffold and then activated with nitric acid or carbon dioxide for capacitive deionization (CDI) application. Calcium ions were selected as the model species because of the importance to hard water. The electronic microscopic images show that the HOMCs contain large domains of highly ordered hexagonal arrays of mesopores with 1-D channels and the ordered structures are retained after activation with nitric acid (HOMC-H). In addition, the oxygen and nitrogen content increase in HOMC-H. Different from HOMC-H, a partial distortion of mesostructures with the increase in micropore surface area is observed after physical activation with CO2. The electrochemical performance of HOMCs shows ideal rectangular voltammograms with non-faradic reaction at scan rates of 1-10 mV s(-1) and the specific capacitance of HOMC-H is 1.4-20 times higher than those of as-prepared and CO2-activated HOMCs. The impedance measurement shows good transport of the bulk electrolyte to the electrolyte/electrode interface of HOMC-H with excellent reversibility and ideal capacitive properties. In addition, the specific electrosorption capacity of HOMC-H electrode materials for Ca2+ removal can be up to 115.4 mu mol g(-1) at 1.2 V. The excellent electrochemical performance of HOMC-H is mainly attributed to the increased mesoporous structures and hydrophilic functional groups after chemical activation. Results clearly indicate that the HOMC-H is a promising electrode which could facilitate good charge propagation and fast ion adsorption to treat grey and brown waters. (C) 2015 Elsevier B.V. All rights reserved.
The replacement of synthetic surface-active compounds (SACs) by their microbial counterparts is carving out a niche for themselves in the field of bioremediation. However, the high cost of microbial products has limited their application at a realistic scale. In the current study, several hydrocarbon-degrading microorganisms were assayed as potential SAC producers in low-cost liquid media. Only the strain CC10, placed within the class Actinobacteria, was able to produce emulsifying molecules by using a combination of sugarcane vinasse or crude glycerol (as cheap carbon substrates) with urea or peptone (as nitrogen sources). The emulsifying activity of the supernatants and the stability of emulsions formed with motor oil depended on the carbon and nitrogen sources. However, the biodegradability of these metabolites was only associated with the carbon substrate, and it was always higher than the two tested synthetic surfactants, sodium dodecyl sulfate and Triton X-100. Also, a positive linear association between emulsifying and lipase activities of the CC10 supernatants was detected (r = 0.781; p = 0.219), with the maximum activities detected in the glycerol-peptone supernatant. Interestingly, this supernatant was able to emulsify different oily substrates, a property that could be used to increase the efficiency of the treatment of effluents with high fat content.
Commercial binders based on formaldehyde are the main adhesive to produce particleboards, however, these binders are harmful to human health and the environment. In this scenario, alternative binders are a possibility to reduce the formaldehyde content in the particleboards. Therefore, the focus of this original scientific study is to explore the thermal, physical and mechanical properties of particleboards produced with natural rubber latex as a potential polymeric binder. Bagasse-latex particleboard (BLP) with nominal density of 800 kg/m(3), with different latex content. 28\% (BLP-28), 42\% (BLP-42) and 56\% (BLP-56) by mass were evaluated. The quality of the particleboards produced was assessed by determining their thermal, physical and mechanical properties. The formation process of interfacial structure between sugarcane bagasse and latex was observed, configuring the adhesion of the two phases. The thermal conductivity of all the particleboard formulations showed attractive performance as thermal insulating material, considering that these are medium to high nominal density particleboards. According to physical tests, higher latex contents in the particleboard did not affect the density, however, it created a binder protection against water absorption. Contrarily, an increase in the latex content (as in BLP-56 formulation) did not cause increase in the mechanical properties under flexural loading. The BLP-42 particleboards performed better mechanically based on modulus of rupture (MOR) and modulus of elasticity (MOE) with average values of 6.32 MPa and 1275 Mpa, respectively. These results indicated the potential use of latex natural rubber as an alternative to produce insulation particleboards in civil construction. (C) 2018 Elsevier Ltd. All rights reserved.
The efficient saccharification of lignocellulosic materials requires the cooperative actions of different cellulase enzyme activities: exoglucanase, endoglucanase, P-glucosidase, and xylanase. Previous studies with the fungi strains Aureobasidium sp. CHTE-18, Penicillium sp. CH-TE-001, and Aspergillus terreus CH-TE-013, selected mainly because of their different cellulolytic and xylanolytic activities, have demonstrated the capacity of culture filtrates of cross-synergistic action in the saccharification of native sugarcane bagasse pith. In an attempt to improve the enzymatic hydrolysis of different cellulosic materials, we investigated a coculture fermentation with two of these strains to enhance the production of cellulases and xylanases. The 48-h batch experimental results showed that the mixed culture of Penicillium sp. CH-TE-001 and A. terreus CH-TE-013 produced culture filtrates with high protein content, cellulase (mainly beta-glucosidase), and xylanase activities compared with the individual culture of each strain. The same culture conditions were used in a simple medium with mineral salts, corn syrup liquor, and sugarcane bagasse pith as the sole carbon source with moderate shaking at 29degreesC. Finally, we compared the effect of the cell-free culture filtrates obtained from the mixed and single fermentations on the saccharification of different kinds of cellulosic materials.
Candida guilliermondii cells were entrapped in Ca-alginate beads and used for xylitol production from concentrated sugarcane bagasse hemicellulosic hydrolysate in three different fermentation systems, namely 125-ml Erlenmeyer flasks (EF), 2.4-1 stirred tank reactor (STR) and 2.4-1 basket-type stirred tank reactor (BSTR). The EF system provided a xylitol production of 21.0 g(P) l(-1), a product yield based on xylose consumption of 0.54 g(P) g(S) (-1), and an overall production rate of 0.44 g(P) l(-1) h(-1) after 48 h of fermentation. By the STR system, 23.5 g(P) l(-1) was produced after 60 h of fermentation, corresponding to a yield of 0.58 g(P) g(S) (-1) and a production rate of 0.39 g(P) l(-1) h(-1). As the average volume of the beads decreased by 10.7\% (p < 0.05) during this fermentation, a basket was fitted into the reactor vessel to prevent the beads abrasion and thus maintain their integrity. However, the xylitol yield (0.46 g(P) g(S) (-1)), production rate (0.21 g(P) l(-1) h(-1)) and concentration (15.0 g(P) l(-1)) attained by this system were affected by mass-transfer limitations. (C) 2003 Elsevier Science Inc. All rights reserved.
A mature crop of sugarcane produces large amount of residue at harvest in the form of tops. The aim of the present work was to use the discarded tops of harvested sugarcane as a potential raw material for the removal of heavy metals from aqueous solution. A hydroxyapatite-carbon adsorbent with the hierarchical porous microstructure of sugarcane stems (SS-HAP/C) was prepared by carbonizing stem internodes of sugarcane tops and subsequent doping with the saturated limewater solution and 0.02 mol/L (NH4)(2)HPO4 solution in turn for five times. The morphological character of 55-HAP/C was inherited from the bio-precursors of sugarcane top stems, which mainly included the macropores from the storage parenchyma thin-walled cells of 30-115 mu m in width, the parallel and densely packed vessels of 20-85 mu m in width, the sclerenchyma thick-walled cells of similar to 30 mu m in width, and the pits in the vessel and cell walls of about similar to 4.0 mu m in width. The specific surface area through the mercury porosimetry method and the Brunauer Emmett Teller (BET) surface area were estimated to be 5.63 m(2)/g and 8.52-28.44 m(2)/g, respectively. For the test at the initial Pb(II) concentrations of 50, 100, 150 and 200 mg/L, the removal capacities of the un-pulverized SS-HAP/C (>3 mm) were determined to be 52.62, 101.85, 152.08 and 210.69 mg/g, respectively, which were comparable to the adsorption capacities of the synthetic nano-hydroxyapatites. The SS-HAP/C showed an excellent removal performance as an adsorbent for Pb(II) ions. The formation of the (PbxCa1-x)(5)(PO4)(3)(OH) solid solution through the coexisting ion exchange (x = 0.01-0.05) and dissolution-precipitation (x = 0.20-0.21) processes was the main mechanism for the Pb(II) uptake. (C) 2018 Elsevier Ltd. All rights reserved.
As a green and efficient component separation technology, organic acid pretreatment has been widely studied in biomass refining. In particular, the efficient separation of lignin by p-toluenesulfonic acid (p-TsOH) pretreatment has been achieved. In this study, the mechanism of the atmospheric separation of bagasse lignin with p-TsOH was investigated. The separation kinetics of lignin was analyzed. A non-simple linear relationship was found between the separation yield of lignin and the concentration of p-TsOH, the temperature and the stirring speed. The shrinking nucleus model for the separation of lignin was established based on the introduction of mass transfer and diffusion factors. A general model of the total delignification rate was obtained. The results showed that the process of lignin separation occurred into two phases, i.e., a fast stage and a slow stage. The results provide a theoretical basis for the efficient separation of lignin by p-TsOH pretreatment.
Fermentation of sugarcane-derived liquors for ethanol production produces a liquid waste called vinasse, which is highly contaminant and constitutes a serious ecological problem. Therefore, to reduce this liquid waste's contamination potential, vinasses from the alcoholic distillation were used as a growth medium for micmalgae species like Chlorella vulgaris, evaluating their possible environmental advantages and industrial uses. Reductions in COD and BOD of up to 49\% and 70\% respectively, were observed, coupled with a maximum algal biomass production of 10.50 +/- 0.92 g/L. Also, after fermentation, the human ingestion toxicity potential, terrestrial toxicity potential, and photochemical oxidation potential were reduced by 85\%, 83\%, and 93\% respectively. These results contribute to the understanding of C. vulgaris growth using vinasses as a culture medium under strict heterotrophic conditions and the use of micmalgal biomass to reduce the environmental burden caused by vinasses.
Survival and nitrogenase efficiency of Nostoc commune and N. austinii were evaluated monthly in four carrier materials (sugarcane bagasse, wheat straw, wheat bran and peat) at 10, 30 and 40 degrees C. Survival, as well as nitrogenase activity, of both species was much better in peat. Followed by wheat bran, sugarcane bagasse than in wheat straw at 10 and 30 degrees C up to three months, the activity of N. commune being better than N. austinii. None of the materials tested was found to be superior to peat as carrier of Nostoc species but the results indicated that wheat bran and sugarcane bagasse can be used as inoculant carriers with relative success. Storage of inoculants in these carriers is feasible at 30 degrees C up to three months.
Composting is a biological process in which the organic matter is degraded by the mixed population of microorganisms in a moist aerobic environment to more stable and humidified end products. The composting process involves an interaction between the organic waste, microorganisms, moisture and oxygen. The molasses-based biomethanated distillery wastewater is presently effectively utilized with sugarcane pressmud through the composting process. The aim of present work was to evaluate the effect of ozone pretreatment on the rate of composting process and the quality of compost obtained. The GC-MS \& FTIR analysis of ozone pretreated wastewater indicated the degradation and/or transformation of the organic compounds to simpler compounds present in the wastewater. Composting was performed by mixing fixed weight ratios of pressmud and different ratios of ozone pretreated wastewater (1:3, 1:4 and 1:5). The composting process was found to occur faster in the ozone pretreated wastewater for all the ratios as compared to the untreated wastewater. The final compost characteristics were found to be optimum for the 1:3 and 1:4 ratios of pressmud and wastewater. The bio-oxidative phase duration of composting has been reduced for the ozone pretreated wastewater.
Bioethanol and other sugarcane by-products, such as the bagasse, are responsible for approximately 12\% of Brazil's total energy generation. This crop is expanding in the Central-Western Region of Brazil, within the Brazilian savannah biome (Cerrado). It is strongly associated with the use of mineral and/or organic fertilizers and irrigation practices due to drought period during winter. However, higher soil moisture content (due to rain or irrigation) and nitrogen (N) application increase nitrous oxide (N2O) emission, which is one of the main greenhouse gases from the agricultural sector. This study aimed to evaluate soil N2O fluxes in sugarcane under field conditions with contrasting water regimes in the Cerrado region of Brazil. Due to watering regimes, based on different crop evapotranspiration demand, it was possible to establish adequate water-use efficiency technologies. Increases in watering regimes did not increase N2O emissions compared to ``rescue irrigation'', commonly used by farmers in the region. However, higher yields were obtained from the higher watering regime (T75\%) compared to the farmers' common practice. (C) 2021 Elsevier B.V. All rights reserved.
The structural polysaccharides contained in plant cell walls have been pointed to as a promising renewable alternative to petroleum and natural gas. Ferulic acid is a ubiquitous component of plant polysaccharides, which is found in either monomeric or dimeric forms and is covalently linked to arabinosyl residues. Ferulic acid has several commercial applications in food and pharmaceutical industries. The study herein introduces a novel feruloyl esterase from Aspergillus clavatus (AcFAE). Along with a comprehensive functional and biophysical characterization, the low-resolution structure of this enzyme was also determined by small-angle X-ray scattering. In addition, we described the production of phenolic compounds with antioxidant capacity from wheat arabinoxylan and sugarcane bagasse using AcFAE. The ability to specifically cleave ester linkages in hemicellulose is useful in several biotechnological applications, including improved accessibility to lignocellulosic enzymes for biofuel production.
The effect of hemicellulose and lignin solubilisation by H2SO4 and NaOH catalysed pretreatments was correlated to the extent of subsequent enzymatic cellulose hydrolysis. Three different grass-type feedstocks, palm empty fruit bunch, sugarcane bagasse and barley straw, were investigated. Soluble fractions after catalysis were characterised for mono- and oligosaccharides contents, while the residues were analysed for constituent monosaccharides composition. Alkali pretreatment resulted into extensive lignin removal. This removal resulted in up to 90\% (w/w) conversion of glucan into glucose by enzymes. But, the alkaline conditions also provoked up to 50\% unwanted xylan losses. Acid pretreatment resulted into solubilisation (70-80\% (w/w)) of xylan with almost no losses, while lignin remained. Although moderate xylan solubilisation increased enzymatic cellulose hydrolysis of residual glucan, extensive removal of xylan decreased it. Therefore, under the treatment conditions, the alkali treatments were the most efficient in terms of enzymatic release of xylose and glucose from the insoluble residues. (C) 2014 Elsevier B.V. All rights reserved.
Wet oxidation (WO) pretreatment of sugarcane bagasse, rice hulls, cassava stalks and peanut shells was investigated. WO was performed at 195 degrees C for 10 min, with 2 g kg(-1) of Na2CO3 and under either 3 or 12 bar of oxygen. Oxygen pressure and the type of raw material used had a major effect on the fractionation of the materials, formation of sugars and by-products, and cellulose enzymatic convertibility. Cellulose content in the solid fraction increased after pretreatment of all materials, except rice hulls. The greatest increase, from 361 g kg(-1) to almost 600 g kg(-1), occurred for bagasse. The solubilisation of individual components was different for each material. Bagasse xylan was solubilised to a large extent, and 45.2\% of it was recovered as xylose and xylo-oligosaccharides in the liquid fraction. In the prehydrolysates of rice hulls around 40\% of the original glucan was recovered as gluco-oligosaccharides, due to hydrolysis of starch contained in grain remains. The formation of by-products was modest for all the materials, but increased with increasing oxygen pressure. The highest yield of acetic acid (34-36 g kg(-1) of raw material) and furfural (0.7-1.8 g kg(-1)) occurred for bagasse. The pretreatment enhanced the enzymatic convertibility of cellulose giving the best result (670.2 g kg(-1)) for bagasse pretreated at the highest oxygen pressure. However, for the other materials the pretreatment conditions were not effective in achieving cellulose conversions above 450 g kg(-1). Some enzymatic conversion of xylan was observed.
Dielectric Barrier Discharge (DBD) can be used to produce a large volume of non-thermal plasma at atmospheric pressure. Such plasmas are sources of highly reactive species (radicals, ozone, atoms, ions and excited molecules). Due to its characteristics, the DBD plasma can be applied for the pretreatment of lignocellulosic materials, in order to extract lignin that prevents the access to remained fermentable sugars in the biomass. In this context, an alternative method for pretreatment of lignocellulosic material in an in-liquid DBD plasma reactor using non-contact electrodes, working with atmospheric air, has been proposed. After the pretreatment, the solids were washed and submitted to enzymatic hydrolysis with a commercial enzyme complex, at 10 FPU/g of pretreated biomass and 50 g/L solids concentration (dry basis), for 72 h. The release of fermentable sugars was measured, comparing the samples obtained with and without plasma treatment. The highest sugar release was achieved using the plasma-in-liquid pretreatment in a single step, with glucose and xylose yields of 51.3 and 38.5\%, respectively, after enzymatic hydrolysis. Thus, an effective pretreatment was developed to be applied to biomass such as: corn cob, sugarcane bagasse, bamboo, eucalyptus, etc., in order to reduce the environmental impact and, at the same time, produce biofuels. Graphic
The objective of this study was to evaluate the physical and mechanical properties of composite panels produced from sugarcane bagasse with different proportions of polystyrene (0\%, 10\%, 20\% and 30\%) and adhesive urea-formaldehyde (8\%, 10\% and 12\%). The panels were pressed at a temperature of 190 degrees C, pressure of 6.2 MPa for 30 minutes. For the physical properties, moisture content, apparent density, water absorption and swelling in thickness were evaluated. The mechanical properties analyzed were modulus of rupture (MOR), modulus of elasticity (MOE) by the test of static bending and perpendicular traction. The dynamic modulus of elasticity (MOEd) was determined by fitting an equation that best represents its relation with the static modulus of elasticity. The panels were classified as of low density, with a mean value of 0.46 g / cm(3) +/- 0.015 g / cm(3). There was a negative correlation in the physical properties of moisture content, water absorption and swelling in thickness with the proportions of polystyrene. The different adhesive percentages did not significantly influence the physical properties; however, the mechanical properties were reduced when 10\% adhesive was used. From the MOEd values it was possible to adjust a significant equation with the coefficient of determination (R-2) of 0.8051 estimate of the static MOE. Panels produced with 8\% adhesive and 30\% polystyrene can be recommended in the production of composite panels. However, the use of paraffin is indicated in order to improve the physical properties of the panels, also a chemical treatment of the bagasse particles before making the panels.
The effect of pretreatment with peracetic acid (PAA) or an ionic liquid (1-ethyl-3-methylimidazolium acetate, {[
High temperature ethanol fermentation from sugarcane molasses B using thermophilic Crabtree-positive yeast Kluyveromyces sp. IIPE453 was carried out in batch bioreactor system. Strain was found to have a maximum specific ethanol productivity of 0.688 g/g/h with 92 \% theoretical ethanol yield. Aeration and initial sugar concentration were tuning parameters to regulate metabolic pathways of the strain for either cell mass or higher ethanol production during growth with an optimum sugar to cell ratio 33:1 requisite for fermentation. An assessment of ethanol recovery from fermentation broth via simulation study illustrated that distillation-based conventional recovery was significantly better in terms of energy efficiency and overall mass recovery in comparison to coupled solvent extraction-azeotropic distillation technique for the same.
An efficient scheme was developed for the conversion of wheat straw (WS) into bioethanol, silica and lignin. WS was pre-extracted with 0.2 mol/L sodium hydroxide at 30 degrees C for 5 h to remove about 91\% of initial silica. Subsequently, the alkaline-pretreated solids were subjected to alkaline hydrogen peroxide (AHP) pretreatment with 40 mg hydrogen peroxide (H2O2)/g biomass at 50 degrees C for 7 h to prepare highly digestible substrate. The results of enzymatic hydrolysis demonstrated that the sequential alkaline-AHP pretreated WS was efficiently hydrolyzed at 10\% (w/v) solids loading using an enzyme dosage of 10 mg protein/g glucan. The total sugar conversion of 92.4\% was achieved. Simultaneous saccharification and co-fermentation (SSCF) was applied to produce ethanol from the two-stage pretreated substrate using Saccharomyces cerevisiae SR8u strain. Ethanol with concentration of 31.1 g/L was produced. Through the proposed process, about 86.4\% and 54.1\% of the initial silica and lignin were recovered, respectively.
This study's overarching aim is to establish the areal extent and characteristics of the rapid sugarcane expansion and land use change in Sao Paulo state (Brazil) as a result of an increase in the demand for ethanol, using Landsat type remotely sensed data. In 2003 flex fuel automobiles started to enter the Brazilian consumer market causing a dramatic expansion of sugarcane areas from 2.57 million ha in 2003 to 4.45 million ha in 2008. Almost all the land use change, for the sugarcane expansion of crop year 2008/09, occurred on pasture and annual crop land, being equally distributed on each. It was also observed that during the 2008 harvest season, the burned sugarcane area was reduced to 50\% of the total harvested area in response to a protocol that aims to cease sugarcane straw burning practice by 2014 for mechanized areas. This study indicates that remote sensing images have efficiently evaluated important characteristics of the sugarcane cultivation dynamic providing quantitative results that are relevant to the debate of sustainable ethanol production from sugarcane in Brazil.
One of the main challenges of second generation (2G) ethanol production is the high quantities of phenolic compounds and furan derivatives generated in the pretreatment of the lignocellulosic biomass, which inhibit the enzymatic hydrolysis and fermentation steps. Fast monitoring of these inhibitory compounds could provide better control of the pretreatment, hydrolysis, and fermentation processes by enabling the implementation of strategic process control actions. We investigated the feasibility of monitoring these inhibitory compounds by ultraviolet-visible (UV-Vis) spectroscopy associated with partial least squares (PLS) regression. Hydroxymethylfurfural, furfural, vanillin, and ferulic and p-coumaric acids generated during different severities of liquid hot water pretreatment of sugarcane bagasse were quantified with highly accuracy. In cross-validation (leave-one-out), the PLS-UV-Vis method presented root mean square error of prediction (RMSECV) of around only 5.0\%. The results demonstrated that the monitoring performance achieved with PLS-UV-Vis could support future studies of optimization and control protocols for application in industrial processes.
China is the third largest sugar producer in the world. However, the sugar industry is challenged by high production costs (attributed to the high cane supply price), which lead to continuous financial deficits for sugar companies. Currently, sugarcane products are primarily composed of white sugar and non-centrifugal sugar (NCS); the utilization of sugarcane by-products (Le. bagasse, filter mud, and molasses) has also been partially industrialized. However, these strategies are far from adequate to address the challenge. China has successfully developed an innovative sugar manufacturing process using nano-ceramic membrane technology to overcome this predicament. In addition, concepts of high-value diversification of sugarcane products and value-added utilization of industrial by-products have been proposed. A series of sugarcane-based products, e.g. NCS produced by nano-ceramic membrane technology (MNCS), sugarcane-based beverages, plant water, and cultivation substrates, have been developed to improve the overall return of sugar enterprises. Thus, this paper mainly summarizes the diversification of sugarcane products and their development opportunities in China.
Knowledge of the effects of seed burial depth and the presence of straw on the soil surface on weed seedling emergence provides useful information for the development of weed management tactics. Buttonweed (Borreria densiflora DC.) is a troublesome weed that occurs in large infestations in soybean and sugarcane crops from north-central Brazil. This study investigated buttonweed emergence at different seed burial depths and straw amounts present on the soil surface. The experiment was conducted in greenhouse conditions, under a factorial design between four seed burial depths and four amounts of surface straw. Percent seedling emergence and fresh biomass (g) were evaluated at twenty-five days after installation (DAI). Greater buttonweed emergence occurred in seeds that were placed on the soil surface either without surface straw or with up to 1,000 kg ha(-1) of straw on the soil surface. With 4,000 kg ha(-1) of surface straw, buttonweed emergence was prevented when seeds were placed at a depth of 0.5 cm or deeper in the soil. These data indicated emergence of this weed species was greater at depths near the soil surface and in soils with the least amounts of surface straw. Information generated in this study provides a starting point for the development of knowledge for understanding the biology of buttonweed emergence and its population dynamics. Such information may be directly transmitted to growers and lays the groundwork for an integrated management approach for this weed species.
Biogas production from sugarcane vinasse has enormous economic, energy, and environmental management potential. However, methane production stability remains key issue, hindered by the presence of inhibitory compounds and other characteristics of the vinasse such as volatile fatty acids (VFA), alkalinity and pH. These parameters are identified as potential auxiliary indicators for diagnosing imbalances in the anaerobic digestion (AD) reactor. This study investigates the influence of VFA/alkalinity ratio on reactor stability, efficiency and optimization of continuous AD of vinasse during mesophilic conditions in terms of methane yield production. To this end, a combined experimental and simulation approach is adopted using the response surface methodology (RSM). Results reveal that for VFA/alkalinity ratio in the range of 0.23-0.3, a higher methane yield is obtained reaching up to 4.0 L CH4/L with an organic loading rate of 4.8 kg/m(3) d and a VFA less than 30 meq/ L. The result of RSM verifies that the methane yield are affected mainly by operating conditions: VFA/ alkalinity ratio (A), VFA (B) and pH (C).In addition, linear model values (A, B, C), quadratic model value (A(2), B-2, C-2), and interactive model values (AB, AC, BC) are found to be significant, with P- values <0.05. The average maximum value of the produced methane is obtained for the following optimum conditions: pH of 7.2, VFA of 10 d, and the VFA/alkalinity ratio of 0.3. These findings provide a foundation for predicting the behavior of anaerobic systems and optimizing the digestion process.
Using organic fertilizers on sugarcane mulches is a potentially interesting substitute for mineral fertilization in terms of economic and environmental impacts. However, no general agreement exists regarding the short-term effect of combining mulching and organic fertilization on greenhouse gas (GHG) emissions. Therefore, we studied different mixtures in the field by combining two amounts of sugarcane mulch (5 and 10 Mg ha(-1)) with different N fertilizers (urea, pig slurry, and digested sewage sludge). We measured CO2 and N2O emissions shortly after application of the mixtures (0-14 days) and the mulch decomposition dynamics from 0 to 120 days after application. We hypothesized that the relative amount of N to C modifies the decomposition dynamics and GHG fluxes. The emitted N2O-N and CO2-C were measured using static chambers. Mulch-C decomposition was measured using litterbags. Our results showed that the proportion of mulch-C remaining on the soil on day 120 was not altered by either the type of N fertilizer or the mulch amount. On a shorter time scale (0-49 days), the different N treatments affected the mulch-C and mulch-N losses and the C:N ratios, indicating a transient interaction between the dynamics of the mulch and the added N. The intensity of N2O-N emission was ranked as pig slurry > urea > digested sewage sludge, underscoring the effect of the physical form of N fertilizer. This work highlights the need to jointly study carbon and nitrogen dynamics and consider both soil carbon and gas emissions to assess the GHG balances of sugarcane farming practices.
Due to its hydrophobicity and high energy yielding, butanol emerged as an important industrial solvent and superior liquid fuel with a potential to replace gasoline. The economic production of butanol is mainly depending on raw material cost. Thus, the development of butanol production process using renewable energy sources such as lignocellulosic crop residues has gained interest. In the present study, production of butanol from sugarcane field residue (SFR) was carried using newly isolated solventogenic Clostridium beijerinckii YVU1. SFR is one of the abundant lignocellulosic potential substrate available in the tropical world. SFR contains 40.3 +/- 3.5\% cellulose, 28.5 +/- 3.0\% hemicellulose and 20.3 +/- 2.6\% lignin. The sequential dilute alkali and acid pretreatment was solubilized around 69\% of lignin and 73\% of hemicellulose. Ten percent (w/v) of pretreated substrate was subjected to enzymatic saccharification with cellulase, and it released 0.681 +/- 0.041 g of glucose/g of pretreated biomass. In the batch fermentation process, 22.8 g/l ABE with 16.5 g/l of butanol, 4.8 g/l of acetone and 1.5 g/l of ethanol was obtained. The performed fermentation process yielded 0.41 g of ABE/g of hydrolysate with 0.16 g/l/h productivity. The current work presents the impact of sequential alkali and acid pretreatment on the enzymatic hydrolysis of SFR as well as its utilization for butanol production by newly isolated C. beijerinckii YVU1. The outcome of the present work could be useful for further development in utilization of various crop residues for economical butanol production.
This study aimed to determine the best dilute acid hydrolysis condition for the hemicellulosic fraction of sweet sorghum bagasse for ethanol production by Scheffersomyces stipitis. The experiment followed a 2(3) factorial design with four central points, and had as variables: sulfuric acid concentration, temperature and hydrolysis time. Sorghum bagasse presented the following chemical composition: 24.77\% of lignin, 31.28\% of hemicellulose and 34.80\% of cellulose. The hydrolysis that resulted in the highest sugars concentration (14.22 g/L of xylose and 2.42 g/L glucose) was 1.75\% H2SO4, 121 degrees C and 40 minutes. This same condition provided low concentrations of toxic compounds (1.34 g/L of acetic acid, 0.90 g/L of phenol; 124.54 mg/L of hydroxymethylfurfural (HMF) and 978 mg/L of furfural). The fermentation of the hemicellulose-derived sugars by S. stiptis resulted in 22 g/L of ethanol, Y-P/S 0.40 g/g and Qp 0.34 g/L.h.
The development of micro-assays suitable for automation systems represents a helpful alternative by which many enzymes and factors can be studied simultaneously for the conversion of lignocellulose. The purpose of the present study was to evaluate a micro-assay method, based on hand-sheets, to reproducibly aliquot-pretreated lignocellulosic biomass at milligramme scale with minimal impact on the digestibility of the material. To favour representative sampling and handling for enzymatic conversion at milligramme scale, the solid fractions from steam-pretreated sweet sorghum bagasse (SSB) and triticale straw (TS) were subjected to homogenisation steps in sequential disintegrator and liquidiser at different severities prior to hand-sheet making (TAPPI). In the case of SSB, the disintegrator treatment (37,500 rpm) was sufficient to obtain the required fibre lengths, while the combined treatment with liquidiser (6250 rpm) and disintegrator (31,250 rpm) was needed for TS. The selected steps were able to improve homogenisation and fibre size distribution in the hand-sheets, attaining the required fibre lengths (less than 8 mm), with minimal influence on glucan conversion when using a conventional enzyme cocktail. The combined treatment and hand-sheet making had a more pronounced effect on the conversion of the xylan, with reduced xylose yields compared to small scale. The carbohydrate conversion in micro-assay was susceptible to more efficient enzyme combinations depending on the structural properties of the pretreated materials, presence and concentration of inhibitors as well as the enzyme dosage used. Nevertheless, the micro-assay method could distinguish between the different enzyme combinations, identifying those resulting in higher sugar yields from different lignocellulose materials pretreated under relatively mild conditions.
Particleboards produced with other lignocellulosic materials, beyond wood, are promising products for the furniture and building construction components, as doors, lining, floor, partitions, and coverings. However, there is little information about the resistance of them to xylophagous organisms. This is important due the different uses of particleboards, where they will be subject to attacks by decaying organisms, which can affect a structure and put people at risk. The present study aims to determine the biological resistance of particleboard produced with pine, sugarcane bagasse and malva particles to xylophagous organisms. The particleboard was produced with different proportions of pine wood heat treated at 200 degrees C and malva fiber (outer layers) and sugarcane bagasse core glued with an adhesive based on polyurethane from castor oil. No-choice and choice feeding tests with dry wood (Cryptotermes brevis) and conehead (Nasutitermes corniger) termites were carried out for the resistance test to xylophagous organisms, in addition to a test with rotting fungi which cause brown (Gloeophyllum trabeum and Rhodonia placenta) and white rot (Irpex lacteus and Trametes versicolor). The trial with dry wood termites showed low mass losses, regardless of the proportions applied. The mass losses were accentuated for the test with conehead termite, having the particleboard composed of 100\% pine been the most resistant among the boards tested. The greatest mass losses for fungal resistance were caused by Gloeophyllum trabeum. The particleboard produced with 100\% pine (outer layer) showed the highest resistance to the tested xylophagous organisms.
The development of a green and efficient process for the pretreatment of lignocellulosic materials using a nontoxic solvent and catalyst is challenging for the conversion of agricultural wastes to fuels and chemicals in biorefineries. Herein, an efficient microwave-accelerated pretreatment and fractionation of sugarcane trash by prehydrolysis using liquid hot water followed by glycerolysis is reported. The use of the liquid hot water results in efficient hemicellulose solubilization with 63.7\% recovery of the mono- and oligosaccharides with a high cellulose recovery of 92.8\% under the optimal condition at 170 degrees C for 40 min. The application of a Lewis acid, alum (AlK(SO4)(2)), at 360 mu mol/g in microwave-accelerated glycerolysis under the optimal condition at 200 degrees C for 10 min affords an enhancement in total delignification to 82.0\% and glucose yield of 78.6\% from enzymatic saccharification. This is 25.2\% and 8.7\% higher than those without alum. Further enhancement in delignification and sugar yield is achieved by supplementing sodium hydroxide to the reaction. The spent liquor containing glycerol with alum is converted to ethanol using recombinant Saccharomyces cerevisiae with the maximum theoretical yield of 82.1\%. The analysis of the recovered lignin by two-dimensional nuclear magnetic resonance spectroscopy shows partial conservation of the molecular structure as compared with the ball-milled lignin. Thus, we herein report the use of alum as a potent green catalyst for the microwave-accelerated solvolysis pretreatment of herbaceous biomass with potent application in sugar platform biorefineries.
During lignocellulosic enzymatic hydrolysis, lignin is generally considered negative. To investigate the relation between lignin profiles and the effect of lignin on hydrolysis, in this study, the enzymatic hydrolysis efficiency and cellulase adsorption amount of Avicel and PB (p-toluenesulfonic acid (p-TsOH) treated sugarcane bagasse) were firstly determined before and after adding the p-TsOH lignin (isolated lignin from PB). Subsequently, the particle size, crystallinity, hydrogen bonds, electrostatic charges and hydrophobicity of PB and Avicel, and the chemical bonds of p-TsOH lignin were measured. The results indicated that adding the p-TsOH lignin inhibited Avicel's hydrolysis, but increased the cellulase adsorption. This might be because after adding p-TsOH lignin, the lignin adsorbed more cellulase and the cellulase molecules on Avicel decreased. For PB, adding the p-TsOH lignin reduced the cellulase adsorption, but did not impact the hydrolysis efficiency. This might be due to the decrease in non-productive adsorption of cellulase.
Subcritical water hydrolysis (SWH) is a promising pre-treatment process for the production of second-generation ethanol (2 G ethanol), furthermore subcritical water is a fast, non-toxic, and green process. To address this issue SWH was performed at follow conditions: 200 degrees C, 15 MPa, 20 e 5 mL min(-1); the hydrolysate was obtained in order to produce a fermentable liquor in three different steps, 1) pure SWH, 2) SWH concentrated and rotary evaporator, and 3) SWH combinated with enzymatic hydrolysis. S. cerevisiae SA-1 and the pentose metabolizing yeast, S. stipitis NRRLY-7124, were used to evaluate fermentation potential. The combination of the products of SWH and the integration of enzymatic hydrolysis provided the greatest fermentable sugar yield with 3.0 +/- 0.53 g L-1 xylose and 6.3 +/- 0.5 g L-1 glucose; subsequent fermentation with S. cerevisiae SA-1 and S. stipitis NRRLY-7124 resulted in a 2 G ethanol yield of 2.20 +/- 0.01 g L-1. (C) 2020 Elsevier B.V. All rights reserved.
An atmospheric argon rf microplasma jet was employed to treat lignin samples. The treatment time was carried out from 30 min to 4h resulting in a strong degradation of the lignin structure. The most important degradation was observed in functional groups having asymmetric in-phase ring stretching as well as in C=C and C=O stretching vibrations. Simple calculations may help us explain the OH bond breakings by electron collisions inside the microplasma. In the afterglow conditions, it was not observed any change on the lignin spectra.
The application of multiphysics models and soft computing techniques is gaining enormous attention in the construction sector due to the development of various types of concrete. In this research, an improved form of supervised machine learning, i.e., multigene expression programming (MEP), has been used to propose models for the compressive strength (fc \& PRIME;), splitting tensile strength (fSTS), and flexural strength (fFS) of sustainable bagasse ash concrete (BAC). The training and testing of the proposed models have been accomplished by developing a reliable and comprehensive database from published literature. Concrete specimens with varying proportions of sugarcane bagasse ash (BA), as a partial replacement of cement, were prepared, and the developed models were validated by utilizing the results obtained from the tested BAC. Different statistical tests evaluated the accurateness of the models, and the results were cross-validated employing a k-fold algorithm. The modeling results achieve correlation coefficient (R) and Nash-Sutcliffe efficiency (NSE) above 0.8 each with relative root mean squared error (RRMSE) and objective function (OF) less than 10 and 0.2, respectively. The MEP model leads in providing reliable mathematical expression for the estimation of fc \& PRIME;, fSTS and fFS of BA concrete, which can reduce the experimental workload in assessing the strength properties. The study's findings indicated that MEP-based modeling integrated with experimental testing of BA concrete and further cross-validation is effective in predicting the strength parameters of BA concrete.</p>
This study puts emphasis on the impact of formic acid-based organosolv (FAOS) pretreatment on sugarcane tops (SCT) for biomass fractionation (cellulose, hemicellulose, and lignin) under mild and harsh pretreatment conditions. The cellulose, hemicellulose, and lignin contents of SCT were 35.0 +/- 0.4\%, 30.3 +/- 0.5\%, and 17.0 +/- 0.7\%, respectively. One hundred twenty-five degree Celsius pretreatment temperature, 90 min pretreatment time, and 1:7.5 solid to liquid ratio were selected as the best conditions for FAOS pretreatment of SCT. Under these conditions, equivalent to 392 +/- 4 kg pretreated SCT was obtained from 1 tonne of moisture-free basis SCT, which contained 296 +/- 3 kg cellulose, 11.1 +/- 0.5 kg hemicellulose, 15.7 +/- 0.3 kg lignin, 8.00 +/- 0.2 kg extractives, and 53.4 +/- 0.9 kg ash. Pretreatment temperature and time higher than the best-selected values (125 degrees C and 90 min) adversely affected SCT fractionation due to damage of fiber surface, high lignin content in pSCT, and lower solids recovery in the hydrolyzate.
This study was conducted to identify the optimum pH range and the appropriate buffer for butyric acid production from rice straw by fermentation using an undefined mixed culture. A series of experiments conducted at pH levels of 5.0 similar to 7.0 showed that neutral pH improved rice straw conversion and consequently carboxylic acid production. The highest butyric acid production (up to 6.7 g/L) was achieved at pH of 6.0 similar to 6.5, while it was only 1.7 g/L without pH control or at pH 5.0. Another series of experiments conducted at pH 6.0 similar to 6.5 buffered with CaCO3, NaHCO3, NH4HCO3 and their combinations indicated that different buffers had different effects onthe product spectrum, and that CaCO3 combined with NaHCO3 was an effective buffer for butyric acid production. The highest total volatile fatty acids (about 12.6 g/L) production and one of the two highest butyric acid concentrations (about 7.6 g/L) were obtained by buffering with CaCO3 combined with NaHCO3. PCR-DGGE analysis revealed that different pH and buffers also influenced the microbial population distribution. Bacteria were suppressed at low pH, while the bacterial community structures at higher pH varied slightly. Overall, this study presents an alternative method for butyric acid production from lignocellulosic biomass without supplementary cellulolytic enzyme.
The harvesting system of green sugarcane, characterized by mechanized harvesting and no crop burning, affects soil quality by increasing the remaining straw left on the soil surface after harvesting, thus, contributing to the improvement of physical, chemical, and microbiological soil attributes, influencing CO2 fluxes. This study aimed to evaluate CO2 fluxes and their relation to soil properties in sugarcane crops under different harvesting managements: burned (B), Green harvesting for 5 years (G-5) and Green harvesting for ten years (G-10). For this, a 1 ha sampling grid with 30 points was installed in each area, all located in the Northeast of Sao Paulo State, Brazil. In each point, CO2 fluxes were measured and the soil was sampled to analyze the microbial biomass, physical (soil moisture and temperature, mean weight diameter, bulk density, clay, macroporosity and microporosity) and chemical characterization (pH, organic C, base saturation and P). The CO2 fluxes were divided into four quantitative criteria: high, moderate, low and very low from the Statistical Division (mean, first quartile, median and third quartile) and the other data were classified according this criterion. The Principal Component Analysis (PCA) was used to identify the main soil attributes that influence CO2 fluxes. The results showed that G-10 CO2 fluxes were 28 and 41 \% higher than those in the G-5 and B treatments, respectively. The PCA analysis showed that macroporosity was the main soil attribute that influenced the high CO2 fluxes.
Simplex-centroid design along with artificial neural network coupled with genetic algorithm (ANN-GA) was applied to maximize exoglucanase production byPenicillium roquefortiATCC 10110 under solid-state fermentation (SSF), using a blend of agroindustrial wastes as substrate. The first statistical treatment determined the ideal contents of green coconut shell, corn cob, and sugarcane bagasse in the substrate, which were 0.44, 2.06, and 2.50 g, respectively. The optimum conditions by the ANN-GA were obtained as follows: 24 h, 21 degrees C, and 8.1 and 81.0\% for the time, temperature, pH, and moisture, respectively. Moreover, the predicted and the experimental values of exoglucanase activity were 267.94 and 268.58 IU/g, respectively. The optimization process increased the enzyme activity by up to 1263\% compared with the preliminary analysis using individual substrates, demonstrating the high efficiency of the algorithms on predicting and optimizing enzyme production. Biochemical characterization demonstrated good thermostability, basic pH stability, halotolerance, and increased enzyme activity in the presence of metal ions (Co2+, Ca2+, Mg2+, and Fe-2), solvents (ethanol and dichloromethane), and organic compounds (EDTA, Triton-X, and lactose,). These results indicate the algorithm efficiency for enzyme production purposes.
Brazil's sugarcane sector is a significant source of employment, and operates at the intersection of energy, agriculture and land use. Its future development will be affected by the values, decisions and actions of key actors. Accordingly, we report on the results of qualitative semi-structured interviews with 19 participants with expertise in relation to Brazil's sugarcane sector. We used visual aids, and reflections on past events, to structure and contextualise discussions about the future prospects for the sector as a whole, and for four of its potential products - sugar, ethanol, electricity and biogas. Interviews revealed general expectations of continued growth in the sector, particularly for its energy-related products. However, the possibility of future challenges and tensions is still evident. We suggest three inter-related areas for ongoing reflection. First, there may be value in balancing the desire for minimal intervention, technology neutral styles of policy, with the need for policy that is clear, long-term and impactful. In some cases, more targeted policies for particular actors or emergent technologies, may also be justified. Second, increased clarity on the broader objectives for the sector, including the relative prioritisation of economic, social and environmental objectives, may help industry to make the long term investments consistent with the kind of deep innovation for which there is potential. Third, it is worth reflecting on how the above issues in combination can be leveraged into a global leadership strategy, with consideration of the relative robustness of different leadership strategies within broader emerging global dynamics.
Pulps obtained from ethanol/water cooking of sugarcane bagasse were treated at different times using xylanase enzyme obtained from Thermomyces lanuginosus IOC-4145 or commercially (Cartazyme HS, Sandoz Products Ltd.). The enzyme dosage was 18 IU per g of dry pulp and the time varied from 4 h to 12 h. When xylanase from T. lanuginosus was used, the kappa number and viscosity improved independently of the processing time used (4 h, 8 h, and 12 h). After chemical evaluation, the obtained pulps were classified using Fourier Transformed Infra-Red Spectroscopy and Principal Component Analysis. The results showed that the first three principal components explained more than 90 \% of the total variance of the pulp spectra.
Inexpensive biomass is an ideal substrate for low-cost production of biohydrogen, but little was known about the biomass utilization performance of the ethanol-type hydrogen-producing bacteria Ethanoligenens harbinense. This study investigated the feasibility and performance of biohydrogen production by Ethanoligenens harbinense from sugarcane juice (Si). Medium and process were firstly optimized with SJ as carbon source and the highest hydrogen yield was obtained when SJ was hydrolyzed by acid, and the medium contained 10 g/L sugar and 3 g/L yeast extract with pH at 6.0. Compared to batch fermentation, fed-batch fermentation with cell recycle showed significant improvement in hydrogen productivity and yield. The maximum productivity reached 5.22 mmol-H-2/L.h, 201.7\% higher than that of the single batch (1.73 mmol-H-2/L.h). The highest H-2 yield was 2.23 mol-H-2/mol-hexose, 65.2\% higher than that of single batch fermentation. Cell immobilization with the fibrous bed bioreactor (FBB) also improved hydrogen productivity to 2.6 times that of batch fermentation with free cells. This study demonstrated the feasibility of hydrogen production from SJ with Ethanoligens sp., and a great improvement in hydrogen production was obtained by recycling cells and immobilizing cells in a fibrous bed bioreactor. (C) 2019 Elsevier Ltd. All rights reserved.
Sugarcane bagasse is an abundant source of lignocellulosic material for bioethanol production. Utilisation of bagasse for biofuel production would be environmentally and economically beneficial but the recalcitrance of lignin continues to provide a challenge. Further understanding of lignin production in specific cultivars will provide a basis for modification of genomes for the production of phenotypes with improved processing characteristics. Here we evaluated the expression profile of lignin biosynthetic genes and the cell wall composition along a developmental gradient in KQ228 sugarcane. The expression levels of nine lignin biosynthesis genes were quantified in five stem sections of increasing maturity and in root tissue. Two distinct expression patterns were seen. The first saw highest gene expression in the youngest tissue, with expression decreasing as tissue matured. The second pattern saw little to no change in transcription levels across the developmental gradient. Cell wall compositional analysis of the stem sections showed total lignin content to be significantly higher in more mature tissue than in the youngest section assessed. There were no changes in structural carbohydrates across developmental sections. These gene expression and cell wall compositional patterns can be used, along with other work in grasses, to inform biotechnological approaches to crop improvement for lignocellulosic biofuel production.
The Zymomonas fermentation for industrial ethanol production has been successfully scaled up. Pilot plant experiments at 100 and 1,000 litre fermentation capacity gave 91-95\% conversion efficiencies and up to 10\% (v/v) ethanol yields within 17-20 hours using sugar cane syrup, A-, B-, and C-molasses with the addition of sucrose or syrup to a final 15\% total sugar concentration.
Production of succinic acid by Actinobacillus succinogenes GXAS137 using sugarcane juice as a low-cost carbon source was developed. The optimum substrate concentration, expressed in its glucose content, was 70 g/L. As yeast extract (YE) supplementation is not economically attractive, various nitrogen sources were compared with YE in terms of their efficiency for succinic acid production. When the elemental nitrogen ratio of corn steep liquor power (CSLP) to peanut meal (PM) was 3:1, the succinic acid concentration was 56.88 g/L. The yield is almost the same supplemented with YE. When batch fermentation was carried out in a 1.3 L stirred bioreactor, 57.06 g/L of succinic acid was produced. Fed-batch fermentation was performed to minimize the substrate inhibition effect, producing 62.06 g/L of succinic acid. These results suggest that sugarcane juice supplemented with CSLP and PM as nitrogen sources could be utilized for the economical and efficient production of succinic acid.
A new approach is reported for techno-economic analysis of lignocellulosic ethanol production. With this methodology, general targets for key process variables can be draw, a valuable feedback for Research \& Development teams. An integrated first-and second-generation ethanol from sugarcane biorefinery is presented as a case study for the methodology, with the biomass pretreated by liquid hot water, followed by enzymatic hydrolysis of the cellulose fraction. The hemicellulose fraction may be either fermented or biodigested. The methodology was able to identify the main variables that affect the process global economic performance: enzyme load in the cellulose hydrolysis reactor, cellulose-to-glucose, and xylose-to-ethanol yields. Windows of feasible operation are the graphical output of the methodology, outlining regions to be further explored experimentally. One example of quantitative result is that the maximum feasible enzyme load was 11.3 FPU/gcellulose when xylose is fermented to ethanol and 7.7 FPU/gcellulose when xylose is biodigested.
Sugarcane ethanol has been produced in Brazil since the early 20th century, but production increased in the mid-1970s aiming at substituting 20\% of the gasoline. Despite an increase in the 2000s production has been stable since 2008. This paper presents a review of the main developments achieved and future challenges. The sector has had positive economic and environmental results through technological development, as a result of research and development by private companies and strong public support. Sugarcane yield has steadily increased and positively impacted production costs, primarily due to better agronomic practices and breeding programs. Owing to environmental and economic reasons, there are on-going programs to phase out burning, with the gradual replacement of manual harvest with burning by unburnt mechanised harvest. Important agronomic impacts are expected, caused by the large amount of straw left on the soil surface, which also represents a significant bioenergy potential. The sugarcane industry in Brazil has taken advantage of the combined production of sugar and ethanol, and, recently, many mills have enlarged their revenues with surplus electricity. The current efforts for diversification aim at ethanol production through hydrolysis of sugarcane residues and the development of chemical routes. From an environmental point of view, impacts related to land use change are expected on greenhouse emissions, water resources, and biodiversity. Ethanol production is likely to expand in Brazil due to the potential size of the domestic market and to the opportunities for exporting, but this will occur in a context of different and new challenges. (C) 2013 John Wiley \& Sons, Ltd.
Lignocellulosic materials are complex, recalcitrant, and difficult to release fermentable carbohydrates, such as xylose. Xylose is the feedstock for the development of products with high added value, such as ethanol, butanol, xylitol, and furfural. A high xylose yield was obtained from epidermis-free stem and external fraction (containing epidermis) of sugarcane with minimal formation of degradation products using dilute acid pretreatment. The influences of variables such as sulfuric acid concentration (\% m/m or \% m/v), reaction time (min), and solid/liquid ratio (\% m/v) on acid pretreatment were investigated through a central composite design. In study region 1, stem and external fraction had xylose yields of 58.69 and 55.33\%, as well as 1.79 and 2.16\% of furfural. The optimal condition to obtain high xylose yield was observed with the use of 50\% m/m or 1\% m/v of sulfuric acid. The highest xylose extraction was achieved in the epidermis-free stem, leading to a less recalcitrant fraction. Xylose has a key role in obtaining products with high added value. For this reason, this study obtained high xylose yield applying optimal conditions of dilute acid pretreatment, with minimum degradation products.
This research was conducted to determine the combined effects of different cellulolytic pretreatments (cellulase vs. mixed enzymes) and extraction methods (water vs. deep eutectic solvent, DES) on the yield, chemical and functional properties of polysaccharide (PS) from sugarcane leaves (SCLs). The DESs used were choline chloride-1,4-butanediol (DESB) and choline chloride-urea (DESU). The SCLs were initially enzyme-pretreated, followed by extraction using water and DES respectively. The produced crude polysaccharide extracts (CPSs) were characterized via FTIR, total phenolics, DPPH free radical scavenging activity and in vitro simulated gastrointestinal analysis. The results indicated that cellulolytic pretreatment improved the PS yield by 14-16\%, but reduced the solubility, DPPH activity and gastrointestinal digestibility of CPS. DES-CPSs possessed higher solubility and DPPH activity than water-CPSs. FTIR analysis unveiled that lignin-carbohydrate-complex was likely the component that restricted the solubility and probably the digestibility of water-CPSs. This study concluded that pretreatment and extraction procedures distinctively affected the chemical characteristics, and subsequently the functional properties of CPS. {[
The microbiological characterization by molecular techniques (DGGE and quantitative PCR) of Archaea, Bacteria domain and sulfate-reducing bacteria (SRB) from a laboratory scale Up-flow Anaerobic Sludge Blanket (UASB) processing sugar cane vinasse was performed during the operational phase with increasing organic loads. The organic load removal efficiency was between 97\% and 75\% for volumetric organic loads (VOL) in the range of 0.6 to 15.4 kgCOD. m(-3). d(-1) and for higher VOL (until 27.0 kgCOD. m(-3). d(-1)) the removal efficiency decreased to 48\%. Archaea represented the majority of the estimated population (10(7) copies of 16S RNA ribosomal gene. mL(-1)) followed by bacteria (10(6) copies of 16S RNA ribosomal gene. mL(-1)) and sulfate-reducing bacteria (SRB) (10(5) copies of dsrB gene. mL(-1)). There was a significant difference between the populations of Archaea and SRB with increasing VOL. DGGE profiles show differences among populations with increasing VOL, especially with respect to sulfate-reducing bacteria. The presence of SRB together with a high sulfate removal percentage (97\%) of about 15 kgCOD. m(-3)d(-1h), indicates the establishment of a sulfidogenic process.
Lignin is widely used as an alternative to fossil resources in industrial production. However, its applications are limited due to its wide molecular weight distribution and chemical heterogeneity. In this study, alkali treated lignin (KL) and dilute acid-alkali treated lignin (DAKL) were prepared and compared through analyzing the functional groups, antioxidant and antibacterial activity of lignin. The results showed that DAKL displayed a smaller weight-average molecular weight (756 g/mol) and higher purity (93.74\%). Further results showed that high contents of phenolic, syringyl (S), and guaiacyl (G) in DAKL increased its antioxidant activity (IC50: 38.5 mu g/ mL). Furthermore, DAKL exhibited a more excellent antibacterial effect on Staphylococcus aureus (96.71\%) and Escherichia coli (100\%) due to (1) the presence of several phenolic substances in lignin that damaged and ruptured the bacterial cell membrane, causing leakage of cell contents and bacterial death and (2) small molecule weight of lignin that allow it to penetrate the bacterial cell membrane, changing the physiological conditions of bacterial cell fluid and leading to cell death.
The overall cost-effectiveness of integrated sugarcane biorefineries were assessed using the aggregated-system exergoeconomic methodology. Using A-molasses from the sugar mill as feedstock, five biorefinery scenarios were simulated in Aspen Plus (R) to produce (i) succinic acid (SA100); (ii) short-chain fructooligosaccharides powder (FOS (p)100); (iii) short-chain fructooligosaccharides syrup (FOS(s)100); (iv) a mixture of short-chain fructooligosaccharides syrup from 30\% A-molasses and succinic acid from the remaining 70\% of A-molasses (SA70-FOS(s)); and (v) a mixture of short-chain fructooligosaccharides syrup from 30\% of A-molasses and succinic acid from a mixture of remaining 70\% A-molasses and residual sugars from the short-chain fructooligosaccharides plant section (SA70I-FOS(s)). The results of exergoeconomics showed that A-molasses and chilled water were the most significant sources of input cost rates for all the scenarios. Scenario SA100 obtained the highest total cost rate and relative cost difference of 1690 US\$/h and 0.38, versus 547 US\$/h and 0.09 for scenario FOS(s)100, which were the lowest. Contrary to the requirement for optimal performance, all the scenarios have higher irreversibility cost rates than their respective investment cost rates except scenario FOS(p) 100, with an exergoeconomic factor of 0.55, which is the closest value to 0.60 for an ideal cost-effective process. With relatively low total cost rate and relative cost difference of 1052 US\$/h and 0.18, scenario FOS(p)100 emerged as the most cost-effective biorefinery for integration into the sugar mill. Sensitivity analysis demonstrated that scenario FOS(p)100 remained relatively optimal within +/- 20\% changes in its capital investment and A-molasses prices. The cost-effectiveness of the other scenarios could be improved by employing more exergy efficient designs at the expense of capital cost.
This experiment was carried to evaluate the effect of forage cactus with different fiber sources (elephant grass hay {[
Bagasse is produced as a waste in the sugar production process, which is used as fuel to stoke boilers in the sugar mills. The concluding product of this burning is residual sugarcane bagasse ash (BA), which is normally dumped or used as low-quality fertilizer. The ash for this study was collected from a reputed sugar mill located in the northern region of Bangladesh. Type I Portland cement (PC) was partially replaced with that finely ground bagasse ash without any pretreatment. The ground BA was used as a replacement for Portland cement at 5, 10, 15, 20, 25 and 30\% of BA, respectively, in structural mortar. In addition, chemical characterization, specific gravity, X-ray diffraction (XRD), scanning electron microscopy (SEM), setting time, a strength activity index, compressive strength, water absorption, density and durability in a chloride environment of mortar were determined. The strength activity index result indicates that the used BA has the pozzolanic properties to be used as a partial cement replacement. The results showed that, at the age of 56 days, the mortar samples containing 5-15\% ground bagasse ash had higher compressive strengths than the control mixture (mortar without ground bagasse ash). Mortar containing 15\% ground bagasse ash had the highest mechanical and durability properties. Therefore, the substitution of 15\% BA is acceptable for producing good quality structural mortar in the civil engineering construction field except in chloride environments.
To effectively produce second-generation L-lactic acid (L-LA), for the first time, rice straw (RS) was pretreated by dilute ethylenediamine (EDA) and followed by fed-batch simultaneous saccharification and fermentation (SSF) under non-sterilized conditions. Specifically, the impact of pretreatment parameters included EDA concentration and pretreatment temperature on sugars and L-LA productions were evaluated. Results indicated that after pretreatment in 6\% (w/v) EDA at 200 degrees C for 1 h and following the enzymatic hydrolysis, 42.25 g L-1 of total monomer sugars was generated. By batch SSF, the maximized 63.5 +/- 3.0 g L-1 and 296.8 g Kg(-1) of L-LA can be obtained from the raw RS using Bacillus coagulant LA-15-2. Fed-batch SSF was further conducted and L-LA concentration of 92.5 g L-1 was obtained in the final fermentation broth. Correspondingly, L-LA productivity and yield reached 2.01 g L-1 h(-1) and 578.1 g Kg(-1) of the pretreated RS, respectively. This study provided a novel environmental-friendly method for L-LA production, which successfully avoided the usage of large amount of inorganic alkali in lignocellulose pretreatment stage.
Simultaneous saccharification and fermentation (SSF) at high solid loading is a potential approach to improve the economic feasibility of cellulosic ethanol. In this study, SSF using high loading of rice straw was assessed using a vertical ball mill reactor. First, the conditions of temperature and number of glass spheres were optimized at 8\% (w/v) initial solids (41.5 degrees C, 18 spheres). Then, assays were carried out at higher solid loadings (16\% and 24\% w/v). At 8\% or 16\% solids, the fermentation efficiency was similar (eta(F)similar to 75\%), but the ethanol volumetric productivity (Q(P)) reduced from 1.50 to 1.14 g/L.h. By increasing the solids to 24\%, the process was strongly affected (eta(F) = 40\% and Q(P) = 0.7 g/L.h). To overcome this drawback, three different feeding profiles of 24\% pre-treated rice straw were investigated. Gradual feeding of the substrate (initial load of 16\% with additions of 4\% at 10 and 24 h) and an inoculum level of 3 g/L resulted in a high ethanol titer (52.3 g/L) with Q(P) of 1.1 g/L.h and eta(F) of 67\%. These findings demonstrated that using a suitable fed-batch feeding strategy helps to overcome the limitations of SSF in batch mode caused by the use of high solid content.
Considering the importance of nutrients in the soil for the plants development and the soil quality conservation and the quantification relevance of them for proper soil management, the aims of this research were: (i) to quantify the clay loss, adsorbed and soluble P from interrill erosion influenced by the presence of sugarcane residues on the ground surface; (ii) to determine the minimum percentage of residues to be maintained on the soil surface to not enrich the eroded sediment by clay and soluble P (P-sed) and adsorbed (P-ads). The experimental area is located in Guariba - SP, with soil classified as Red Dystrophic Oxisol. The experiment was designed based on results of previous experiments with residue analysis of variance for 40 plots. These experiments were conducted by our research group, which provided field representation and the establishment of a minimum number of degrees of freedom necessary to ensure normal distribution of results and variance homoscedasticity. The experimental design was completely randomized in a factorial design, 5 treatments with straw sugarcane and 3 repetitions, totaling 15 plots. In the treatments, the straw was manually distributed across the surface of the soil in amounts of 0; 0.16; 0.35; 0.52 to 0.7 Kg by plot, giving 0\% coverage (SC0), 25\% (SC25), 50\% (SC50), 75\% (SC75) and 100\% (SC100), respectively. The experimental plots were subjected to simulated rain with average intensity of 60 mm h(-1) for 65 minutes. To avoid enrichment ratio (ER) of the sediment eroded by Psed, Pads and clay, a minimum soil surface coverage (SC) of 42\% is necessary.
Inulinase is an enzyme relevant to fructose production by enzymatic hydrolysis of inulin. This enzyme is also applied in the production of fructo-oligosaccharides that may be used as a new food functional ingredient. Commercial inulinase is currently obtained using inulin as substrate, which is a relatively expensive raw material. In Brazil, the production of this enzyme using residues of sugarcane and corn industry ( sugarcane bagasse, molasses, and corn steep liquor) is economically attractive, owing to the high amount and low cost of such residues. In this context, the aim of this work was the assessment of inulinase production by solid state fermentation using by Kluyveromyces marxianus NRRL Y-7571. The solid medium consisted of sugar cane bagasse supplemented with molasses and corn steep liquor. The production of inulinase was carried out using experimental design technique. The effect of temperature, moisture, and supplements content were investigated. The enzymatic activity reached a maximum of 445 units of inulinase per gram of dry substrate.
The stalk internodes of sugarcane tops were used as the biotemplate to prepare a hydroxylapatite-carbon adsorbent with the hierarchical porous microstructure of sugarcane stalks (HAP/C-SS). The HAP/C-SS adsorbent retained the porous microstructure of sugarcane top stalks, which essentially consisted of micropores, mesopores and macropores originating from the cavities of vessels, parenchyma cells, sclerenchyma cells and pits. The specific surface area was estimated to be 8.52-28.44 m(2)/g by the Brunauer-Emmett-Teller method and 5.63 m(2)/g by the mercury porosimetry method. The HAP/C-SS showed an excellent removal performance for Cd(II) ions. The removal capacities were determined to be 10.89, 18.00 and 51.93 mg/g for the adsorption at the initial Cd(II) concentrations of 10, 20 and 50 mg/L, respectively, which were comparable with the adsorption capacities of the synthetic hydroxylapatite nanoparticles. The pseudo-second-order kinetic model and the Langmuir isotherm could very well fit the experimental data. The formation of the (CdxCa1-x)(5)(PO4)(3) (OH) solid solution through the coexisting ion exchange and dissolution-precipitation (x = 0.03-0.17) processes was the main mechanism for the Cd(II) adsorption onto the HAP/C-SS adsorbent.
Both ciprofloxacin (CIP) and sugarcane bagasse have brought enormous pressure on environmental safety. Here, an innovative technique combining Fe-Mg-layered double oxides and ball milling was presented for the first time to convert bagasse-waste into a new biochar adsorbent (BM-LDOs-BC) for aqueous CIP removal. The maximum theoretical adsorption capacity of BM-LDOs-BC reached up to 213.1 mg g(-1) due to abundant adsorption sites provided by well-developed pores characteristics and enhanced functional groups. The results of characterization, data fitting and environmental parameter revealed that pore filling, electrostatic interactions, H-bonding, complexation and pi-pi conjugation were the key mechanisms for CIP adsorptive removal. BM-LDOs-BC exhibited satisfactory environmental safety and outstanding adsorption capacity under various environmental situations (pH, inorganic salts, humic acid). Moreover, BM-LDOs-BC possessed excellent reusability. These superiorities illustrated that BM-LDOs-BC was a promising adsorbent and created a new avenue for rational placement of biowaste and high-efficiency synthesis of biochar for antibiotic removal.
The stability of biocrude produced from the liquefaction of sugarcane bagasse in ethanol was observed. The degradation characteristics of biocrude and reference fuels, such as diesel, waste cooking oil biodiesel, and their blends, were studied under three different storage environments and temperatures over 24 weeks, namely, hot (43 degrees C), cold (4 degrees C), and outdoor (variable temperature) conditions. Higher Heating Values of biocrude had only small changes for all storage conditions, and this was similar to the behavior of the reference fuels. Density changes were significant in hot conditions for biocrude oil compared with outdoor and cold conditions. The change in chemical composition reflects changes in densities. Upon different storage conditions, the chemical composition of waste cooking oil biodiesel and biocrude changed considerably over the time period, whereas diesel and biodiesel blend B20 remained relatively stable. The instability of the biocrude was mainly due to oxygenated compounds, especially phenols forming cyclic and aromatic compounds. The degradation rate of biocrude was the slowest in cold conditions.
The extensive use of Portland cement (PC) in the manufacturing of concrete is responsible for the depletion of natural resources that are part of cement production. Cement supply is permanently threatened by the ongoing depletion of natural materials, including sand, limestone, and clay. Concurrently, the incineration of agricultural residues presents a significant ecological problem. This study explores the substitution of cement in concrete with 5\%, 10\%, 15\%, and 20\% wheat straw ash as an environmentally friendly alternative. The purpose of this investigation is to evaluate the effect of substituting wheat straw ash (WSA) for PC on the mechanical characteristics of concrete. A total of 75 concrete samples were made by cement or cement + WSA/fine aggregate/coarse aggregate ratio of 1:1, 5:3, and water-to-cement ratio was kept constant at 0.50. All of these specimens were cured and tested at 28 days. The properties tested in the paper were workability, compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, and permeability. The outcomes showed that the substitution of PC with WSA 10\% resulted in the greatest concrete strength. In contrast, the mechanical properties and permeability of concrete were reduced when 20\% WSA was substituted for PC at 28 days. In addition, the slump value dropped as increasing the content of WSA diminished the weight of PC in the concrete. This could be attributed to the fact that the water content in the WSA 20\% concrete was not enough for mechanical strength. Other concretes with WSA showed similar properties to those of the WSA 10\% concrete. It was concluded from the results that since the WSA 10\% concrete showed the best properties, it can be recommended as the best recipe in this research work.
Energy is an important aspect for the development of the human race. The demand for energy rises day-by-day due to increasing population and economic conditions. This energy demand can be fulfilled by finding a renewable energy source. Among the various renewable energy sources, bio-mass has higher potential. The biomass based fuel can be easily obtained from forest, agriculture and food waste by employing thermo-chemical and bio-chemical processes. In this article, two biomass wastes namely sugarcane bagasse and saw dust were considered for the pyrolysis process. The physical and chemical properties of the biomass wastes were analysed by using ultimate, proximate and thermo gravimetric analyses to find the elemental composition, moisture content, volatile matter, fixed carbon and ash contents and decomposition temperature respectively. Based on decomposition temperature from TGA, the biomass is subjected to pyrolysis process. The properties of the bio-oil were analysed by using standard methods and FTIR analyser to find the various functional groups present in the bio-oil. Based on the investigation, it is concluded that the bio-oil can be upgraded and used as alternate fuel in IC engines and also as a feedstock to produce value added compounds.
Thermophilic hydrogen production from xylan by Thermoanaerobacterium thermosaccharolyticum KKU-ED1 isolated from elephant dung was investigated using batch fermentation. The optimum conditions for hydrogen production from xylan by the strain KKU-ED1 were an initial pH of 7.0, temperature of 55 degrees C and xylan concentration of 15 g/L. Under the optimum conditions, the hydrogen yield (HY), hydrogen production rate (HPR) and xylanase activity were 120.05 +/- 15.07 mL H-2/g xylan, 11.53 +/- 0.19 mL H-2/L h and 0.41 units/mL, respectively. The optimum conditions were then used to produce hydrogen from 62.5 g/L sugarcane bagasse (SCB) (equivalent to 15 g/L xylan) in which the HY and HPR of 1.39 +/- 0.10 mL H-2/g SCB (5.77 +/- 0.41 mL H-2/g xylan) and 0.66 +/- 0.04 mL H-2/L h, respectively, were achieved. In comparison to the other strains, the HY of the strain KKU-ED1 (120.05 15.07 mL H-2/g xylan) was close to that of Clostridium sp. strain X53 (125.40 mL H-2/g xylan) and Clostridium butyricum CGS5 (90.70 mL H-2/g xylan hydrolysate). Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Plant food processing by-products (PFPB) have attracted industrial attention as a potential source of natural antioxidants that can be used in meat industry. This study investigated the combined effects of PFPB including sugarcane bagasse (SCF), orange peel (ORP) and tomato pomace (TMT), and high oxygen modified atmosphere packaging (HOMAP; 80 \% O2: 20 \% CO2) on the oxidative and microbial stability of beef patties during cold storage for up to 12 days. The total phenolic content (TPC) and antioxidant activity of the PFPB were also evaluated. ORP was found to have the highest TPC, followed by TMT and SCF. DPPH-radical and ABTS-radical assays demonstrated a similar trend. The PFPB were proved to successfully improve the meat properties of a{*
Diabrotica speciosa (Germar) larvae have been considered one of the major subterranean pests of several crops, including maize (Zea mays L) in South America. Currently, there are limited options for managing this pest in maize, and botanical insecticides are a potential option that could provide additional modes of action against D. speciosa. One of the major barriers to using botanical insecticides is their instability due to their rapid degradation in the environment. Lignin extracted from sugarcane bagasse, a byproduct which is largely produced in the Brazilian sugarcane industries, was tested for encapsulating neem (Azadirachta indica A. Juss) extract with and without additional additives to provide stability in some formulations. Thus, this research aimed to evaluate the effect of neem extract in different microencapsulated formulations and doses to control D. speciosa. In addition, effects on maize plant development were assayed. In low-dose neem testing, the microencapsulated formulations with the additives Tinogard (R), Silicone, Styleze (R) and Styleze (R) + Tinogard (R) were the most efficient in controlling D. speciosa larvae. Most of the formulations delayed the larva to adult period, which could lead to fewer generations per year. Moreover, LigN + silicone caused reduction in the weight of adults. All additives were not toxic to D. speciosa. Overall, the low doses of neem had no negative effect on the development of maize plants. In high-dose neem testing all the insects died, but the high-doses were toxic to plants. The aforementioned low-dose formulations seem a promising tool for controlling D. speciosa in maize fields.
In this study, jackfruit peel (JP) was blended into sugarcane bagasse (SB) powder during co-hydrothermal carbonization (Co-HTC) to improve the physicochemical properties of JP/SB@4:1 hydrochar for the removal of methylene blue (MB), malachite green (MG), and crystal violet (CV) dyes from aqueous solutions. JP/SB@4:1 was systematically characterized. Spectroscopic, morphological, and elemental analyses confirmed successful binding of MB, CV, and MG dyes with JP/SB@4:1 surface. Influence of various parameters such as contact time, pH, initial dyes concentration, and temperature on the adsorption process was studied. The optimized magnitudes for these parameters were found to be 480 min of contact time; pH 6.6 for MB, 7.6 for MG, and 8.3 for CV; and 328K of temperature. Non-linear kinetic and isotherm models were applied to the experimental data. Results revealed the fitting of pseudo-second-order (PSO) and Langmuir isotherm (LIM) models to experimental data, while the maximum monolayer adsorption capacities (q(m)) of JP/SB@4:1 toward MB, CV, and MG were 326.79, 300.87, and 922.29 mg/g, respectively. The adsorption of dyes on JP/SB@4:1 was ascribed to electrostatic interaction, hydrogen bonding, and pi-pi/n-pi interactions. Thermodynamics evaluation showed the feasible, spontaneous, and endothermic adsorption of the dyes.
The hydrogen production efficiency of sulfate-reducing bacteria (SRB) is governed by complex hydrogenase metabolism functions depending on the metal co-factors concentrations. The potential of SRB rich in hydrogenase enzyme activity for hydrogen production is rarely explored. Therefore, in this study, the hydrogenase enzyme cofactors of Fe2+ (0.67-0.85 mM), Ni2+ (0.01-0.02 mM), and Se4+ (0.1 mM) were tested for hydrogen production from rice straw hydrolysate using response surface methodology optimized conditions. The Fe2+ and Se4+ ions are essentially required to express hydrogenases in SRB. The positive contribution of {[
Ga2S3 and sulfur co-modified biochar (Ga/S-BC) composites were prepared for enhancing the adsorption of ciprofloxacin from sugarcane bagasse via the high-temperature sulfurization. In contrast with sulfur-modified biochar, Ga/S-BC exhibited the better adsorption capacity for ciprofloxacin removal. The increasing Ga content induced to the climbing and then declining adsorption activity of Ga/S-BC. Among these obtained Ga/S-BC composites, optimal 3-Ga/S-BC with a Ga content of 7.40\% and surface area of 681.67 m(2) g(-1) exhibited the superior capacity of 330.21 mg g(-1). The adsorption capacity of 3-Ga/S-BC declined to 301.66 mg g(-1) after nine cycles. pH and inorganic salts also affected the adsorption capacity of 3-Ga/S-BC for ciprofloxacin removal. The adsorption isotherms of obtained Ga/S-BC composites were well described by Langmuir isotherm, and their adsorption kinetics were well estimated via second-order model. The adsorption performance of 3-Ga/S-BC in ciprofloxacin removal was a physisorption and spontaneous process.
This study examined the effect of conversion from a conventional tillage (CT) to a no-tillage (NT) practice and of bagasse mulching (M) on soil microbial community composition and potential functions, using phospholipid fatty acid (PLFA) analysis and shotgun metagenome sequencing. Our results showed that both the NT and the M treatment increased microbial PLFAs. The shotgun sequencing results suggested that the functional profiles are more resistant to agricultural managements than to community compositions, which supports the hypothesis of the functional redundancy of soil microbial communities. However, some metabolism-related sequences were significantly affected by different treatments. The percentage of sequences related to metabolism of carbohydrates, especially saccharide groups, was significantly higher in the CT soils than in NT and M soils, which may be linked to lower carbon (C) availability in CT soils. Compared with CT, the NT had higher alpha diversity and more sequences related to DNA metabolism, which may be associated with higher nutrient availability. On the other hand, the M treatment decreased the percentages of sequences related to the metabolism of amino acids and derivatives, which may be due to the limited nitrogen (N) because of the high C/N ratio of bagasse. We also observed interaction effects of the NT and M treatments; although both the NT and M treatments increased the relative abundance of Proteobacteria, this variable in NT + M soils was not higher than in each single treatment. Overall, our findings suggest that the microbial communities change their composition and functionality in response to the NT and M treatments, and these shifts have the potential to affect important soil processes that sustain crop productivity, such as C sequestration and major nutrient cycles.
Polymers are used for numerous applications in different industrial segments, generating enormous quantities of discarding in the environment. Polymeric materials composites account for an estimated from 20 to 30\% total volume of solid waste. Polypropylene (PP) undergoes crosslinking and extensive main chain scissions when submitted to ionizing irradiation; as one of the most widely used linear hydrocarbon polymers, PP, made from cheap petrochemical feed stocks, shows easy processing leading it to a comprehensive list of finished products. Consequently, there is accumulation in the environment, at 25 million tons per year rate, since polymeric products are not easily consumed by microorganisms. PP polymers are very bio-resistant due to involvement of only carbon atoms in main chain with no hydrolysable functional group. Several possibilities have been considered to minimize the environmental impact caused by non-degradable plastics, subjecting them to: physical, chemical and biological degradation or combination of all these due to the presence of moisture, air, temperature, light, high energy radiation or microorganisms. There are three main classes of biodegradable polymers: synthetic polymers, natural polymers and blends of polymers in which one or more components are readily consumed by microorganisms. This work aims to biodegradability investigation of a PP/HMSPP (high melt strength polypropylene) blended with sugarcane bagasse, PHB (poly-hydroxy-butyrate) and PLA (poly-lactic acid), both synthetic polymers, at a 10\% level, subjected to gamma radiation at 50, 100, 150 and 200 kGy doses. Characterization will comprise IR, DSC, TGA, OIT and Laboratory Soil Burial Test (LSBT). (C) 2013 Elsevier Ltd. All rights reserved.
Biochar (BC) is used as a soil amendment to enhance plant growth by improving mainly soil chemical and hydrophysical properties. In this work the effects of two types of BCs on soil water retention properties were analysed. The first type of BC was made from sugarcane bagasse. It was added to a clay ``Shimajiri Maji{''
Lipase from Aspergillus sp. obtained by solid-state fermentation (SSF) on wheat bran (LWB), soybean bran (LSB) and soybean bran combined with sugarcane bagasse (LSBBC) were 67.5, 58 and 57.3U of crude lipase per gram substrate, respectively. The optimum pH of activity and stability of the LWB was between 8 and 9, and the optimum temperature of activity and stability was 50 degrees C and up to 60 degrees C, respectively. The LSB and LSBBC showed two peaks of optimum pH (4 and 6) and optimal values of temperature and stability at 50 degrees C. The LSB was stable in the pH range of 6-7, while LSBBC in the range of pH 4-7. All the enzymes show activities on p-nitrophenyl esters (butyrate, laurate and palmitate). LWB stood out either on the hydrolysis of sunflower oil, presenting 66.1\% of the activity over commercial lipase and on the esterification of oleic acid and ethanol, surpassing the activities of the commercial lipases studied. The thin layer chromatography showed that LWB and LSB have produced ethyl esters from corn oil, while LWB produced it from sunflower oil.
Thermochemical characterization of four different biomasses sawdust (SD), rice husk (RH), cotton stalk (CS) and sugarcane bagasse (SB) was investigated to understand their kinetic characteristics. The TGA experiments were done using inert and oxidative atmospheres to understand the reaction kinetics of selected biomasses. The temperature was enlarged from room temperature to 900 degrees C at a heating rate of 10 degrees Cmin(-1) under non-isothermal conditions. The weight loss of all the four biomass materials under an inert and oxygen environments showed alike weight loss trend occurring in three main stages. It was observed that all four biomass materials degraded in three identical regions. In the first region of weight loss, moisture evaporation was observed, in second region cellulose and hemicellulose degradation was achieved, whereas in third region lignin degradation was achieved under both an inert and oxy-combustion atmospheres at different temperature ranges. The activation energy, pre-exponential factors were evaluated through Arrhenius correlation equations. The values of E calculated during pyrolysis for CS, SB, SD and RH were 79.10, 68.32, 53.46, 52.9 (kJmol(-1)) during oxy-combustion atmospheres 122.6, 106.31, 123.28 and 118 (kJmol(-1)), respectively.
In this paper a techno-economic and environmental analysis for a sugar cane bagasse biorefinery in Colombia is presented as a case study. An optimization procedure is shown in order to select the most promising process pathway for the production of fuel ethanol, poly-3-hydroxybutyrate (PHB), and electricity. Once the optimization procedure was done, the results served as criteria for the selection of technologies and raw materials distribution. The distribution results and technologies were used to feed the knowledge-based approach in process synthesis. Then three scenarios were simulated using the Aspen Plus software. The first scenario consisted of energy cogeneration, the second one was an arbitrary distribution, and the third one corresponded to the preselected pathway using the optimization subroutine. Each scenario was assessed from the technoeconomic and environmental point of view according to the Colombian conditions. The best was subjected to the configuration previously designed through the optimization subroutine. For this case, the obtained economic margin was 53.83\%, the potential environmental impact was 0.16 PEI/kg products, and the biological GHG emissions of the processing stage represented 1.55 kg. of biological CO2-e/kg of bagasse.
The objective of this work was to evaluate the agronomic efficiency of the nitrogen sources urea (U), ammonium nitrate (AN), ammonium sulfate (AS), and ammonium chloride (AC) on green harvesting sugarcane ratoon, as well as the residual effect of these sources on crop productivity in the subsequent crop year. A randomized block design was used with four replicates. Treatments consisted of applying 120 kg ha(-1) of N fertilizer on a Typic Hapludox covered by straw residues resulting from the harvest without burning of the first ratoon. A control treatment was included with no N fertilizer. To evaluate the residual effect of the nitrogen fertilizers, 450 kg ha(-1) of a 20-5-19 formulation was applied to soil after sugarcane ratoon harvest. The highest production of stalks and sugar, in the 2006/2007 season, was obtained with the source AS. In the 2007/2008 harvest season, no residual effect of N fertilization was observed and there was a productivity decrease in the AC treatment in comparison to the control. The AC source, at a dose of 120 kg ha(-1) N in the fertilization of the second ratoon, is agronomically as efficient as the other N sources used, but shows less efficiency in the subsequent crop year.
Fractionation of lignocellulosic components is a primary step for maximizing value-added conversion of plant biomass to biofuels and chemicals. In this study, different organic solvents (methyl isobutyl keone, ethyl acetate, toluene and diethyl ether) in the ternary water/alcohol/organic solvent system and acid promoters (H2SO4, HCl, and H3PO4) were studied on a single-step solvothermal fractionation of rice straw. Ethyl acetate was found to be a superior composite solvent to the conventional solvent MIBK by providing higher glucan and lignin yields. Glucan and xylan could be further solubilized and lignin recovery increased at higher temperature and acid concentration. The optimal fractionation conditions were found to be water/ethanol/ethyl acetate (62.5\%:25\%:12.5\%) mixture using 0.05 M H2SO4 at 160 degrees C for 1 h, which gave cellulose-enriched solid with 71.4 wt\% glucan yield. Hemicellulose (53.2 wt\%) was obtained as sugars, and dehydration products in the aqueous/alcohol phase were minimal. 63.1 wt\% lignin was recovered in the organic solvent phase with no cross-contamination of sugars. Microwave-assisted heating at 300 W, corresponded to the temperature of 160 degrees C for 1 h resulted in comparable glucan and lignin yields in the respective phases to conventional heating with the advantages of increased pentose yield and lower furan formation in the aqueous phase. (c) 2015 Elsevier Ltd. All rights reserved.
This work reports the development of a fast and reliable amperometric sensor for the detection of amino acids. The detector was constructed using copper nanoparticles (CuNPs) supported on reduced graphene oxide (RGO) modified glassy carbon electrode (CuNPs-RGO/GCE) and based on the application of high performance anionexchange chromatography with pulsed amperometric detection (HPAEC-PAD). Under optimized isocratic HPAEC-PAD conditions (using 40 mmol L-1 NaOH as mobile phase, flow rate of 0.30 mL min-1 and detection potential of 0.45 V vs. Pd/PdO), the linear dynamic ranges of the concentration of amino acids obtained were 0.50-50 mu mol L-1 for lysine, 1.0-100 mu mol L-1 for alanine, glycine and serine, and 5.0-100 mu mol L-1 for leucine. The limits of detection (S/N = 3) obtained ranged from 0.10 (for lysine and leucine) to 0.50 mu mol L-1 (for alanine, glycine and serine) and sensitivity varied from 6.1 (for leucine) to 21.5 nA mu mol- 1 L (for serine). The average recovery percentages ranged from 97\% (for glycine) to 102\% (for leucine and serine). The results obtained showed that the CuNPs-RGO/GCE has good long-term stability, repeatability and reproducibility; this makes the device suitable for application as an electrochemical detector. The successful application of the proposed method for the analysis of sugarcane vinasse demonstrates its suitability for separation and determination of amino acids in complex matrices.
Research focused on reusing lignocellulosic waste has been gaining ground, both for the purpose of obtaining energy from renewable sources, as well as for reducing feedstock costs and preventing environmental pollution. Despite being currently evaluated as a promising feedstock, large-scale application of lignocellulosic waste to obtain bioenergy is still scarce. One of the obstacles in terms of reusing it is its recalcitrant composition, often requiring pretreatment applications to break its fibers, increasing its bioavailability. In addition to the type of substrate, there are many operational parameters that may affect the process efficiency, including the type of reactor, temperature, pH, inoculum source, among others. Considering this, it is interesting to consider using statistical tools instead of ``one-factor-at-a-time{''
BACKGROUNDRice straw (RS), one of the most plentiful lignocellulosic wastes worldwide, has been considered a potential candidate to produce bioethanol. The object of this work was to develop an efficient and feasible pretreatment process for RS with alkaline peroxide combined with ionic liquid (IL)-water mixtures, reveal the mechanism, and achieve biomass valorization. RESULTSAlkaline peroxide pretreatment under mild conditions combined with IL-water mixtures pretreatment at a water content of 30wt\% was established, leading to a maximum lignin removal of 63.8\% with an enzymolysis efficiency of 92.1\% and a simultaneous saccharification and co-fermentation efficiency of 91.0\%. Furthermore, the recycled IL also showed good performance with the established pretreatment process, resulting in 251.6gL(-1) of reducing sugar and 91.9gL(-1) ethanol at high solid loading. The alkaline peroxide pretreatment enhanced lignin extraction and disrupted the RS structure to facilitate the dissolution of amorphous components by the IL-water mixtures. CONCLUSIONA simple and efficient pretreatment was successfully established. The IL was successfully recycled for further pretreatments, and high concentrations of reducing sugars and ethanol were achieved using the pretreated RS. The effectiveness of the pretreatment process suggested potential application in future biorefineries. (c) 2018 Society of Chemical Industry
This paper compares the effectiveness of chemical and physical methods in treating the wash water collected from automobile service stations. Wash water was collected from two service stations in the city of Bangalore, and the effluent was characterised for different parameters such as pH, turbidity, conductivity, total solids, oil and grease, COD (chemical oxygen demand), BOD (biological oxygen demand), chlorides, sulphate and total hardness. For chemical treatment, alum was used and locally available natural materials such as saw dust and sugarcane bagasse were used for physical treatment. Alum at different concentrations was agitated with the effluent for a prescribed contact period which led to the formation of flocs. The filtered samples were tested for COD and oil \& grease. in the form of filter columns of three different heights. The percentage reduction in COD and oil and grease was correlated with the depth and type of filter media. A comparison of physical and chemical methods of treatment revealed that natural materials are effective in removing oil \& grease and COD from the automobile effluent and hence provide a viable solution because of its eco-friendliness. From the experimental studies it is observed that in physical treatment, the sorption capacity of any material is dependent on its porosity, surface area and height of filter bed. (C) 2016 Published by Elsevier B.V.
Data of the commercial parameters of Pleurotus ostreatus and Pleurotus djamor were analyzed using the data mining technique: K-means clustering algorithm. The parameters evaluated were: biological efficiency, crop yield ratio, productivity rate, nutritional composition, antioxidant and antimicrobial activities in the production of fruit bodies of 50 strains of Pleurotus ostreatus and 50 strains of Pleurotus djamor, cultivated on the most representative agricultural wastes from the province of Guayas: 80\% sugarcane bagasse and 20\% wheat straw (M1), and 60\% wheat straw and 40\% sugarcane bagasse (M2). The database of the parameters obtained in experimental procedures was grouped into three clusters, providing a visualization of the strains with a higher relation to each parameter (vector) measured.
Wastes from agricultural industry are often disposed. Nevertheless, these wastes contain nutraceuticals and functional compounds. Xylooligosaccharide (XOS) was extracted from two sugarcane wastes (SW); rind (SR) and pith (SP), and the prebiotic properties of both XOS were examined. SR and SP had different mixture of XOS and were resistant towards alpha-amylase and gastric juice digestion in vitro. Although the growth of Lactobacillus casei Shirota (LcS) and Bifidobacterium animalis subsp. Lactis ATCC (R) 700541 (TM) increased significantly in both XOS after 48 h of incubation, XOS from SR showed better enrichment of probiotics growth. Both XOS were found to be more fermentable by LcS and acetic acid was the predominant end product of the fermentation. Since XOS composition was different between SR and SP and such difference can affect their prebiotic properties, it is important to choose the appropriate parts of SW to extract XOS with high fermentable properties and obtain the best synbiotics combination.
The oyster mushroom, Pleurotus ostreatus, cultivated in solid state on sugarcane bagasse-wheat bran (5:1) medium in the presence of veratryl alcohol resulted in an increased production of the fruiting body at earlier times compared to when the fungus was grown in the absence of veratryl alcohol. The results indicate a new physiological role for veratryl alcohol in stimulating fruiting body formation. Veratryl alcohol also stimulated laccase production during the mycelial growth stage. Evidence is also presented that laccases were involved in the physiological development of the fruiting body. (C) 2001 Federation of European Microbiological Societies. published bq Elsevier Science B.V. All rights reserved.
Cellulose II hydrate was prepared from inicrocrystalline cellulose (cellulose I) via its mercerization with 5 N NaOH Solution over 1 h at room temperature followed by washing with water. The structure of cellulose II hydrate changed to that of cellulose II after drying. Compared with cellulose II, cellulose II hydrate exhibited a slightly (8.5\%) expanded Structure only along the {[
The alcohol and sugar industry in Brazil uses a feedstock for sucrose extraction, resulting in waste production, one of them being the sugarcane bagasse. A possible relocation for the use of this residue, produced in millions of tons annually, would be its use in the production of carbonaceous materials, such as activated carbon (AC). The purpose of this study was the production of activated carbon using a faster, simpler and more efficient process with low energy requirements and chemical reagents to obtain a material with a high surface area. The AC samples were prepared by chemical activation with ZnCl2 and carbonization at 600 degrees C in an oxygen-limiting atmosphere. The average specific surface area of the samples, estimated by the BET method, was 1544 m(2) g(-1) and the average pore size was 2.6 nm. The surface morphologies of the ACs were characterized using SEM analysis, which showed that the surfaces were irregular, with cracks, pores. The solids were also characterized by FTIR, presenting mainly stretching bands corresponding to O-H, C-O, and C=C groups. EPR analysis showed a resonance line characteristic of an organic free radical with g similar to 2.0031, which is typical of free radicals centered on carbon atoms. The material efficiency for removal of aromatic organic pollutants was evaluated in continuous-flow adsorption tests with the antibiotic amoxicillin. The method provided very satisfactory results, reducing the concentration of the antibiotic from an initial value of 1.37 x 10(-3) mol L-1 to about 3.5 x 10(-8) mol L-1. The concentration of the antibiotic in water, after adsorption, was therefore reduced by four to five orders of magnitude, confirming the potential application of the materials prepared in this work for the removal of antibiotics residues from the environment.
This article focuses on the development of starch-based biodegradable polymer composites reinforced by agricultural by-products. Maize hull and sugarcane bagasse were used as reinforcements in maize starch, which was plasticized by glycerol and maltitol. Compounds with different compositions were produced by compounding in a twin screw extruder. The mechanical (tensile-, three point bending-, and Charpy-impact) properties and shrinkage were determined on injection-molded specimens and compared with those of commercial HDPE. The mechanical properties of thermoplastic starch increased with the addition of both maze hull and sugarcane bagasse, but only the latter ensured comparable results with reference HDPE. This was traced to differences in the interfacial adhesion between filler and matrix as observed by scanning electron microscopy. Distance spacers for pizza boxes, usually made from HDPE, were injection molded from these biodegradable composites and subjected biodegradation in soil. The related results indicated that this biodegradable spacer is a good and environmentally benign alternative for the HDPE counterpart.
Bioethanol has emerged as a major alternative and environment-friendly fuel to face with energy consumption increasing in recent decades. In bioethanol processing factories, new technologies using steam explosion pretreatments are developed to improve ethanol production from cellulose (e.g. sugarcane bagasse). However, wastewater from this step with high chemical oxygen demand (COD), high soluble total organic carbon (S-TOC), low pH, and dark brown color cause serious environmental problems. This research focused on the high-rate anaerobic wastewater treatment from bioethanol production using a fixed-bed reactor. A 10.8 L lab-scale reactor was continuously operated at 35 degrees C for 160 d with a volumetric loading rate of 10.9 kg-COD/m(3)/d. A kinetic model based on a modification of anaerobic digestion model no. 1 and activated sludge models was used to reasonably simulate the methane production, soluble TOC, suspended solid as well as the soluble effluent constituents in terms of carbohydrate, protein, propionate, acetate, lignin, and ammonium nitrogen. The steady-state simulation results showed that 45\% of COD was converted to methane with a high organic loading rate (9.72 kg-COD/m(3)/d). In addition, tests using physicochemical methods were conducted to remove un-biodegradable materials and color from the effluent. Oxidation, coagulation/flocculation, and adsorption removed 88\% of soluble TOC and 98\% of color.
In this study, we proposed a simple and effective sodium perborate (SPB) pretreatment method to enhance the enzymatic hydrolysis efficiency of rice straw (RS). The lignin removal rate reached 45.76\% under the optimum pretreatment conditions of 8\% SPB and 80 degrees C for 4 h, and the enzymatic hydrolysis efficiency of pretreated RS was 84\% at a cellulase loading of 20 FPU/g RS. Through simultaneous saccharification and co-fermentation (SScF) of the pretreated RS solid with Saccharomyces cerevisiae SHY07-1, the maximum ethanol concentration was 15.29 g/L at 72 h, with a fermentation efficiency as high as 91.96\%. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) analyses revealed that the RS structure was destroyed by SPB pretreatment, and lignin was effectively removed. The overall data of this study indicate that SPB pretreatment is a promising method to improve enzymatic hydrolysis and bioethanol production from RS by inoculating Saccharomyces cerevisiae SHY07-1.
Enzymes from phytopathogenic fungi are desirable for biotechnological applications and a highly virulent phytopathogen shows great appeal for enzymes production. To assess the biotechnological potential of Kretzschmaria zonata, a plant pathogenic fungus, we analyzed its enzymatic profile after growth on six different types of lignocellulosic biomasses. The fungus was able to produce a wide variety of enzymes with superior xylanase activity. The corn cob induced the highest specific activity of xylanase, 56.30 U/mg of protein, as well as other important enzymatic activities such as endoglucanase, 11.20 U/mg of protein; pectinase, 4.52 U/mg of protein; and beta-glucosidase, 2.77 U/mg of protein. The highest release of xylose, 0.88 g/L, was observed after saccharification of 10\% of alkaline pretreated sugarcane bagasse by a commercial cocktail supplemented with the crude extract from K. zonata after growth on corn cob. The fungus extract is rich in hemicellulases and accessory enzymes and the result showed synergism between the enzymes present in the commercial mixture and in the K. zonata extract. This is the first report concerning the biotechnological potential of the fungus K. zonata, especially regarding to its ability to produce plant biomass degrading enzymes related to second generation ethanol production.
In recent years, toxic pollutants in industrial wastewater are seriously considered as one of the environmental problems due to the heavy metals present in it. Currently, biosorption has been strongly recommended by researchers as an efficient and economical technique to reduce the amount of heavy metals in the different industrial wastewater sources. Chitosan and sugar bagasse ash are the well-known biosorbents due to their low cost, available and effective in adsorption process. In this study, the composite biosorbent was prepared by mixing chitosan and sugar bagasse ash prepared by microwaving at a ratio of 1:5 (ASB-CBs) in acid condition. Adsorbents were characterized by SEM analysis method and FTIR infrared spectra. The parameters affecting the Pb(II) and Cd (II) adsorption such as pH, adsorption time, dose of adsorbent was studied by running the batch experiments. Research data show that the optimal pH for the biosorption process is 5.0. Experimental data is described by the Freundlich equation. Thermodynamic process is also studied in which the negative free Gibbs energy indicated the metal ions adsorption on the ASB-CBs was spontaneous and endothermic nature.
BACKGROUND: The profitable production of gluconic acid (GA), an organic acid extensively used in the food and beverages industries, relies on the use of cheap and available substrates with high sugar content. The high oxygen demand for the microbial conversion of glucose to GA is still a bottleneck of industrial production in conventional stirred-tank reactors. Therefore, in this study, for the first time, the effect of increased air pressure up to 4 bar on GA production and sugar consumption in batch and step-wise fed-batch cultures in sugarcane molasses (ScM) and grape must (GM) medium was studied. RESULTS: ScM and GM, by-products of the agro-food industry, proved to be adequate feedstocks to replace pure glucose in GA batch production by Aspergillus niger MUM 92.13. A threefold improvement in GA productivity was obtained in batch experiments carried out at 4 bar with ScM and GM compared to those at 1 bar. Furthermore, the addition of two pulses of ScM, under pressurized conditions, increased the GA production, reaching a final concentration of 140 g L-1. CONCLUSION: This work proved that the use of total air pressure up to 4 bar is an effective approach to enhance GA productivity using ScM and GM as substrates in batch and step-wise fed-batch cultures. Also, this study provides a novel strategy for developing a biotechnological bioprocess for GA production by A. niger from low-cost and sugar-rich by-products performed in pressurized stirred tank reactors. (c) 2023 Society of Chemical Industry (SCI).
Fructooligosaccharides (FOSs)-fructose-based oligosaccharides-are typical prebiotics with health-promoting effects in humans and animals. The trisaccharide 1-kestotriose is the most attractive inulin-type FOS. We previously reported a recombinant sucrose:sucrose 1-fructosyltransferase (1-SST, EC 2.4.1.99) from Schedonorus arundinaceus (Sa) that efficiently converts sucrose into 1-kestotriose. In this study, Pichia pastoris PGFT6x-308 constitutively expressing nine copies of the Sal-SST gene displayed fructosyl-transferase activity in undisrupted biomass (49.8 U/ml) and culture supernatant (120.7 U/ml) in fed-batch fermentation (72 hr) with sugarcane molasses. Toluene permeabilization increased 2.3-fold the Sal-SSTrec activity of whole cells entrapped in calcium-alginate beads. The reaction with refined or raw sugar (600 g/l) yielded 1-kestotriose and 1,1-kestotetraose in a ratio of 8:2 with their sum representing above 55\% (wt/wt) of total carbohydrates. The FOSs yield decreased to 45\% (wt/wt) when sugarcane syrup and molasses were used as cheaper sucrose sources. The beads retained 80\% residual Sa1-SSTrec activity after a 30-day batchwise operation with refined cane sugar at 30 degrees C and pH 5.5. The immobilized biocatalyst is attractive for the continuous production of short-chain FOSs, most particularly 1-kestotriose.
Sugarcane bagasse (SB) and rice husks (RH) are agroindustrial byproducts which can be hydrolyzed to release sugars for the production of valuable bioproducts. However, the exposure of their carbohydrates to the action of hydrolytic enzymes depends on the removal/modification of lignin by a pretreatment. Here we report a biological strategy for pretreatment of SB and RH using a crude enzyme extract rich in laccases to delignification and improvement of reducing sugars yield after saccharification. Enzyme extracts were produced by different species of fungi cultured in a medium with agroindustrial byproducts and other components in static semi-solid condition. The highest yields of laccase production were obtained by Trametes villosa (9467.8 U/L). SB and RH were pretreated with this crude enzyme extract in various conditions and the process optimization resulted in the choice of proper mediators for laccases oxidative action and an increase of more than 10-fold in reducing sugars concentration in the saccharified samples (291 mg/g of sugars were obtained from SB and 193 mg/g from RH) when compared to the control (non pre-treated). Results of MIR-ATR suggested that RH were less susceptible to enzymatic pretreatment than SB and partial removal/modification of lignin was sufficient to improve saccharification. (C) 2020 Elsevier Ltd. All rights reserved.
Basic information on the biology of weeds can contribute significantly to building appropriate strategies for their management, and developing non-chemical control tools. The aim of this work was to study the effect of sowing depth, soil type, and litter type and amount on the emergence of Vernonia ferruginea seedlings. In the first experiment, seeds of this species were placed in two substrates (soil and sand) at seven depths (0, 0.0025, 0.005, 0.01, 0.02, 0.04 and 0.08 m). In the second experiment, the effect of sugarcane straw, signal grass and maize was determined in five amounts (0.0, 1.5, 3.0, 6.0 and 9.0 t ha(-1)) on the emergence of V. ferruginea. The highest emergence was observed on the surface and at 0.0025 m in both substrates. Corn straw inhibited emergence of V. ferruginea the most, in all the amounts tested.
In the present investigation, a novel chemical treatment was introduced for the extraction of nanocellulose fibers from sugarcane bagasse and applied as reinforcement material to enhance the physical properties and thermal stability of epoxy nanocomposites. Epoxy nanocomposites with different weight fractions were fabricated using a wet layup process followed by furnace heating to remove the residual moisture content. The influence of surface modified sugarcane nanocellulose fiber loading on morphological (transmission electron microscope) properties of epoxy nanocomposites was investigated. The porosity and water absorption increase with the increment in fiber weight fraction for both treated and untreated nanocellulose fiber-epoxy composites. Among the various treatment processes, the alkali-treated fibers reinforced epoxy composites showed better thermal stability and water absorption resistance under 10 wt.\% of nanocellulose fiber reinforcement.
Due to high volumes of production from the consumer electronics industry, it is highly desirable to develop green electronics comprised of biodegradable components derived from cheap resources or even agro-industrial wastes. In this work, a facile and benign production route is proposed to transform the agro-industrial waste sugarcane bagasse into value-added super-clear nano-paper for flexible and transparent electronics. High-value cellulose nanocrystals (CNCs) are isolated from abundant and inexpensive sugarcane bagasse by a one-step 2,2,6,6-tetramethylpiperidine-1-oxyl treatment, and the obtained CNCs are then used to fabricate a super-clear nanopaper substrate for next-generation flexible electronics. The super-clear nanopaper exhibits superior optical properties (91\% transmittance and 1.4\% transmission haze at 600 nm), excellent nanometer-scale surface roughness (3.08 nm), and good oxygen barrier properties (1.2 cm(3) mu m (m(2) day kPa)(-1) at 50\% relative humidity). Moreover, proof-of-concept field-effect transistors with an on/off ratio of >10(3) are demonstrated on this super-clear nanopaper. The efficient and scalable production of value-added CNCs from bagasse waste coupled with advanced applications of CNC-based super-clear nanopaper in electronic devices presents a solution for the conversion of agricultural wastes to value-added electronic applications, which is beneficial for green electronics and recycling and ecoindustries.
Sugarcane honey (SCH) is a syrup produced on Madeira Island and recognized by its unique aroma, a complex attribute of quality with an important influence on the final consumer's acceptance of the product, and determined by a complex mixture of a large number of volatile organic compounds (VOCs) generated during its traditional making process and storage. Therefore, the purpose of this study was to establish the volatile profile of genuine SCH produced by a regional certified producer for seven years and compare it with syrups from non-certified regional producers and with producers from different geographical regions (Spain, Egypt, Brazil and Australia), as a powerful strategy to define the volatomic fingerprint of SCH. Different volatile profiles were recognized for all samples, with 166 VOCs being identified belonging to different chemical classes, including furans, ketones, carboxylic acids, aldehydes and alcohols. Chemometric analysis allowed (i) the differentiation between all syrups, being more pronounced between SCH and other syrups; and (ii) the identification of 32 VOCs as potential markers for the traceability and authenticity of SCH on the global market.
Continuous H-2 production from alkali-hydrolyzed rice straw in two mesophillic anaerobic baffled reactors (ABRs) was investigated in parallel. ABR(1) was inoculated with thermally pretreated sludge while the sludge in ABR(2) was amended with magnetite nanoparticles (MNPs). Both reactors were operated at organic loading rates (OLRs) ranged from 0.8 to 4.8 g(COD)/L/day. The addition of MNPs significantly improved the H-2 production and yield, ie, maximum H-2 yield was 21.4 +/- 3.2 and 60.6 +/- 5.7 mL/g CODremoved for both ABR(1) and ABR(2), respectively, at OLR of 1.6 g(COD)/L/day. Likewise, substrate degradation efficiency (SDE) was augmented from 48.4 +/- 3.9\% (ABR(1)) to 55.8 +/- 4.2\% (ABR(2)). The enhancement effect of MNPs can be emphasized by hydrogenase enzyme activity increase from 0.097 +/- 0.013 to 0.205 +/- 0.019 mg MBreduced/min at ABR(1) and ABR(2), respectively. Besides, ABR(2) witnessed higher concentrations of acetate (HAc) and butyrate (HBu) coupled with lower values of propionate (HPr). Additionally, HAc/HBu ratio for ABR(2) (3.03 +/- 0.31) was higher than that for ABR(1) (1.95 +/- 0.29). Microbial analysis indicated that Bacillus and Clostridium species became dominant in mixed culture bacteria supplemented with MNPs. Furthermore, economic analysis revealed that the minimum payback period of 10.5 years at OLR of 3.2 g(COD)/L/day was recorded for ABR(2) compared with 14.6 years at OLR of 4.8 g(COD)/L/day for ABR(1).
Malaysia is the second largest producer of palm oil and generates 18 million tons of empty fruit bunches annually. Sugarcane is another important crop that is widely planted throughout Southeast Asia for sugar production. Both crops generate large amounts of lignocellulosic waste biomass in the form of sugarcane bagasse (SCB) and oil palm fibres (OPF), which can be converted into carboxymethyl cellulose (CMC) and subsequently cross-linked into hydrogels using electron beam irradiation. The irradiated CMC yielded hydrogels with up to 40\% gel fraction, which can be increased to 50\% with the addition of acrylamide as copolymer. The addition of acrylamide increased hydrogel yields and protected the polymer from chain scission at high radiation doses, up to 40 kGy. Furthermore, the hydrogels produced were stable at pH 3-10, suggesting that pH had a minimal impact on swelling, which affects their performance as absorbents. The methylene blue absorption of all SCB and OPF hydrogels examined in this study ranged from 0.722-0.987 mmol/g, which far exceeded that of bamboo-based activated carbon (0.142 mmol/g). This makes these hydrogels suitable for cationic dye removal and may be applied for the absorption of fertiliser ions in the future.
The present study deals with the enhanced production of polyhydroxybutyrate (PHB) using a novel potent strain. On the basis of morphological, biochemical, and 16S rRNA analysis, the strain was identified as Bacillus safensis EBT1. The presence of PHB in the cells was identified and affirmed using fluorescent microscopy and Fourier transform infrared spectroscopy. The molecular weight of PHB was ascertained by gel permeation chromatography. Under optimized conditions, B. safensis EBT1 showed maximum PHB production and growth with glucose as the carbon source, yeast extract as the nitrogen source, and sugarcane bagasse as the substrate. The process parameters were optimized using central composite design: pH 7, 45 degrees C and 48 h incubation time. At these conditions, highest biomass concentration of 7.54 g/L and PHB production of 6.41 g/L were observed.
A comparison of lignocellulose degradation, energy requirements, biogas production and microbial community analysis was done between a fungal (Pleurotus ostreatus, 28 d, 35 degrees C), thermal (1 h, 121 degrees C) and acid (2\% HCl, 2 h, 123 degrees C) pre-treatment of bean straw. The results revealed that the type of pre-treatment had a great impact on lignocellulose degradation and energy demand, where the acid pre-treatment had higher solubilization capacity (lignin 67\%, hemicellulose 68\% and 0.49 g sugars.g(-1) bean straw) and demanded less energy as compared with the fungal pre-treatment. Contrary, the type of pre-treatment did not have an apparent effect on the anaerobic digestion of the hydrolysates after 37 days of bioreactors operation in terms of biogas yield (142-165 mL.g(-1) chemical oxygen demand-COD), COD and sugars degradation (>80\%). The bioreactor using acid pre-treatment hydrolysates showed differences in the total bacterial and archaea estimates, with a more pronounced increase in archaea (Euryarchaeota) and bacteria (Bacteroidetes, Firmicutes, and Proteobacteria), suggesting a more favorable composition for microbial growth. Overall, the acid pre-treatment was the most effective on all the parameters compared in this study. Further studies should include other important parameters to consider when selecting a pre-treatment method including environmental and economic implications of solid phase disposal and pH adjustment.
Different species of the Convolvulaceae and Euphorbiaceae family infest sugarcane Culture rapidly at id aggressively, especially it it areas covered by the unburned straw remaining from the harvest. This in station, combined with extensive cultivation areas, have made it difficult to manage the chemical application exclusively during the rainy season of the year, forcing producers to apply the herbicides also during the drought period. Within 0 Lis context, this work aimed to study the persistence of the herbicides applied during drought in resisting bad weather until the start of the rainy season, by evaluating the control over the species of the genera Ipomoea, Merremia and Euphorbia. The experimental design was a randomized block with 42 treatments distributed in a split-plot with six replications. The herbicides amicarbazone (1050 g ha(-1)): imazapic (122,5 g I ha(-1)): sulfentrazone (600 9 ha-1) and associations clomazone (1000 g ha-1) + hexazinone (250 9 ha:1), sulfentrazone (600 g ha(-1)) + diurom (936 g ha:1) + hexazinone (264 g ha(-1)); sulfentrazone (500 g 11CC9 + amicarbazone (700 g ha-1) and control were allocated to the plots. The species Ipomoea nil, I. hederifolia. L quamoclit, L grandifolia, Merremia aegyptia and Euphorbia heterophylla were Sown directly into the soil, covered with the equivalent of 15 t ha(-1) sugarcane straw and allocated to the sub-plots. After herbicide application, 70 days without rain were recorded, with water stress rendering evaluation impossible, since no weed emergence occurred in all treatments. after treatment, evaluations on the effectiveness However, in the beginning of the rainy season 90 days a of weed emergence could be carried out. At 150 DAT (days after treatments), the herbicides sulfentrazone and sulfentrazone, associated with amicarbazone, were the most persistent and presented an effective control mean over 85\%, considering all species when compared with the control.
The jaggery making from sugarcane is one of the traditional process industries contributing to the local employment and entrepreneurship opportunities to the rural population. Jaggery is a condensed form of sugarcane juice produced by evaporation of moisture. Bagasse which is internally generated during juice extraction from sugarcane is used as the fuel for evaporation in a jaggery furnace. Any efficiency improvement in the thermal performance of a jaggery furnace leads to bagasse saving which provides additional revenue for the jaggery manufacturer. A procedure for thermal evaluation using mass and energy balance for a jaggery furnace is proposed to establish furnace performance and loss stream analysis. The proposed method is used to investigate a four pan traditional jaggery furnace in India. The loss stream analysis indicates that the theoretical energy required for jaggery processing is only 29\% of total energy supplied by bagasse combustion. The major loss is associated with heat carried in flue gas and wall losses. The air available for combustion depends upon the draft created by chimney in natural draft furnaces. The oxygen content in the flue gas is a measure of degree of combustion. A controlled fuel feeding based on the oxygen percentage in the flue gases is proposed and demonstrated. The traditional practice of fuel feeding rate is changed to control feeding rate leading to reduction in specific fuel consumption from 2.39 kg bagasse/kg jaggery to 1.73 kg bagasse/kg jaggery. This procedure can be used for evaluation of jaggery furnaces for identification and quantification of losses, which will help in improving thermal energy utilization. (C) 2010 Elsevier Ltd. All rights reserved.
The performance of steers fed diets using as roughage rice straw treated with anydrous ammonia, rice straw+urea, sugarcane + urea and sorghum silage were evaluated. Sixteen PO Simental steers, averaging 400 kg initial LW, were assigned to a completely randomized design. The experiment last 88 days, 15 days of adaptation and 61 experimental days, divided in three periods of 21 days. Total DM intake, that ranged from 7.1 to 10.0 kg/day, differ among treatments, where higher intakes were observed for the animals fed ammoniated rice straw and sorghum silage, that did not differ. Feed:,gain ratio did not differ among different diets, and an average value of 6.6 was recorded. It was observed higherweight gain for the animals fed ammoniated rice straw (1.59 ka/day) in relation to the animals fed straw+urea (1.25 kg/day). The treatement with anydrous ammonia improved the rice straw nutritive value resulted in higher voluntary intake of this roughage and, consequently, in higher daily weight gain in relation to no treated rice straw and supplemented with urea.
The present study proposes a novel system for power, heat, and hydrogen generation comprising a biomass gasification unit, Rankine cycle, dual-fuel combustion engine, and a waste heat recovery unit. Exhausting hot gases from the engine is recovered for the gasification of the biomass. A part of the generated hydrogen serves as the second fuel in a Heptane-fueled engine to improve its performance. Energy and exergy analyses are carried out for Sugarcane bagasse, Rice Straw, Wheat Straw, and Rice Husk biomass fuels. A good consistency can be seen between the findings of the current study and experimental reports in the literature. The developed trigeneration system improved both exergy efficiency and thermal efficiency by 19\% when compared to the conventional system. The exergy efficiency is maximized by using sugarcane bagasse. Furthermore, the results show that Wheat Straw has a maximum total thermal efficiency of 95\%. The maximum system exergy destruction of 54\% is observed by using Rice Straw and Rice Husk.
Bioconversion of the complex carbohydrates present in lignocellulosic biomass into simple sugars, in order to obtain biofuels and bio-based products, is still limited by the low performance of the enzymatic saccharification reaction and the high cost of cellulolytic enzymes. Low-cost additives such as soybean protein can reduce the unproductive adsorption of cellulases onto lignin, increasing conversion rates and reducing enzyme losses. Here, investigation was made of the effects of different soybean protein fractions, extracted in-house, on the enzymatic saccharification of hydrothermally pretreated sugarcane bagasse. The glucose released during biomass saccharification increased by up to 76\% in the presence of the in-house extracted soybean protein, compared to the control (without additive). A remarkable finding was that the technique allowed the enzyme loading to be decreased four-fold. The results suggested that the alkali-extracted proteins presented high surface hydrophobicity, which enhanced their interaction with lignin and reduced the unproductive binding of cellulases. Among the main soybean protein fractions, glycinin had the best effect in improving saccharification, which could have been due to its higher hydrophobicity. Hence, in-house extracted soybean proteins seem to be interesting alternative additives capable of increasing the lignocellulosic biomass conversion efficiency in future biorefineries.
Arabinoxylans (AX) are hemicellulose polysaccharides comprising a linear backbone of xylose sugars with arabinose residues attached along the chain. They offer interesting functional properties that could have application as a new class of food ingredients or for non-food applications. The emergence in recent decades of biorefineries gives a context in which commercial production of a portfolio of AX products could be feasible, through integration with bioethanol production, using ethanol to precipitate the AX. Extending the concept, AX fractions of different functionality can be precipitated at different ethanol concentrations, giving further scope for efficiencies through bioethanol pinch analysis, while producing a portfolio of products with different potential markets and end uses. The current work demonstrates the potential of AX fractions extracted from sugarcane bagasse as bread ingredients. Bagasse AX fractions increased the water absorption in dough formulations, by more than double their own weight for fractions larger than 10 kDa, and increased dough development time in a Chopin Mixolab. As well as promising in their own right, AX also illustrate the more general opportunity for synergies between biorefining and the food industry, with the rise of biorefineries giving opportunities to provide the food industry with new ingredients not currently available. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
This study deals with improvement in the properties of ABTRAP (Beneficiated RAP aggregates by Abrasion \& Attrition technique) inclusive concrete by incorporating mineral admixtures such as Silica Fume (SF), Fly ash (FA) and Sugarcane Bagasse Ash (SCBA). 6 mixes were prepared by partially replacing Ordinary Portland Cement (OPC) by SF (5\% \&10\%), FA (10\% \& 20\%) and SCBA (5\% \& 10\%). Maximum improvement in compressive, flexural and split tensile strength of ABTRAPC mix was found when 10\% OPC was part replaced by SF followed by 20\% replacement by FA and 5\% replacement by SCBA. Even SF20 mix showed comparable strength to that of natural aggregate concrete (NAC) mix. Reductions in permeable voids, water absorption, initial rate and coefficient of water absorption and improved abrasion resistance was observed for all the considered mixes. A power regression equation (flexural strength = 0.368 x (compressive strength) 32) of high co-relation (R-2 = 0.93) was established to predict flexural strength from compressive strength results of ABTRAPC mixes. Based on the finding of the present part of investigation, it is recommended to replace 10\% OPC by SF, FA (20\% in sulphate free environment) and 5\% by SCBA in ABTRAP inclusive concrete mixes. (C) 2017 Elsevier Ltd. All rights reserved.
In order to elucidate the reaction behavior of cellulose component in bagasse, the homogeneous phthalation of bagasse was investigated comparatively with the isolated cellulose in 1-allyl-3-methylimidazium chloride (AmimCl) with phthalic anhydride (PA) at the dosage of 10-50 mmol/g. The phthalation degrees of bagasse and the isolated cellulose were in the range of 5.66\% to 22.71\% and 11.61\% to 44.11\%, respectively. A phthalation degree increase of cellulose was proportional to phthalic anhydride dosage due to its regular macromolecular structure and followed the equation gamma(PDI) = 0.004x - 0.02. FT-IR and 2D HSQC NMR analyses confirmed the attachment of phthaloyl group. The phthalation reactivity of the three hydroxyls in the isolated cellulose followed the order of C-6 > C-2 > C-3, and the more selective phthalation to C-6 position was found in the cellulose component in bagasse. These results provide detailed understanding of the homogenous modification mechanism of lignocellulose.
Agriculture is a great emission source of CO2 into the atmosphere, contributing significantly to the greenhouse effect. Considering the hypothesis that there are differences in soil carbon dynamics due to the distinct physiological and morphological characteristics of sugarcane cultivars, the aim of this study was to characterize the short-term soil CO2 emission associated with soil attributes in agricultural areas under cultivation of five sugarcane cultivars. The experiment was conducted in an area of high-clay Oxisol (Hapludox, USDA Soil Taxonomy) located at the Cerrado biome, Midwestern region of Brazil. Over the course of 20days, ten measurements of soil CO2 emission (FCO2), soil temperature (Ts), and soil moisture (Ms) were carried out. Subsequently, soil samples were collected at a depth of 0-0.20m to determine soil physical and chemical attributes. In timescale, FCO2, Ts, and Ms varied depending on the amount of straw produced by each cultivar. The cultivars RB935608, RB935744, and SP832847 induced a higher soil CO2 emission since they are associated with controlling factors of the primary CO2 production process (higher organic matter content and lower C/N ratio in the soil). Thus, strategies to reduce greenhouse gas emissions in agriculture, such as the choice of sugarcane cultivars that provide lower soil CO2 emissions, are essential to mitigate important environmental issues such as the global warming.
Efficient products can be developed for the ornamental plant sector using agro-industrial waste. This study evaluated the agronomic performance and ornamental quality of calendula plants (Calendula officinalis) cultivated in substrates formulated with solarized aerobic sewage sludge (SASS), rice husk ash (RHA), and sugarcane bagasse (SB). Five additive rates were used: S2: 33.33\% SASS + 33.33\% RHA + 33.33\% SB; S3: 16.65\% SASS + 41.67\% RHA + 41.67\% SB; S4: 12.48\% SASS + 43.76\% RHA + 43.76 \% SB; S5: 8.32\% SASS + 45.84\% RHA + 45.84 \% SB; S6: 4.16\% SASS + 41.07\% RHA + 54.76\% SB; and S1: commercial substrate (reference). Raw materials and substrate formulations were characterized and agronomic and ornamental aspects were evaluated in calendula plants cropped in all substrates. The lowest agronomic performance was observed in S6 (lowest SASS rate), while the highest occurred in S3 compared to the other treatments. Regarding the ornamental potential, S3 and S4 and the commercial substrate (S1) were classified as excellent. This study highlights the successful use of organic raw materials (SASS and agro-industrial waste) to compose substrates for calendula production in pots, with the recommended proportions ranging from 12.48 to 16.65\% of SASS combined with RHA and SB.
Removal of emerging contaminants such as pesticides from aqueous systems is of growing concern. The usage of sustainable materials as adsorbents is an eco-friendly approach to water purification. Sugarcane bagasse is an abundant waste material that can serve as a sustainable source for preparing adsorbents. This work investigated the removal of chlorpyrifos from aqueous systems using a composite adsorbent prepared from sugarcane bagasse-derived biochar and encapsulated in alginate. The batch studies were conducted to examine the effect of contact time, initial pH, initial concentration of adsorbate, sorbent dosage and temperature on the extent of chlorpyrifos removal by biochar alginate beads. Adsorption thermodynamics, equilibrium isotherms, and kinetics were studied to elucidate the chlorpyrifos uptake phenomenon. The error functions were used to determine model parameters using non-linear regression approach. Biochar alginate beads showed 86 \% chlorpyrifos removal under optimized conditions. The adsorption capacity was found to be 6.25 mg g-1 for pH 10 at 10 ppm chlorpyrifos concentration. The analysis of experimental isotherm data revealed Freundlich isotherm model to be the best fitting with regression coefficient value of 0.9332 Kinetic studies showed that adsorption followed intraparticle diffusion model with R2 value of 0.9750, where Boyd model was further studied to confirm rate constant. Adsorption of chlorpyrifos onto biochar beads is showed to be exothermic with type of adsorption to be physisorption.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
This study evaluated the feasibility of H-2 and CH4 production in two-stage thermophilic (55 degrees C) anaerobic digestion of sugarcane stillage (5,000 to 10,000 mg COD.L-1) using an acidogenic anaerobic fluidized bed reactor (AFBR-A) with a hydraulic retention time (HRT) of 4 h and a methanogenic AFBR (AFBR-S) with HRTs of 24 h-10 h. To compare two-stage digestion with single-stage digestion, a third methanogenic reactor (AFBR-M) with a HRT of 24 h was fed with increasing stillage concentrations (5,000 to 10,000 mg COD.L-1). The AFBR-M produced a methane content of 68.4 7.2\%, a maximum yield of 0.30 +/- 0.04 L CH4.g COD-1, a production rate of 3.78 +/- 0.40 L CH4.day(-1).L-1 and a COD removal of 73.2 +/- 5.0\% at an organic loading rate (OLR) of 7.5 kg COD.m(-3).day(-1). In contrast, the two-stage AFBR-A system produced a hydrogen content of 23.9 +/- 5.6\%, a production rate of 1.30 +/- 0.16 L H-2.day(-1)L(-1) and a yield of 0.34 +/- 0.08 mmol H-2.g COD.m(-1). Additionally, the decrease in the HRT from 18 h to 10 h in the AFBR-S favored a higher methane production, improving the maximum methane content (74.5 +/- 6.0\%), production rate (5.57 +/- 0.38 L CH4.day(-1).L-1) and yield (0.26 +/- 0.06 L CH4.g COD-1) at an OLR of 21.6 kg COD.m(-3).day(-1) (HRT of 10 h) with a total COD removal of 70.1 +/- 7.1\%. Under the applied COD of 10,000 mg L-1, the two-stage system showed a 52.8\% higher energy yield than the single-stage anaerobic digestion system. These results show that, relative to a single-stage system, two-stage anaerobic digestion systems produce more hydrogen and methane while achieving similar treatment efficiencies. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
This study assesses the environmental potential of crop residues and the techno-economic potential of biojet fuel (BJF) production in Brazil. Different production routes are evaluated from two types of biomass residues (sugarcane straw and eucalyptus harvest residue), and four different technological pathways (alcohol to jet, Fischer-Tropsch, hydrothermal liquefaction and pyrolysis). The environmental potential of biomass residues is determined utilizing spatio-temporal projections of land-use change in Brazil and by explicitly modeling the erosion risk and the soil organic carbon (SOC) balance spatially. The assessment of the techno-economic potential of BJF production from the environmental potential of sugarcane straw (SCS) and eucalyptus harvest residues (EHRs) considers the BJF total costs, which result from a summation of biomass residue recovery costs, BJF conversion costs, and BJF transportation costs. These BJF total costs are compared with the range of fossil jet fuel prices at Brazilian airports to quantify the techno-economic potential. The environmental potential of biomass residues varies from 70 Mt in 2015 to 102 Mt in 2030, with SCS being highly constrained by SOC, whereas EHRs are more constrained by the high erosion risk. These quantities can generate a techno-economic BJF potential ranging from 0.45 EJ in 2015 (46 US\$/GJ - 65 US\$/GJ) to 0.67 EJ in 2030 (19 US\$/GJ - 65 US\$/GJ). In 2030, several BJF production routes can be competitive with fossil jet fuel prices. The northeast and southeast regions have the highest potential, especially in 2030. (c) 2020 The Authors. Biofuels, Bioproducts, and Biorefining published by Society of Chemical Industry and John Wiley \& Sons, Ltd.
Pumpkin pulp shell (PPS) is an agricultural by-product with contaminating potential that can be used to ensile. The objective of this study was to determine the quality and bromatological characteristics of ensilages made with PPS, pangola grass hay, urea and two percentages of fermented molasses during 14 and 21 days. Ensilage types (2 kg) were E1 (72.5\% PPS, 22.5\% grass, 3\% molasses and 2\% urea) and E2 (72.5\% PPS, 19.5\% grass, 6\% molasses and 2\% urea). Both ensilages were fermented for 14 and 21 days. The pH was evaluated, along with thy matter (DM), lactic acid, ash (As), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and hemicellulose content. The statistical analysis was a completely randomized 2 x 2 design with ensilage types and fennentation time as factors. The pH of E2 did not vary (p > 0.05) at 14 and 21 days of fermentation, averaging 3.85. A higher production of lactic acid was quantified with E1 at 14 days, and it also presented a higher DM than E2 (p <= 0.05). The content of CP, NDF, ADF, As and hemicellulose did not show differences (p > 0.05) by ensilage type or fermentation times. It is concluded that PPS can be ensiled with pangola grass hay, urea and up to 6\% sugarcane molasses fermented for 14 or 21 days without affecting its quality and bromatological characteristics.
The aim of this study was to investigate the use of phenotypic and genotypic values in the path analysis involving agronomic characteristics in sugarcane at the stages of plant cane and ratoon cane. Under these two approaches it was calculated the direct and indirect effects of yield components number of stalks per plot, diameter of stalk and average height of stalk - on sugarcane yield per hectare. To ensure a better consistency of results, data were obtained in two experiments in randomized blocks with five replications. The experiments were carried out at the Center of Sugarcane Experimentation of the UFV, Oratorios, MG, Brazil. Each experiment consisted of 22 full-sib families of sugarcane. The coefficients of determination were high in all path analysis, indicating that the evaluated components explain most of the variation in straw yield. Practically there was no difference in interpretations and conclusions from the analysis based on arrays of genotypic or phenotypic correlations. From the analysis of the direct phenotypic and genotypic effects, number of stalks was the variable that best correlated with sugarcane yield per hectare in both experiments and harvest stages, demonstrating the possibility of obtaining significant gains by means of indirect selection of sugarcane yield per hectare using number of stalks. There was variation in the estimates of correlation in the comparison between experiments, probably due to different origin of the families surveyed in each experiment.
Bagasse fibers reinforced poly(vinyl alcohol) (PVA) composite films were successfully prepared by solution casting method. To enhance the dispersing effect of the fillers, alkali treatment of the plant fibers was adopted before the fabrication of composites. The structure and properties of the resulting composites were characterized by scanning electron microscopy (SEM), X-ray diffraction, differential scanning calorimetry, mechanical tests, water uptake and thermal stability in detail. The results showed that bagasse fibers after surface modification exhibited good compatibility with PVA matrix. The increased polarity as well as the roughness would be beneficial to the interaction and mechanical interlocking between the fiber and matrix. Acting as the heterogeneous nucleation agents, the fibers could enhance the degree of crystallization and decrease the supercooling degrees of PVA matrix. The fibers exhibited dramatically reinforcing effect in the matrix, and with the increase of fiber, the Young's modulus and tensile yield stress increased. The Young's modulus and tensile yield stress of composites with 8\% filler would be 3 and 2 times compared with neat PVA films. The thermal stability decreased a little and the water uptake increased with the increase of filler content. These composite films would find wide applications in green packaging areas for their fine mechanical and thermal properties.
The purpose of this study is to demonstrate the impact of incorporating two different types of green nanomaterials (sugarcane and eggshell) on destructive and non-destructive properties of mortar. Nano sugarcane (NSC) was manufactured by calcining sugarcane at temperatures of 600 degrees C for 3 h. On the other hand, nano eggshell (NES) was manufactured by calcining eggshell at temperatures of 600 degrees C for 6 h. The sugarcane ash and eggshell ash were then milled to nano size. The final nano-sized product replaced Portland cement with different dosages of 2, 4 and 6\%. Sixteen mortar mixtures were designed and prepared using only NSC or only NES or a combined hybrid of NSC and NES. Consistency, compressive strength, flexural strength and microstructure analysis (scanning electron microscopy and energy-dispersive X-ray) tests were conducted to investigate the influence of replacement materials on the performance and properties of mortars. The results showed that the use of nano sugarcane and nano eggshell enhanced the compressive strength and reduced permeability of green mortar due to the micropore structure. At the ages of 7 and 28 days, mortars containing a replacement ratio of 2\% (0.5\% NSC + 1.5\% NES) had remarkably improved mechanical properties, and the improvement in compressive strength reached 21.3\% and flexural strength to 10.08\% when compared to the control sample. The efficiency of NSC and NES in increasing mortar strength was also confirmed by microstructure analysis.
In this paper, the productivity of the use of sugarcane bagasse and petroleum derivatives for the generation of electric energy was evaluated using the DEAP and Malmquist indexes. The results show that the total productivity of the factors of the use of bagasse to generate electrical energy registers an interannual decrease. In the case of the use of petroleum derivatives to generate energy, the total factor productivity in general average registered deterioration; however, some of the thermal plants studied registered a growth rate. This means that there is an opportunity for the review of production processes to increase the productivity of the use of bagasse and that oil derivatives are being managed with greater productivity to generate electricity.
The aim of the research work is to study the physical, mechanical, and erosive wear properties of sugarcane bagasse fiber-reinforced epoxy composites. The physical (density, void content) and the mechanical (hardness, tensile strength, impact energy, flexural strength) properties of the composites were found to increase with the content of bagasse fiber. For erosive wear analysis, the experiments were carried out with the help of erosion test machine. To minimize the erosive wear rate, Taguchi technique is executed to explore the influence of five control factors including fiber content, impact velocity, impingement, stand-off distance, and erodent size at three levels. Using Taguchi (L-27) orthogonal array, the optimal combination of control factors, which yielded minimum erosive wear rate, was statistically predicted and experimentally verified. The fiber content and impact velocity were the two most contributing control factors for the minimization of erosive wear rate. The important sequence of the parameters is fiber content > impact velocity > impingement angle > erodent size > stand-off distance. The optimal combination of control factors was obtained at 10 wt\% of fiber content, 30 m/s of impact velocity, 30 degrees of impingement angle, 85 mm of stand-off distance, and 250 mu m of erodent size. Finally, composites worn surfaces were examined with scanning electron microscope to study the possible erosive wear mechanism. POLYM. COMPOS., 40:3777-3786, 2019. (c) 2019 Society of Plastics Engineers
Background: Preservation of green sugarcane tops (SCT) as silage is still challenging due to its low fermentation coefficient. Present study was undertaken to assess the effect of different combination of additives on nutrient utilisation and growth performance in crossbred (Karan fries) heifers fed SCT silage based total mixed diet. Methods: Sugarcane tops (300 g DM/kg fresh matter) ensiled for 30 days in plastic jumbo silo bags (500 kg capacity) in three different treatments viz. SCTB1, SCTB2 and SCTB3 silages. Total mixed ration (TMR) TMRB1, TMRB2 and TMRB3 were prepared, containing 40 part concentrate and 60 part sugarcane tops SCTB1, SCTB2 and SCTB3 silages, respectively. Eighteen crossbred calves of similar body weights (115 kg) and age (11 months) were divided in three group and offered dietary treatments: TMRB1, TMRB2 and TMRB3 for sixty days. Feed intake (daily) and body weight (weekly) was recorded. Blood samples were collected (monthly) for glucose, creatinine, BUN, plasma calcium, ALT and AST levels estimates. Result: On 30th day SCT silage samples were analysed, pH and NDF content was found lower (p<0.05) whereas lactic acid content was higher (p<0.05) in SCTB2 and SCTB3 than SCTB1 silage. Feed intake, growth performance, nitrogen balance and blood biochemical parameters were remained similar among the groups. Total tract digestibility of NDF and ADF was found higher (p<0.05) in groups TMRB2 and TMRB3 than TMRB1. It may be concluded that LAB and EFE supplementation on SCT silage improved fibre digestibility (NDF and ADF) of TMR diet however, feed intake, growth performance and blood parameters were not affected in crossbred calves.
The potential of dilute-acid prehydrolysis as a pretreatment method for sugarcane bagasse, rice hulls, peanut shells, and cassava stalks was investigated. The prehydrolysis was performed at 122 degrees C during 20, 40, or 60 min using 2\% H2SO4 at a solid-to-liquid ratio of 1 : 10. Sugar formation increased with increasing reaction time. Xylose, glucose, arabinose, and galactose were detected in all of the prehydrolysates, whereas mannose was found only in the prehydrolysates of peanut shells and cassava stalks. The hemicelluloses of bagasse were hydrolyzed to a high-extent yielding concentrations of xylose and arabinose of 19.1 and 2.2 g/L, respectively, and a xylan conversion of more than 80\%. High-glucose concentrations (26-33.5 g/L) were found in the prehydrolysates of rice hulls, probably because of hydrolysis of starch of grain remains in the hulls. Peanut shells and cassava stalks rendered low amounts of sugars on prehydrolysis, indicating that the conditions were not severe enough to hydrolyze the hemicelluloses in these materials quantitatively All prehydrolysates were readily fermentable by Saccharomyces cerevisiae. The dilute-acid prehydrolysis resulted in a 2.7- to 3.7-fold increase of the enzymatic convertibility of bagasse, but was not efficient for improving the enzymatic hydrolysis of peanut shells, cassava stalks, or rice hulls.
Sugarcane trash (SCT) is an under-utilized biomass with potential for conversion to fuels and chemicals. Here, we report an organosolv process involving pretreatment by aqueous glycerol followed by mild delignification with acetone for fractionation of SCT. The effects of glycerol and oxalic acid on efficiency and selectivity of the reaction were studied at different temperatures. The higher glycerol content was found to promote delignification efficiency and enhanced enzymatic digestibility of the solid. An optimal reaction using 80\%v/v glycerol at 170 degrees C, with 300 mM oxalic acid followed by acetone extraction at 30 degrees C led to cellulose recovery of 71.7\%, whereas 96.8\% and 83.9\% of the initial hemicelluloses and lignin was removed into the aqueous-glycerol and acetone fractions, respectively. The isolated lignin was recovered with 73.7\% yield and 94.6\% purity and showed similar chemical profiles with higher thermal stability compared to commercial organosolv lignin according to Fourier Transform Infrared Spectroscopy and Thermogravimetric analysis.
The material use of agricultural by-products helps to not only reduce severe environmental problems, but also permits the production of value-added products at the same time. Extensive experiments produced and tested different erosion control blankets, adsorbents, and soil improvers from rice straw, rice husks, and bagasse. This led to the creation of an integrated process scheme, which permits side streams from one branch to be reused in other process branches. This integrated process scheme is presented that is demonstrated and supported by the material balance numbers based on the test results.
Ferulic acid is a renewable chemical found in lignocellulose from grasses such as wheat straw and sugarcane. Pseudomonas putida is able to liberate and metabolize ferulic acid from plant biomass. Deletion of the hydroxycinnamoyl-CoA hydratase-lyase gene (ech) produced a strain of P. putida unable to utilize ferulic and p-coumaric acid, which is able to accumulate ferulic acid and p-coumaric acid from wheat straw or sugar cane bagasse. Further engineering of this strain saw the replacement of ech with the phenolic acid decarboxylase padC, which converts p-coumaric and ferulic acid into 4-vinylphenol and the flavor agent 4-vinylguaiacol, respectively. The engineered strain containing padC is able to generate 4-vinylguaiacol and 4-vinylphenol from media containing lignocellulose or Green Value Protobind lignin as feedstock, and does not require the addition of an exogenous inducer molecule. Biopolymerization of 4-vinylguaiacol and 4-vinylcatechol styrene products is also carried out, using Trametes versicolor laccase, to generate ``biopolystyrene{''
In the present study, a magnetic nanocomposite based on biochar (BC) derived from sugarcane bagasse, nanoscale zerovalent iron (nZVI), and chitosan (CS) was fabricated to investigate its efficacy for the removal of two widely used pharmaceutically active compounds (PhACs), namely aspirin (ASA) and carbamazepine (CBZ). The synthesized nanocomposite (BC-CS@nZVI) was characterized using XRD, FTIR, and FESEM-EDX. The Response Surface Methodology-Central Composite Design (RSM-CCD) model was used for the optimization of removal efficacies for both drugs using five variables, i.e., adsorbent dose (0.05-0.1 g), pH (2-10), drug concentration (20-40 ppm), time (40-80 min), and temperature (40-60 ?). Under optimized conditions of adsorbent dose: 0.075 g, pH: 2, drug concentration: 30 ppm, time: 60 min, and temperature: 50 ?, the maximum removal efficiency of ASA drug was observed to be 97.8\%, while in the case of CBZ drug under similar conditions with pH 6, the maximum removal was found up to 89.32\%. The isotherm models revealed that both ASA and CBZ adsorption data fit well with the Langmuir isotherm showing monolayer adsorption. The kinetics of adsorption was well explained by the pseudo-first- and pseudo-second-order models in the case of ASA and CBZ, respectively. Thermodynamic parameters confirmed the feasibility of the reaction and its spontaneous and exothermic nature. The reusability and efficiency in water samples of the Ha'il region were investigated to demonstrate its potential for practical application.
The main purpose of this study was to analyze the effects of different carbon source (Na2CO3, NC; sugarcane molasses, SM) additives on dissolved organic matter (DOM), cbbL-containing autotrophic microbes (CCAM), and the relationship among physico-chemical parameters, DOM and CCAM to better understand carbon transformation in composting. The results showed that SM or NC additive could promote the degradation and transformation of OM and DOM. After adding SM or NC, the Simpson index decreased by 2.03\% and 0.51\%, respectively, and Luteimonas and Thermomonspora were detected using high throughput sequencing, indicating that SM and NC increased the diversity of CCAM community. Additionally, both NC and SM contributed to improve the abundance of cbbL gene (45.91\% and 2.15\%) based on fluorescence quantitative PCR (qPCR) analysis at the cooling phase of composting. Pearson correlation analysis revealed that Proteoobacteria, Firmicutes, Acidobacteria and Nematoda were positively related with C/N, OM and DOM (0.5 < R < 0.9, P < 0.05).
Acid hydrolysis of dried fodder's yeast Candida utilis was studied by a central composite design taking into account three independent variables: temperature (105-165C), processing time (30-70 min) and HCl concentration (7.5-17.5\%). Response variables were: color, dry matter solubilization and amino nitrogen. Temperature was the most significant variable followed by acid concentration and processing time. Response surfaces were generated from fitted polynomials. Higher temperatures to prevent amino nitrogen degradation were not investigated. As different effects were found for color development and amino nitrogen, a combined function was tested which yields the behavior of all responses simultaneously. The best conditions were: 150C, 15\% HCl and 40 min. After neutralization with 6N NaOH and centrifugation, the raw sauce was supplemented with 12\% NaCl, 0.1\% monosodium glutamate, 2\% vinegar and 0.1\% sodium benzoate and evaluated by sensory analysis for eight distinct attributes. Imitation sauce from yeast was at least as good as commercial hydrolyzed soybean sauce.
The aim of this study is to investigate the actions of sugarcane bagasse and cassava wastewater (two residues from the food industry) when used as hematite depressants. Additionally, the effect of each residue preparation method on the flotation results was analysed. The efficiencies of the depressors were investigated through microflotation tests utilising samples of pure hematite and quartz from Quadrilatero Ferrifero, which is in the state of Minas Gerais (Brazil). The pH of 10.5 was selected due to its frequent use in the concentration of iron ore via flotation in Brazil. Three residue gelatinisation methods (natural, heated, and conventional) were evaluated to determine the most efficient method for the flotation process. Further, zeta potential measurements were performed on the hematite to ascertain the performances of the residues. Microflotation test results showed that hematite recovery decreased with increasing depressant concentration, for all reagents. Finally, the actions of residues gelatinised with the addition of sodium hydroxide (i.e. the conventional method) were shown to be similar to that obtained from corn starch, which indicates their potential application in the flotation process.
Sugarcane straw burning generates particulate matter with complex composition resulting in atmosphere pollution. Sugarcane straw sugarcane burning particles (PSSB) contain several chemical compounds that were previously identified to be associated with carcinogenic and mutagenic processes. The aim of the present study was to extract PSSB under lab conditions and subsequently determine phyto- and cytogenotoxicity of these particles using Lactuca sativa L. and Allium cepa L. bioassays. Seeds of lettuce var. Cinderela and onion cv. Vale-Ouro IPA-11 were germinated in Petri dishes containing different concentrations of PSSB at 25, 50, 100, 200 or 300 mg/ml as well as control for 72 hr. Seed germination of lettuce was inhibited by PSSB, in a concentration-dependent manner, accompanied by decreased root growth, suggesting phytotoxic effects. Further, reduction of mitotic index and high number of chromosomal alterations in onion of meristematics cells indicated a cytogenotoxic action attributed to PSSB. Although the chemical composition of PSSB in question has not been determined, the phyto- and cytogenotoxic effects may be linked to the possible presence of polycyclic aromatic hydrocarbons (PAHs), which are were identified as the main constituents of particulate matter resulting from burning of sugarcane straw, in addition to exerting adverse biological effects that might result in mutations and cancer. Data demonstrated that the use of plants bioassays might be an important tool for biomonitoring air quality.
Hydrothermal CO2-assisted pretreatment was carried out for selective degradation of hemicellulose in wheat straw to produce pentose and enhancement the efficiency of enzymatic hydrolysis for glucose production. The FT-IR analysis and HPLC method was adopted to determine the observed chemical composition. Up to 90.0\% of hemicelluloses were degraded under the optimum condition with temperature of 200 degrees C, CO2 pressure of 3 MPa and reaction time of 10 min, following with cellulose content in substrate increase from 37.6 to 58.1\%. The efficiency of enzymatic hydrolysis was significantly improved after pretreatment, attributing to the loose structure of lignocelluloses after hemicellulose removal. More than 72.7\% of glucose was achieved after enzymatic hydrolysis, by contrast, while the untreated sample was merely 30.2\% due to enzymatic indigestibility. Additionally, SEM observations demonstrated that the densified structure of substrate was destructed, enhancing the accessibility and absorption of enzymes in the hydrolysis processing. The current results indicated that the hydrothermal CO2-assisted pretreatment was a feasible and effective approach for pretreatment of lignocellulosic biomass.
Co-pyrolysis of biomass with abundantly available materials could be an economical method for production of bio-fuels. Pyrolysis behavior of rice straw (RS) and water hyacinth (WH) were carried out in fixed bed reactor at temperature ranging from 300 to 450 degrees C at a heating rate of 20 degrees C/min. Co-pyrolysis of biomass with different reaction mixture were carried out at optimum condition 400 degrees C. The maximum liquid product yields for the pyrolysis of RS and WH obtained were 28.2 wt\% and 24.7 wt\%, respectively, whereas the maximum liquid product yield for RS + WH co-pyrolysis was 44.4 wt\% at 400 degrees C with 5: 5 biomass mixture ratio. The bio-oils obtained from pyrolysis and co-pyrolysis was analyzed by using GC-MS, FT-IR, H-1 NMR. The results of GC-MS and FT-IR analysis confirmed the interaction between RS and water hyacinth during co-pyrolysis, which resulted into increases the number of compounds and compound selectivity. The intensity of the peak enhanced at 1633 cm(-1) in the case of bio-char due to an increase in the amount of aromatic carbon and decreased cellulose and hemicellulose contents in the biomass. This work aimed to summarize research progress on co-pyrolysis as well as their benefits on enhancement of bio-oils derived from biomass.
Total pressure (TP) affects the level of dissolved hydrogen gas in the fermentation medium leading to metabolic shifts in mixed microbial-culture-based systems. In this study, the effect on hydrogen production rate and yield was investigated at different TP of a hydrogen-producing system using a microbial non-sterile culture previously heat-treated. Four continuous stirred-tank reactors (CSTR) were operated in parallel on a mineral salts molasses medium (21 g-COD. L-1) at 35 degrees C, pH 5.5 and hydraulic retention time (HRT) of 6 h. The TP was set at 80 kPa (R1), 100 kPa (R2), 120 kPa (R3) and 140 kPa (R4) for which reactor performances were estimated at steady-state conditions. As the increase of TP conse quently increased the partial pressure of hydrogen (p(H2)), the hydrogen production rate (HPR) and yield (HY) were consistently negatively influenced. The highest HPR and HY (406.1 +/- 36.8 mL-H-2 h(-1) ; 4.51 molH(2) mol(-1)suc eq.) were achieved at low pressure conditions (80 kPa). The composition of the microbial community mainly represented by species from Sporolactobacillus and Clostridium genera, did not change with the increase and/or decrease of the TP, indicating a regulation at cellular but not population level. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Objective: Present work was focused on utilization of lignocellulosic substrates like bagasse and citrus peel powder for CMCase (endoglucanase) production through submerged fermentation by Cladosporium sp. NCIM 901. Methods: Fungal strain Cladosporium sp. was procured from NCIM, Pune. Peracetic acid pretreated bagasse was used in order to reduce the crystallinity of bagasse. Mary Mandels medium was used for enzyme production. Central composite design was evaluated to study the effect of five variables on CMCase production and to optimize the medium composition. Results: Experimental results showed the optimal medium for higher enzyme production was composed of 10\% (w/v) bagasse substrate, 4.5\% (w/v) citrus peel powder, 0.17\% (w/v) MgSO4, 0.17\% (w/v) urea with the initial pH of medium at 5.5. Maximum enzyme yield (15.02 IU/ml) was obtained on by the interaction of optimal level of process involved parameters. There is a good correlation between actual and predicted results. The coefficient of determination (R-2) is 0.9414. Conclusion: Use of cheap and environment friendly available agricultural and fruit waste substrates for enzyme production eventually reduces the production cost of enzymes. Peracetic acid pretreated bagasse was used with citrus peel powder as fermentation medium constituent to induce the enzyme production. Observed actual enzyme activity was well agreed with the predicted enzymatic activity, shown the model was applicable for enzyme production through submerged fermentation.
Lytic polysaccharide monooxygenases (LPMOs) are auxiliary enzymes catalyzing oxidative cleavages of cellulose chains in crystalline regions, resulting in their increasing accessibility to the hydrolytic enzyme counterparts and hence higher released sugars from biomass saccharification. In this study, a novel auxiliary protein family 9 LPMO (BgAA9) was identified from a metagenomic library derived from a thermophilic microbial community in bagasse collection site where diverse AA9 and AA10 putative sequences were annotated. The enzyme showed highest similarity to a glycoside hydrolase family 61 from Chaetomium thermophilum. Recombinant BgAA9 expressed in Pichia pastoris cleaved cellohexaose (DP6) into shorter cellooligosaccharides (DP2, DP3, and DP4). Supplementation BgAA9 to a commercial cellulase, Accellerase (R) 1500 showed strong synergistic effect on saccharification of Avicel (R) PH101, decrystallized cellulose, filter paper, and alkaline-pretreated sugarcane bagasse, resulting in 63-93\% increase in the total reducing sugar yield after incubation at 50 degrees C for 72 h. Strong synergism was shown between BgAA9 and the cellulase with the highest total fermentable sugar yield obtained from 75:25\% of Accellerase (R) 1500:BgAA9 which released 39 mg glucose/FPU (filter paper unit) equivalent to 38.7\% higher than Accellerase (R) 1500 alone at the same total protein dosage of 5 mg/g substrate according to the mixture design study. The enzyme represented the first characterized LPMO from environmental metagenome and a potent auxiliary component for biomass saccharification.
Despite the recent discoveries of considerable fossil fuel reserves, Brazil is one of the only great economic and industrial powers with very high amounts of renewable energy in its electricity matrix. Approximately 79.3\% of the electric energy supply comes from renewable resources, of which hydroelectric power represents 70.6\%. The two primary concerns regarding hydroelectricity are the damage caused to the environment by the construction of dams and the uncertainty of the supply in cases of long drought seasons. This article presents an analysis on the availability and energy exploitation of sugarcane straw and forest residues derived from eucalyptus for decentralized generation using a Geographic Information System-based model. The potential bioelectricity and bioethanol production from sugarcane and eucalyptus biomass in the Administrative Region of Campinas (ARC) is higher than the demand in this region. The results provide guidelines for designing alternatives to the intended Nationally Determined Contributions in Brazil within the scope of the ARC, and they can be used to provide energy empowerment, electric matrix diversification, and new policies that address the residue availability and demand.
Plant cell wall-degrading enzymes produced by microorganisms possess important biotechnological applications, including biofuel production. Some anaerobic bacteria are able to produce multienzymatic complexes called cellulosomes while filamentous fungi normally secrete individual hydrolytic enzymes that act synergistically for polysaccharide degradation. Here, we present evidence that the fungus Trichoderma harzianum, cultivated in medium containing the agricultural residue sugarcane bagasse, is able to secrete multienzymatic complexes. The T. harzianum secretome was firstly analyzed by 1D-BN (blue native)-PAGE that revealed several putative complexes. The three most intense 1D-BN-PAGE bands, named complexes {[
Louisiana hard-to-boil (HTB) massecuites (mixtures of sucrose crystals in molasses) with markedly low heat transfer properties are a sporadic problem in sugarcane factories, which cause raw sugar and molasses production to decrease and increase, respectively. This usually occurs after severely deteriorated sugarcane has been processed, but the specific cause is unknown and only limited correction has been achievable. At the end of the 2006 sugarcane processing season, HTB and normal massecuites and molasses were collected from four Louisiana factories. Compared to normal samples, the HTB samples had 9.1-33.2\% lower heat conductivity and 10.0-49.2\% higher heat resistivity. The more HTB a sample is, the greater the increase in heat resistivity compared to the corresponding decrease in heat conductivity. Excess lime addition to neutralise acids during juice clarification is not the direct cause of hard boiling. Oscillatory deformation rheology applied at 20 degrees C to normal molasses samples gave typical mechanical spectra of concentrated solutions. In contrast, a highly viscous, intermolecular (gel) network was present in the HTB molasses, which would explain the difficulty of removing entrapped water on boiling. Polysaccharides in the samples were characterised. GFC, TLC. and methylation analyses suggested the presence of an arabinogalactan and endo-dextranase-resistant dextran structures. The HTB phenomenon may have different causes and mannitol is a contributing factor. Published by Elsevier Ltd.
The bio-char arising from slow pyrolysis of raw agricultural wastes from sugarcane (Saccharum officinarum) at two different temperatures (600 and 800 C) is characterized. According to international standards, the bio-char derived at both temperatures has potential as a solid bio-fuel for domestic use, whereas only the biochar produced at 800 C might be employed for industrial targets. Textural characterization also points to the potential use of the latter as an inexpensive rough adsorbent or soil amender Besides, acid-pretreatment of the wastes subjected to pyrolysis at 600 C promotes an enhanced yield of the bio-char with a well-developed porous structure. Its effectiveness in removing synthetic melanoidin from a dilute solution, as a model of molasses wastewater from the sugar industry and related factories generating environmental pollution, is comparable to that of a commercial activated carbon used for comparison.
Efficient, low-cost enzymatic hydrolysis of lignocellulosic residues is essential for cost-effective production of bioethanol. The production of beta-glucosidase, beta-xylosidase and xylanase by Colletotrichum graminicola was optimized using Response Surface Methodology (RSM). Maximal production occurred in wheat bran. Sugarcane trash, peanut hulls and corncob enhanced beta-glucosidase, beta-xylosidase and xylanase production, respectively. Maximal levels after optimization reached 159.3 +/- 12.7 U g(-1), 128.1 +/- 6.4 U g(-1) and 378.1 +/- 23.3 U g(-1), respectively, but the enzymes were produced simultaneously at good levels under culture conditions optimized for each one of them. Optima of pH and temperature were 5.0 and 65 degrees C for the three enzymes, which maintained full activity for 72 h at 50 degrees C and for 120 min at 60 degrees C (beta-glucosidase) or 65 degrees C (beta-xylosidase and xylanase). Mixed with Trichoderma reesei cellulases, C. graminicola crude extract hydrolyzed raw sugarcane trash with glucose yield of 33.1\% after 48 h, demonstrating good potential to compose efficient cocktails for lignocellulosic materials hydrolysis.
Ethiopia is one of the fastest growing countries in the world with a 10.9\% GDP growth rate in 2017. This high growth cannot be sustained without the deployment of modern energy in its different forms. To this end, the government is approaching the production of different types of modern and renewable energy. Among the renewable energy, molasses ethanol is the one given attention. This piece of research is aimed at evaluating the sustainability of molasses ethanol production and consumption considering gasoline substitution potential and eco-efficiency. The results show that achieving a 10\% molasses-based ethanol blend with gasoline (E10) throughout the country is difficult even with production at full capacity of the existing factories. To achieve E10, 76.2 million liter annual production of ethanol is required, while the current production potential is only 20 million liter. The ambitious government plan of E15 by 2020 can only be achieved by 2025 if all the plants under construction are operational by 2025 and can operate at full capacity. If the plan is achieved, 31.85, 74.5 and 159 million USD can be saved yearly from the E10, E15 and E20 mandates, respectively. Using the byproducts as much as possible within the ethanol-processing framework significantly increases the eco-efficiency (40\%) of the products.
In present study, the water-soluble extractives removal prior to alkali pretreatment of sugarcane tops (SCT) was carried out. The solid alkali pretreated SCT (apSCT) recovered on Field-emission scanning electron microscopy (FE-SEM) analysis showed exposure of cellulosic fibres as compared with raw SCT. The analyses of apSCT by Fourier Transform Infrared (FT-IR) Spectroscopy, X-ray diffraction (XRD) and High performance liquid chromatography (HPLC) analysis also confirmed the enhanced cellulose content in apSCT. Optimum conditions for response surface methodology based saccharification of apSCT at 40 degrees C, 150 rpm were 2.14\% (w/v) apSCT loading in citrate-phosphate buffer (50 mM, pH 6.0), recombinant hydrolytic enzymes (from Clostridium/Hungateiclostridium thermocellum) loading for endo-1,4-beta-glucanase (CtCel8A) = 213.2 U/g, cellobiohydrolase (CtCBH5A) = 272.5 U/g and beta-glucosidase (HtBg1) = 299.8 U/g for 49.2 h. Under optimized saccharification conditions, the total reducing sugar yield was 265 mg/g (glucose 214 mg/g) of apSCT. Fermentation of produced glucose by S. cerevisiae gave 0.19 g/g glucose of bioethanol.
This study presents a technical and economic assessment of the potential of a second-generation biorefinery process targeted at the conversion of lignocellulosic biomass to ethylene and propylene. The process was developed through the integration of several catalytic processes involving hydrolysis, hydrogenation, decarboxylation, metathesis and cracking. Additional alternative configurations were developed as an improvement to the base case process using the combustion of all generated hydrocarbon and solid by-products, and reduced levulinic acid concentration in the hydrolysis process. The viability of the proposed bio-olefin production route was assessed using the target product yield, energy efficiencies and the minimum olefin selling price (MOSP). The results revealed that 30 ktonnes per year of lower olefins can be produced from the process at a plant processing capacity of 701 ktonnes of sugarcane bagasse per year with a base case energy efficiency and MOSP of 40\% and \$4.8/kg respectively. However, a reduction in the energy requirement of the hydrolysis unit in the alternative configurations (scenarios A, B and C) resulted in scenario C as the most viable process with a reduced MOSP of \$2.8/kg. A sensitivity analysis of the effect of the major cost drivers on the MOSP showed that the cumulative effect of the reduction in the feedstock cost, nitrogen gas cost and other economic parameters could lead to a more cost-competitive MOSP. Therefore, the developed process is a viable option for the production of ethylene and propylene from lignocellulosic biomass.
Residual biomasses from agro-industries in Paraguay, including soybean hulls (SBHs) and sugarcane bagasse (SCB), were studied as a source for nanocellulose extraction for the first time. For that purpose, both biomasses were delignified in a semi-pilot stainless-steel reactor, and the cellulose pulp was subjected to a bleaching process with NaClO (2.5\%, w/v). The nanocellulose (CNC) was obtained after two-step acid hydrolysis. Firstly, the bleached cellulose was hydrolyzed with HCl (17\%, w/w) for two hours at 60 degrees C to obtain microcrystals by removing most of the amorphous fraction. The celluloses were then treated with H2SO4 (65\%, w/w) at 45 degrees C for 45 min to obtain nanocellulose. Physicochemical and morphological properties were analyzed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction analysis (XRD). The SBHs nanocellulose had a whisker-like form with a 230 +/- 42 nm diameter and a 12 +/- 2 nm height, and the SCB nanocellulose had a fibril-like form with a 103 +/- 30 nm diameter and a height of 6 +/- 3 nm. The nanocellulose from SBHs and SCB had good thermal stability as its degradation temperature started at 250 degrees C. Furthermore, the nanocellulose obtained was negatively charged and formed stable dispersion in water at 0.1 mg/mL concentration and a pH of around 6.5.
Sugarcane breeding has traditionally been geared towards maximiing sugar production. The sugarcane crop biomass is now being recognised as an alternative source of renewable energy. The objectives of this study were to characterise and identify different types of high biomass genotypes obtainable from early generation hybrid populations. Sixty potentially high biomass genotypes with variable fibre content were screened from the MSIRI germplasm collection and were evaluated over two harvests. Randomised Complete Block design was used and four commercial varieties were included for comparison purposes. Based on inherent variations in cane quality and biomass traits, four different types of canes were identified. A selection algorithm was developed that involved culling levels for several traits. The algorithm simultaneously identified 11 high biomass genotypes with variable proportions of sucrose and fibre. The different types of varieties defined should provide additional opportunities to exploit the biomass of sugarcane crop for different end-uses. With minor adjustments to suit local realities, the selection model can be adapted in any sugarcane breeding programme for targeting and exploiting different types of canes. (C) 2013 Elsevier Ltd. All rights reserved.
In this study, we investigate the release of melanoidin-like product (MLP) from hybrid silica xerogels to control the quantity of MLP in the medium for lead phytoextraction. In the preparation of the hybrid organic-inorganic xerogels with MLP, tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), propyltriethoxysilane (PTES), and 3-aminopropyltriethoxysilane (APTES) were used as precursors. The experimental results suggest that the release of MLP can be easily controlled by partially substituting TEOS with the organosilanes. The addition of the organosilanes lowered the release rate of MLP in the following order of xerogels: TEOS, MTES/TEOS, PTES/TEOS, and APTES/TEOS. Furthermore, a novel phytoextraction of lead through the Indian mustard was conducted using the MLP-doped TEOS xerogel. Results show that the addition of TEOS xerogel did not have any influence on the growth of the mustard, whereas the lead uptake significantly increased in a nutrition medium with 1-mM Pb(NO3)(2). In conclusion, the beneficial effect of the MLP-doped TEOS xerogel on lead phytoextraction was confirmed.
Microbial degradation of lignocellulosic biomass is primarily affected by the composition and structure of biomass, as well as enzyme activities that are influenced by the presence of in-process degradation products. This study focuses on the latter, and demonstrates that cellulase activity of Neurospora discreta is stimulated in the presence of in-process soluble lignin degradation products. Two types of biomass - cocopeat and sugarcane bagasse, with contrasting lignin content and cellulose structure were tested at two biomass loadings each. At the higher biomass loading, cocopeat showed the highest amount of hydrolyzed cellulose and cellulase activity, despite its low cellulose content and recalcitrant cellulose structure. A strong positive correlation was revealed between the amount of in-process degraded lignin and cellulase activity, indicating a stimulatory effect on cellulase, which contradicts most previous literature. Furthermore, the causal relationship between the amount of degraded lignin and cellulase activity was established in a model system of commercial cellulase and standard soluble lignin. This work could pave the way for using biomass loading as a process lever to enhance cellulose hydrolysis in microbial conversion of lignocellulosic biomass.
The present work focuses on the feasibility of elimination of Methylene Blue dye from the textile wastewater with the use of economical organic biosorbents like Sugarcane Bagasse (SCB), Peanut Hull (PHB) and Orange peel (OPB). Batch adsorption tests were performed based on pH, temperature, contact time, initial adsorbate concentration, and dose of biosorbents as independent variables by employing a central composite design (CCD) approach of response surface methodology (RSM). After 90 min of contact time, the dye adsorption equilibrium was reached. It was explained with the help of Langmuir and Freundlich adsorption isotherms for the full concentration ranges of 20-100 mg/L. RSM combined with CCD is used to optimize the experiments for achieving the optimum conditions for the removal of dye. The adsorption data are used for the kinetic modeling from the pseudo-first- and pseudo-second-order kinetic equations. Thermodynamic parameters such as changes in entropy ( increment S), enthalpy ( increment H), and free energy ( increment G) were investigated, also showed that the adsorption was natural and endothermic by removing the randomness of color at the solid and liquid interface. Biosorbent characterization was additionally performed by Fourier-transform infrared spectroscopy (FTIR) to study the adsorption of Methylene Blue before and after the tests. The dimensionless separation factor (RL) and expected results illustrated that SCB, PHB, and OCB could be used to substitute commercially available biosorbents for aqueous solutions and eliminate Methylene Blue dye from textile wastewater.
In our study we used holocelluloses from sugar beet and bagasse for film preparation. Films from sugar beet holocellulose have better mechanical properties than from bagasse holocellulose. By subsequent carboxymethylation of bagasse holocellulose, films with better properties were produced. Specimens prepared from combined sugar beet and bagasse carboxymethylated holocellulose had the best mechanical properties. The results could be explained by the ratios of cellulose, arabinan, polygalacturonan and xylan content in individual films, based on the elemental analysis data. The use of microwaves to prepare holocellulose film speed up the process, but negatively affected the mechanical properties. Lignin content of the sugar beet holocellulose and bagasse samples was low and did not affect the mechanical properties. Both types of agricultural by-products could be used for preparation of composite film with high strength and stiffness suitable for broad range of applications. (C) 2016 Elsevier Ltd. All rights reserved.
Agro-wastes such as sugar cane bagasse can be explored for use in different aspects. Its applicability as a source of cellulose has attracted much interests especially in biomedical field among various applications. In the current work chemically purified cellulose (CPC) and cellulose nanocrystals (CNCs) were effectively extracted from sugarcane bagasse (SCB). The cellulose was obtained by chemical treatment of SCB using HNO3, NaOH and a bleaching agent. Nanocrystals were further prepared from the extracted cellulose using H2SO4 hydrolysis followed by washing with deionized water and acetone. The obtained materials were characterized for surface morphological using Fourier transform infrared (FTIR) spectroscopy, Transmission Electron Microscopy (TEM) and X-ray diffraction (XRD) analysis. The thermal properties were evaluated using TGA/DTG. The FTIR showed the disappearance of the peaks responsible for the hemicelluloses and lignin. These results were confirmed by TGA which proved gradual elimination of non-cellulosic constituents. X-ray Diffractometer depicted an increase in crystallinity occasioned by sequential treatments to get the cellulose nanocrystals. Cellulose nanocrystals had a spherical shape with a diameter of 38nm as compared to the chemically purified cellulose which had a diameter of 76nm. The CNCs prepared with this method were seen to be less agglomerated and more crystalline thus possess a higher potential as bionanocomposite either for biomedical applications or for wastewater treatment among other industrial application. This approach also provides an opportunity for the sugar companies to effectively manage their waste product.
This paper examines the effect of microwave drying on biomass characteristics and subsequent dry pyrolysis and characteristics of produced biochar from rice straw, sugarcane bagasse, rice husk and cotton stalk compared to oven drying at 105 degrees C. Dried samples from both methods are torrefied at 250 and 300 degrees C with 30-minutes residence time. Drying time reached 60 times faster with microwave. The fast and violent microwave drying ruptured the biomasses' surface, releasing more volatiles and having lower crystallinity; these lowered the heating value, energy yield and elemental carbon compared to oven drying except for cotton stalk only due to its woody nature which reduced devolatilization. Sugarcane, rice husk and cotton stalk have the most promising values of elemental carbon, energy yield and heating value reaching that of the bituminous coal. Torrefied rice straw showed high crystallinity of 50.7\% while sugarcane and rice husk were completely amorphous.
Carbon-based catalysis for green and sustainable degradation of phenol in water and soil has attracted extensive concern. In this study, mesoporous biochar produced by bagasse calcination with KOH and CaCl2 modified activation (Ca/BS-800-KOH) was used to stimulate persulfate (PS) for the surface oxidation degradation of phenol, which exhibited excellent removal rate of 90\% in 60 min (k = 0.0404 min(-1)) with a relatively low dosage (0.066 g/L). Compared with untreated materials (BS-800, 27\% removal rate in 180 min), after KOH and CaCl2 treatment, the functional groups (C-OH), increased porosity, defective structure and the more efficient electron transfer of Ca/BS-800-KOH were probably responsible for its good adsorptive and catalytic performance, which also closely related to the inactivation of Ca/BS-800-KOH. In the (Ca/BS-800-KOH)/PS/phenol system, PS was successfully activated in the presence of catalyst, and radical and non-radical reaction pathways were firstly found, in which the non-radical pathway like O-1(2) accelerated quickly the oxidative degradation of phenol. While in radical pathway involving SO4 center dot(-) and center dot OH, center dot OH was the main oxidative species and also played an irreplaceable role in the degradation of phenol. The Ca/BS-800-KOH as a medium promotes the electron transfer between phenol (electron donor) and PS (electron acceptor), in which Ca accelerates the electron transfer rate on the surface of Ca/BS-800-KOH, thereby causing oxidative degradation of phenol. The superior removal efficiencies of common environmental pollutants (all more than 93\%) and phenol in water (100\%) and soil samples were found. This research proposed an insightful mechanism of the low cost and feasible carbon-material-based PS-AOPs in degrading organic pollutants.
Crop productivity and sustainability have often been related to soil organic matter and soil microbial biomass, especially because of their role in soil nutrient cycling. This study aimed at measuring fungal and bacterial biomass by epifluorescence microscopy and arbuscular mycorrhizal fungal (AMF) spore density in sugarcane (Saccharum officinarum L.) fields under different managements. We collected soil samples of sugarcane fields managed with or without burning, with or without mechanized harvest, with or without application of vinasse and from nearby riparian native forest. The soil samples were collected at 10cm depth and storage at 4 degrees C until analysis. Fungal biomass varied from 25 to 37 mu g C g(-1) dry soil and bacterial from 178 to 263 mu g C g(-1) dry soil. The average fungal/bacterial ratio of fields was 0.14. The AMF spore density varied from 9 to 13 spores g(-1) dry soil. The different sugarcane managements did not affect AMF spore density. In general, there were no significant changes of microbial biomass with crop management and riparian forest. However, the sum of fungal and bacterial biomass measured by epifluorescence microscopy (i.e. 208-301 mu g C g(-1) dry soil) was very close to values of total soil microbial biomass observed in other studies with traditional techniques (e.g. fumigation-extraction). Therefore, determination of fungal/bacterial ratios by epifluorescence microscopy, associated with other parameters, appears to be a promising methodology to understand microbial functionality and nutrient cycling under different soil and crop managements.
The aim of this work was to study an environmentally friendly method for pretreating rice straw by using 1-butyl-3-methylimidazolium chloride ({[
A total of 16 different combinations of the liquid nutrient medium used for impregnating sugar-cane pith bagasse have been evaluated for the production of total alkaloids by Claviceps purpurea 1029c in a solid-state fermentation system, and for their effects on the spectra of the alkaloids produced The data indicated large differences in the alkaloids' spectra. There is therefore the possibility of achieving tailor-made spectra of ergot alkaloids by changing the liquid nutrient media composition.
Isomaltulose is attracting interest due to its unique health properties, making it an ideal substitute for sucrose. Nevertheless, the industrial production of isomaltulose from sucrose is currently expensive, thus limiting its application. Molasses is an industrial by-product of sugar refining and contains abundant sucrose, which suggests it could be a cost-effective feedstock for manufacturing isomaltulose. Although isomaltulose can be obtained successfully from molasses, the yield and purity reported in previous studies are insufficient for industrial-scale application. To overcome previous disadvantages, a new strategy was devised in this study considering the molasses composition features, where the sucrose component is used for isomaltulose biosynthesis, while the monosaccharides (glucose and fructose) are used as the energy source for strain growth. Further elements of this strategy involved a series of metabolic engineering steps to construct a recombinant Corynebacterium glutamicum strain IS7 with redirected metabolic flux and fine-tuned sucrose isomerase (SIase) activity. Under the optimum conditions, the maximum production of isomaltulose using the engineered strain IS7 was 170.1 g L-1 with a yield of 0.97 g/g with cane molasses as substrate, and 167.0 g L-1 with a yield of 0.97 g/g with beet molasses as substrate, after 72 h fermentation. Moreover, isomaltulose purity was 98\% using either cane or beet molasses as substrate. Therefore, this study may provide a robust foundation for efficient industrial-scale bioproduction of high-purity isomaltulose from low-cost cane and beet molasses using the recombinant strain IS7. Moreover, it validates the concept of the sustainable conversion of agricultural residues by biosynthesis to high-value-added products.
The objective of this study was to optimize the culture conditions for simultaneous saccharification and fermentation (SSF) of cellulose for bio-hydrogen production by anaerobic mixed cultures in elephant dung under thermophilic temperature. Carboxymethyl cellulose (CMC) was used as the model substrate. The investigated parameters included initial pH, temperature and substrate concentration. The experimental results showed that maximum hydrogen yield (HY) and hydrogen production rate (HPR) of 7.22 +/- 0.62 mmol H-2/g CMCadded and 73.4 +/- 3.8 mL H-2/L h, respectively, were achieved at an initial pH of 7.0, temperature of 55 degrees C and CMC concentration of 0.25 g/L. The optimum conditions were then used to produce hydrogen from the cellulose fraction of sugarcane bagasse (SCB) at a concentration of 0.40 g/L (equivalent to 0.25 g/L cellulose) in which an HY of 7.10 +/- 3.22 mmol H-2/g cellulose(added). The pre-dominant hydrogen producers analyzed by polymerase chain reaction-denaturing gel gradient electrophoresis (PCR-DGGE) were Thermoanaerobacterium thermosaccharolyticum and Clostridium sp. The lower HY obtained when the cellulose fraction of SCB was used as the substrate might be due to the presence of lignin in the SCB as well as the presence of Lactobacillus parabuchneri and Lactobacillus rhamnosus in the hydrogen fermentation broth. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
In the present work, the gene xynB2, encoding a beta-xylosidase II of the Glycoside Hydrolase 39 (GH39) family, of Caulobacter crescentus was cloned and successfully overexpressed in Escherichia coli DH10B. The recombinant protein (CcXynB2) was purified using nickel-Sepharose affinity chromatography, with a recovery yield of 75.5 \%. CcXynB2 appeared as a single band of 60 kDa on a sodium dodecyl sulfate polyacrylamide gel and was recognized by a specific polyclonal antiserum. The predicted CcXynB2 protein showed a high homology with GH39 beta-xylosidases of the genus Xanthomonas. CcXynB2 exhibited an optimal activity at 55 A degrees C and a pH of 6. CcXynB2 displayed stability at pH values of 4.5-7.5 for 24 h and thermotolerance up to 50 A degrees C. The K (M) and V (Max) values were 9.3 A +/- 0.45 mM and 402 A +/- 19 mu mol min(-1) for rho-nitrophenyl-beta-d-xylopyranoside, respectively. The purified recombinant enzyme efficiently produced reducing sugars from birchwood xylan and sugarcane bagasse fibers pre-treated with a purified xylanase. As few bacterial GH39 family beta-xylosidases have been characterized, this work provides a good contribution to this group of enzymes.
In this work, batch adsorption studies were carried out using three low-cost adsorbents like rice husk ash (RHA), corncob ash (CA) and sugarcane bagasse fly ash (BFA) with the aim of removing COD from textile wastewater (TWW) having an initial concentration of 1026 mg/L. Batch experiments were conducted to study the adsorption behaviour through the effect of adsorbent dosage, pH and contact time on the adsorption of COD removal. The results showed that the removal percentage of COD could be over 70-75\% at the optimal adsorbent dosage of 6 g/L, at a pH of 8.0 to 8.5 and a contact time of 40 min for RHA and BFA. At the same time, less COD removal was observed while using CA as an adsorbent giving only 50-55\% COD removal. The applicability of the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models for the three low-cost adsorbents adsorption data was tested. Langmuir isotherm plots indicated that the adsorption process is favourable and best fitted. In the Temkin adsorption isotherm, the values of `B' (heat of adsorption) showed positive values, which indicates that the reaction with all three adsorbents was an exothermic reaction. From the results of the Dubinin-Radushkevich adsorption isotherm, the constant E (mean free energy) values lying within 8 indicated that the adsorption process is physical adsorption. Kinetics data showed that the pseudo-second-order kinetic model showed a good correlation for the adsorption than the pseudo-first-order. Therefore, RHA and BFA can be potentially used as low-cost adsorbents for treating TWW.
In this study, sweet sorghum bagasse was used as an immobilized carrier for acetone-butanol-ethanol (ABE) fermentation production. Scanning electron microscopy revealed the relationship between Clostridium cells and the sorghum bagasse in terms of adsorption and embedding. The ABE productivity and yield of ABE solvents in batch fermentation were 0.37 g L-1 h(-1) and 0.41 g g(-1), with 68\% and 24\% improvement than free cells, respectively. Repeated batch fermentation was carried out under optimized conditions, plus a total of 970 h of continuous fermentation at different dilution rates. A maximum ABE concentration of 16.5 g L-1 was obtained at a dilution rate of 0.08 per h, with optimized yield and productivity. This novel immobilization method using sweet sorghum bagasse offers an attractive prospect for the industrial production of bio-based butanol.
In this article, the compatibility of blends produced from recycled materials-cellulose acetate (from sugarcane bagasse) and polystyrene (from plastic cups)was studied using diffusion of water, Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and scanning electron microscopy. With these techniques, it was possible to confirm the existence of miscibility microregions in blends produced according to what has already been pointed out in a previous paper (Filho et al., J Appl Polym Sci 2005, 96, 516). In addition, all the results present a transition occurring in blends containing 30\% polystyrene. This composition indicates the starting limit for a possible inversion between the matrix and the disperse phase in the system. (c) 2007 Wiley Periodicals, Inc.
This study aims to evaluate plant fibers that were surface activated with NaOH and corona discharge before incorporating in ortho unsaturated polyester-based fiber composites. It demonstrates the potential use of lignocellulosic particles, especially eucalyptus that presented the higher values for all the mechanical properties analyzed. The corona discharge treatment increased impact strength and tensile strength of the composites, and decreased water absorption. SEM images showed that the surface activation generally improved the interfacial adhesion between fibers and polyester matrix. Corona treatment may depolymerize the lignocellulosic material and smaller fragments may actually help increase the interaction with the polyester.
Synthesis of extracellular xylanase in Cellulomonas flavigena is induced in the presence of xylan and sugarcane bagasse as substrates. The essential factors for efficient production of xylanase are the appropriate medium composition and an inducing substrate. The increase in xylanase production levels in C. flavigena were tested with a number of carbon sources and different culture conditions. Xylose, arabinose, glycerol and glucose did not induce xylanase production in this microorganism. beta-Methyl-xyloside (beta-mx), a structural analog of xylobiose, also did not induce xylanase when used as the sole carbon source, but when xylan or sugar cane bagasse was supplemented with beta-mx, extracellular xylanase production increased by 25 or 46\%, respectively. The response of C. flavigena to xylan plus beta-mx was accompanied by a significant accumulation of reducing sugar, an effect not observed with the combination sugarcane bagasse plus beta-mx as substrate. To our knowledge, this is the first report on the effect of beta-mx on the induction of xylanase in C. flavigena.
A new one-pot synthesis method optimized by a 2(3) experimental design was developed to prepare a biosorbent, sugarcane bagasse cellulose succinate pyromellitate (SBSPy), for the removal of Cu(II) and Zn(II) from single-component aqueous solutions, in batch and continuous modes. The bi-functionalization of the biosorbent with ligands of different chemical structures increased its selectivity, improving its performance for removing pollutants from contaminated water. The succinate moiety favored Cu(II) adsorption, while the pyromellitate moiety favored Zn(II) adsorption. Sugarcane bagasse (SB) and SBSPy were characterized using several techniques. Analysis by C-13 Multi-CP SS NMR and FTIR revealed the best order of addition of each anhydride that maximized the chemical modification of SB. The maximum adsorption capacities of SBSPy for Cu(II) and Zn(II), in batch mode, were 1.19 and 0.95 mmol g(-1), respectively. Homogeneous surface diffusion, intraparticle diffusion, and Boyd models were used to determine the steps involved in the adsorption process. Isothermal titration calorimetry was used to assess changes in enthalpy of adsorption as a function of SBSPy surface coverage. Fixed-bed column adsorption of Cu(II) and Zn(II) was performed in three cycles, showing that SBSPy has potential to be used in water treatment. Breakthrough curves were well fitted by the Thomas and Bohart-Adams models.
Clostridium beijerinckii CC101 was engineered to overexpress aldehyde/alcohol dehydrogenase (adhE2) and CoA-transferase (ctfAB). Solvent production and acid assimilation were compared between the parental and engineered strains expressing only adhE2 (CC101-SV4) and expressing adhE2, ald and ctfAB (CC101-SV6). CC101-SV4 showed an early butanol production from glucose but stopped pre-maturely at a low butanol concentration of similar to 6 g/L. Compared to CC101, CC101-SV6 produced more butanol (similar to 12 g/L) from glucose and was able to re-assimilate more acids, which prevented ``acid crash{''
Sugarcane processing generates a large quantity of residues, such as filter cake and ashes, which are sometimes composted prior to their amendment in soil. However, important issues still have to be addressed on this subject, such as the description of bacterial succession that occurs throughout the composting process and the possibilities of using phosphate-solubilizing bacteria (PSB) during the process to improve phosphorus (P) availability in the compost end product. Consequently, this study evaluated the bacterial diversity and P dynamics during the composting process when inoculated with Pseudomonas aeruginosa PSBR12 and Bacillus sp. BACBR01. To characterize the bacterial community structure during composting, and to compare PSB-inoculated compost with non-inoculated compost, partial sequencing of the bacterial 16S rRNA gene and sequential P fractionation were used. The data indicated that members of the order Lactobacillales prevailed in the early stages of composting for up to 30 days, mostly due to initial changes in pH and the C/N ratio. This dominant bacterial group was then slowly replaced by Bacillales during a composting process of up to 60 days. In addition, inoculation of PSB reduced the levels of Ca-bound P by 21\% and increased the labile organic P fraction. In PSB-inoculated compost, Ca-P compound solubilization occurred concomitantly with an increase of the genus Bacillus. The bacterial succession and the final community is described in compost from sugarcane residues and the possible use of these inoculants to improve P availability in the final compost is validated. (C) 2017 Elsevier GmbH. All rights reserved.
Thermodynamic, microstructural, chemometrics, and analyses of mechanical properties of cement-based materials are performed with the addition of agro-industrial residues, which are often discarded in landfills. In this sense, two types of waste ashes of sugarcane bagasse were investigated. All investigated materials were characterized by XRF, TGA, XRD, and SEM/EDS analyses. The experiments of XRF data revealed that the ash additions increased the presence of reactive inorganic compounds, such as K2O, in the mixture of concrete ingredients. Subsequently, thermodynamic properties revealed that the complex hydration reactions associated with the processing of the concrete admixture are spontaneous processes (Delta(r)G similar to -400 kJ.mol(-1)). Further, XRD and SEM/EDS data showed that the hydrated waste ashes presented elevated quantities of amorphous phases. For all concretes, the presence of the main cementitious amorphous phase CSH was detected. Finally, chemometric analysis of the axial compressive strength and tensile resistances of the cement-based materials revealed that, after 365 days, the ashes could be used as partial cement substitutes that typically emit CO2 when applied to constructions.
Fermentable components of municipal solid wastes (MSW) such as fruit and vegetable wastes (FVW), leaf litter, paddy straw, cane bagasse, cane trash and paper are generated in large quantities at various pockets of the city. These form potential feedstocks for decentralized biogas plants to be operated in the vicinity. We characterized the fermentation potential of six of the above MSW fractions for their suitability to be converted to biogas and anaerobic compost using the solid-state stratified bed (SSB) process in a laboratory study. FVW and leaf litter (paper mulberry leaves) decomposed almost completely while paddy straw, sugarcane trash, sugarcane bagasse and photocopying paper decomposed to a lower extent. In the SSB process between 50-60\% of the biological methane potential (BMP) could be realized. Observations revealed that the SSB process needs to be adapted differently for each of the feedstocks to obtain a higher gas recovery. Bagasse produced the largest fraction of anaerobic compost (fermentation residue) and has the potential for reuse in many ways.
Background The acid buffering capacity of high free ash in waste wheat straw (WWS) has been revealed to be a significant hindrance on the efficiency of autohydrolysis pretreatment. Previous researches have mainly relied on washing to eliminate the influence of ash, and the underlying mechanism of the ash influencing was not extensively investigated. Presently, studies have found that cations can destroy the acid buffering capacity of ash through cation exchange. Herein, different cations were applied to presoak WWS with the aim to overcome the negative effects of ash on autohydrolysis efficiency, further improving its enzymatic digestibility. Results Results showed that cations can be adsorbed on the surface of the material by electrostatic adsorption to change the acid buffering capacity of WWS. The acid buffering capacity of 120 mM Fe2+ presoaked WWS is reduced from 226.3 mmol/pH-kg of original WWS to 79.3 mmol/pH-kg. This reduced the autohydrolysis pretreatment medium pH from 5.7 to 3.8 and promoted the removal of xylan from 61.7 to 83.7\%. In addition, the enzymatic digestibility of WWS was enhanced from 49.7 to 86.3\% by presoaking with 120 mM Fe2+ solution. The relationship between enzymatic accessibility and hydrophobicity with enzymatic digestibility of the autohydrolyzed WWS was analyzed. Conclusions The results showed that the acid buffering capacity of the high free ash was detrimental for the autohydrolysis efficiency of WWS. After WWS was presoaked with different cations, the acid buffering capacity of ash was weakened by cation exchange and electrostatic adsorption, which improved the autohydrolysis efficiency. The results expound that the enzymatic digestibility of WWS can be enhanced through presoaking to reduce the ash-influencing effect on autohydrolysis.
Efficient pretreatment of wheat straw (WS) under mild conditions facilitates its further enzymatic hydrolysis and conversion. Three pretreatment processes with mild conditions including formic acid pretreatment (FAP), sodium chlorite pretreatment (SCP), and alkaline hydrogen peroxide (AHP) pretreatment were investigated in this study. The chemical components of WS before and after pretreatment were compared, and the samples were characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The lignin removal by FAP, SCP, and AHP pretreatment was 55.79\%, 99.33\%, and 94.97\%, and the enzymatic hydrolysis yields (EHY) were 68.03\%, 75.52\%, and 90.76\%, respectively. The results showed that AHP pretreatment had a better performance on enzyme accessibility thus improving the EHY. Meanwhile, lignin can be separated from the AHP pretreatment liquid, which helps to improve the economics of the process. The effects of enzymes and additives on enzymatic hydrolysis were further optimized by response surface methodology. Under the conditions of 20.37 FPU/g cellulase, 32.14 IU/g xylanases, and 19.15 mg/g Tween 80, the experimental result showed that the maximum EHY was 94.15\%, which was close to the predicted EHY (96.19\%). The experiments on fed-batch mode after AHP pretreatment with high-solid loadings (20\% w/v) were conducted, and the EHY reached 86.05\%. These results contributed to improving the economic feasibility of WS pretreatment and enzymatic hydrolysis process.
The chemical modification of SCB cellulose with succinic anhydride using 1-butyl-3-methylimidazolium chloride ionic liquid/DMSO system as reaction medium was studied. The parameters including the molar ratio of succinic anhydride/anhydroglucose units in cellulose from 1:1 to 12:1, reaction time 5-120 min, and reaction temperature 85-105 degrees C were investigated. The results showed that the degree substitution of succinylated cellulosic preparations ranged from 0.037 to 0.53. It was found that the treatment of the native cellulose in the ionic liquid/DMSO system under the conditions given significantly degraded the cellulose and completely destroyed the cellulose crystals. FT-IR and solid-state CP/MAS C-13 NMR spectra produced evidence for succinoylation reaction and the results showed that succinoylation occurred at positions C-6, C-2 and C-3. The thermal stability of the succinylated cellulose decreased upon chemical modification. (c) 2006 Elsevier Ltd. All rights reserved.
Butanol and isopropanol are important commodity chemicals with a variety of applications. One of the main obstacles for biobutanol production by IBE (isopropanol-butanol-ethanol) fermentation is the intensive energy consumption for product recovery by conventional distillation due to low butanol titer in fermentation broth caused by butanol toxicity to cells. In the present study, butanol production by batch IBE fermentation coupled to an in situ gas stripping-pervaporation process to recover the butanol is proposed using Clostridium beijerinckii DSM 6423 and a mixture of sugarcane-sweet sorghum juices as substrate. Gas stripping was used to continuously remove butanol from the fermentation broth, followed with pervaporation to further concentrate butanol. The strategy used allows alleviating butanol inhibition and to recuperate a condensate containing high butanol concentration (559 g/L). A kinetic model describing butanol production by IBE fermentation was developed. Kinetic parameters and experimental data were used to estimate the energy consumption of the sugarcane-sweet sorghum IBE production process. It was found that although the IBE production process showed less energy consumption (15\%) than the butanol production process by ABE (acetone-butanol-ethanol) fermentation, a substantial improvement is still necessary for the process to be energetically/economically attractive.
Alkali-oxygen pulping has received increasing attention as an environmentally compatible pulping process; however, the resulting pulp has low yield and properties due to carbohydrate degradation. In this work, the effect of regulating superoxide anion radicals (O-2(-center dot)) on delignification selectivity in alkali-oxygen pulping was investigated. The pulp was characterized by Brunauer-Emmett-Teller (BET) analysis, scanning electron microscope (SEM), and X-ray diffraction (XRD). Lignin removal was improved by the regulation of O-2(-center dot) in the 1,2,3-trihydroxybenzene auto-oxidation system with addition of sodium 2-anthraquinonesulfonate, especially for the pulp from cooking time 120 min. The degree and selectivity of delignification were improved with alkali-oxygen pulping when sodium 2-anthraquinonesulfonate was added to facilitate the generation of superoxide anion radicals. The results showed that the increased fiber liberation was beneficial for the accessibility of O-2(-center dot) to lignin, which would improve the removal of lignin with negligible damage on cellulose, especially with regards to crystal area.
In this work, carbon dots/hydroxyapatite (CD-HAP) nanocomposite has been synthesized and used as drug carrier for acetaminophen. Carbon dots are synthesized from a biowaste precursor, which is sugarcane bagasse char using hydrothermal method. The synthesis of carbon dots is studied under four different temperatures of 150, 170, 190, and 210 degrees C. The fluorescence behaviour of carbon dots is greatest at an optimum temperature of 190 degrees C. Carbon dots with the best fluorescence properties are merged with the hydroxyapatite. The transmission electron microscopy (TEM) analysis confirms the formation of spherical nanodots with average diameter of 7.5 nm. The field emission scanning electron microscopy (FESEM) analysis confirms the formation of rod-shaped hydroxyapatite with an average diameter of 142 nm. Elemental analysis shows a Ca/P ratio of 1.71, which is close to Ca/P ratio of 1.67 found in natural bone, indicating the biocompatibility of the nanocomposite. Elemental analysis also shows an increase in carbon weight percentage in CD-HAP when compared with blank HAP, proving the formation of carbon dots in the nanocomposite. The pairing of carbon dots and hydroxyapatite improved the fluorescence of composite greatly, as well as the surface area from 41.631 to 78.752 m(2)/g. The drug loading and release performance is evaluated by loading acetaminophen into the nanocomposite. CD-HAP-40 gives the highest loading capacity of 48.5\%. Acetaminophen release is slower in CD-HAP-20, and the release kinetics fits the Higuchi model. This finding shows that the acetaminophen is released via a diffusion mechanism. {[
A low temperature alkali (LTA) pretreatment method was used to treat wheat straw. In order to obtain good results, different factors like temperature, incubation time, NaOH concentration and solid to liquid ratio for the pretreatment process were optimized. Wheat straw is a potential biomass for the production of monomeric sugars. The objective of the current study was to observe the saccharification (\%) of wheat straw with immobilized magnetic nanoparticles (MNPs). For this purpose, immobilized MNPs of purified beta-xylanase enzyme was used for hydrolysis of pretreated wheat straw. Wheat straw was pretreated using the LTA method and analyzed by SEM analysis. After completion of the saccharification process, saccharification\% was calculated by using a DNS method. Scanning electron micrographs revealed that the hemicellulose, cellulose and lignin were partially removed and changes in the cell wall structure of the wheat straw had caused it to become deformed, increasing the specific surface area, so more fibers of the wheat straw were exposed to the immobilized beta-xylanase enzyme after alkali pretreatment. The maximum saccharification potential of wheat straw was about 20.61\% obtained after pretreatment with optimized conditions of 6\% NaOH, 1/10 S/L, 30 degrees C and 72 hours. Our results indicate the reusability of the beta-xylanase enzyme immobilized magnetic nanoparticles and showed a 15\% residual activity after the 11th cycle. HPLC analysis of the enzyme-hydrolyzed filtrate also revealed the presence of sugars like xylose, arabinose, xylobiose, xylotriose and xylotetrose. The time duration of the pretreatment has an important effect on thermal energy consumption for the low-temperature alkali method.
ABS T R A C T Sugarcane leaf (SL) is an attractive lignocellulosic feedstock for methane production by anaerobic digestion (AD), but the resistant structure and irregular components of SL hinder its effective use. To provide a comprehensive understanding of the different SL components, the physicochemical properties, methane production perfor-mance, and a techno-economic analysis (TEA) of the mesophyll (SL-MPL) and midrib (SL-MRB) parts of SL were investigated in this study. The results showed that the chemical components, physical properties, and structures of SL-MPL and SL-MRB were markedly different. After AD, SL-MPL showed methane production of 124.2 +/- 8.5 mL/g volatile solid (VS), which was 121.4\% higher than that of SL-MRB. Besides, the VS removal and hydrolysis rates for SL-MPL were 1.4 and 2.9 times higher than those for SL-MRB, respectively. The AD of SL-MRB was predominantly limited by its high lignin content, low nutrient element contents, smooth surface, and dense spatial structure. The TEA revealed that the revenue from SL-MPL was 74.9\% of total revenue in the AD scenario, which was three times that of SL-MRB. Therefore, SL-MPL was more techno-economically efficient than SL-MRB under the AD scenario. This study provides a theoretical basis and data support for the effective utilization of SL.
The nutritional value and the temperature of aerobic stability of the hydrolyzed sugarcane by sodium hydroxide (NaOH) or calcium oxide (CaO) were evaluated. The experiment was carried out in factorial arrangment 2x4, two additives (NaOH and CaO) and four doses (0; 0.75; 1.5; and 2.25\%), in a completely randomized design with four repetitions per treatment. The material, after the addition of the additive, was stored per 24 hours in 10-L plastic pails. Both additives controlled the increase of temperature of sugarcane, but NaOH was more efficient. The dry matter and mineral matter contents lineally increased, while the cell wall contents decreased with the increase of the doses. Either NaOH or CaO promoted increment in values of sugarcane dry matter digestibility. NaOH and CaO improved the nutritional value of the sugarcane and NaOH was more efficient.
The aim of this work was to prepare the bio-crudes from agricultural wastes (i.e., rice straw, rice husk, sugarcane bagasse and coconut shell) by using induction-heating pyrolysis at specified conditions. The quantitative analysis of 21 priority pollutant polycyclic aromatic hydrocarbons (PAHs) in bio-crudes examined using gas chromatography/mass spectrometry (GC/MS) revealed that the PAHs in biocrudes were primarily dominant in the low molecular weight (LMW) PAHs, including naphthalene (1.10-2.45 mg/L) and acenaphthene (0.72-7.61 mg/L). However, by considering carcinogenic potency, the bio-crudes from rice husk and sugarcane bagasse contained higher contents of benzo{[
Polyhydroxyalkanoates (PHA) are biopolymers that can be produced by mixed microbial cultures using wastes or industrial by-products, which represent an economical and environmental advantage over pure culture processes. The use of alternate feedstocks enables using seasonal by-products, providing that the process is resilient to transient conditions. The mixed microbial communities of a 3-stage PHA producing system fed initially with molasses and then cheese whey were investigated through amplicon sequencing of the 16S rRNA gene. The transition in feedstock resulted in an adaptation of the acidogenic community, where Actinobacteria dominated with sugarcane molasses (up to 93\% of the operational taxonomic units) and Firmicutes, with cheese whey (up to 97\%). The resulting fermentation products profile also changed, with a higher fraction of HV precursors obtained with molasses than cheese whey (7.1 +/- 0.5 and 1.7 +/- 0.7 gCOD/L, respectively). As for the PHA storing culture, the genera Azoarcus, Thauera and Paracoccus were enriched with fermented molasses (average 89\% of Bacteria). Later, fermented cheese whey fostered a higher diversity, including some less characterised PHA-storers such as the genera Paenibacillus and Lysinibacillus. Although the microbial community structure was significantly affected by the feedstock shift, the acidogenic and PHA storing performance of the 3-stage system was very similar once a pseudo steady state was attained, showing that a reliable level of functional redundancy was attained in both mixed cultures.
Phosphorus (P) use in global food and bioenergy production needs to become more efficient and sustainable to reduce environmental impacts and conserve a finite and critical resource (Carpenter \& Bennett, Environmental Research Letters, 2011, 6, 014009; Springmann et al., Nature, 2018, 562, 519). Sugarcane is one crop with a large P footprint because production is centered on P-fixing soils with low P availability (Roy et al., Nature Plants, 2016, 2, 16043; Withers et al., Scientific Reports, 2018, 8, 2537). As global demand for processed sugar and bioethanol continues to increase, we advocate that improving P efficiency could become a key sustainability goal for the sugarcane industry. Here, we applied the 5R global P stewardship framework (Withers et al., Ambio, 2015, 44, 193) to identify more sustainable options to manage P in Brazilian sugarcane production. We show that current inputs of P fertilizer to the current crop area could be reduced by over 305 Gg, or 63\%, over the next three decades by reducing unnecessary P fertilizer use, better utilization of recyclable bioresources and redesigning recommendation systems. Adoption of these 5R options would save the sugarcane industry in Brazil 528 US\$ million and help safeguard global food and energy security.
The development of technologies based on energy renewable sources is increasing worldwide in order to diversify the energy mix and satisfy the rigorous environmental legislation and international agreements to reduce pollutant emission. Considering specific characteristics of biofuels available in Brazil, studies regarding such technologies should be carried out aiming energy mix diversification. Several technologies for power generation from biomass have been presented in the technical literature, and plants with BIGCC (biomass integrated gasification combined cycle) emerge as a major technological innovation. By obtaining a fuel rich in hydrogen from solid biomass gasification, BIGCC presents higher overall process efficiency than direct burning of the solid fuel in conventional boilers. The objective of this paper is to develop a thermodynamic and chemical equilibrium model of a BIGCC configuration for sugarcane bagasse. The model embodies exergetic cost and CO2 emission analyses through the method of CET (carbon exergy tax). An exergetic penalty comparison between the BIGCC technology (with and without CO2 capture and sequestration), a natural gas combined cycle and the traditional steam cycle of sugarcane sector is then presented. It is verified that the BIGCC configuration with CO2 capture and sequestration presents technical and environmental advantages when compared to traditional technology. (C) 2016 Elsevier Ltd. All rights reserved.
The bagasse products generated after the extraction process have significant use in several industrial sectors however its application in the energy sector stands out, avoiding the use of fossil fuels. In this study an enzymatic process was applied through the Pleurotus sajor-caju fungus, for decomposition of the lignin present in the sugarcane bagasse, with the objective of improving the kinetic and bioenergetic parameters of this biomass. Detailed analyzes were carried out, such as kinetic, morphological, elementary and calorific, to verify its quality as biofuel. Values of E-a =31 kJ/mol to 65 kJ/mol, A = 1.4 10(5) s(-1) to 3.0 10(5) s(-1), Delta H = 26 kJ/mol to 60 kJ/mol, Delta G = 124 kJ/mol to 154 kJ/mol and Delta S = 150 J/mol to 157 J/mol for the conversion range (alpha) from 0.20 to 0.95, were obtained, with little variability in thermo-kinetic parameters. The HHV and fixed carbon values were 19.37 MJ/kg and 83.1\%, respectively, demonstrating that this sugar cane residue has the potential to be used as a solid biofuel, after its use in the production of Pleurotus sajor-caju fungi, thus allowing to create more economic value in the sugar cane transformation chain.
The hydroxymethylation of Acetosolv lignin from sugarcane bagasse was studied at 40 degrees C between 0.25 and 8 h by Fourier-transformed infrared spectroscopy (FTIR). Principal Component Analysis (PCA) of the spectra has determined that addition of formaldehyde to the lignin fragments was completed within 4 h. After that time, only condensation of the fragments occurs, leading to a resol-type crosslinked resin. PCA performed in selected regions of the FTIR spectra showed that the same results are also obtained for the stretching region of O-H and C-H within the range from 2800 to 3800 cm(-1), which is not usually considered in the spectroscopic evaluations of modified lignins.
In this investigation, the thermal and mechanical properties of cellulose fibers from sugarcane bagasse reinforced with high density polyethylene composites were evaluated. Cellulose fibers were modified with hydrous Zr oxide to clean the fiber surface and improve the fibers-matrix adhesion. Composites were manufactured using a thermokinetic mixer process and the fiber content was responsible for 5, 10, 20, 30, and 40wt\% in the composition. The chemical modification of the cellulose fibers with zirconium oxide was verified by FTIR analysis and the fibers' morphological aspects by SEM. After the chemical modification, the FTIR results showed reduction of OH bonds. SEM characterization showed that the modification changed the morphology of fibers. The results show that composites reinforced with modified cellulose fibers have an improvement in the thermal and mechanical properties, when compared to the non-cellulose fibers. In addition, an enhancement on the mechanical properties of composites was found, i.e. a gain of 122.4\% compared to neat polymer at 40wt.\% fiber loading in Young's modulus. The thermal properties show a slight decrease with increase of modified cellulose.
Bioconversion of agro-industrial residues has gained much focus worldwide as effective strategy to reduce environmental pollution and improve ethanol production. Therefore, the Brazil as one of the world's biggest agro-industrial residues producer can use residues such as rice straw, sugarcane bagasse and others to produce cellulolytic enzymes for enzymatic hydrolysis for second-generation bioethanol production. The objective of this work was to produce cellulolytic enzymes and use these enzymes to produce second generation ethanol from sugarcane bagasse. Twelve cellulolytic enzymes micro-organism from Brazilian Cerrado (Savanna) were tested to produce crude enzyme extract by solid state fermentation and the enzyme complexes were used to produce ethanol from exploded sugarcane bagasse using Saccharomyces cerevisiae Y904. All crude enzymatic complex used were able to produce ethanol from sugarcane bagasse, thus suggesting that the Brazilian Cerrado appears to be a promising source of cellulolytic enzymes. The best results were found for 48h of fermentation using crude enzymatic extract produced by Aspergillus niger (11.5 g/L of ethanol) and Mucor racemosus Fresenius (7.2 g/L of ethanol).
Four organosolv pretreatment processes, namely Formiline, Acetoline, sulfuric acid-catalyzed ethanol (SACE) and auto-catalyzed ethanol (ACE) pretreatments were used to pretreat wheat straw under respective optimal conditions. Comparative studies were performed in terms of the enzymatic digestibility of cellulosic solids, simultaneous saccharification and fermentation (SSF) for ethanol production, mass balance analysis and structural features of the pretreated solids. The results indicated that Formiline and Acetoline pretreatments showed higher degrees of delignification, lower xylose degradation and lower solid glucan recoveries than SACE and ACE processes. The SACE and ACE pretreated solids still had high lignin contents but demonstrated higher initial enzymatic hydrolysis rates than Formiline and Acetoline pretreated solids. Formiline pretreatment obtained the highest final enzymatic glucan conversion, glucose concentration and ethanol yield, while Acetoline pretreatment obtained the lowest. After organosolv pretreatment, the compact and beehive-like cell wall structure was disrupted and cellulose fibers became separated. The SACE and ACE pretreated solids showed more depositions on fiber surface, which probably came from the condensation and precipitation of lignin. (C) 2015 Elsevier Ltd. All rights reserved.
Glass-ceramic material prepared with sugar cane bagasse ash as one of the raw materials was characterized to determine some important properties for its application as a coating material. X-ray diffraction patterns showed that wollastonite-2M (CaSiO3) was the major glass-ceramic phase.The Rietveld method was used to quantify the crystalline (60 wt.\%) and vitreous (40 wt.\%) phases in the glass-ceramic. The microstructure (determined by scanning electron microscopy) of this material had a marble appearance, showing a microporous network of elongated crystals with some areas with dendritic, feather-like ordering. Microhardness data gave a mean hardness value of 564.4 HV (Vickers-hardness), and light microscopy disclosed a greenish brown colored material with a vitreous luster. (C) 2014 Elsevier Inc. All rights reserved.
Propionic acid (PA) is widely used as additive in animal feed and also in the manufacturing of cellulose-based plastics, herbicides, and perfumes. Salts of propionic acid are used as preservative in food. PA is mainly produced by chemical synthesis. Nowadays, PA production by fermentation of low-cost industrial wastes or renewable sources has been an interesting alternative. In the present investigation, PA production by Propionibacterium acidipropionici ATCC 4965 was studied using a basal medium with sugarcane molasses (BMSM), glycerol or lactate (BML) in small batch fermentation at 30 and 36 C. Bacterial growth was carried out under low dissolved oxygen concentration and without pH control. Results indicated that P. acidipropionici produced more biomass in BMSM than in other media at 30 degrees C (7.55 g l(-1)) as well as at 36 degrees C (3.71 g l(-1)). PA and biomass production were higher at 30 degrees C than at 36 degrees C in all cases studied. The best productivity was obtained by using BML (0.113 g l(-1) h(-1)), although the yielding of this metabolite was higher when using glycerol as carbon source (0.724 g g(-1)) because there was no detection of acetic acid. By the way, when using the other two carbon sources, acetic acid emerged as an undesirable by-product for further PA purification.
The objective of this work was to evaluate the tensile strength, friability, aggregation, and the physical fractions of soil organic matter of a Rhodic Hapludox cultivated with sugarcane (Saccharum officinarum). The treatments consisted of one, three, and five years of cultivation of sugarcane, in the state of Rio Grande do Sul, Brazil. As a reference, a native forest adjacent to the cultivation area, with soil and relief characteristics similar to those of the cultivation areas, was used. Deformed samples were collected at 0.00-0.05, 0.05-0.10, and 0.10-0.20-m soil depths, for the determination of the soil physical attributes and for the physical fractionation of particle-size and density of the organic matter. The physical attribute evaluations were able to detect changes in the structural quality of the Oxisol, which resulted from the sugarcane cultivation. In comparison with the native forest, the stability and tensile strength of the aggregates decreased with the time of sugarcane cultivation. Tensile strength increased with soil depth, proportionally to the reduction of total soil organic carbon content. Soil preparation and straw burning reduce the input of fresh organic matter into the soil and accelerate the decomposition of the labile organic matter compartment, with negative consequences to soil physical properties over time.
Sugarcane is an important global crop for fuel and energy production, and its harvested area and production have increased in Brazil over the last decade. The method of harvesting recently shifted from manual to mechanized, and it is suspected that the unburned straw left on the soil after harvesting has changed the epidemiology of diseases caused by necrotrophic fungi, increasing their importance. Ring spot (caused byLeptosphaeria sacchari) was considered of secondary importance, but is now more frequently observed on both old and new leaves. This study aimed to develop and validate a standard area diagram (SAD) set to help assess ring spot severity in sugarcane leaves. A nine-level SAD set was developed and subsequently validated by 16 inexperienced raters. Accuracy and precision of the estimates by each rating, with and without the SADs, were determined based on Lin's concordance correlation coefficient. Inter-rater reliability was measured using the coefficient of determination (R-2) and intraclass correlation. The proposed SADs improved the accuracy and precision of the estimates, in addition to reducing absolute error and increasing inter-rater reliability. The SAD set studied here is a useful tool in providing accurate, precise, and reliable assessments of ring spot severity in sugarcane for epidemiological research, when comparing treatments, or in breeding programs.
During microbial deterioration of sugarcane, a variety of extracellular polysaccharides (EPS, e.g., dextran, fructans) and other impurities (e.g., organic acids, sugar alcohols, alcohols) are produced. The microbial-derived EPS dextran (a polymer of glucose) has generally been considered the main problem in sugarcane processing, with its main production source being attributed to the bacterium Leuconostoc mesenteroides. Technical problems associated with the presence of dextran at the sugar factory can affect every step of sugar processing resulting in high viscosities, reduced efficiencies, elongation of sugar crystals, and the loss of sucrose to molasses. In recent years, fructans (a polymer of fructose) concentrations have been increasingly reported in both cane juice and molasses at Louisiana sugar factories. With the limited information that exists on the microbial origin of fructans at the sugar factories and its possible impact on Louisiana sugarcane processing, this research study aimed at identifying the microbial populations present in high numbers in the crusher juice or first extraction juice, and determining the effect of processing conditions on their ability to produce EPS. Our findings indicate that Lactobacillus, Lactococcus, Leuconostoc, Pantoea, Pseudomonas, and Saccharomyces were the microbial genera present in high cell numbers and that all isolates were capable of producing dextran and/or fructans. Leuconostoc had the most diverse number of species. A single isolate of L. suionicum A14 was identified and produced only fructans from sucrose. This is the first study to report on a fructan-only producing Leuconostoc isolate from sugarcane. EPS production was affected by temperature, sucrose concentrations, and medium pH.
Universal access to modern energy is required if the world is to reduce poverty and enable sustainable development. Energy poverty is the lack of access to safe and efficient energy carriers. It affects more than 1.3 billion people without electricity and 2.7 billion without appropriate cooking facilities and fuels, particularly in sub-Saharan Africa (SSA). Under these conditions, people rely on traditional biomass to fulfil basic needs. Traditional biomass use causes death and disease associated with indoor air pollution, high labor demands to obtain biomass, and environmental damage due to deforestation. This paper analyzes the potential for modern energy production based on sugarcane in SSA. A standard, business-as-usual (BAU), sugar-based project is explored vis-a-vis more aggressive scenarios for producing modern energy, including electricity, ethanol, and solid fuel pellets. All scenarios considered are based on a single sugarcane mill processing one million tonnes of cane per year, grown in an area of 15 000 hectares. Our simulations show that over 210 000 households could be served with electricity and other 31 000 with modern cooking fuels under the scenarios examined. Less dependence on traditional biomass may also spare wooded environments from deforestation. However, harnessing modern energy from sugarcane does not come without challenges. Economic pitfalls (e.g. investment costs and affordability) coupled with poor political environments are among the main obstacles. Nevertheless, encouraging local and regional trends proved bioenergy a feasible way out of energy poverty and an alternative to sustainable development. (c) 2016 Society of Chemical Industry and John Wiley \& Sons, Ltd
Vegetable crop residues, such as sugarcane bagasse (SCB), despite their limited biodegradability, are potential materials for anaerobic processes because of their low cost, high availability, and sugar content. The difficulty of biodegrading this type of material is primarily related to its chemical composition and to the complex interactions between its compounds (cellulose, hemicelluloses, and lignin). Thus, the following supercritical and near critical carbon dioxide (CO2) pre-treatments were evaluated with and without the addition of sodium hydroxide (NaOH): (i) 40 degrees C/70 kgf center dot cm(-2); (ii) 60 degrees C/200 kgf center dot cm(-2); and (iii) 80 degrees C/200 kgf center dot cm(-2), aiming to enhance the anaerobic biodegradability of SCB. The methanogenic production of SCB increased in all cases in which the material was pre-treated, except the case in which NaOH was used together with a high temperature. The condition using CO2 at 60 degrees C/200 kgf center dot cm(-2) was highlighted with a lignin removal of 8.07\% and an accumulated methane production of 0.6498 +/- 0.014 L-N (273.15K, 1.01325 x 10(5) Pa), 23.4\% higher than the value obtained with the untreated material. This condition also showed the highest net energy at the energy balance that was calculated for comparison with the tested conditions. The results showed that pre-treatments with near critical and supercritical fluids have the potential to reduce structural obstacles of lignocellulosic materials and to enhance their anaerobic biodegradability.
Rice straw is a lignocellulosic biomass that constitutes a renewable organic substance and alternative source of energy; however, its structure confounds the liberation of monosaccharides. Pretreating rice straw using a TiO2/UV system facilitated its hydrolysis with Accellerase 1000((TM)), suggesting that hydroxyl radicals (OH center dot) from the TiO2/UV system could degrade lignin and carbohydrates. TiO2/UV pretreatment was an essential step for conversion of hemicellulose to xylose; optimal conditions for this conversion were a TiO2 concentration of 0.1\% (w/v) and an irradiation time of 2 h with a UV-C lamp at 254 nm. After enzymatic hydrolysis, the sugar yields from rice straw pretreated with these parameters were 59.8 +/- A 0.7\% of the theoretical for glucose (339 +/- A 13 mg/g rice straw) and 50.3 +/- A 2.8\% for xylose (64 +/- A 3 mg/g rice straw). The fermentation of enzymatic hydrolysates containing 10.5 g glucose/L and 3.2 g xylose/L with Pichia stipitis produced 3.9 g ethanol/L with a corresponding yield of 0.39 g/g rice straw. The maximum possible ethanol conversion rate is 76.47\%. TiO2/UV pretreatment can be performed at room temperature and atmospheric pressure and demonstrates potential in large-scale production of fermentable sugars.
To control acid mine drainage (AMD) at source, biochar, a new green and environmentally friendly passivator has been introduced to passivate pyrite. However, the raw material and pyrolysis temperature largely determine the physical and chemical properties of biochar, the causal relationship between biochar and pyrite and the underlying mechanism are still unknown. Here, biochar materials (rice-straw biochar (RSB) and sugarcane bagasse biochar (SBB)) at different pyrolysis temperatures (300-600 degrees C) were utilized for the passivation of pyrite. The results of our investigations revealed that the passivation ability of RSB was superior to that of SBB. The addition of RSB with higher pyrolysis temperatures could greatly enhance the passivation efficiency of pyrite. RSB-500 (produced at a pyrolysis temperature of 500 degrees C) achieved the best passivation effect on pyrite. RSB can form Fe-O bonds through C=O bonding with pyrite. Moreover, the addition of RSB created a reducing environment in the mixture system because of its strong electron-donation capacity (EDC) and altered the energy-band structure of pyrite, which promoted the transfer of electrons from biochar to pyrite. On the contrary, the addition of SBB did not result in the formation of Fe-O bonds with pyrite. In addition, the EDC of SBB was also lower than that of RSB and it had almost no effect on the band structure of pyrite. Hence it did not alter the direction of the electron migration. These findings shed light on the mechanism of biochar passivation of pyrite and provide a theoretical foundation for selecting suitable biochar materials for AMD prevention at source.
The start-up conditions of mesophilic anaerobic co-digestion of restaurant food waste and vinasse, a waste from sugarcane industry, was investigated for efficient biogas production. A pilot plant, containing two reactors, was designed and used sequentially and semi-continuously for biogas production. All effective operational parameters were controlled in both reactors over the course of the study. The results indicated that the organic matters were quickly decreased during the start-up phase in the first reactor, resulting in 52\% and 64\% reduction in total solids and total volatile solids, respectively, while the corresponding reductions in the methanogenic reactor were 39.7\% and 51.4\%. The production of hydrogen was observed during the first 20 d of digestion, where the maximum concentration of 76.5\% was detected after 8 d when the pH stood at 5.96. After 21 d of digestion, hydrogen concentration was decreased to less than 4.5\%, while methane content was increased leading to an accumulated biogas yield of over 300 mL per g of total volatile solids. The high concentration of hydrogen in biogas was possibly due to the improvement in the growth of acidogenic bacteria in response to maintaining pH at their optimum value, leading to a more efficient organic residues hydrolysis. (C) 2018 BRTeam. All rights reserved.
In an effort to make rational use of resources, wasted bagasse were collected, and then fabricated by layer-by-layer (LbL) assembly to prepare an environmentally benign flame retardant for epoxy resin (EP). Six chitosan/ammonum polyphosphate bilayers were successfully deposited on the surface of bagasse, which endows EP/6BL@BF composites with a limiting oxygen index value of 24.1\% and V-1 rating in UL-94 test. Compared with untreated bagasse, cone calorimetry test reveals that the incorporation of6BL@BF reduces the peak heat release rate and total heat release by 64.6\% and 13.2\%, respectively. Besides, expandable graphite (EG) was combined with6BL@BF to further enhance the fire safety and thermal stability of EP composites. Furthermore, the gas and condensed phase analysis of EP/6BL@BF/EG-3 composite was investigated by TG-IR, scanning electronic microscopy, Laser Raman spectroscopy, and X-ray photoelectron spectroscopy, and the flame retardant mechanism of6BL@BF/EG was proposed. Finally, the mechanical properties of EP composites were investigated systematically.
A freeze concentration system with two-stage heat pump was investigated for pre-concentrating sugarcane juice in a jaggery making process. Two identical vented double-wall tube-and-tube heat exchangers were used as latent heat exchangers. One latent heat exchanger was operated as an evaporator, which selectively froze water from the juice. Another latent heat exchanger was operated as a condenser, which melted ice formed in a previous half cycle. Excess condenser duty, as a result of compressor work input and heat leakage into the cold sections of the system, was rejected with the help of second-stage compressor and concentrated juice and water heater. High juice velocity in the tube-and-tube heat exchanger helped to reduce inclusion in layer freezing. Raw juice was pre-cooled in a three fluid heat exchanger using concentrated juice and cold water streams from the latent heat exchangers. Pre-concentration of sugarcane juice from 20 to 40 A degrees Brix helped to save about 63\% of bagasse. Heat removed during freezing was one-seventh of that required for evaporation. R290 was found the best option amongst refrigerants R744 (CO2), R290 (C3H8) and R22 (CHClF2). Performance of system was evaluated considering the effect of thermal mass, ambient heat gain, variation in freezing point depression and ice layer thickness. Cooling COP of 14 can be achieved in a practicable system with evaporation at - 8 A degrees C, condensation at 3 A degrees C and the excess heat rejection at 34 A degrees C. This shows that specific energy consumption can be as low as 8.8 kWh(e)/m(3) of separated water.
Endoglucanase production under submerged fermentation was studied using sugarcane bagasse (SCB) and oat bran (OB) as carbon source and corn steep liquor (CSL) as nitrogen source, in different concentrations using factorial design. Streptomyces diastaticus PA-01, isolated from a soil cave in Brazil, was selected as cellulolytic strain. The results after experimental validation showed that a medium containing 2.4\% (w/v) SCB and 1.3\% (w/v) CSL led to the highest production, 1,180.3 U.L-1 of endoglucanase, after the 5th-day. A good level of endoglucanase (1,039.3 U.L-1) was obtained after the 4th-day when 2.0\% (w/v) OB and 1.65\% (w/v) CSL were used. The pH and temperature profiles showed thermoacidophilic endoglucanase activity, with 70\% of maximum activity at 50 degrees C, after 4 hours of pre-incubation. This is the first report on endoglucanase production by S. diastaticus PA-01 in the presence of SCB and OB. The strong positive effects of some metal ions (Zn2+, Mn2+ and Ba2+) on endoglucanase activity when this strain was grown on OB is an interesting biochemical characteristic for future biotechnological applications.
Three plant substrates, sugarcane bagasse, paddy straw and dried Eichhornea, were compared for enhancing fish growth through bacterial biofilm development. The substrates were suspended in water supplemented with cowdung and urea. For comparison, control cisterns applied with only cowdung and urea were maintained. The cisterns were stocked with common carp (Cyprirrus carpio) and rohu (Labeo rohita) fingerlings at 10000 ha(-1) The-growth of fish was significantly higher in substrate-based treatments than that in control, with the highest value achieved in the treatment with sugarcane bagasse, followed by the treatments with paddy straw and Eichhornea. This enhanced fish growth in treatments was attributed to the difference in primary bacterial biofilm formation which enhanced attached microbial biomass forming food for fish food organisms and fish. (C) 1999 Elsevier Science B.V. All rights reserved.
In arid/semi-arid regions, soil salinization, sodification and contamination by heavy metals (HMs) are the main constrains to plant growth, crop production and human health. Biochar can affect soil behaviors, e.g. adsorption of HMs that is one of the most effective techniques for reducing their bioavailability. Effect of three levels (0\%, 2\% and 4\% wt) of sugarcane bagasse-derived biochar and two cadmium (Cd) levels (0 and 50 mg Cd kg(-1) soil as Cd(NO3)(2)) on Cd adsorption of saline, sodic, saline-sodic and normal soils were evaluated through studying adsorption isotherms. Six isotherm models were fitted to the data and the best model were chosen. The maximum Cd adsorption (694 mg kg(-1)) obtained in sodic soils without biochar treatment. Cadmium removal decreased when dosage of the applied biochar increased. The minimum Cd removal obtained as 17\%, 21\%, and 23\% in control, 2\% and 4\% biochar-treated saline soils, respectively. Biochar increased Cd adsorption in salt-affected soils. Increasing pH in soil solution after biochar addition resulted in an increase in net negative surface charge and the affinity of soil particles for Cd adsorption. Consequently, 2\% biochar could ameliorate Cd contamination. However, Cd adsorption decreased when dosage of the applied biochar increased from 2\% to 4\%.
Present study deals with the adsorption of Auramine-O (AO) dye by bagasse fly ash (BFA) and activated carbon-commercial grade (ACC) and laboratory grade (ACL). BFA is a solid waste obtained from the particulate collection equipment attached to the flue gas line of the bagasse fired boilers of cane sugar mills. Batch studies were performed to evaluate the influences of various experimental parameters like initial pH (pH(0)), contact time, adsorbent dose and initial concentration (CO) for the removal of AO. Optimum conditions for AO removal were found to be pHo approximate to 7.0 and equilibrium time approximate to 30 min for BFA and;: 120 min for activated carbons. Optimum BFA, ACC and ACL dosages were found to be 1, 20 and 2 g/l, respectively. Adsorption of AO followed pseudo-second order kinetics with the initial sorption rate for adsorption on BFA being the highest followed by those on ACL and ACC. The sorption process was found to be controlled by both film and pore diffusion with film diffusion at the earlier stages followed by pore diffusion at the later stages. Equilibrium isotherms for the adsorption of AO on BFA, ACC and ACL were analyzed by Freundlich, Langmuir, Dubinin-Radushkevich, and Temkin isotherm equations using linear correlation coefficient. Langmuir isotherm gave the best correlation of adsorption for all the adsorbents studied. Thermodynamic study showed that adsorption of AO on ACC (with a more negative Gibbs free energy value) is more favoured. BFA which was used without any pretreatment showed high surface area, pore volume and pore size exhibiting its potential to be used as an adsorbent for the removal of AO. (C) 2006 Elsevier B.V. All rights reserved.
Sugarcane (Saccharum officinarum) is an important crop for generating fiber, biofuel and other bioproducts. Brazil is the largest sugarcane producer in the world; however, limited knowledge is available with respect to soil erosion in the sugarcane cropping system. This study reviews the soil erosion rates in sugarcane cropping and evaluates the effects of soil management and land conversion on soil erosion. Eighteen studies (using conventional tillage) reporting 43 outcomes of soil erosion rates were examined using the Scopus (R) database. Different methods were used to measure soil erosion yielded different soil loss rates; highest values were recorded in the natural rain method, i.e., experimental plots with a median of 28 Mg ha(-1) yr(-1) , were obtained followed by modeling with 9.3 Mg ha(-1) yr(-1) and simulated rain with 2 Mg ha(-1) yr(-1) . The median soil loss using all data ( n = 43) obtained by the three methods was 7.2 Mg ha(- 1) yr(- 1) . The soil type increases soil erosion; the sugarcane cropping system is practiced over the most erodible Brazilian soils (e.g., Ultisols and Oxisols) where sand fraction is dominant, particularly fine sand. Most studies focused on rainsplash and interrill erosion. However, rill, ephemeral and permanent gullies should be examined, particularly in sugarcane-cropping areas.
Gasification is the process of producing syngas with acceptable heat value from a feedstock. Co-gasifying biomass and using syngas thus produced reduce the net CO2 emission as biomass is effectively CO2 neutral. An Aspen plus (R) model for co-gasification of Indian lignocellulosic biomass is developed and validated against available experimental results. Performance of co-gasification as obtained from this developed model is also assessed by energy and exergy efficiencies of the process. Variations of these two efficiencies with gasification parameters are also reported. Results show that best performance of gasification may be obtained for rice straw with sugarcane bagasse energetically and wheat straw with sugarcane bagasse exergetically. The methodology and results may help selecting Indian biomass for co-gasification with further experimental investigations to decide the suitable one(s). {[
The study evaluated the preparation of a biocomposite using waste-derived polyhydroxybutyrate (PHB) and bagasse cellulose (alpha-cellulose) in a biorefinery approach. PHB was produced using dark fermentation effluent rich in volatile fatty acids (VFA) derived from vegetable waste and alpha-cellulose was extracted from sugarcane bagasse (SCB). Nutrient limitation induced microbial PHB accumulation, wherein maximum production of 0.28 +/- 0.06 g PHB/g DCW (28\%) was observed. Confocal examination showed the deposition of PHB granules in the cell cytoplasm and NMR spectrum exhibited a structural correlation. alpha-Cellulose (0.22 +/- 0.02 g alpha-cellulose/g SCB) was extracted through SCB pretreatment. Thereafter, grafting a-cellulose with PHB offered intermolecular bonding, which resulted in enhanced thermal stability of the biocomposite than corresponding pristine PHB. FE-SEM morphological examination of biocomposite depicted that alpha-cellulose functioned as a filler to PHB. XRD profiles showed significant decrement in PHB crystallinity, signifying the functional role of alpha-cellulose as an effective reinforcing agent. Additionally, ether functional group of alpha-cellulose and ester group of PHB also appeared in XPS analysis of the composite, thus authorizing the effective blending of alpha-cellulose and PHB. Utilization of bagasse-derived cellulose for strengthening biologically produced PHB expands its applications, while simultaneously addressing the plastic pollution issues. Additional value from this process was further achieved by incorporating the concept of biorefinery, wherein acidogenic fermentation effluents were used for the production of PHA, which enabled the re-entry of products (VFA) to the production cycle, thus achieving circularity. (C) 2021 Elsevier Ltd. All rights reserved.
Developing the ideal biomaterials for wound dressing still remains challenging nowadays due to the non-biodegradable features and the lack of antimicrobial activity of conventional synthetic polymer-based dressing materials. To tackle those problems, a novel and green-based antimicrobial hydrogel dressing was synthesized in this work via modifying sugarcane bagasse cellulose with guanidine-based polymer, followed by crosslinking antimicrobial-modified cellulose with unmodified one at various ratios. The resulting hydrogels were comprehensively characterized with swelling measurements, compression test, Fourier transform infrared spectroscopy, and scanning electron microscopy. The results indicated that the dressing possessed the degree of swelling up to 2000\% and the compress strength as high as 31.39 Kpa, at 8:2 ratio of pristine cellulose to modified cellulose. The antibacterial activities of the dressing against E. coli were assessed using both shaking flask and ring diffusion methods. The results demonstrated that the dressings were highly effective in deactivating bacterium without leaching effect. Moreover, these hydrogels are biocompatible with live cell viability responses of (NIH3T3) cells above 76\% and are very promising as wound dressing.
Pre-harvest sugarcane straw burning affects the dynamics of soil chemistry and delta C-13 and delta N-15 abundance, but further studies are needed to understand the long-term effects of this practice on the degradation of chemical attributes of soil and sugarcane production. The present study evaluates chemical modifications of soil and natural delta C-13 and delta N-15 abundance in sugarcane crops managed with pre-harvest straw burning for I, 5,10 and 20 years. For comparison purposes, soil covered with natural Cerrado vegetation and forage grass (pasture) were also evaluated. After chemical characterization of the areas studied, according to Embrapa (1997) total organic carbon (TOC), bulk density (Bd) and natural delta N-15 and delta C-13 abundance were determined in soil samples, and carbon stocks calculated from TOC values. In general, the pasture area had the highest delta C-13 and delta N-15 content, the Cerrado vegetation area had the lowest values for these elements and sugarcane crops exhibited intermediary levels. Areas subjected to sugarcane field burning for a shorter period had the highest Ca and Mg and lowest P and K content. Sugarcane crops managed with straw burning for 1 and 5 years produced lower carbon stocks in the top soil layer (0-10 cm) than sugarcane crops with 10 and 20 years, pasture and Cerrado areas. The replacement of natural Cerrado vegetation by sugarcane crops changed delta C-13 profile, likely because sugarcane is a C-4 plant, which has a specific carbon accumulation pattern. Areas cropped with sugarcane for 1, 10 and 20 years and subjected to different types of soil use after replacement of the original Cerrado vegetation had the highest delta N-15 values, indicating accelerated mineralization of soil organic matter. (C) 2013 Elsevier B.V. All rights reserved.
Brazil is one of the major players in the biofuels market worldwide, and its existing biorefining infrastructure can be used as the basis to support the implementation of new advanced biofuel production routes at a large scale. This paper demonstrates the benefits of the integration of both biochemical and thermochemical processes and how this configuration has the potential to overcome the main barriers that the Biomass-to-Liquids (BtL) route currently faces. Important bottlenecks such as the high equipment costs, low industrial process efficiency, and high feedstock prices were studied in detail by assessing a series of production scenarios that take into account the Brazilian context for building new biorefinery plants. By carrying out a techno-economic analysis aided by a simulation framework (the Virtual Sugarcane Biorefinery), we evaluated the potential technological synergies of a BtL plant processing sugarcane bagasse and straw integrated into a first-generation sugarcane ethanol distillery. Results in this paper indicate that it is possible to achieve economic feasibility with the implementation of the BtL route in the country. Under a base scenario, a greenfield plant would be very close to the range of economic viability (IRR from 10 to 12\% per year), whereas more optimistic economic conditions (e.g., lower CAPEX and higher fuel prices) would induce even better results (IRR greater than 16\% per year). Doubling the milling capacity also favors the BtL process, with IRR reaching 20\% per year if the best economic conditions are achieved in the Brazilian context.
Due to the high amount of carbon dioxide emission from conventional cement production, sustainable alternative cementitious materials are preferred in the construction sector. Earlier studies were focused only on the use of industrial by-products such as fly ash, slag and silica fume as alternative cementitious materials. A comprehensive review of the use of a wide range of agro-waste ashes is highly limited. Therefore, the present review focuses on the potential of several agro-waste ashes including sugarcane bagasse ash, rice husk ash, palm oil fuel ash, corncob ash, coconut shell ash, wood ash, groundnut husk ash, cassava peel ash, wheat straw ash, elephant grass ash, rice straw ash, sugarcane straw ash, tobacco ash and bamboo leaf ash as alternative cementitious materials in concrete. Physical, chemical and morphological characteristics of different agro-waste ashes and their influences in the blended cement concrete are presented. Besides, the effects of these agro-waste ashes on workability, strength, water absorption, sorptivity, porosity, permeability, drying shrinkage, resistance to acid and sulfate attacks of blended concretes are critically compared. Agro-waste ashes consist of silica content above 50\% with the exception of tobacco ash and groundnut husk ash. Addition of the agro-waste ashes reduces the slump of concrete except for palm oil fuel ash, wheat straw ash and rice straw ash blended concretes. Significant reduction in the permeability and subsequent enhancement in the durability of agro-waste blended concretes are evidently witnessed. (C) 2021 Elsevier Ltd. All rights reserved.
Sugarcane is one of the main agricultural cultivations of Brazil, and one of the crops in which herbicides are most applied. In the 2017/2018 season, the estimated sugarcane production was 694.54 million tons, with an estimated increase of 0.9\% in yield for this season. In order to evaluate the use of herbicides in this crop in the Sao Paulo State during a five-year period, a survey was carried out with sugarcane fanners. The use of herbicides applied alone and in a formulated mixture, according to their mechanism of action, were evaluated from 2010 to 2014. Photosystem II inhibitor herbicides were the most used in this period and the total amount of herbicides of almost all mechanism of action increased from 2010 to 2014, except for photosystem I inhibitors herbicides. The use of formulated mixtures also increased during this period. The area treated with carotenoid biosynthesis and photosystem II inhibitor herbicides was the largest for the control of monocotyledonous species (Poaceae, Cyperaceae and Commelinaccae). In relation to the dicotyledonous species, the area treated with PROTOX inhibitor herbicides was the largest in all evaluated years.
The conversion of sugarcane, the world's largest crop, to energy vectors, namely first and second-generation ethanol and electricity, is an ongoing scientific endeavor. This conversion makes use of complex processes with numerous unit operations and process blocks addressed in literature. Such processes have also been the subject of detailed thermo-economic and techno-economic evaluations as well as the application of systematic methodologies involving simulation, heat integration, optimization and selection. Key works related to this field are discussed in this review along with their hypotheses and results. The main future technologies are also presented. This review is realized to provide the scientific community with accessible references, information and ideas that will ultimately help researchers build consolidated and optimal designs for this process.
Biomass size reduction is a key operation in the process of ethanol production from lignocellulosic materials, since enzymatic saccharification of carbohydrate polymers occurs at the molecular level. Torrefaction technique has been used widely in increasing energy density, hydrophobicity, grindability, enhancing pore structure and reducing the cost of transportation. The aim of this study was to employ torrefaction prior to size reduction of sugarcane bagasse (SB) and waste jute caddies (WJC) and also to investigate its effect on biomass structure, glucose and ethanol yields. The torrefaction experiments of SB and WJC were performed at temperatures of 160, 180, 200 and 220 degrees C and residence times of 20, 40, and 60 min. The crystallinity and chemical nature of biomass materials were analyzed by XRD and FTIR. The pore structure was also examined for pretreated and untreated samples. The sugarcane bagasse pretreated at 200 degrees C for 20 min and waste jute caddies pretreated at 180 degrees C for 40 min were observed to produce highest glucose yields of 199.62 and 234.77 mg g(-1), respectively after saccharification. Furthermore, these pretreated SB and WJC under anaerobic fermentation with supplementation of cysteine hydrochloride were noticed to produce ethanol yields of 81.85 and 95.08 mg g(-1), respectively. Also, these ethanol yields represent 19.34\% increase for SB and 20.28\% increase for WJC when compared with ethanol yields of untreated biomass fermented under anaerobic conditions with cysteine hydrochloride supplement. The study demonstrates the possibility of incorporating torrefaction before size reduction in bioethanol production process. In addition, cysteine hydrochloride supplementation enhances ethanol yields through anaerobic fermentation.
Sugarcane plantations promote impressive drainage of atmospheric carbon dioxide reaching 781 t/h for a 1000 t/h sugarcane-biorefinery. For first-generation bioethanol sugarcane-biorefineries, only 10\% of sugarcane carbon dioxide equivalent leaves as hydrous-ethanol, while 90\% return to atmosphere through bagasse-fired power cogeneration in steam-Rankine cycles. Thus, a sugarcane-biorefinery exports two bioenergy flows - electricity and hydrous-ethanol- and its impressive Bioenergy Carbon Capture and Storage potential is wasted. Capture of fermentation carbon dioxide merely means 5\% of Bioenergy Carbon Capture and Storage efficiency. This work assesses a new sugarcane-biorefinery concept dramatically raising the Bioenergy Carbon Capture and Storage efficiency. With fermentation carbon dioxide already captured, it is advocated to implement 90\% post-combustion capture of flue-gas carbon dioxide. Then, captured carbon dioxide is compressed and traded as Enhanced Oil Recovery agent transported to deep-water offshore oil fields via high-pressure pipelines counting on topographic gravitational effects to lower compression power. Aggregating pipeline/compression investment to the biorefinery, it is shown that such new Plantation-Biorefinery-Post-Combustion-Pipeline-Oil-Recovery enterprise is technically feasible for 5.22 MtCO(2)/y of Bioenergy Carbon Capture and Storage capacity and is economically feasible under certain conditions: (i) idle pipeline capacity rental to fossil carbon emitters at 10-20 USD/tCO(2); (ii) recovered oil revenues traded at 1-2 bbl/tCO(2) and 50-80 USD/bbl; (iii) carbon-taxation at 40-80 USD/tCO(2); and (iv) carbon Cap-and-Trade at 30-70 USD/tCO(2). Under such conditions the PlantationBiorefinery-Post-Combustion-Pipeline-Oil-Recovery can attain 7 MMMUSD net value and 6 years payback-time.
This study investigates the efficacy of chemically modified bone adhesive as a formaldehyde-free binder for wood-based industries. Two different types of adhesive are formulated after chemical modification of bone powder using sulfuric acid (0.5 M) and polyvinyl acetate (PVA). Gel time, solid content, Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), viscosity, and single lap joint test for shear strength are analyzed in order to assess the adhesive properties. To analyze the efficacy of the formulated adhesive, particleboards are fabricated using boiled and unboiled sugarcane bagasse. The physical and mechanical properties of the fabricated panels are measured following ASTM standards. It is found that adhesive Type C (T-C) has the shortest gel time of 4.2 min for the highest shear strength, i.e., 5.31 MPa. The particleboard (BTC-2) fabricated using T-C adhesive shows a highest density of 0.73 g cm(-3), a modulus of elasticity (MOE) of 1975 N mm(-2), and a modulus of rupture (MOR) of 11.80 N mm(-2). The dimensional stability of the fabricated particleboards does not follow the standard requirements; however, further study might be helpful for using the chemically modified bone adhesive as a biobased adhesive.
This research aimed to evaluate the effects of burning and the use of dry additive on the sugar cane silage fermentative pattern. Six treatments were tested: natural or burned sugarcane, associated to three supplementation levels: 0, 50 or 100 g/kg of dehydrated corn grain, cob, and straw (CGCS) based on forage fresh mater. The following response variables were determined in the forage: DM, CP, acid detergent insoluble nitrogen (ADIN), NDF, ADF, cellulose, hemicellulose and lignin concentrations. Considering the fermentative traits, Soluble carbohydrate levels, buffering capacity, pH, ammonia nitrogen and ethanol levels were measured. The CGCS inclusion increased DM concentration and slightly reduced ethanol and N-NH3 levels in silages, but did not affect pH or yeast growth. Burning reduced DM and N-NH3 concentration, as well as increased ethanol levels and yeast growth. Ethanol production in sugarcane silage was not controlled by using dry additive or burning.
The use of packed-bed reactors for biohydrogen production often results in performance losses in the short term because of the negative effects of operational factors, such as biomass accumulation and inadequate pH conditions. Because packed -bed systems constitute a promising technology for biohydrogen production, studies on continuous hydrogen production over the long term must be carefully conducted by applying proper operational strategies. Therefore, this study assessed continuous biohydrogen production in a packed -bed reactor operated under thermophilic conditions (55 degrees C) using sugarcane stillage as the substrate. The results indicated that the acidogenic reactor presented a capacity for recovering from performance losses, regardless of their cause, and maintaining continuous hydrogen production rates under long-term operation (240 days). pH proved to be a key factor for obtaining continuous hydrogen production, and the optimal results were observed in a pH range from 5.1 to 5.2. Furthermore, an optimal specific organic loading rate of 6.3-6.4 g carbohydrates g(-1) volatile suspended solids d(-1) was observed, and this value is consistent with the results of previous studies focused on hydrogen production from fermentative systems. (C) 2015 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
A maltooligosaccharide-forming alpha-amylase was produced by a new soil isolate Bacillus subtilis KCC103. In contrast to other Bacillus species, the synthesis of alpha-amylase in KCC103 was not catabolite-repressed. The alpha-amylase was purified in one step using anion exchange chromatography after concentration of crude enzyme by acetone precipitation. The purified alpha-amylase had a molecular mass of 53 kDa. It was highly active over a broad pH range from 5 to 7 and stable in a wide pH range between 4 and 9. Though optimum temperature was 65-70 degrees C, it was rapidly deactivated at 70 degrees C with a half-life of 7 min and at 50 degrees C, the half-life was 94 min. The K-m and V-max for starch hydrolysis were 2.6 mg ml(-1) and 909 U mg(-1), respectively. Ca2+ did not enhance the activity and stability of the enzyme; however, EDTA (50 mM) abolished 50\% of the activity. Hg2+, Ag2+, and p-hydroxymercurybenzoate severely inhibited the activity indicating the role of sulfydryl group in catalysis. The alpha-amylase displayed endolytic activity and formed maltooligosaccharides on hydrolysis of soluble starch at pH 4 and 7. Small maltooligosaccharides (D2-D4) were formed more predominantly than larger maltooligosaccharides (D5-D7). This maltooligosaccharide forming endo-alpha-amylase is useful in bread making as an antistaling agent and it can be produced economically using low-cost sugarcane bagasse.
Background: Single-cell oils obtained from oleaginous microorganisms by using lignocellulosic waste hydrolysates are an alternative for producing biodiesel. Aims: To isolate a yeast strain able to produce lipids from centrifuged nejayote (CN), hydrolyzed nejayote solids (HNS) and hydrolyzed sugarcane bagasse (HSB). Methods: In order to identify the yeasts recovered, 26S ribosomal DNA was sequenced. The metabolic profile was assessed by using API20C AUX strips. The nutritional characterization of CN, HNS and HSB was performed by quantifying reducing sugars, total carbohydrates, starch, protein and total nitrogen. The biomass and lipid production ability were evaluated by performing growth kinetics of Clavispora lusitaniae Hi2 in combined culture media. Results: Six oleaginous yeast strains were isolated and identified, selecting C. lusitaniae Hi2 to study its lipids production by using nejayote. The C. lusitaniae Hi2 strain can use glucose, xylose, arabinose, galactose and cellobiose as carbon sources. Cultures of C. lusitaniae Hi2 presented the best biomass (5.6 +/- 0.28 g/L) and lipid production (0.99 +/- 0.09 g/L) at 20 h of incubation with the CN:HNS media in the 25:75 and 50:50 ratios, respectively. Conclusions: The use of CN, HNS and HSB for the growth of C. lusitaniae Hi2 is an option to take advantage of these agro-industrial residues and generate compounds of biotechnological interest. (c) 2022 Asociacion Espanola de Micologia. Published by Elsevier Espana, S.L.U. All rights reserved.
To improve the accuracy of discrete element simulation parameters of sugarcane tail-leaf (STL) feed during dust removal and crushing, this study used a combination of physical tests and EDEM software simulations to calibrate the discrete element simulation parameters of crumbs and dust in the feed. Taking the experimental physical stacking angle (SA) as the response value, the second-order regression models of SA and significant factors were established by Plackett-Burman test, steepest climb test, and Box-Behnken test. Variance analysis and interaction effect analysis were conducted. Taking the accumulation angle of 41.27 degrees obtained by physical experiments as the target value, the significant parameters were optimized. The optimal combination of the following parameters was obtained: tail stem-dust static friction coefficient (SFC) of 0.46, tail leaf-dust coefficient of sliding friction (COSF) of 0.205, JKR surface energy of 0.26, and dust-steel collision recovery coefficient (CRC) of 0.338. Through software simulation verification, the average value was 40.81 degrees, and the relative error of the SA with the physical experiment was 1.13\%. The results showed that the calibrated parameters are real and reliable, which can provide a theoretical reference for the design optimization of the straw crushing device, feed processing device, and other related components.
In this study, the ability of Yarrowia lipolytica to produce the recombinant lipase CalB from Candida antarctica, used as a model protein has been compared across different bioreactor processes using glycerol, a byproduct from the biodiesel industry as the main carbon source. Batch, pulsed fed-batch (PFB), and continuous fed-batch (CFB) strategies were first compared using classical stirred tank (STR) bioreactors in terms of biomass production, carbon source uptake, and lipase production. Additionally, an in situ fibrous bed bioreactor (isFBB) was developed using sugarcane bagasse as a cell immobilization support. The maximum lipase titer achieved using the isFBB culture mode was 38\%, 33\%, and 49\% higher than those obtained using the batch, PFB, and CFB cultures, respectively. The lipase productivity in isFBB mode (142 U/mL/h) was 1.4-fold higher than that ob-tained using batch free cell cultures. These results highlight that isFBB is an efficient technology for the pro-duction of recombinant enzymes.
Herein, residual lignin was extracted from unbleached sugarcane bagasse pulp via the sequential enzymatic-weak acid hydrolysis method. Subsequently, chlorine dioxide delignification was applied to the extracted lignin. The structural changes of lignin during chlorine dioxide delignification were characterized by Fourier transform infrared spectroscopy (FT-IR), C-13-nuclear magnetic resonance (C-13 NMR), H-1-C-13 heteronuclear single quantum coherence (2D HSQC), and quantitative P-31-nuclear magnetic resonance (P-31-NMR) spectroscopy. The degradation products of lignin dissolved in the simulated bleaching liquor, extracted, and quantified via gas chromatography-mass spectrometry (GC-MS). Lignin was significantly degraded during the delignification process, showing cleavage of the aromatic ring, removal of the methoxyl group, and cleavage of major inter-unit linkages. However, the carboxylic acid content increased and GC-MS analysis indicated that lignin was degraded into several organic substances dissolved in the liquor. However, only a few absorbable organic halides (AOX) were generated, confirming that chlorine dioxide bleaching is an ideal bleaching method.
This work describes an environmentally friendly method for pretreating rice straw by using 1-Allyl-3-methylimidazolium chloride ({[
In this study, Raman peak ratio was used as a screening parameter to evaluate antimicrobial tendency before conducting a susceptibility test between lignin extracts and targeted pathogenic bacteria. Methoxyl group in lignin basic units, syringyl (S) and guaiacyl (G) units, was reported to be responsible for antimicrobial characteristic in lignin extracts. By using Raman spectroscopy to quantify relative amount of methoxyl group based on peak of lignin basic units in lignin extracts, quick evaluation of antimicrobial tendency can be identified. Due to an overlapping peak, only syringyl was used in calculation. Raman peak ratio of lignin basic unit was calculated by dividing represented peak height over peak height of lignin peak signature from Raman wave number at 1600 cm(-1). A 4-hydroxyl phenyl (H-unit), a lignin basic unit without methoxyl group, was used to construct normalizedS/Hratio. Peak height ofS-unit at Raman wave number 1331 cm(-1)and peak height ofH-unit at Raman wave number 1213 cm(-1)were used in evaluation. Bagasse lignin extracts from two different conditions (NaOH 1\% and NaOH 4\%) and commercial alkaline lignin extracts were used. Peak ratios were calculated and compared with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against two gram-positive pathogenic bacteria:Staphylococcus epidermidisandStaphylococcus aureusand two gram-negative pathogenic bacteria:Pseudomonas aeruginosaandEscherichia coli. Different in antimicrobial tendency, decreased in MIC and MBC, was observed whenS/Hratio increased from 1.2 to 2.0 for gram-positive bacteria. For samples with similarS/Hratio, lignin-free basis value is required to identify the antimicrobial tendency. Graphic
The goal of the present work was to carry out a review of the disposal practices for the agro-industry's sugarcane residue and the trends of energy use in Cuba. The lack of an alternative energy carrier to electricity with storage capability for use in off-season has to date been an unsolvable question. The improvement of cogeneration capacity via implementation of CEST or BIG/GTCC and the barriers for their implementation, the introduction of a medium size (3 ton/h) fast pyrolysis module (FPM3) as a solution for off-season energy demand in the agro-industry, and an assessment of the energy required to do so, were also analyzed. Bio-oil production from bagasse and sugarcane agriculture residues (SCAR) and their particularities at the sugar mill are treated. The influence of sugar facility production process configuration is analyzed. The fast pyrolysis products and the trends of their end uses in Cuba are presented. The production cost of a ton of Bio-oil for FPM3 conditions was calculated at 155 USD/ton and the payback time as a function of selling price between 160 and 110 USD/ton was estimated to be from 1.5 to 4 years. The economic feasibility of the FPN3 was estimated, comparing the added values for three scenarios: 1st case, currently-used sugar production, 16.5 USD/ton of cane; 2nd case, factoring in the cogeneration improvement, 27 USD/ton of cane; and 3rd case, with cogeneration improvement and Bio-oil production, 40 USD/ton of cane. The energy use of SCAR and the introduction of FPM3 in the sugar mill are promising improvements that could result in a potential surplus of 80 kW h(e)/ton of cane in-season, or 6 x 10(6) ton of Bio-oil (LHV= 15 MJ/kg) for use off-season in a milling season of 4 million tons of raw sugar. (c) 2006 Elsevier Ltd. All rights reserved.
A bio-based ceramic/organic xerogel (BCO-xerogel) was obtained from the combination of sugarcane bagasse ash, polyvinyl alcohol, and pine cone-derived tannin extract, which are abundant, non-toxic, and renewable sources. The as-prepared BCO-xerogel was used as a low-cost green adsorbent for the eliminate of four types of the most widely used antibiotics, including amoxicillin (AMX), tetracycline (TC), cefalexin (CLX), and penicillin G (PEN G) residuals from contaminated water. The simultaneous effects conventional variables including adsorbent dosage, antibiotic concentrations, solution pH, and contact time were studied and optimized by central composite design (CCD) under response surface methodology (RSM). Analysis of variance (ANOVA) was employed as a statistical formula to determine the significance of operating environmental conditions and their interactions with 95\% confidence limits. Under optimized conditions, the experimental removal efficiencies for AMX, TC, CLX, and PEN G were 98.78 +/- 3.25, 99.12 +/- 2.52, 98.02 +/- 1.98, and 98.42 +/- 2.19, respectively. The adsorption isotherms and kinetics were better fitted with Langmuir and pseudo-second-order models, respectively. Thermodynamic studies showed that the adsorption process was endothermic, spontaneous, and occurred by combination of physical and chemical mechanisms. Also, evaluating the ability of BCO-xerogel to adsorptive removal of AMX, TC, CLX, and PEN G antibiotics in real wastewaters showed about 97.4-98.6\% adsorption efficiency in river water and about 67.1-71.3\% in three hospital effluents. After the adsorption process, the
This study investigated the effects of sugarcane bagasse compost (SBC) and chicken manure compost (CMC) on the sorption desorption, leaching and bioavailability of the fungicide penconazole in soil in a laboratory setting. The autoclave-treated SBC or CMC was applied at 2.5\% and 5.0\% (w/w). Results of batch equilibrium experiments exhibited that the sorption capacity of soils for penconazole was significantly promoted by the addition of SBC or CMC, whereas desorption of penconazole was drastically reduced; the influence was enhanced as the amount of organic amendments increased. Results of column leaching experiment indicated that the addition of SBC or CMC significantly limited the vertical movement of penconazole through the soil columns, considerably decreasing the content of penconazole in the soil leachate. Furthermore, results of bioavailability experiments demonstrated that the addition of organic amendments (SBC or CMC) remarkably influenced the uptake and translocation of penconazole, decreased penconazole accumulation in the plant tissues and increased the plant elongation and biomass. These data revealed important changes in pesticide behavior under SBC or CMC application, which should be useful for developing strategies to protect groundwater and crops from contamination from the residual pesticides in soil. (C) 2015 Elsevier Ltd. All rights reserved.
In Tanegashima, an isolated island in Japan, a 1500 ton/day sugar mill produces raw sugar and residual bagasse simultaneously. The bagasse is burned to generate steam that drives power turbines, but the bagasse boiler burns more bagasse than that is required. Accordingly, the process has a high temperature flue gas and a sizeable amount of unused heat at around 200 degrees C is exhausted from the sugar mill. Conversely, many other factories on the island burn imported oil in package boilers to generate process steam at temperatures up to 120 degrees C, all year around. To resolve this spatial and seasonal mismatch, we employ a thermochemical energy storage and transport system that uses a zeolite steam adsorption and desorption cycle. We introduce a basic design of a heat discharging device (a ``zeolite boiler{''
Microbially induced calcite precipitation (MICP) is a ground improvement method often driven by ureolytic bacteria to precipitate calcite in a soil mass. While in previous studies MICP was often accomplished by the injection of exogenous bacterial solutions, this study utilizes the soil's native ureolytic microorganisms. The roles of yeast extract, molasses, and biochar as different sources of carbon and nutrients for stimulating native microorganisms are examined and compared with MICP induced by bioaugmentation. Biochar as a carbonized biomass has the potential to enhance a soil's enzymatic activity by providing high concentrations of organic carbon, phosphorus, and ammonium nitrogen, making it an attractive substance to catalyze ureolysis and bio-cementation in the field. In this research, a mixture of wheat straw and sugarcane bagasse is used to produce biochar. This material is then enriched with sugarcane molasses and mixed with specimens of a natural sand to stimulate native microorganisms with a long-lasting source of energy and produce ureolytic enzymes for bio-cementation. After 5, 10, and 15 cycles of injecting the cementation solution, shear strength and permeability of treated specimens were measured in direct shear and hydraulic conductivity tests. The specimens' structural changes were also examined using scanning electron microscopy (SEM) images and energy-dispersive X-ray spectroscopy (EDS). The results show a higher gain in strength and lower permeability in biochar-assisted microbially treated sand specimens compared to the untreated sand. Physical model experiments conducted in this study further demonstrated the application of this technique along with natural microorganisms for stabilizing a model slope against wave-induced erosion.
Fungi play an essential role in recovering the quality and fertility of soil. There is a limited understating of the complex response of fungal diversity to different organic materials in clay loam soil. Here, we report the response of soil fungi toward the short-term application of manure (M), sugarcane straw (S), and sugarcane straw plus manure (MS), including no organic material control (CK) at two different time points (50 and 100 days after application). Illumina sequencing was used to examine the fungal communities. Our results reveal a significant shift among the soil fungal community structure associated with each organic material application. After both time points, amendments-especially M and MS-decreased the fungal richness and stimulated the copiotrophic fungal group (Ascomycota) compared to the control soil (CK) and S-amended soil. On the contrary, as compared to the M and MS-amended soils, the CK and S-amended soils at both time points increased the fungal richness and stimulated the oligotrophic fungal groups. Organic material use, especially M and MS, showed variable results regarding pathogenic fungi enhancing the abundance of Lophodermium and Cercophora and decreasing Fusarium. Concerning the abundance of plant-beneficial fungi, Mortierella was reduced, and Podospora was increased by M and MS input. FUNGuild showed that the amendment of organic materials efficiently declined the abundance of endophytes and plant pathogens, but also enhanced the animal pathogens in terms of abundance with respect to CK at two time points. This study could be useful to provide a novel understanding of the management of soil-borne pathogens by organic amendments for the sustainable production of short-term crops.
The productivity of small ruminants in Ethiopia is low due to a shortage of feed supply throughout the year, both in terms of quality and quantity. This problem leads to the utilization of locally available lignocellulose by-products, which encompass high cellulose, hemicellulose, and lignin. It is known that the nutritive value of these lignocellulose by-products can be improved through biological, chemical, or a combination of both treatments This study was aimed at evaluating body weight change, carcass characteristics, and economic efficiency of rams fed a total mixed diet containing biologically treated rice husk (RH) or sugarcane bagasse (SCB). Thirty-six sheep, weighing an average initial body weight of 18 +/- 1.8 kg were used. Two feeds (SCB and RH) and three biological treatments (Control, Trichoderma viride {[
This paper presents results on the characterization of corn starch by X-ray powder diffraction and thermal analysis, as well as processing and characterization of starch-banana/sugarcane bagasse fiber composites. X-ray diffraction studies revealed that the starch sample belongs to the A-type, common in cereals. Thermal analysis showed good thermal stability for making composites, while fractographic studies of 70 wt.\% starch and 30\% glycerol matrix revealed cracks between smooth and rough surface and dimples in rough regions, Suggesting the sample was ductile. The composites of this matrix with banana and bagasse fibers prepared by compression molding showed more homogeneous composites with crude glycerin and structural changes in both the fiber composites, while their morphology was dictated by the properties of the fibers rather than by those of the matrix. Improvements in tensile properties were observed in these composites over those of the matrix, which are explained based on fractographic observations. (C) 2009 Elsevier Ltd. All rights reserved.
The biobutanol production by ABE (acetone-butanol-ethanol) fermentation with an integrated product recovery system by gas stripping was studied. A mixture of industrial sugarcane-sweet sorghum juices was fermented using Clostridium acetobutylicum DSM 792. Empirical models were developed to determine an operational condition for the integrated process that contributes both to mitigate the butanol inhibitory effect and to obtain a highly concentrated butanol condensate. A Monod model supplemented with a term describing product inhibition was employed to describe cell growth, butanol formation, and substrate consumption, respectively. Gas stripping was described by a first order model. The models showed satisfactory agreement with the experimehtal data in terms of cell growth, sugar consumption, and butanol production and extraction. A gas recycle flowrate in the range 0.3-0.6 vvrti allowed to maintain butanol concentration below the inhibitory concentration (8 g/L) and to obtain a concentrated butanol condensate after phase separation, which could reduce energy consumption in the final product recovery. In a fed-batch fermentation coupled with in situ gas stripping, total sugar conversion and 18.6 g/L butanol distributed 42\% in the fermentation broth and 58\% in the condensate, were obtained. (C) 2017 Elsevier Ltd. All rights reserved.
The use of agroindustrial waste for chemicals, biofuels and food ingredients production has been studied considering limitations of natural resources. Therefore, sugarcane bagasse was studied to produce arabinoxylan, xylanases, xylooligosaccharides and lignocellulose by the improvement of some technologies. A comparison two methods of extraction of arabinoxylan was performed. Arabinoxylan was obtained in a soluble fraction in better extraction by KOH method with higher yield (72.1\%) and efficiency (84\%) than H2O2 method, which only produced 64.9 and 43.3\%, respectively. Lignocellulose was obtained after filtration, as the solid fraction, representing 66.2\% (KOH) and 78.8\% (H2O2 method) of the total biomass. The endoxylanase was produced Aspergillus fumigatus CCT7732 in submerged fermentation with bagasse culture medium reaching 40.2 U/mL optimal conditions, pH 5.0 and 31.5 degrees C. In addition, NH4H2PO4 was efficient as phosphorus and nitrogen sources for xylanases production in the culture, when the more expensive salts K2HPO4 and KH2PO4 were replaced. An enzymatic hydrolysis of arabinoxylan in Xylooligosaccharides (XOS) by xylanases of A. fumigatus resulted 3.3\% (m/v) XOS, 46.9\% yield using 7\% arabinoxylan, 350 U/g of xylanases at 50 degrees C in 48 h. These methods provided a prebiotic XOS since mainly xylobiose and xylotriose were produced with potential applications for food and feed. The set of chemical and biological methods applied in bagasse indicated that these methods should be evaluated in scale up of an integrated biosystem including economic studies for industrial purposes.
Bagasse; a lignocellulosic Waste of sugarcane industry is Utilized for,producing the phosphate biofertilizer. Phosphate biofertilizer is suited-for all varieties of crops. It solubilizes the bound phosphate and contributes 20-30 \% of phosphate required for crops, Selection of Bacillus megaterium was made due to its capability to survive and solubilize the rock phosphate as compared to other bacteria. By using; biological and organic fertilizers a low input system can be carried out and it can be helpful for achieving the sustainability of farms In order to reduce the cost and also to manage the waste, sugarcane bagasse, i.e., lignocellulosic Waste is used in this experiment to replace the commercially Used carrier material(lignite). The chemical-parameters (protein, Carbohydrate; chlorophyll contents) in vigna Unguiculata plant grown using bagasse biofertilizer and lignite biofertilizer are comparable. The soil analysis also indicated signs of improvement in nutrient content, hence bagasse could be replaced in part of lignite in commercial production of biofertilizer.
Single and binary effects of dye Basic Violet 3 and heavy metals. `namely', Pb(II) and Cd(II), were investigated for their role in dye and heavy metal bioaccumulation by Candida tropicalis that was grown in a sugarcane bagasse extract medium containing 8 g/L, 16 g/L or 24 g/L of sugar. The optimum pH was found to be 4.0 in the single system and 5.0 in the binary system. A central composite design was successfully used to analyse the experimental results. Four numerical correlations that were fitted to a second order quadratic equation were used to estimate optimum combinations predicted by response surface methodology. In the dye-Pb(II) binary system, C. tropicalis was capable of bioaccumulating 49.5\% of the dye and 49.6\% of the Pb(II), in comparison to 15.9\% of the dye and 55.5\% of the Cd(II) in the dye-Cd(II) binary system. In these two systems, the pollutants were dispersed at minimum working concentration levels. Competitive inhibition was observed in both the single and binary systems, which was suggested by an increase in the saturation constant, K-s, and a simultaneous decrease in the specific growth rate that was calculated from Lineweaver-Burk plots. Atomic force microscopy images demonstrated changes in yeast cell morphology by exposure to these contaminants in the dye-Pb(II) binary system grown in a bioaccumulation medium. (C) 2010 Elsevier B.V. All rights reserved.
Sugarcane culture is replanted after five-eight successive harvests and intensely fertilised and mechanised. The influence on bacteria (total, nitrifying, denitrifying), fungi, microbial biomass-C, and dynamic processes (respiratory activity, N mineralisation, potential nitrification, P-solubilising activity) and enzymatic activities (dehydrogenase, urease, phosphatase) was studied for six successive harvests of the crop. The straw of the second and third harvest was burned. Soil microbial counts and activities were reduced after successive harvests. Fungi counts, N mineralisation, potential nitrification, and the P-solubilising, urease, and phosphatase activities decreased gradually from the first harvest to the third, increased again after the fourth, and then decreased again. Total, nitrifying, and denitrifying bacteria and fungi counts decreased, on average, 55, 22, 17, and 77\%, respectively, in the sixth harvest in relation to the first. Reductions also occurred in microbial biomass-C (43\%), respiratory activity (39\%), N mineralisation (35\%), potential nitrification (40\%), and P-solubilising activity (35\%). Reductions were observed in dehydrogenase (58\%) and urease (36\%) activities, but not in phosphatase activity. Successive sugarcane harvests may significantly influence microbial populations and activities, with harmful consequences to the C, N, and P cycles, and may decrease crop productivity.
A novel pretreatment using NaOH/Urea (NU) solution at outdoor cold-winter conditions was developed to enhance the enzymatic saccharification and hythane production from rice straw (RS). Results revealed that the reducing sugar conversion of RS reached 90.02\% after NU pretreatment at outdoor freezing temperature. Chemical composition analysis showed that the lignin removal was up to 62.74\% with cellulose and hemicellulose loss of 0.56\% and 18.87\% after 3\%-6\% NU pretreatment at 100\% solid loading for 3 months. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (MR) and X-ray photoelectron spectroscopy (XI'S) analysis confirmed that the surface of pretreated RS exposed more cellulose and hemicellulose due to the disruption of resistant structure of lignocellulose. Subsequently, the enzymatic hydrolysate of pretreated RS was used as substrate to produce hythane by two-stage fermentation with the yield of 225.1 mL H-2/g sugar and 112.8 mL CH4/g sugar. The energy conversion efficiency of hythane fermentation attained 10.4\%, which was 22.8\% and 190.5\% higher than that for single H-2 and CH4 fermentation. These results demonstrated that NU pretreatment at outdoor cold-winter conditions was practically and feasible way for improved hythane recovery from lignocellulosic biomass. (C) 2020 Elsevier B.V. All rights reserved.
Xylitol is gaining great attention in current pharmaceutical markets. Commercial production by chemical hydrogenation of xylose is however associated with several inevitable drawbacks. Biotechnological route of xylitol production is a superior alternative, if performed at a lower process costs. The goal of present study was to evaluate the efficiency of bacterial cellulose-sodium alginate (BC-AG) composite as an immobilization matrix for Candida tropicalis GS18 in the production of xylitol through a repeated batch fermentation of rice straw hemicellulosic hydrolysate. Different concentrations of bacterial cellulose, sodium alginate, and calcium chloride were screened to select the stable composite for immobilization. Comparative studies for xylitol production using adsorbed yeast cells on BC-AG composite and suspended cells in different production media like synthetic, non-detoxified, and detoxified hydrolysate were carried out. BC-AG composite prepared by using 3.0\% alginate and bacterial cellulose in 1:1 ratio through cross-linking with 3.0\% CaCl2 solution was found to be most suitable for cell immobilization. The maximum xylitol yield and productivity obtained from immobilized cells on BC-AG composite in synthetic and detoxified media were 0.67 g/g; 0.70 g/L/h and 0.55 g/g; 0.52 g/L/h, respectively. The composite was successfully used for up to five repeated batch fermentations in synthetic and detoxified hydrolysate media. However, the composite was unstable in the non-detoxified medium. Hence, BC-AG composite was found to be an effective immobilization matrix for bioconversion of xylose into xylitol.
The main aim of this work was to study the effect of pH on lactate-and acetate-based bioH(2) production from the dark co-fermentation of 80\% tequila vinasse and 20\% nixtamalization wastewater (w/w) by mixed culture. A 3-L well-mixed batch reactor was operated at constant pH values of 5.8 and 6.5, with an accuracy of +/- 0.05 pH units in all the cases. Regardless of pH, bioH(2) production derived mostly from the consumption of lactate. No significant differences were observed in the amount of bioH2 produced, i.e. 2133 NmL/L-reactor with a maximum rate of 155 NmL/L-h. Compared to a pH of 5.8, pH 6.5 shortened the lag time but promoted bioH(2) sink through propionate formation. Based on the above results, a two-stage controlled-pH strategy was proposed by maintaining the first stage at pH 6.5 and the second stage at pH 5.8 for avoiding long fermentation time and propionogenesis, respectively. The pH-shift strategy reduced the operational time and enhanced bioH(2) production by 17\%. Besides, this strategy also stimulated the syntrophy between Clostridium and Lactobacillus, and reduced the proliferation of Blautia and Propionibacterium, trending bioH(2) production to enhanced efficiency. Overall, microbial dynamics showed that successful bioH(2) production from lactate and acetate relies on having an optimum microbial equilibrium between producers and consumers of lactate and acetate, which was found to be pH-dependent.
The surface reactivity of waste glass powder (WGP) and sugarcane bagasse ash (SCBA) was evaluated in the partial replacement of cement using simple experimental procedures. As a blend, WGP and SCBA showed an excellent dosage at 5 wt \% of each, and the availability and reactivity of silanol groups seem to have been the most important aspect in allowing the growth of calcium silicate hydrate (CSH) onto the quartz surface. XRD and SEM analyses have indicated that WGP and SCBA did not dissolve in the reaction and may have worked as a platform for the conversion of Ca(OH)(2) into CSH. In addition, amorphous WGP was converted into quartz phase during hydration step. Unlike SCBA, whose surface is formed by ``pure{''
This work presents a comparison of three forward osmosis (FO) membranes viz. HTI-TFC, HTI-CTA, and aquaporin-TFC for water recovery from a high strength wastewater of sugarcane molasses distillery. Surface properties of the membranes were assessed using scanning electron microscopy (SEM), zeta potential measurement and attenuated total reflection infrared spectroscopy (ATR-IR). A commercial magnesium chloride hexahydrate (MgCl2 center dot 6H(2)O) (1M to 4 M) solution was used as the draw and a 3M concentrationwas identified to be optimal in obtaining stable flux. During a 24 h FO operation, the average water flux and water recovery respectively were 2.8 L/m(2)h and 81\% (HTI-TFC), 2.4 L/m(2)h and 71\% (HTI-CTA) and 1.9 L/m(2)h and 66\% (aquaporin-TFC). FO operation over five 24 h cycles along with membrane physical cleaning after every cycle resulted in water recovery of 82-70\% for HTI-TFC and HTI-CTA membranes and 65-52\% for aquaporin-TFC membrane. The rejection of distillery wastewater components that contribute to the COD, melanoidins and antioxidants content was similar for all the three membranes. Fouling due to deposits on the membrane surface occurred for all membranes but the ease of cleaning was better for HTI-TFC followed by HTI-CTA and aquaporin-TFC membranes. Periodic physical cleaning by water flushing was adequate to remove surface deposits. Overall, HTI-TFC membrane was most suited for concentrating distillery wastewater, but the effect of high reverse salt flux of this membrane needs to be further investigated.
Here, a comprehensive review of sugarcane industrialization and its relationship with bioactive compounds (BCs) detected in various products and by-products generated during its processing is presented. Furthermore, it is discussed how these compounds have revealed important antioxi-dant, antineoplastic, antidiabetic, and antimicrobial activities. From this bibliographic research highlights the significance of two types of BCs of natural origin (phenolic compounds (PCs) and terpenoids) and a group of compounds synthesized during industrial transformation processes (Maillard reaction products (MRPs)). It was found that most of the studies about the BCs from sugarcane have been conducted by identifying, isolating, and analyzing ones or a few compounds at a specific period, this being a conventional approach. However, given the complexity of the synthesis processes of all these BCs and the biological activities they can manifest in a specific biological context, novel approaches are needed to address these analyses holistically. To over-come this challenge, integrating massive and multiscale methods, such as omics sciences, seems necessary to enrich these studies. This work is intended to contribute to the state of the art that could support future research about the exploration, characterization, or evaluation of different bioactive molecules from sugarcane and its derivatives.
The use of biomass has been a recent trend as a potential feedstock for char generation with improved energetic value. In this work, agricultural residues such as sugarcane bagasse (SCB) and rice husk (RH) were submitted to slow pyrolysis and their calorific value potential was evaluated in comparison with industrial woodchip biochar (WC) (Pyreg GmbH). The samples were characterized by thermogravimetry (TG), differential thermal analysis (DTA), elemental analysis (CNHS) and Fourier-transform infrared spectroscopy. The chars/biochar had a high energetic profile, as indicated by the prominent exothermic peaks in DTA curves, along with the major mass losses, as demonstrated in the TG curves. The combination of fixed carbon (FC) and ash content (A) proved to be essential to produce a char with enhanced higher heating value (HHV), as observed for SCB (FC = 54.6\%; A = 6.2\%) and RH (FC = 51.0\%; A = 38.4\%). SCB and RH chars presented an improved stability reflected by a C/N molar ratio higher than 90\%. The low nitrogen content (SCB = 0.8\%; RH = 0.6\%) and surface area (SCB = 6.0 m(2) g(-1); RH = 11.2 m(2) g(-1)) of the produced chars suggest that they are not indicated for agricultural applications, unless chemical activation is applied. Furthermore, the post-treatment applied for WC (biological activation) is possibly the cause for the improved physicochemical properties, particularly in terms of potential soil conditioning, at the expense of estimated calorific value.
The aim of this study was to develop optimized enzyme cocktails, containing native and recombinant purified enzymes from five fungal species, for the saccharification of alkali-and acid-pretreated sugarcane bagasse (SCB), soybean hulls (SBH) and oil palm empty fruit bunches (EFB). Basic cellulases were represented by cellobiohy-drolase I (CBH) and endo-glucanase II (EG) from Penicillium verruculosum and ?-glucosidase (BG) from Aspergillus niger. Auxiliary enzymes were represented by endo-xylanase A (Xyl), pectin lyase (PNL) and arabinoxylanhy-drolase (AXH) from Penicillium canescens, ?-xylosidase (BX) from Aspergillus japonicus, endo-arabinase (ABN) from A. niger and arabinofuranosidase (Abf) from Aspergillus foetidus. Enzyme loads were 5 mg protein/g dry substrate (basic cellulases) and 1 mg/g (each auxiliary enzyme). The best choice for SCB and EFB saccharification was alkaline pretreatment and addition of Xyl + BX, AXH + BX or ABN + BX + Abf to basic cellulases. For SBH, acid pretreatment and basic cellulases combined with ABN + BX + Abf or Xyl + BX performed better than other enzyme preparations.
Vinasse, a liquid waste which originates from the production of ethanol fuel from sugarcane, has been widely used as soil amendment in Brazil. An important concern that arises from vinasse reuse is the dissemination of antibiotics to the environment through crop soils. This work evaluated the performance of Pressurized Liquid Extraction (PLE) and QuEChERS (quick, easy, cheap, effective, rugged and safe) to extract several multipleclass antibiotics, such as cephalosporins, fluoroquinolones, ionophores, lincosamides, macrolides, quinolones, streptogramin, sulfonamides, tetracyclines and others, from agricultural soils. The performance of several parameters was evaluated for both PLE and QuEChERS, such as the extraction temperature (for PLE), solvents composition, pH and the addition of EDTA. Both methods were able to extract most target antibiotics. However, QuEChERS showed higher recoveries for macrolides and nitroimidazoles, while PLE was more suitable for fluoroquinolones and ionophores (i.e. monensin). The use of citrate-phosphate buffer at pH 7.0, in combination with methanol for PLE and with acetonitrile for QuEChERS, provided the highest antibiotic recoveries for both methods. The use of EDTA did not increase antibiotic recovery rates for QuEChERS, while the temperature had almost no influence on the extraction efficiency in PLE. Citrate-phosphate buffer at pH 7.0 provided higher antibiotic recoveries for QuEChERS and PLE. The combination buffer-methanol provided higher recoveries for PLE. QuEChERS and PLE methods were able to extract most of the target antibiotics. (C) 2020 The Authors. Published by Elsevier B.V.
The sugarcane bagasse was biologically pretreated with three white-rot fungi; Pleurotus florida, Coriolopsis caperata RCK 2011 and Ganoderma sp. rckk-02, individually under solid-state fermentation. P. florida, C caperata RCK 2011 and Ganoderrna sp. rckk-02 degraded lignin up to 7.91,5.48 and 5.58\%, respectively. The lignocellulolytic enzymes produced by these fungi were also monitored during solid state fermentation of sugarcane bagasse. The fungal fermented sugarcane bagasse when hydrolyzed with crude cellulases from brown-rot fungus, Fomitopsis sp. RCK2010, released comparatively 1.5-2.4 fold higher sugars than-in case of untreated sugarcane bagasse. The study demonstrated that white-rot fungal pretreatment improved the amenability of plant material for enzymatic hydrolysis. (C) 2013 Elsevier Ltd. All rights reserved.
In this study, pyrolysis of agricultural residues, such as rice straw (RS), wheat straw (WS), and sugarcane bagasse (SB), was performed in a fixed-bed reactor. The experiments were carried out at varying operating conditions, such as temperature, heating rate, biomass particle size and sweeping gas flow rate, such that the bio-oil yield could be maximized. Small particle size and high heating rate contributed to more bio-oil yield as compared to large particle size and low heating rate. Physicochemical properties of bio-oil samples, evaluated in a comparative manner with maximum focus devoted on analyzing the chemical constituents through GC-MS and FTIR analysis. Biochar was also examined through different physicochemical techniques (e.g., HHV, pH, SEM-EDX, FTIR, CHNS, ICP-AES) for understanding pyrolysis mechanism and its practical usability. Analysis of non-condensable gas through GC-TCD, revealed co-existence of H-2, CO, CO(2)and CH(4)molecules, with greater percentage of H(2)and CH(4)at high temperature resulted enhancement in calorific value.
To set suitable weed management programs. one the most important parameters is knowing the specific composition of the seedbank and its correlation with the established flora. Such information is fundamental to guide the control strategy to be adopted and the herbicide choices. Mechanical harvest of no-burn sugar-cane maintaining a layer of straw on the soil surface promoted important changes in weed seed germination and seedling survival. Lack of soil mobilization and the lack of sugarcane burning are two additional factors influencing weed flora composition and population densities. Field sampling was conducted in twenty-eight no-burn sugarcane areas to evaluate (i) seedbank composition and seedpopulation densities and later (ii) weed Community composition and population density. A predominance of broad-leaf weeds was foud in the seed bank mainly Amaranthus spp., as well as species of the families Euphorbiaceae and Convuluvlaceae. The traditional gramineous seeds were not profuse in the seedbanks of the Studied areas. The correlation between the seedbank and the weed community compositions was small, regardless of the harvesting time, seedbank quantification methodology and weed species.
An acidophilic-solvent-thermostable endo beta-1,4-D-glucanase produced from a potential Trichoderma harzianum strain HZN11 was purified to homogeneity by DEAE-Sepharose and Sephadex G-100 chromatography with 33.12 fold purification with specific activity of 66.25 U/mg and molecular mass of similar to 55 kDa. The optimum temperature and pH were 60 degrees C and 5.5 retaining 76 and 85 \% of activity after 3 h, respectively. It showed stability between pH 4.5-6.0 and temperature between 50-70 degrees C indicating thermostability. Endo beta-1,4-D-glucanase was activated by Ca2+ and Mg2+ but inhibited by Hg2+, Pb2+ and Cd2+. The effect of thiol reagents, metal chelators, oxidizing agents and surfactants on enzyme activity has been studied. Purified endo beta-1,4-D-glucanase exhibited highest specificity towards carboxymethyl cellulose. Kinetic analysis showed the K-m, V-max and K-i (cellobiose inhibitor) of 2.5 mg/mL, 83.75 U/mg and 0.066 M, respectively. The storage stability of purified endo beta-1,4-D-glucanase showed a loss of mere 13 \% over a period of 60 days. The hydrolysis efficiency of purified endo beta-1,4-D-glucanase mixed with cocktail was demonstrated over commercial enzyme. Optimized enzymatic hydrolysis of sweet sorghum and sugarcane bagasse released 5.2 g/g (36 h) and 6.8 g/g (48 h) of reducing sugars, respectively. Separate hydrolysis and fermentation of sweet sorghum bagasse yielded 4.3 g/L bioethanol (16 h) confirmed by gas chromatography-mass spectrometry (GC-MS). Morphological and structural changes were assessed by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy. Elemental analysis was carried out by SEM equipped with energy dispersive X-ray technique. These unique properties prove the potentiality of enzyme for biomass conversion to biofuel and other industrial applications.
5-hydroxymethyl furfural (5-HMF) is an important organic compound for production of renewable plastics, fine chemicals and fuel. Nowadays, the manufacturing of 5-HMF is mainly derived from edible glucose and fructose. In order to replace the use of food crops such as glucose and fructose as a feed stock, experiment were conducted by using sugarcane bagasse as a raw material. These experiments were performed in a batch-type reactor containing slurry of 10 ml of water and 1.2 g of solids. Effect of temperature (200 degrees C and 300 degrees C) and reaction times (3 to 30 min) on 5-HMF yield was studied. The highest yield of 5-HMF was found at 270 degrees C (10 min). Moreover, at temperature (>300 degrees C) and long reaction time, 5-HMF production yield decreased, this is mainly because of the heightened decomposition and polymerization of 5-HMF to formic acid and char, respectively. This study reveal that, condition for production of 5-HMF achieved at medium range of temperature and reaction time.
Increased Brazilian sugarcane ethanol production is expected in response to increasing domestic and international ethanol demand. The Pontal do Paranapanema region, located in the western parts of the Sao Paulo state, is one of the regions where sugarcane is expected to expand on a large scale. This expansion will most likely affect small-scale dairy farmers in the region and may lead to displaced milk production. Interviews have been made with small-scale dairy farmers in areas where sugarcane has already been established. These interviews show that many farmers who substitute milk production for sugarcane production experience economic stagnation after the change. However, both systems can coexist, using sugarcane residues as high-quality cattle feed. This feed can easily be made at the ethanol mills using sugarcane residues and some additional protein and mineral supplements. Analyses indicate that the dairy farmers can increase their income ten-fold by adopting this integrated system. The increased total output and higher land-use efficiency in dairy production may counteract possible indirect land-use change. Greenhouse gas emissions per unit of milk produced as well as liter ethanol produced depend on several factors, including effects of diverting bagasse from other uses to feed production. (C) 2011 International Energy Initiative. Published by Elsevier Inc. All rights reserved.
The production of rum consists of fermentation, distillation, and aging. To check the influence of each step on the final rum aroma, molasses, mash, distillate, and the final rum were analyzed using the sensomics concept. The changes in key aroma compounds were determined by application of aroma extract dilution analysis (AEDA) in combination with gas chromatography mass spectrometry for identification and by stable isotope dilution assays (SIDAs) for quantitation. Odor activity values (OAVs; ratio of concentration to respective odor threshold) were calculated for the compounds determined in the rum and, finally, the rum aroma was successfully simulated by recombination. (E)-beta-Damascenone showed by far the highest OAV (3280) in rum. Although this compound was determined already in molasses, its concentration increased significantly during distillation, indicating a thermolabile precursor. Vanillin, 4-ethylphenol, 2-methoxyphenol, 4-ethyl-2-methoxyphenol, and 2-methoxy-4-propylphenol are well-known compounds mainly stemming from the wood barrels used for aging and showed an OAV >= 1. Another important group of aroma-active compounds in rum were ethyl esters, for which a significant increase was determined during fermentation but also to a lesser extent during aging. Altogether, the concentrations of 68\% of the aroma active compounds increased during the process, demonstrating its influence on the overall rum aroma.
Biomass pyrolysis is a fundamental thermochemical conversion process that is of both industrial and ecological importance. From designing and operating industrial biomass conversion systems to modeling the spread of wildfires, an understanding of solid state pyrolysis kinetics is imperative. A critical review of kinetic models and mathematical approximations currently employed in solid state thermal analysis is provided. Isoconversional and model-fitting methods for estimating kinetic parameters are comparatively evaluated. The thermal decomposition of biomass proceeds via a very complex set of competitive and concurrent reactions and thus the exact mechanism for biomass pyrolysis remains a mystery. The pernicious persistence of substantial variations in kinetic rate data for solids irrespective of the kinetic model employed has exposed serious divisions within the thermal analysis community and also caused the broader scientific and industrial community to question the relevancy and applicability of all kinetic data obtained from heterogeneous reactions. Many factors can influence the kinetic parameters, including process conditions, heat and mass transfer limitations, physical and chemical heterogeneity of the sample, and systematic errors. An analysis of thermal decomposition data obtained from two agricultural residues, nutshells and sugarcane bagasse, reveals the inherent difficulty and risks involved in modeling heterogeneous reaction systems. (C) 2011 Published by Elsevier B.V.
Bioethanol and biodiesel are the most important biofuels worldwide. Although the production processes of these two biofuels are well established, there is still room for improvements. The integration of these two processes would allow the use of their wastes or by-products for increasing productivity or generating additional products. This would make it possible to improve the economics and sustainability of both processes. This article presents an overview focusing on a soybean biodiesel plant integrated into a sugarcane biorefinery. The process integration was evaluated considering agricultural, logistic, geographic, industrial, process stream, equipment, administrative, and commercial aspects. The integrated plant offers the opportunity for cost-effective and environmentally friendly biofuels processing, while expanding the portfolio of potential products.
By 2013, the province of Cienfuegos in Cuba consumed about 5165 GWh of primary energy, of which an estimated 60 \% was used to produce 767 GWh of electricity. 29 \% of the primary energy was obtained from renewable fuel, and only less than 5 \% of the biomass energy, was used to produce about 27 GWh of biomass based electricity. This study proposes and assesses opportunities to produce electricity from biomass in the sugar industry of the province. The scenarios considered include: upgrading the agricultural yield of sugarcane, producing energy cane and combusting it after the sugarcane milling season, combusting the filter cake, combusting marabu (Dichrostachys cinerea, a bush tree considered a plague in Cuba) after the sugarcane milling season, and updating the electricity generation technology. Results are given for the different scenarios and it is shown that a combined scenario, including upgrading agricultural yield of sugarcane, upgrading electricity generation technology, combusting filter cake, and producing energy cane to generate electricity after the sugarcane milling season, thus allowing to use the generation units in sugar factories during 8000 h per year affords a potential production of 1150 GWh of electricity, 50 \% more than consumed in Cienfuegos province in 2013.
High potential, thermotolerant, ethanol-producing yeasts were successfully isolated in this study. Based on molecular identification and phylogenetic analysis, the isolated thermotolerant yeasts were clustered in the genera of Pichia kudriaozeoii, Candida tropicalis, Candida orthopsilosis, Candida glabrata and Kodamea ohmeri. A comparative study of ethanol production using 160 g/L glucose as a substrate revealed several yeast strains that could produce high ethanol concentrations at high temperatures. When sugarcane bagasse (SCB) hydrolysate containing 85 g/L glucose was used as a substrate, the yeast strain designated P. kudriaozeoii RZ8-1 exhibited the highest ethanol concentrations of 35.51 g/L and 33.84 g/L at 37 degrees C and 40 degrees C, respectively. It also exhibited multi-stress tolerance, such as heat, ethanol and acetic acid tolerance. During ethanol fermentation at high temperature (42 degrees C), genes encoding heat shock proteins (ssg1 and hsp90), alcohol dehydrogenases (adh1, adh2, adh3 and adh4) and glyceraldehyde-3-phosphate dehydrogenase (tdh2) were up-regulated, suggesting that these genes might play a crucial role in the thermotolerance ability of P. kudriaozeoii RZ8-1 under heat stress. These findings suggest that the growth and ethanol fermentation activities of this organism under heat stress were restricted to the expression of genes involved not only in heat shock response but also in the ethanol production pathway. (C) 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda.
Pyrolysis of sugarcane (Saccharum officinarum L) leaves (SCL) has been investigated using DTA/TGA and DSC techniques. Proximate and ultimate analyses and calorific value measurement have been carried out using standard protocols. The sugar cane leaves contain 44\% cellulose, 22\% hemicellulose and 17\% lignin. The pyrolysis have been carried out at six heating rates varying from 5 to 40 degrees C/min. Analysis of the pyrolysis results has been carried using iso-conversional model free methods as well as multiple linear regression method. For the fractional conversion range of 0.05-0.95, the average apparent activation energy values evaluated from iso-conversional methods have ranged from 214.9 to 239.6 kJ/mol where as in the case of multiple linear regression analysis it has ranged from 25.06 to 57.23 kJ/mol. The multi-step reaction mechanism has been investigated using the Criado method. The results of this study are useful for the design of large scale biomass thermal conversion process.
Rice straw (RS) is a promising feedstock for transformation into biofuels and bioproducts due to its high sugar content and worldwide availability. However, a pretreatment step is necessary in order to disrupt the RS complex lignocellulosic matrix. The aim of this work was to study RS pretreatment with the ionic liquid 1-ethyl-3-methylimidazolium acetate ({[
The objective of this work was to assess the combined effects of the blending ratio in a fluidized gasification process, where the focus was to quantify the relationships between the response variables and vital operating factors. The response variables used in this work were gasification efficiency, tar yield, and carbon conversion with different bed materials such as silica and limestone. Experiments were conducted over a temperature range of 700-900 degrees C, using equivalent to 0.35. All of the response variables were successfully fitted to either a two-factor interaction or quadratic model. Using response surface methodology (RSM), the effects of individual operating factors and their interactions were categorically determined, which were not otherwise possible by the classical design of experiment methodology. Using the resultant response variable correlations, gas efficiency was optimized as a function of the different blending ratios and bed materials. The full potentiality of wheat husk, sugarcane bagasse, and coconut shell for fluidized gasification was successfully investigated via RSM.
Marine-derived fungi are prone to produce structurally unique secondary metabolites, a considerable number of which display the promising biological properties and/or industrial applications. Among those, ligninolytic enzymes have attracted great interest in recent years. In this work, about 20 strains were isolated from sea mud samples collected in the East China Sea and then screened for their capacity to produce lignin-degrading enzymes. The results showed that a strain, named J63, had a great potential to secrete a considerable amount of laccase. Using molecular method, it was identified as an endophytic fungus, Pestalotiopsis sp. which was rarely reported as ligninolytic enzyme producer in the literature. The production of laccase by Pestalotiopsis sp. J63 was investigated under submerged fermentation (SF) and solid state fermentation (SSF) with various lignocellulosic by-products as substrates. The SSF of rice straw powder accumulated the highest level of laccase activity (10,700 IU/g substrate), whereas the SF of untreated sugarcane bagasse provided the maximum amount of laccase activity (2,000 IU/ml). The value was far higher than those reported by other reports. In addition, it produced 0.11 U/ml cellulase when alkaline-pretreated sugarcane bagasse was used as growth substrate under SF. Meanwhile, the growth of fungi and laccase production under different salinity conditions were also studied. It appeared to be a moderately halo-tolerant organism.
The acute toxicity, cytotoxicity, genotoxicity and antigenotoxic effects of BC were studied. Cytotoxicity of BC was evaluated in cultured C3A hepatoma cells (HepG2/C3A) using a lactate dehydrogenase (LDH) activity assay. Acute toxicity was tested in adults Wistar rats treated with a single dose of BC. The genotoxicity of BC was evaluated in vivo by the micronucleus assay. BC (0.33-170 tig/mL) added to C3A cell culture medium caused no elevation in LDH release over the background level recorded in untreated cell wells. The treatment with the BC in a single oral dose (2000 mg/kg body weight) caused no deaths or signs of toxicity. BC attenuated CP-induced and inhibition the incidence of MNPCE (female: 46.94\%; male: 22.7\%) and increased the ratio of PCE/NCE (female: 46.10\%; male: 35.25\%). There was no alteration in the LDH release in the wells where C3A cells were treated with increasing concentrations of BC compared to the wells where the cells received the cell culture medium only (background of approximately 20\% cell death), indicated that in the dose range tested BC was not cytotoxic. BC was not cytotoxic, genotoxic or acutely toxic. BC attenuated CP-induced genotoxic and myelotoxic effects. (C) 2015 Elsevier Ltd. All rights reserved.
The use of lignocellulosic hydrolysate is a promising strategy to make fuel and chemical production feasible through biological processes. The major challenges facing this process are the presence of inhibitors in hydrolysate, as furan derivatives and phenolic compounds, and the inefficient consumption of the xylose found in hydrolysate. Therefore, this study aimed to select ideal Clostridium strains and an optimal medium for microbiological production of n-butanol from sugarcane straw hydrolysate with high yield and productivity. From a screening of twelve Clostridium strains, two strains stood out: Clostridium saccharoperbutylacetonicum DSM 14923, by its potential to produce high titer of n-butanol (4.95 g/L from 11.6 g/L glucose and 3.6 g/L xylose), and Clostridium saccharobutylicum DSM 13864, by its capacity to concomitantly consume similar quantities of glucose and xylose. Optimization of culture medium and inoculum preparation allowed an improvement in n-butanol production from 0.65 g/L for 5.39 g/L. Moreover, with optimized medium, a higher tolerance to lignocellulosic hydrolysate was obtained, avoiding a premature end to fermentation at hydrolysate and enabling the cultivation of these strains in 79\% pure lignocellulosic hydrolysate. Among all the strains tested for lignocellulosic hydrolysate fermentation, C. saccharobutylicum DSM 13864 has the best performance. This strain, in a culture medium composed by 79\% of pure lignocellulosic hydrolysate, showed a consumption of 95\% of all sugar available (34 g/L of glucose and 22 g/L of xylose) and a total acetone, n-butanol, and ethanol (ABE) production of 10.33 g/L, being the most suitable strain for n-butanol production using this substrate.
The performance of sugarcane baggase (SCB) treated with gamma-APS filled polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr) biocomposites were investigated. The composites with different filler loading ranging from 5 to 30 wt \% were prepared using heated two roll mill by melt mixing at temperature of 180 degrees C. Tensile properties of the PP/NBRr/SCB composites which is tensile strength, Young Modulus and elongation at break were investigated. Increasing of treated SCB filler loading in PP/NBRr/SCB composites have increased the Young modulus however decreased the tensile strength and elongation at break of the PP/NBRr/SCB composites. From the results, gamma-APS treated SCB composites shown higher tensile strength and Young Modulus but lower elongation at break when compared to the untreated SCB composites. This is due to the stronger bonding between.-APS treated SCB with PP/NBRr matrices. These findings was supported by micrograph pictures from morphological study. SCB filler treated with gamma-APS has improved the adhesion as well as gave strong interfacial bonding between SCB filler and PP/NBRr matrices which results in good tensile strength of PP/NBRr/SCB composites.
Vitrimeric materials have emerged as fascinating and sustainable materials owing to their malleability, reprocessability, and recyclability. Sustainable vitrimeric materials can be prepared by reinforcing polymeric matrix with bioderived fillers. In the current work, a sustainable vitrimer is prepared by incorporating biomass-derived activated carbon (AC) filler into the epoxy matrix to achieve enhanced thermal and mechanical properties. Thus, prepared biocomposite vitrimers demonstrate a lower-temperature self-healing (70 degrees C for 5 min) via disulfide exchanges, compared to the pristine epoxy vitrimers (80 degrees C for 5 min). Significantly, the self-healing performances have been studied extensively with the flexural studies; and changes in material healing efficiency have been demonstrated based on the observed changes in modulus.
An engineered yeast producing all the cellulases needed for cellulose saccharification could produce ethanol from lignocellulose at a lower cost. This study aimed to express fungal beta-glucosidases in Saccharomyces cerevisiae to convert cellobiose into ethanol. Furthermore, two engineering platforms (laboratory vs industrial strain) have been considered towards the successful deployment of the engineered yeast under simulated industrial conditions. The industrial S. cerevisiae M2n strain was engineered through the delta-integration of the beta-glucosidase Pccbgl1 of Phanerochaete chrysosporium. The most efficient recombinant, M2n{[
Low-cost adsorbents prepared from industrial wastes such as sugarcane bagasse (BC), rice husk (RC), and textile waste cloth (TC) are identified as suitable sorbents for removing basic violet 10 (BV). Fourier transform infrared (FTIR) and scanning electron microscopic (SEM) studies were carried out to characterize the prepared sorbents. The effects of dosage, time, and pH on dye removal were examined. It was observed that BV sorption takes place in acidic, neutral, and alkaline aqueous solutions. The work discussed the best-fit sorption isotherms among Freundlich and Langmuir, in addition to the reaction and diffusion-based kinetic models. Based on the data obtained, it was found that the BV sorption took place in acidic, neutral, and alkaline aqueous solutions and sorption kinetics found to be controlled by pseudo-second-order and pore diffusion models. Also, thermodynamic parameters such as Delta G(o), Delta H-o, Delta S-o, and E-a were calculated in order to understand the nature of the sorption process. The maximum dye removal capacity (DRC) was found to be 5608, 1244, and 27,495 mg/kg for BC, RC, and TC, respectively. Collectively, it can be concluded that the activated carbon sorbents, prepared from the named wastes, can used to adequately remove the basic violet dye from its aqueous waste solution.
In previous work we showed that the yeast Dekkera bruxellensis (strain GDB 248) is capable of assimilating cellobiose and converting this sugar to ethanol, a characteristic that may help in reducing the cost of biomass hydrolysis with commercial enzyme. In the present work we tested the efficiency of ethanol production by this yeast from bagasse of sugarcane (SCB) and sweet sorghum (SSB) after alkaline H2O2 pretreatment and enzymatic hydrolysis treatment. SSB contained less lignin and ashes and more waxes than SCB, resulting in more efficient pretreatment and enzyme hydrolysis, as evidenced by chemical and physical analysis. Glucose and cellobiose were released from cellulose, as well as xylose from the remaining hemicellulose. The hexoses were completely consumed with final yields of 0.42 (+/- 0.04) g/g for SCB and 0.44 (+/- 0.03) gig for SSB. Acetate was not produced, which indicated that the fermentations were carried out under anaerobic condition. This yeast was capable of metabolising cellobiose for ethanol production, which therefore proves to be a promising industrial microorganism for the production of second-generation ethanol. (C) 2016 Elsevier B.V. All rights reserved.
A quick fed-batch saccharification (QFBs) strategy of pretreated wheat straw at high solid loadings (HSL) was developed to achieve high sugar concentrations and increase lignocellulosic ethanol productivities in the fermentation stage. Pretreatment time, number of feedings, and the time between them were evaluated using a Box-Behnken design. A surface response model was employed to maximize sugars released at 20\% (w/w) HSL. Total sugar concentrations after 60 h with 20\% (w/w), 25\% (w/w), and 30\% (w/w) HSL were 128.5 g/l, 142.4 g/l, and 163.5 g/l, respectively. These were 14.6-42\% higher than their batch saccharification counterparts. The QFBs was implemented as part of sequential (SHF) and simultaneous saccharification-fermentation (SSF) strategies as well as the presaccharification stage of a semi-simultaneous saccharification-fermentation (SSSF) strategy. In the latter strategy, the highest ethanol concentration achieved was 31.7 g/l. The ethanol volumetric productivity was 2.2- and 3-fold their SHF and SSF counterparts.
Different biomass components have different effects on the microstructures and physicochemical properties of biocarbons. And the properties of biocarbons still need to be further improved. Nanoscale/microscale graphene-like sheets are synthesized with KOH as micropore-forming agent, FeoNO3thorn 3 9H2O as mesopore-forming agent and graphite catalyst. It is systematically researched to get the effects of biomass components on them. Cane sugar can form flat graphene- like nanosheets with high conductivity. Their performance drops sharply at 100A g 1, indicating that biocarbons need a support of carbon skeleton to operate normally at high current density. Bagasse pith contains amount of cellulose and hemicellulose, which are good for forming pores. Bagasse pithderived graphene-like sheets possess large specific surface area (2923: 58m2 g 1), high specific capacitance (514: 14 F g 1 at 0: 3A g 1 and 372: 57 F g 1 at 100A g 1) and high energy density. Due to homogeneous coated doping with graphenelike nanosheets, sugarcane pith-derived graphene-like sheets possess low impedance (Rs = 0: 02X), high rate capability (maintained 82.34\% from 0.3 to 100A g 1) and high cycling stability (maintained 101.51\% after 5000 cycles), which is better than lots of graphene doping. Sugarcane skin contains more lignin which has hexagonal carbon rings. The graphitization extent of sugarcane skin-derived graphene-like sheets is significantly high. The results provide references to select carbon precursors, and show a novel graphene-like doping method which is suitable for different materials and various fields.
One of the critical steps in lignocellulosic deconstruction is the hydrolysis of crystalline cellulose by cellulases. Endoglucanases initially facilitate the breakdown of cellulose in lignocellulosic biomass and are further aided by other cellulases to produce fermentable sugars. Furthermore, if the endoglucanase is processive, it can adsorb to the smooth surface of crystalline cellulose and release soluble sugars during repeated cycles of catalysis before dissociating. Most glycoside hydrolase family 9 (GH9) endoglucanases have catalytic domains linked to a CBM (carbohydrate-binding module) (mostly CBM3) and present the second-largest cellulase family after GH5. GH9 endoglucanases are relatively less characterized. Bacillus licheniformis is a mesophilic soil bacterium containing many glycoside hydrolase (GH) enzymes. We identified an endoglucanase gene, gh9A, encoding the GH9 family enzyme H1AD14 in B. licheniformis and cloned and overexpressed H1AD14 in Escherichia coli. The purified H1AD14 exhibited very high enzymatic activity on endoglucanase substrates, such as beta-glucan, lichenan, Avicel, CMC-Na (sodium carboxymethyl cellulose) and PASC (phosphoric acid swollen cellulose), across a wide pH range. The enzyme is tolerant to 2 M sodium chloride and retains 74\% specific activity on CMC after 10 days, the highest amongst the reported GH9 endoglucanases. The full-length H1AD14 is a processive endoglucanase and efficiently saccharified sugarcane bagasse. The deletion of the CBM reduces the catalytic activity and processivity. The results add to the sparse knowledge of GH9 endoglucanases and offer the possibility of characterizing and engineering additional enzymes from B. licheniformis toward developing a cellulase cocktail for improved biomass deconstruction.
Porous nitrogen-doped carbons derived from biomass wastes are considered as promising materials for energy storage devices. Herein, a novel and scalable synthesis route for preparation of these materials from sugarcane bagasse waste is demonstrated. The synthesis process includes a hydrogel intermediate in which delignified bagasse and polyacrylamide networks are interlaced in molecular scale and calcium acetate serves as a hard template within the polymeric chains. After pre-carbonization and chemical activation of the hydrogel, porous nitrogen-doped carbon with high surface area of 1834.3 m(2) g(-1) and considerable pore volume of 1.03 cm(3) g(-1) was obtained with nitrogen and oxygen contents of 3.6\% and 14.5\%, respectively. The fabricated supercapacitor electrode demonstrated high specific capacitance of 241 F g(-1) at 0.5 A g(-1) current density with capacitance retention of 96.5\% after 5000 charge-discharge cycles at 2 A g(-1). In a symmetrical two-electrode cell, the porous nitrogen-doped carbon demonstrated high energy density of 14.8 W h kg(-1) at power density of 1001.6 W kg(-1), which is comparable to many nitrogen-doped carbon materials found in the literature. (C) 2020 Published by Elsevier B.V.
The effect of four bottom substrates, oyster shell powder (OP), sugarcane bagasse (SB), a mixture of OP and SB (OS) and fresh soil (FS), on the water quality and bacterial and zooplankton density of intensive shrimp (Litopenaeus vannamei) culture tanks without water change and the growth performance of cultured shrimp were compared in this study. At the end of a 110 days culturing trial, the total ammonium-N (TAN) of the water on SB and the nitrite nitrogen (NO2-N) on OS was significantly lower than that on the other substrates (P<0.05), which coincided with the high density of ammonium-and nitrite-oxidizing bacteria in the water on SB and OS, respectively. The concentration of chlorophyll a (Chl a) increased slowly on OP, SB and OS but remained low on FS. The density of total bacteria on OP, SB and OS was one order of magnitude higher than that on FS, and the density of zooplankton on SB and OS was significantly higher than that on FS or OP (P<0.05). The improved water quality and increased density of bacteria and zooplankton on SB and OS may have had a synergistic effect on shrimp culture, improving its growth performance (high survival rate and yield and low feed conversion rate). SB and OS were more effective for improving the growth performance of intensively cultured L. vannamei without water change than OP and FS. To our knowledge, this study presents the first evidence regarding the effect of different bottom substrates on intensive shrimp culture.
N-2-fixing cyanobacteria (Anabaena azollae, symbiont strains) were immobilized in polyurethane foam and ammonia production by the cyanobacteria was investigated in the laboratory and rice field. The cyanobacterial symbiont, A. azollae-MPK-SK-AM-24 showed the highest growth rate and biomass production amongst the 5 isolates examined while A. azollae-AS-DS showed the highest nitrogenase activity followed by A. variabilis-SA(0) (wild type, non-symbiotic). Treatment of the foam-immobilized cyanobacteria with the systemic fungicide Bavistin stimulated nitrogenase activity while inhibiting glutamine synthetase (GS) activity. Free-living A. azollae-MPK-SK-AF-38, A. azollae-MPK-SK-AM-24 and A. azollae-MPK-SK-AM-27 excreted the highest amounts of ammonia into the growth medium; under foam - immobilized conditions the ammonia production increased further. Treatment of the foam - immobilized cyanobacteria with the fungicides Bavistin and Vitavax resulted in ammonia production at significantly higher rates. Rice seedlings (var. ADT 36) grown in the laboratory in conjunction with foam - immobilized A. azollae showed increased growth. A field experiment with paddy rice and foam - immobilized A. azollae strains indicated that the cyanobacteria excreted significant amounts of ammonia into the flood water in the rice fields resulting in increased chlorophyll content of the plants and increased the rice grain and straw yields. A combination of fertilizer nitrogen and inoculation with foam - immobilized cyanobacteria also significantly increased the rice grain and straw yield. Additionally, both A. azollae and A. variabilis were immobilized in sugarcane waste (bagasse), added to the rice paddy and resulted in increased rice grain yield.
Recycling bioresources is the only way to sustainably meet a growing world population's food and energy needs. One of the ways to do so is by using agro-industry wastewater to cultivate microalgae. While the industrial production of microalgae requires large volumes of water, existing agro-industry processes generate large volumes of wastewater with eutrophicating nutrients and organic carbon that must be removed before recycling the water back into the environment. Coupling these two processes can benefit the flourishing microalgal industry, which requires water, and the agro-industry, which could gain extra revenue by converting a waste stream into a bioproduct. Microalgal biomass can be used to produce energy, nutritional biomass, and specialty products. However, there are challenges to establishing stable and circular processes, from microalgae selection and adaptation to pretreating and reclaiming energy from residues. This review discusses the potential of agro-industry residues for microalgal production, with a particular interest in the composition and the use of important primary (raw) and secondary (digestate) effluents generated in large volumes: sugarcane vinasse, palm oil mill effluent, cassava processing waster, abattoir wastewater, dairy processing wastewater, and aquaculture wastewater. It also overviews recent examples of microalgae production in residues and aspects of process integration and possible products, avoiding xenobiotics and heavy metal recycling. As virtually all agro-industries have boilers emitting CO2 that microalgae can use, and many industries could benefit from anaerobic digestion to reclaim energy from the effluents before microalgal cultivation, the use of gaseous effluents is also discussed in the text.
This study presents epoxidizing podocarpus falcatus seed oil through epoxidation reaction by using synthesized solid sulfonated silica catalyst from locally available sugarcane bagasse ash. The prepared sulfonated solid acid silica catalyst was characterized using bulk density, porosity, surface area, thermogravimetric, powder X-ray diffractometer, and FT-IR (Fourier-transform infrared spectroscopy). Thus, synthesized sulfonated silica catalyst works successfully for epoxidation of podocarpus falcatus seed oil. The epoxidation reaction was analyzed by design expert software Box-Behnken with four factors three-level: reaction temperatures, the molar ratio of hydrogen peroxide to the podocarpus falcatus seed oil double bond, reaction times, and catalyst loading. From the experimental results, the maximum relative conversion of oxirane of 84.75\% was obtained using a temperature of 70 degrees C, hydrogen to carbon carbon double bond molar ratio of 2.5:1, using catalyst 5 (\% w/w), and at 4-h reaction time. The product of epoxidized podocarpus falcatus oil was characterized by identifying the functional group, and composition of podocarpus falcatus seed oil, in comparison to epoxidized podocarpus falcatus oil, using Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. The produced epoxidizing podocarpus falcatus seed oil can be substitutes for petrochemical resources because of its sustainable, renewable, and environment-friendly nature.
Ethanol production on small scale (on-farm) substantially contributes to the effort to replace fossil fuels. However, the share of small scale production remains incipient, either due to inefficiency in the process or legal restrictions on the commercialization of hydrous ethanol fuel. The aim of this paper is to justify this incipient industry by detailing the small-scale ethanol production process and presenting operational data collected in the literature from the last three decades. The reviewed data showed that the inefficiency of the process affects the economic feasibility by product losses in bagasse and vinasse or through excessive energy consumption. The feasibility of ethanol production on small scale requires addressing these technological obstacles through the integral use of co-products. (C) 2014 Elsevier Ltd. All rights reserved.
The use of by-products reduces costs for the cultivation of Se-enriched mushrooms, whose consumption could reduce problems associated with Se deficiency. Treatments to decrease by-products contamination, such as sterilization, are also expensive and thus are not accessible for small producers. In this way, this work aimed to evaluate the influence of Se at 25 mg kg(-1) (sodium selenite) on the growth, composition, and antioxidant activity of Pleurotus ostreatus mushrooms cultivated on substrates composed of sugarcane bagasse (CB) and spent brewer's grain (BSG) treated with a hydrated lime solution. The use of sodium selenite did not affect the biological efficiency (33.79-52.31 g 100 g(-1)), antioxidant activity (32.79-44.67\%), and phenolic content (458.78-754.96 mg EAG 100 g(-1)) of mushrooms, which had high concentrations of protein (17.07-23.50\%), fibers (11.13-13.32\%) and ash (4.46-7.21\%). The mushrooms grown on CB alone presented 179.07 mu g g(-1) of Se, so the consumption of 0.31 g of dry mushroom would be sufficient to achieve the recommended daily intake of Se. The CB treated with the hydrated lime solution can be used as an inexpensive and efficient substrate to produce Se-enriched P. ostreatus mushrooms.
Lignocelluloses prepared from woody tea stalk, pine sawdust and sugarcane bagasse were used as adsorbents to isolate decaffeinated catechins from tea extracts and compared with synthetic macroporous resin HPD 600. HPD 600 had the highest adsorption capacity to catechins, followed by tea stalk lignocellulose while lignocelluloses of pine sawdust and bagasse the least. Tea stalk lignocellulose absorbed preferentially tea catechins and showed a good selectivity. HPD 600 absorbed caffeine and tea catechins simultaneously. The kinetics data of tea stalk lignocellulose showed a good fit with the Langmuir isotherm model. It is considered that tea stalk lignocellulose is an alternative low-cost adsorbent for preparing decaffeinated tea catechins. (c) 2008 Elsevier Ltd. All rights reserved.
n-Psicose has been drawing increasing attention in recent years because of its medical and health applications. The production of D-psicose from n-glucose requires the co-expression and synergistic action of xylose isomerase and n-psicose 3-epimerase. To co-express these genes, vector pET-28a(+)-dual containing two T7 promoters and RBS sites and an Multiple Cloning Sites was constructed using the Escherichia colt expression plasmid pET-28a). The xylose isomerase gene from E. coli MG1665 and the 0-psicose 3-epimerase gene from Agrobacterium tumefaciens CGMCC 1.1488 were cloned and co-expressed in E. coli BL21(DE3). After 24 h incubation with the dual enzyme system at 40 degrees C, the sugar conversion ratio from n-glucose to D-psicose reached 10\%. The optimal conditions were 50 degrees C, pH 7.5 with Co2+ and Mg2+. The D-psicose yields from sugarcane bagasse and microalgae hydrolysate were 1.42 and 1.69 g/L, respectively.
A lab-scale ensiling study was carried out to investigate the fermentation quality of water hyacinth (WH) supplemented with molasses, rice bran, as an absorbent, and an inoculant in the form of fermented vegetable juice and their combinations. After wilting the water hyacinths for 7 h to a dry matter (DM) content of 240 to 250 g/kg, the following treatments were applied: i) Control (C), WH only; ii) WH with sugarcane molasses at 40 g/kg WH (CM); iii) WH inoculated with fermented vegetable juice at 10 ml/kg WH (CI); iv) CM and CI (CMI) combined; v) WH with 150 g rice bran/kg WH (CA); vi) CA and CI combined (CM); vii) CA and CM combined (CAM); and viii) CA, CM and CI combined (CAMI). After application of additives, the differently treated forages were mixed and ensiled in triplicates in 1,500-ml polyethylene jars. After ensiling for 3 d, pH values in all treatments, except C and CI, had decreased to approximately 4.0 and remained low till 14 d. After 56 d, pH had increased between 0.4 to 0.9 pH-units compared to those at 14 d. The ammonia nitrogen (NH3-N) concentration ranged from an acceptable level in treatment CM (8 g/kg N) to a high NH3-N value in treatment CMI (16 g/kg N). Lactic acid formation was higher in CI than in all other treatments. Butyric acid contents, which indicate badly fermented silages, were low in all silages (<2 g/kg DM). There were two-way interactions (p-values from <0.001 to 0.045) for almost all fermentation end-products and pH, except for the molassesxinoculant interaction on NH3-N (p = 0.26). Significant 3-way interactions were found on all observed variables except for weight losses of silages. It is concluded that conserving wilted WH as silage for ruminants may be improved by the addition of molasses or rice bran.
This research is focused on the development of ZnO-NPs hydrogels through in situ method. The powerful absorption peak within the order of 320 nm confirms the presence of the zinc oxide nanoparticles arrangement because of the surface Plasmon resonance (SPR). ZnO-NPs characterization was performed by SEM, TEM, PSA, EDX, and FTIR. Additionally, the behaviour of prepared nanocomposite hydrogels swelling was examined at different pH and salt solutions. Furthermore, the antibacterial activity of ZnO-NPs hydrogels againstEscherichia coli(ATCC 433) andBacillus subtilis(ATCC 1688) was measured by the use of agar disk plate diffusion process. ZnO-NPs hydrogels extracted from lab-made CMC showed a greater antibacterial action through Gram-positive bacteria (B. subtilis) and Gram-negative bacteria (E. coli) relative to synthetic CMC acquired from the market. The hydrogels developed by ZnO-NPs can be utilized in biomedical applications efficiently. {[
This research investigates the environmental impacts and economic benefits of six molasses-based ethanol production schemes using open lagoon or upflow anaerobic sludge blanket (UASB) waste-water management system in Thailand (schemes A-F). The aim is to determine the most environmentally and economically favorable scheme in terms of the environmental cost, payback period, and cost savings, using analytic hierarchy process (AHP). Schemes A and B use open lagoon for treating wastewater from ethanol production. The ethanol production of scheme A relies on steam and electricity from a sugar mill on the premises, and scheme B is a stand-alone ethanol plant that purchases steam and electricity from external sources. Schemes C - F use UASB technology. In scheme C, the ethanol plant acquire power from a sugar mill on the premises, and biogas from UASB is used for electricity generation. In scheme D, the stand-alone ethanol plant utilizes both biogas and natural gas in combined heat and power system, while in scheme E, biogas and natural gas are used for steam production while electricity is acquired from external sources. In scheme F, a stand-alone ethanol plant uses biogas for electricity generation and purchases steam. The results indicate that the overall environmental cost of open lagoon is greater than that of UASB. Scheme C has the lowest environmental impacts and environmental cost. The payback period of scheme E is the shortest (2.19 years), and the ethanol production costs after payback period decrease by 3.11, 0.24, and 2.92 Thai baht per liter ethanol under schemes C, E, and F. Scheme C is the most environmentally and economically favorable scheme, given the highest AHP weighted score of 0.354. Since the country's ethanol production is expected to increase to 9 million liters per day by 2021, scheme C should be adopted to make use of molasses and mitigate the environmental impacts. (C) 2019 Elsevier Ltd. All rights reserved.
A comparison study on the energy recovery from single and two-stage anaerobic digestion of Agave tequilana bagasse hydrolysates is presented in this contribution. Firstly, the A. tequilana bagasse was acid or enzymatically hydrolyzed and then both hydrolysates were digested at different concentrations (20-100\% v/v) in batch reactors. Results showed that the two-stage anaerobic digestion outperformed the single-stage process. During the acidogenesis phase of the two-stage process, high hydrogen yields were reached with the enzymatic hydrolysate at a concentration of 40\% (3.4 mol H-2/mol hexose); whilst during methanogenic phase, the highest methane yield was obtained at a concentration of 20\% for both hydrolysates (0.24 L CH4/g COD). The overall energy recovery analysis demonstrated that the two-stage process outperformed 3.3 times the single-stage process when comparing the highest energy recoveries obtained in each process. This is the first study that reveals such enhancement for the anaerobic digestion of lignocellulosic hydrolysates. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Rice straw (RS) is a lignocellulosic biomass generated in huge amounts as agricultural wastes, facing improper disposal issues that can severely deteriorate the environment. This is the first study investigating the integration of sustainability, bio-energy, economic feasibility, and zero-waste from RS, meeting the sustainable development goals (SDGs). The RS feedstock was employed to recover dual biogas and biochar using a combined hydrodynamic cavitation (HC), anaerobic digestion (AD), and pyrolysis scheme. The effect of HC on disrupting the three-dimensional matrix of cellulose-hemicellulose-lignin was evidenced via XRD, FTIR, TGA, and SEM characterizations. The optimum HC condition was NaOH = 0.5 M, S/L = 3\%, and time = 60 min, giving xylan and lignin removal efficiencies of 47.69 +/- 2.56 and 65.02 +/- 3.30\%, respectively. In the subsequent AD process, the pre-treated RS attained methane productivity of 411 +/- 21 mL-CH4/g-VS, demonstrating an enhancement percentage of 118\% compared with the raw RS application. The AD digestate was pyrolyzed to prepare biochar, showing appropriate elemental composition to be further utilized as an effective soil amendment in farmlands. The dual biogas/biochar production from RS depicted a techno-economic feasibility scenario with a maximum net profit of 127.9 US\$/t. The beneficial products of the proposed scheme complied with several environmental, economic, and social related SDGs. Accordingly, the study findings would encourage stakeholders, policymakers, and public and private sectors to invest in the ``Biomass-to-bioenergy{''
It was found that Corynebacterium glutamicum Delta iolR devoid of the transcriptional regulator IolR accumulates high amounts of D-xylonate when cultivated in the presence of D-xylose. Detailed analyses of constructed deletion mutants revealed that the putative myo-inositol 2-dehydrogenase IolG also acts as D-xylose dehydrogenase and is mainly responsible for D-xylonate oxidation in this organism. Process development for D-xylonate production was initiated by cultivating C. glutamicum Delta iolR on defined D-xylose/D-glucose mixtures under batch and fed-batch conditions. The resulting yield matched the theoretical maximum of 1 mol mo1(-1) and high volumetric productivities of up to 4 g L-1 h(-1) could be achieved. Subsequently, a novel one-pot sequential hydrolysis and fermentation process based on optimized medium containing hydrolyzed sugarcane bagasse was developed. Cost-efficiency and abundance of second-generation substrates, good performance indicators, and enhanced market access using a non-recombinant strain open the perspective for a commercially viable bioprocess for Dxylonate production in the near future.
This study investigated the detoxification of dilute ammonia pretreated energy cane bagasse enzymatic hydrolysate using polyelectrolyte flocculants. Non-sugar compounds such as formic acid, acetic acid, levulinic acid, furfural, 5-hydroxymethylfurfural (HMF), and phenolic compounds can be generated during pretreatment, which have negative effects on downstream processes. Flocculation was carried out to remove these non-sugar compounds while retaining the fermentable sugars. The flocculants polyethylenimine (PEI) and poly-diallyldimethylammonium chloride (pDADMAC) were used and parameters including flocculant dose and hydrolysate pH were evaluated. The recyclability of PEI and recovery of non-sugar compounds were also assessed. Optimum conditions for both PEI and pDADMAC were 15 g/L dose at unadjusted pH 4.5. At these conditions, PEI outperformed pDADMAC by having greater adsorption efficiencies towards non-sugar compounds with minimal sugar losses. PEI removed 43\% organic acids, 73\% total phenolic compounds and 100\% furans with less than 10\% total fermentable sugar losses. However, after two cycles, only 20\% of the adsorbed organic acids and total phenolic compounds, and 80\% of the furans were recovered. Sugar losses of less than 10\% were observed throughout the recycling process. PEI can significantly remove the non-sugar compounds from dilute ammonia pretreated energy cane bagasse enzymatic hydrolysate with minimum sugar losses. However, recycling of PEI and recovery of adsorbed non-sugar compounds are not recommended for more than two cycles.
Utilizing renewable and locally available raw materials in flexible film production with modifications and re-inforcements is crucial in the fight against plastic pollution. This study investigates the use of sonicated guar gum for film production with reinforcement from cellulose nanofibers derived from sugarcane bagasse. Cellulose nanofibers were obtained with a yield of 46.6\% and a purity of 95\%, exhibiting a crystallinity of 75.64\% and thermal stability up to 323 degrees C. Films were prepared using sonicated guar gum under varying process conditions (time: 0-12.5 min, amplitude: 50,100\%), and the film with optimal properties was chosen for reinforcement with varying mass percentages of nanofibers. The film with 0.01 g of nanofiber reinforcement demonstrated signifi-cant improvements in tensile strength (23.04 MPa), elongation (39.19\%), ultimate modulus (134.94 MPa), and a reduction in water vapor permeability (1.76 x 10-10 gm/m2Pas). This film also showed exceptional resistance to oil permeation, making it a promising candidate for packaging oil-based foods.
Sugarcane (Saccharum officinarum L., Gramineae) bagasse and leaves were investigated for their flavonoid content and transgenic sugarcane ({''
Pre-emergent herbicides are applied directly in the soil or over the straw in no-till systems and can be retained, reducing the product's availability. The current study characterizes the retention of diclosulam and diuron in forage turnip (FT), buckwheat (BW), and black oat (BO) straws. Radiometric techniques evaluated the sorption-desorption and leaching processes. Spectroscopic and microscopic methods characterized chemical and morphological alterations in the straw. Sorption rates (Kf) of diclosulam and diuron followed the order BO > BW > FT. Irreversible sorption (hysteresis < 0.7) occurs to diclosulam applied to BO straw. The BO straw showed porous structures, indicating physical entrapment of the herbicides. Straw fragments (<1 mm) increased the sorption of herbicides. The increase in straw amount (2.5 to 5 t ha(-1)) reduced herbicide leaching to 18.8\%. Interactions between chemical groups (C-Cl, C-F, and C-N) from herbicides with straw characterize a chemical barrier. The present research suggests that entrapment and chemical interaction are involved in the sorption-desorption process of herbicides, such as diclosulam and diuron, in the straw matrix, directly interfering with their availability in the environment. This process can reduce the herbicide environmental risk but can decrease weed control efficiency.
The main task of the present work is to enhance the photocatalytic degradation efficiency of methylene blue (MB) by using CeO2/sugarcane bagasse (SCB) composite catalysts. Homogeneous precipitation method was used to synthesis CeO2-SCB composite catalysts by adding SCB powder to precursor solution of Ce base-metal. The structural analytical data indicated the pure cubic fluorite structure of CeO2. Morphological images revealed the coating of CeO2 layer on high surface area of SCB core-shell. The Chemical analysis presented spectrum of the Ce3d in CeO2/SCB sample existed in the form of the Ce3+ and Ce4+ mixed-valence states. Optical spectra showed the shift of absorption edge towards longer visible region upon supporting CeO2 with SCB. The main chemical composition of the SCB was K, Ca, and Si. Furthermore, recombination of the photogenerated electrons and holes was identified by photoluminescence techniques (PL), the data suggested inhibition of electron hole pairs recombination by the cations from SCB loaded in CeO2/SCB composite. Photocatalytic activity of CeO2/SCB catalyst was investigated via the degradation of MB under UV-A irradiation. Experimental kinetic data followed the pseudo-first order model. CeO2 supported with SCB adsorbent had higher photocatalytic activity in dye.wastewater treatment compared to the pure CeO2. The proposed mechanism explaining the high photo catalytic efficiency of CeO2/SCB was associated with high surface properties and the suppression of recombination of the photogenerated electron-hole pairs by the SCB adsorbent. (C) 2017 Elsevier B.V. All rights reserved.
A combined severity factor (R-CSF) which is usually used to evaluate the effectiveness of hydrothermal pretreatment at above 100 degrees C had been developed to assess the influence of temperature, time, and alkali loading on pretreatment and enzymatic hydrolysis of lignocellulose. It is not suitable for evaluating alkaline pretreatment effectiveness at lower than 100 degrees C. According to the reported deducing process, this study modified the expression of R-CSF = log{[
The objective of this study was to evaluate the effects of sugarcane tops (STs) and napiergrass (NG) silage on fermentative quality, nutritional value and milk yield in water buffaloes. Silage were prepared either conventionally without ST (C) or mixed with 25\% (S1), 50\% (S2), and 75\% (S3) ST based on fresh matter. Twenty-eight lactating buffaloes were divided into four groups with seven replicates and fed four experimental diets containing the corresponding silages. The S3 silage fermented well with a higher (P < 0.05) lactic acid content and lower (P < 0.05) pH and ammonia-N level than those of other mixed silage. Silage with increasing ST proportions showed a significant increase (P < 0.05) in the apparent digestibility of dry matter, crude protein, organic matter, and gross energy. As a result, water buffalo fed S3 silage increased dry matter intake (P < 0.05) and tended to have higher milk yield and feed efficiency as compared with the C group. Our study indicates that adding ST improves NG silage fermentation and enhances the nutrient digestibility and milk production in water buffaloes, and mixing ratio of 25\%NG and 75\%ST had the highest lactate fermentation quality and presented a high feed value.
Reforestation is considered an effective method to improve soil quality and drain atmospheric CO2 by sequestering carbon, in both soil and vegetation. In this regard, the aim of this study was to evaluate the effects of converting areas cultivated with sugarcane to eucalypt plantations (Eucalyptus spp.) on soil quality and carbon sequestration in a Latossolo (Ferralsol) in the Atlantic Forest region of the Alagoas state, Brazil, through multivariate analysis. The systems under evaluation consisted of four areas: one area cultivated with sugarcane for approximately 20 years, taken as the reference area of this study, and the other three adjacent areas cultivated with eucalypt at 1 (E1), 3 (E3) and 6 (E6) years of age, previously cultivated with sugarcane. Physical (bulk density - BD, Mean weight-diameter - MWD, geometric mean diameter - GMD and aggregate stability index - ASI), chemical (soil organic carbon - SOC, total nitrogen - TN, labile carbon - LC and recalcitrant carbon - RC) and biological (Microbial biomass carbon - MBC, soil carbon respiration - C-CO2 and metabolic quotient - qCO(2)) properties of soil were evaluated. Data were collected, standardized and submitted to exploratory analysis with principal components. The results show that SOC, LC, TN, GMD, MWD and ASI increased, while BD showed a reduction in E3 and E6 systems. The conversion of sugarcane cultivation with burning of straw and manual harvest into eucalypt plantations was efficient at promoting SOC sequestration and improving physical, chemical and biological properties of soil.
Anaerobically digested stillage (ADS) requires treatment before being discharged into water bodies or soils to avoid adverse effects. Phytofiltration systems are eco-friendly technologies for wastewater treatment, and they simultaneously serve as a source of biomass for biofuel production. The aim of the present study was to investigate the phytofiltration of ADS using Azolla sp. The effects of the ADS strength (dilutions 1:50 and 1:25 v/v) and initial biomass density (IBD) {[
This study explores the feasibility of an integrated system comprising adsorption and crystallization in a pellet reactor to remove and recover lead from aquatic environment. The selective adsorption of Pb2+ over Ca2+ and Mg2+ was investigated using citric acid modified sugarcane bagasse (SCA) in batch and column systems. Selective separation of Pb2+ from the mixed solution was achieved at a molar ratio 3.22 < C-o,batch(ca+)Mg/C-o,C-batch (pb) 4.49 in batch mode while in a packed bed column, lead was selectively adsorbed by SCA up to a capacity of 0.767 mmol/g with a bed height of 7 cm, a flow rate of 1.5 ml/min and an initial lead concentration of 0.482 mmol/L. The dynamic study shows a close agreement between the experimental results and the Thomas and Yoon-Nelson models. The desorption study of equilibrium biosorbent SCA in a column system demonstrates that sodium chloride is a promising desorption reagent, with a desorption capacity of 80\% Pb2+. In addition, synthetic lead wastewater with characteristics simulating the concentrate from desorption of saturated SCA was further treated in a fluidized bed denoted as pellet reactor. Lead (II) was quantitatively recovered at optimized conditions of pH 10, molar ratio{[
Laccases are very interesting biocatalysts of recognized importance for several industrial applications. Its production by Trametes versicolor, a white-rot fungus, was induced by a combination of cotton gin wastes (1\%), a lignocellulosic waste, and vinasse (15\%), an industrial by-product from sugarcane industry. The use of these agro-industrial wastes are interesting, since it helps in reducing the enzyme production costs, due to their low cost and wide availability, as well as the environmental contamination issues, due to their improper disposal. Thus, laccase production was studied in submerged fermentation of T. versicolor using these agro-industrial wastes (cotton gin waste and vinasse) as carbon source and an additional nitrogen source (0.1\% peptone). Three different bioreactors were evaluated for laccase production, such as BioFlo 310 bioreactor, aluminium tray and Erlenmeyer flasks to achieve high levels of laccase production. The highest specific production of laccase was found in BioFlo 310 bioreactor with 12 days of fermentation (55.24 U/mg prot.), which has been shown to be closely related to the oxygen supply to the microorganism through aeration of the fermentation medium. This study brings new insights into green biotechnology regarding vinasse utilization, which is frequently discharged in soils, rivers, and lakes causing adverse effects on agricultural soils and biota, as well as the cotton gin waste recovery.
The objective of this work was to adequate artificial diets for the development of larva and adult stages of South-American fruit fly (Anastrepha fraterculus). For the larval stage, the following diets were tested: D1, original diet, with 10 g agar; D2, modified diet, with 3.6 g agar; and D3, modified diet, with dry sugarcane bagasse. For adults, four diets were tested: A, brewers' yeast + honey (2:1); B, refined sugar + yeast extract + crude wheat germ (3:1:1); C, soybean extract + brown sugar + crude wheat germ (3:1:1); and D, brewers' dried yeast + honey (2:1). The evaluated biological parameters were: duration of the egg-pupa period, duration and feasibility of the pupa stage, average mass of pupae, sexual ratio, and duration and feasibility of the egg-adult period. Larval stage development for D1 and D2 was similar, and indicated that the larval rearing can be managed with 1/3 agar quantity used in D1. The dry sugarcane bagasse, used in the artificial diet, negatively affected the larval development. Artificial diets with brewers' yeast + honey and with refined sugar + yeast extract + crude wheat germ are the most adequate ones for adult rearing.
The enzymatic hydrolysis of steam-exploded sugarcane bagasse (SESB) was investigated using enzymatic extracts (EE) and whole fermentation media (WM), produced in-house, from Aspergillus niger 3T5B8 and Trichoderma reesei Rut-C30 cultivated on wheat bran under solid-state fermentation (SSF). A detailed and quantitative comparison of the different hydrolysis conditions tested was carried out using the Chrastil approach for modeling enzymatic reactions by fitting the experimental data of total reducing sugar (TRS) released according to hydrolysis time. Conversion of SESB using A. niger enzymatic complex were up to 3.2-fold higher (in terms of TRS) than T. reesei at similar enzyme loadings, which could be correlated to the higher -glucosidase levels (up to 35-fold higher) of A. niger enzymatic complex. Conversion yields after 72 h exceeded 40\% in terms of TRS when the WM was supplemented with a low dosage of a commercial enzyme preparation. When the combination of WM (from either T. reesei or A. niger) and commercial cellulase was used, the dosage of the commercial enzyme could be reduced by half, while still providing a hydrolysis that was up to 36\% more efficient. Furthermore, SESB hydrolysis using either EE or WM resulted in similar yields, indicating that the enzyme extraction/filtration steps could be eliminated from the overall process. This procedure is highly advantageous in terms of reduced enzyme and process costs, and also avoids the generation of unnecessary effluent streams. Thus, the enzymatic conversion of SESB using the WM from SSF is cost-effective and compatible with the biorefinery concept. (c) 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1430-1440, 2013
A pot trial was conducted in order to relate the increase in the cation exchange capacity (CEC) of an acid soil (Quartspsament) to the CEC of several organic materials which were added to it. Peat, sugarcane bagasse and filter cake from sugar industry, worm compost, poultry and cattle manure, compost, and papermill sludge were incubated in natural and limed soil under controlled soil water content. Soil CEC was measured at soil pH after 30 and 90 days of incubation and results were strongly affected by pH of the incubated soil. About 32\% of the soil CEC would be predicted by the CEC of the organic material measured at pH 7.0. This proportion increased to 78\% when soil pH was included in the regression.
The gradual change in management practices in sugarcane (Saccharum spp.) production from burning straw to a green harvesting system, as well as the use of minimum soil tillage during field renovation, may affect soil fertility and soil organic matter (SOM) contents. The objectives of this work were to investigate the influence of sugar cane production systems on: (1) soil fertility parameters; (2) on physical carbon fractions; (3) and on humic substance fractions, in a long-term experiment, comparing two soil tillage and two residue management systems an Xanthic Udult, in the coastal tableland region of Espirito Santo State, Brazil. The treatments consisted of plots (conventional tillage (CT) or minimum tillage (MT)) and subplots (residue burned or unburned at harvesting), with five replicates The highest values of Ca2+ + Mg2+ and total organic carbon (TOC) were observed in the MT system in all soil layers, while high values of K+ were observed in the 0.1-0.2 m layer. The CT associated with the burned residue management negatively influenced the TOC values, especially in the 0.1-0.2 and 0.2-0.4 m layers. The carbon in the humin fraction and organic matter associated with minerals were significantly different among the tillage systems; the MT showed higher values than the CT. However, there were no significant differences between the sugarcane residue management treatments. Overall, fractioning the SOM allowed for a better understanding of tillage and residue management systems effects on the soil properties.
BACKGROUND: This work is focused on inulinase production by solid-sate fermentation (SSF) using sugarcane bagasse, corn steep liquor (CSL), pre-treated cane molasses, and soybean bran as substrates in a 3-kg (dry basis) packed-bed bioreactor. SSF was carried out by the yeast Kluyveromyces marxianus NRRL Y-7571 and response surface methodology was used to optimize the temperature, air flow rate and initial mass of cells. RESULTS: The optimum inulinase activity (436.7 +/- 36.3 U g(-1) dry substrate) was obtained at 24 h at an inlet air temperature of 30 degrees C, air flow rate 2.2 m(3) h(-1) and 22 g of cells for fermentation. Inulinase productivity at these conditions was 18.2 U gds(-1) h(-1). Kinetic evaluation at the optimized conditions showed that the maximum inulinase production was verified at 24 h of fermentation. The carbon dioxide and the metabolic heat generation are directly associated with the consumption of total reducing sugars present in the medium. CONCLUSION: The high productivity achieved in this work shows the technical viability of inulinase production by SSF in a packed-bed bioreactor. (C) 2009 Society of Chemical Industry
This study investigates the potential of bioethanol production and fossil fuel substitution using sugarcane feedstock in Indonesia. Current production practices, government biofuel policies (esp. mandatory blending targets), and sugar self-sufficiency are simulated to project the total potential of fuel ethanol and land requirements in the timeframe between 2015 and 2025. At present conditions, 450 million liters bioethanol can be annually produced in Indonesia using sugarcane molasses, a low-value co-product. This gives only a marginal contribution equivalent to 1\% of the total gasoline consumption in 2015. The study examines the ethanol production potential after domestic sugar self-sufficiency is achieved by 2020. In 2015, 0.71 Mha land were required for sugarcane cultivation in order to meet a 2\% blend mandate i.e. 0.68 billion liters (BL) ethanol using only cane-molasses. Juice ethanol is needed to meet the blending targets set for 2020 (i.e., 4.45 BL ethanol) and 2025 (i.e., 11.48 BL ethanol). This translates into sugarcane feedstock obtained from 1.60 Mha to 2.76 Mha land, respectively. The study also evaluates how improved resource efficiency can be achieved, exploring the bioelectricity production potential from sugarcane biomass, improvements in yields, and modernization of sugarcane mills. The results highlight how the use of established technologies and production methods can help develop agro-industries in the sugar ethanol segment of Indonesia. (C) 2016 Elsevier Ltd. All rights reserved.
Rapid, efficient, and low-cost technologies for monitoring the fermentation process during second generation (2G) or cellulosic ethanol production are essential for the successful implementation of this process at the commercial scale. Here, the use of near-infrared (NIR) spectroscopy associated with partial least squares (PLS) regression was investigated as a tool for monitoring the production of 2G ethanol from lignocellulosic sugarcane residues including bagasse, straw, and tops. The spectral data was based on a set of 103 alcoholic fermentation samples. Models based on different pre-processing techniques were evaluated. The best root mean square error of prediction (RMSEP) values obtained in the external validation were around 3.02 g/L for ethanol and 6.60 g/L for glucose. The findings showed that the PLS-NIR methodology was efficient in accurately predicting the glucose and ethanol concentrations during the production of 2G ethanol, demonstrating potential for use in monitoring and control of large-scale industrial processes. (C) 2015 Elsevier Ltd. All rights reserved.
Cellulose isolation, a promising way for lignocellulosic biomass utilization, is always restricted by the poor solubility of cellulose. In this paper, tetra-n-methylammonium hydroxide (TMAH) was confirmed to be capable of readily dissolving/regenerating cellulose without chemical modification at room temperature. Meanwhile, cellulose isolation from lignocellulosic biomass by initially dissolving the biomass in TMAH followed by cellulose precipitation was proposed, and the isolated substance with average cellulose purity of 92.1 +/- 0.3\% could be obtained throughout this process under the optimum conditions: temperature 52 C, time 60 min, and loading ratio of TMAH/biomass (w/w) 7.2:1. Besides, high efficiency cellulose isolation (i.e. >70\% cellulose purity) could be continuously remained during 4-round cycles by using the recycled TMAH solvent without distinct activity loss. (C) 2015 Elsevier Ltd. All rights reserved.
The composition of lignocellulosic materials used as enzyme inducers have different effects on enzyme production by fungal cultures. This work reports a comparative study of different cultivation systems for the production of xylanase and beta-glucosidase by the fungus Aspergillus fumigatus SCB4 during solid-state fermentation (SSF), using sugarcane bagasse (SCB) or commercial substrates (Kraft pulp and Avicel). SCB was submitted to chemical pretreatments with H2O2, NaOH and ethanol (organosolv) and pretreated SCB samples were subsequently employed for the synthesis of enzymes. Pretreatments were efficient in the lignin reduction. Among them, the alkaline pretreatment was the most efficient with a reduction of 81.9\% of lignin content in NaOH pretreated SCB in comparison to untreated SCB. In NaOH-alkali-pretreated SCB, the fibers structure were also more efficiently altered with disrupted arranges and increased porosity. Despite the structural advantages obtained after pretreatments, the enzymatic biosynthesis was favored in cultivations using untreated SCB and commercial substrates as carbon sources. For beta-glucosidase, it was noted a peak of production of 30.52 U/g after 96 h of SSF using untreated SCB as substrate. For xylanase, the maximum activity was detected using Kraft pulp (1878.76 U/g of substrate) after 120 h of SSF, probably due to the high concentration of hemicelluloses (19.52\%) and low quantity of lignin (1.3\%) in this material. Fermentations with untreated SCB also showed high xylanase activities (1647.20 U/g after the same period of incubation). This minor enzymatic biosynthesis after SSF using pretreated SCB might be due to the presence of some inhibitors produced after pretreatrnents which could be restricting fungal growth and consequently, the production of enzymes. (C) 2016 Elsevier B.V. All rights reserved.
Agricultural wastes have attractive potential as alternate energy sources. However, a major bottleneck is to identify eco-friendly treatment methodologies to utilize them. The large diversity of unexplored, novel, and potential microorganisms hold great promise and require periodic isolation and characterization of microorganisms for bioprospection. In this study, approximately 100 fungal isolates were tested for their lignocellulolytic enzyme activities, based on plate assay, followed by quantification of enzyme activity. From this, M2E (Inonotus tropicalis) and 2a (Cerrena unicolor) showed good growth and proficient ligninolytic activity; isolates GK1 (Chaetomium globosum) and GK2 (Chaetomium brasiliense) exhibited exceptional cellulolytic activity on lignocellulosic substrates such as rice straw and sugarcane bagasse. Consortia of the potential ligninolytic and cellulolytic isolates were set up to determine their ability to biodegrade the lignocellulosic substrates such as rice straw and sugarcane bagasse. The efficiency of the consortia was determined on the basis of the increase in enzyme activity; it was also evident through scanning electron microscopy, x-ray diffraction analysis of the degraded substrates, and the sugar yield. Experiments were also carried out to compare the biological with the physical pretreatment methods. The consortium of ligninolytic and cellulolytic marine-derived fungi developed in this study prove to have the potential for application in the effective utilization of agricultural wastes.
Two sugar mills in Nicaragua plan to generate electricity from bagasse during the sugarcane season and eucalyptus during the rest of the year, and to sell it to the national grid. This study compared this concept with the most logical alternative at the moment, which is electricity generated from fuel oil. Costs, macro-economic impacts and environmental emissions are considered. The low cost of land and labour means that eucalyptus can be produced more cheaply than fuel oil (1.7 as compared to 3.2 \$/GJ(LHV)). Consequently, it was calculated that a sugar mill can produce electricity from biomass for 4.9 cent /kWh as compared to 5.8 cent /kWh for electricity from an oil fired plant. About 64\% of the money spent on biomass power stays within Nicaragua, thus contributing to its GDP, whereas in the case of fuel oil 83\% goes abroad. The employment generated by the production of electricity from fuel oil is 15 person.yr/MW.yr, compared to 32 person.yr/MW.yr for biomass. Comparing biomass with fuel oil, emissions of CO2 and SO2 equivalents are, respectively, 67 and 18 times lower. Particulate emissions can be much higher in the biomass case because of lack of flue gas cleaning. We can conclude that biomass electricity generation by sugar mills in Nicaragua can compete with power generation from fuel oil. Moreover, it has an overall better environmental performance, creates double the amount of jobs, and contributes about four times as much to the GDP of Nicaragua, (C) 2000 Elsevier Science Ltd. All rights reserved.
The objective of the work was to study the effect of agri-residue solid contents (2-20\% w v(-1)) in fermentation medium on fungal growth, soluble and insoluble nutrient consumption and laccase production. Fungal strain Ganoderma lucidium and wheat straw substrate was screened for maximum laccase production. At low solid content submerged fermentation (SmF), fungus utilized mainly soluble nutrient and was unable to access the insoluble nutrient in media due to lack of contact with solid. At high solid content solid-state fermentation (SF), fungi grew on solid surface with dense and thin hyphae, utilized mainly insoluble nutrient. At medium solid content (8\% w v(-1)) semi-solid fermentation (sSF), fungi grew on solid substrates with network of thick intercrossed hyphae, utilized both soluble and insoluble nutrients optimally resulting in highest fungal growth and laccase activity (similar to 3.5 folds than in SmF and similar to 2.5 folds than in SF). Importance of soluble and insoluble nutrients was also established after isolation of their individual effects. Morphology of fungal growth (SEM), composition, thermal analysis (TGA/DTG) of substrates confirmed the results. sSF showed potential for the production of enzymes through utilization of agricultural residues as substrate.
Rice straw is an agricultural residue rich in cellulose and hemicelluloses. Therefore, the objective of this study was to obtain fermentable sugars and bioproducts from this biomass by subcritical water hydrolysis (SWH) in a scaleable semi-continuous mode. Temperatures of 180 degrees C, 220 degrees C and 260 degrees C, and liquid/solid mass ratios of 7.5 g water/g straw and 15 g water/g straw were evaluated on the reducing sugar yield (Y-RS), efficiency of conversion (E), kinetic profiles, composition of inhibitors and bioproducts, and physicochemical characteristics of remaining solid material. The pressure was set at 25 MPa and the reaction time was evaluated up to 15 min. The thermogravimetric analysis and Fourier Transform Infrared Spectroscopy provided additional information on the bulk and surface modification of the residual biomass. The highest YRS (33.4 +/- 4.3 g/100 g dry straw) and E (72.1 +/- 4.6 g sugar equivalents in glucose per 100 g of carbohydrates) were obtained at 220 degrees C and liquid/solid mass ratio of 7.5 g water/g straw. The analysis of the hydrolyzed solution indicated xylose (0.29-7.81 wt.\%), arabinose (0.35 -4.85 wt.\%), cellobiose (0.04-3.41 wt.\%), glucose (0.05-1.54 wt.\%), and levulinic acid (0.04-0.77 wt.\%). The fermentable sugars and bioproducts can be applied in several industrial fields, especially for the production of bioethanol and other higher value-added chemical compounds. Furthermore, SWH performed in semi-continuous mode is a green technology within the biorefinery concept that can be operated at industrial scale for processing lignocellulosic biomass. (C) 2018 Elsevier Ltd. All rights reserved.
In situ fibrous bed bioreactor (isFBB) for efficient succinic acid (SA) production by Yarrowia lipolytica was firstly developed in our former study. In this study, agricultural residues including wheat straw, corn stalk and sugarcane bagasse were investigated for the improvement of isFBB, and sugarcane bagasse was demonstrated to be the best immobilization material. With crude glycerol as the sole carbon source, optimization for isFBB batch fermentation was carried out. Under the optimal conditions of 20 g sugarcane bagasse as immobilization material, 120 g L-1 crude glycerol as carbon source and 4 L min(-1) of aeration rate, the resultant SA concentration was 53.6 g L-1 with an average productivity of 1.45 g L-1 h(-1) and a SA yield of 0.45 g g(-1). By feeding crude glycerol, SA titer up to 209.7 g L-1 was obtained from fed batch fermentation, which was the highest value that ever reported.
Biodegradable foams made from cassava starch, polyvinyl alcohol (PVA), sugarcane bagasse fibers and chitosan were obtained by extrusion. The composites were prepared with formulations determined by a constrained ternary mixtures experimental design, using as variables: (X-1) starch / PVA (100 - 70\%), (X-2) chitosan (0 - 2\%) and (X-3) fibers from sugar cane (0 - 28\%). The effects of varying proportions of these three components on foam properties were studied, as well the relationship between their properties and foam microstructure. The addition of starch/PVA in high proportions increased the expansion index and mechanical resistance of studied foams. Fibers addition improved the expansion and mechanical properties of the foams. There was a trend of red and yellow colors when the composites were produced with the highest proportions of fibers and chitosan, respectively. All the formulations were resistant to moisture content increase until 75\% relative humidity of storage.
In the present study, effect of adsorbent dose, pH and agitation speed on nickel removal from aqueous medium using an agricultural waste biomass, Sugarcane bagasse has been investigated. Batch mode experiments were carried out to assess the adsorption equilibrium. The influence of three parameters on the removal of nickel was also examined using a response surface methodological approach. The central composite face-centered experimental design in response surface methodology (RSM) by Design Expert Version 6.0.10 (Stat Ease, USA) was used for designing the experiments as well as for full response surface estimation. The optimum conditions for maximum removal of nickel from an aqueous solution of 50 mg/L were as follows: adsorbent dose (1500 mg/L), pH (7.52) and stirring speed (150 rpm). This was evidenced by the higher value of coefficient of determination (r(2) = 0.9873). (C) 2007 Elsevier Ltd. All rights reserved.
For producing second-generation ethanol (cellulosic ethanol) and other value-added bioproducts, magnetic graphene oxide (GO-MNP) was synthesized in this work and used as the immobilization support for an industrial cellulase-and xylanase-containing preparation. GO-MNP characterization by TEM, SEM and ATR-FTIR spectroscopy showed that the magnetic nanoparticles are homogeneously distributed onto the GO sheets surface. The enzymatic preparation was immobilized by means of carbodiimide cross-linking chemistry using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (NHS). The supported final biocatalyst (GO-MNP-Enz) showed high activity for the hydrolysis of pretreated sugarcane bagasse (PSB) and presented relative endoglucanase, xylanase, beta-glucosidase, and beta-xylosidase activities of 70\%, 66\%, 88\%, and 70\%, respectively, after 10 cycles of hydrolysis of their respective substrates. The biocatalyst also maintained approximately 50\% and 80\% of its efficiency for cellulose and xylan hydrolysis, respectively, being the TOF (g.g(-1).h(-1)) the highest observed when compared with previous results reported in literature. These findings suggest that GO-MNP-Enz may be a prospective candidate for industrial applications such as second-generation ethanol production. (C) 2020 Elsevier Ltd. All rights reserved.
Fish silage is a liquefied product resulting from tissue hydrolysis and the richness of the silage is characterized by its nutritional profile comprising of proteins, amino acids, and fats. For the production of fish silage of high nutritional value, a precise assessment of the degree of hydrolysis, particularly proteolysis becomes a paramount importance. The goal of this study is to assess the changes in protein content in fish silage prepared from the Indian mackerel (Rastrelliger kanagurta) waste using 10\% (v/w) sugarcane molasses, during 8 days of fermentation (DoF). The resultant ensiled product was evaluated for changes in titratable acidity, nutrients, total protein, total carbohydrate, total lipids content, and amino acid composition. Altogether, 17 types of amino acids were identified. Concentrations of total amino acids (TAAs, 15.627 +/- 0.03 mg/g) and free amino acids (5.556 +/- 0.08 mg/g) peaked at the end of 6 DoF with the predominance of histidine, arginine, alanine, asparagine, aspartic acid, and glutamic acid. Results of the non-metric multidimensional scaling (nMDS) plots and oneway analysis of similarities (ANOSIM) test indicated significant differences in the composition of TAAs at different DoF were discernible (nMDS, stress 0.03162, one-way ANOSIM R = 1; p < 0.0001). Similarity percentage ( SIMPER) analysis indicated that the maximum content of amino acids (TAA and FAA) were released in silage during 4-6 DoF. A significant difference was observed in concentrations of most amino acids except cysteine, serine, and tryptophan (ANOVA, p < 0.05) at 2, 4, 6 and 8 DoF. Considering the vital role played by amino acids in providing resistance to plant pathogens as well as contributing to animal nutritional supplements, the results of the present study are highly noteworthy.
The need to diversify energy sources and to change from the present non-renewable hydrocarbon sources to renewable energy sources has prompted huge investments in research activities to produce bioethanol from carbohydrate-rich foodstuffs such as cassava tuber, sugarcane molasses, yam tubers, rice grains, corn grains, and a host of others. In recent times, however, more attention has been given to producing bioethanol from the non-edible parts of carbohydrate-rich foodstuffs, which are obtained mainly as waste products from food-crop processing. Such non-edible components include peels, bagasse, straw, stalk, and cobs. The most important component of the biomass is lignocellulose, which is broken down into carbohydrates and then fermented. The major challenge in deploying biomass as feedstock for bioethanol production is the fact that lignocellulosic biomass is highly recalcitrant and therefore requires more vigorous pretreatment prior to saccharification and fermentation. The main techniques used for pretreating lignocellulosic materials are physical and thermal as well as chemical and biological methods. In Nigeria, lignocellulosic bioethanol production potential from agricultural residues amounts to about 7.556 x 10(9) L per annum with more than 62\% generated from process residues. Cassava biomass alone can produce more than 114 L of bioethanol for every ton of cassava peels after processing. Nigeria has more than enough agricultural residues for bioethanol production to meet its sustainable bioethanol-blending demands. (c) 2018 Society of Chemical Industry and John Wiley \& Sons, Ltd.
The objective of this work was to evaluate the solubilization of phosphorus from a phosphate rock by Aspergillus niger, under solid-state cultivation (SSC) in sugarcane (Saccharum officinarum) bagasse, by maximizing the efficiency of citric acid production. The phosphate rock (IPR) chosen for the study is a type of igneous rock with a very low phosphorus solubility, obtained from the Itafos company, in Arraias, in the state of Tocantins, Brazil. The rotatable central composite design (RCCD) was used as a statistical tool to evaluate the effect of the concentrations of the carbon source (sucrose) and of the IPR on the SSC medium as a strategy to improve P solubilization. In the process without the IPR, there was a citric acid production of up to 300 g per kilogram of substrate. The experiments in the RCCD showed that the addition of the IPR affected citric acid production, with values of solubilized P ranging from 1.44 to 2.72 g per kilogram of substrate and of solubilized P yield from 12.96 to 48.94\%. The analysis of the solubilized P/sucrose ratio showed favorable conditions for P solubilization and citric acid production. The obtained solubilized P values are promising considering that the IPR has a very low solubilization, with only 8.6\% P2O5. Overall, these findings could contribute to the development of biotechnological processes for producing eco-friendly phosphate fertilizers, as an alternative for a more sustainable agriculture.
This study investigated the effectiveness of sugarcane bagasse biochar (SBB) in reducing the toxicity of heavy metals (HMs) in Cd-contaminated calcareous clay soil and improving the growth of rice (Oryza sativa L.). A pot experiment with a randomized complete block design (RCBD) was used to examine the adsorption kinetics and growth improvement of rice. Three Cd levels (0.0, 30.0, and 60.0 mg kg(-1) of soil from CdSO4. 8H(2)O) and three SBB levels (0.0, 3.0, and 6.0\% by weight) were considered. The study found that the biochar's surface contains functional groups that aid in the immobilization of Cd in contaminated soil. The Langmuir model best fit the Cd adsorption data of all studied soils, predicting the highest adsorption capacity with an R-2 value of 0.9902 for the adsorption of Cd onto soil-SBB 6\%. Single application of SBB at a 6\% level significantly increased rice grain and biomass by 45.41 and 57.82\%, respectively, in soils containing 30 and 60 mgkg(-1) soil Cd, compared to single soil Cd treatments. Addition of SBB at a 6\% level also significantly reduced the amounts of Cd extracted using DTPA by 53.37 and 45.14\%, respectively, and absorption of Cd by 67.00 and 52.14\% in soils containing 30 and 60 mgkg(-1) Cd. The results suggest that incorporating SBB into soil is a suitable remedial method for promoting plant growth in Cd-contaminated soils.
The aim of this study is to optimize Organosolv pretreatment parameters for efficient lignin removal and polysaccharide release using response surface methodology based on central composite design. Organosolv pretreatment conditions (60-100 degrees C, 10-50 min and 50-90\% acid concentration) were tested for maximum cellulose release and lignin solubilization and minimum hemicellulose decomposition. The optimum Organosolv pretreatment condition was achieved at an acid concentration of 69.85\%, pretreatment time 29.68 min and pretreatment temperature of 75.41 degrees C. At optimal condition, 73.17\% of lignin and 46.62\% hemicellulose were solubilized, and 74.09\% of cellulose was released. The high R squared and adjusted R squared values of 0.9801 and 0.9622 for lignin removal, 0.9831 and 0.9695 for cellulose released and 0.9851 and 0.9717 for hemicellulose solubilization shows that the quadratic models are adequate and the experimental data adequately fitted to the design model. Moreover, all the process parameters: temperature, time and concentration have a significant impact on the responses (disruption or depolymerization of rice straw biomass) where time had a very strong effect on the rice straw components (cellulose, lignin, and hemicellulose). The study demonstrated that the potential of the combination of Organosolv pretreatment and Bacillus sp. BMP01 hydrolysis of rice straw for enhancing sugar and ethanol yields. (C) 2019 Elsevier Ltd. All rights reserved.
For suitable design of equipment and process optimization, the determination of thermophysical properties of the raw materials is necessary. Therefore, this work was aimed at determining and modeling the density, specific heat, thermal diffusivity, and thermal conductivity of acid slurries of cassava bagasse used during its conversion into bioethanol. Experimental measurements were carried out in slurries with different mass fractions of cassava bagasse (0.00 to 0.10) and phosphoric acid (0.00 to 0.10) at temperatures from 278.13 to 318.13 K. Results obtained show that density varied from 986.5 to 1,029.3 kg center dot m(-3), specific heat from 3,830.0 to 4,142.6 J center dot kg(-1)center dot K-1, thermal diffusivity from 0.9624 x 10(-7) to 1.5249 x 10(-7) m(2)center dot s(-1) and thermal conductivity from 0.3825 to 0.6212 W center dot m(-1)center dot K-1. While density increased with increasing solids and acid content at decreasing temperature, the thermal properties decreased at higher solids and acid content and increased when heating the slurries. The values were well-fitted to polynomial models with good accuracy (R-2 > 0.921 and MRE < 1.75\%), allowing the application of the models to obtain reliable and ready-to-use data for cassava bagasse processing. Thus, the data reported in this study can be used for designing and managing momentum, heat and mass transfer processes for enhancing bioethanol production from cassava bagasse.
The objectives of the study were to assess genome wide association study (GWAS) for sugarcane on a panel of 183 accessions and to evaluate the impact of population structure and family relatedness on QTL detection. The panel was genotyped with 3327 AFLP, DArT and SSR markers and phenotyped for 13 traits related to agro-morphology, sugar yield, bagasse content and disease resistances. Marker-trait associations were detected using (i) general linear models that took population structure into account with either a Q matrix from STRUCTURE software or principal components from a principal component analysis added as covariates, and (ii) mixed linear models that took into account both population structure and family relatedness estimated using a similarity matrix K{*
Low-cost Ionic Liquid (IL) is a promising method for the lignocellulosic biomass pretreatment to produce bioethanol. This study investigates utilizing low-cost IL, {[
Dewaxing effects on the pretreatment, saccharification and fermentation are rarely reported due to the low abundance of wax in lignocellulose. This study aimed to investigate the effect of wax removal on saccharification and ethanol yield from lignocellulose by using Rice straw (RS), Napier grass (NG), and sugarcane bagasse (SB). The wax contents of 0.56\%, 1.7\%, and 0.6\% were obtained from RS, NG and SB after the wax extraction, respectively. The alkaline pretreatment was applied in combination with dewaxing to decipher the synergistic effect of these treatments. Dewaxing and alkaline pretreatment of lignocellulosic biomass showed changes in the plant compositions. Removal of wax from RS, NG and SB showed significant changes in the surface morphology and functional groups. A higher yield of sugars and ethanol was observed in dewaxed and alkaline pretreated samples. The ethanol yields of 75.4\%, 89.85\%, and 74\% from RS, NG, and SB were obtained after fermentation, respectively.
The present study deals with the issue of bio-briquette fuel produced from specific agriculture residues, namely bamboo fiber (BF) and sugarcane skin (SCS). Both materials originated from Thua Thien Hue province in central Vietnam and were subjected to analysis of their suitability for such a purpose. A densification process using a high-pressure briquetting press proved its practicability for producing bio-briquette fuel. Analysis of fuel parameters exhibited a satisfactory level of all measured quality indicators: ash content A(c) (BF-1.16\%, SCS-8.62\%) and net calorific value NCV (BF-16.92 MJ.kg(-1), SCS-17.23 MJ.kg(-1)). Equally, mechanical quality indicators also proved satisfactory; bio-briquette samples' mechanical durability DU occurred at an extremely high level (BF-97.80\%, SCS-97.70\%), as did their bulk density (BF-986.37 kg.m(-3), SCS-1067.08 kg.m(-3)). Overall evaluation of all observed results and factors influencing the investigated issue proved that both waste biomass materials, bamboo fiber and sugarcane skin, represent suitable feedstock materials for bio-briquette fuel production, and produced bio-briquette samples can be used as high-quality fuels.
The dissolution of lignocellulosic materials based on ionic liquid (IL) pretreatment represents a promising technology for bioethanol production. In this study, sugarcane bagasse was submitted to pretreatment with 1-ethyl-3-methylimidazolium acetate ({[
There is tremendous interest in using agro-industrial wastes, such as cellulignin, as starting materials for the production of fuels and chemicals. Cellulignin are the solids, which result from the acid hydrolysis of the sugar-cane bagasse. The objective of this work was to optimize the enzymatic hydrolysis of the cellulose fraction of cellulignin, and to study its fermentation to ethanol using Saccharomyces cerevisiae. Cellulose conversion was optimized using response surface methods with pH, enzyme loading, solid percentage, and temperature as factor variables. The optimum conditions that maximized the conversion of cellulose to glucose, calculated from the initial dried weight of pretreated cellulignin, (43 degrees C, 2\%, and 24.4 FPU/g of pretreated cellulignin) such as the glucose concentration (47 degrees C, 10\%, and 25.6 FPU/g of pretreated cellulignin) were found. The desirability function was used to find conditions that optimize both, conversion to glucose and glucose concentration (47 degrees C, 10\%, and 25.9 FPU/g of pretreated cellulignin). The resulting enzymatic hydrolyzate was fermented yielding a final ethanol concentration of 30.0 g/L, in only 10 h, and reaching a volumetric productivity of 3.0 g/L.h, which is close to the values obtained in the conventional ethanol fermentation of sugar cane Juice (5.0-8.0 g/L.h) in Brazil.
The objective of this study was to evaluate the effects of hydraulic retention time (HRT) (8 -1 h) on H-2 production from sugarcane juice (5000 mg COD L-1) in mesophilic (30 degrees C, AFBR-30) and thermophilic (55 degrees C, AFBR-55) anaerobic fluidized bed reactors (AFBRs). At HRTs of 8 and 1 h in AFBR-30, the H-2 production rates were 60 and 116 mL H-2 h(-1) L-1, the hydrogen yields were 0.60 and 0.10 mol H-2 mol(-1) hexose, and the highest bacterial diversities were 2.47 and 2.34, respectively. In AFBR-55, the decrease in the HRT from 8 to 1 h increased the hydrogen production rate to 501 mL H-2 h(-1) L-1 at the HRT of 1 h. The maximum hydrogen yield of 1.52 mol H-2 mol(-1) hexose was observed at the HRT of 2 h and was associated with the lowest bacterial diversity (0.92) and highest bacterial dominance (0.52). (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Purpose Furfural is a furanic aldehyde obtained from the acid treatment of pentoses found in lignocellulosic material. It has excellent physical and chemical properties that allow its application in the generation of fertilizers, antacids, plastics, paints, fungicides, among many others, besides having important derivatives for the chemical industry, such as furfuryl alcohol and tetrahydrofuran. The production potential of this compound in Brazil is enormous as the country is the world's largest producer of sugarcane, and the surplus bagasse of this activity is a source of lignocellulosic biomass. Methods This work experimentally optimized two routes for furfural production: (1) from sugarcane biomass and (2) from the hemicellulosic hydrolysate. Additionally, techno-economic analyses of the optimal sceneries were developed. Results For the simulation, an initial flow of 71 tonne h(-1) of sugarcane biomass was used: case 1 produced 3.93 tonne h(-1) of furfural with a heating demand of 44.7 MJ kg(-1) (688.7 kW tonne(-1) of feed); case 2 produced 2.96 tonne h(-1) of furfural with a heating demand of 106.3 MJ kg(-1) (1230.3 kW tonne(-1) of feed). An economic evaluation of two cases resulted in revenues of U\$ 50 million and U\$ 31 million for cases 1 and 2, respectively. Furthermore, the internal rate of return (IRR, \%) for both cases (72 and 56\%, respectively) was greater than the rate of return (ROR = 15\%), indicating that the investment will earn profits. Conclusion Likewise, the integration of furfural production to the first and second-generation (1G and 2G) ethanol production chain could sustain the process, favoring the full use of biomass generating higher value-added bioproducts. {[
Aims: To investigate the effect of pH regulation and nutrient concentration on cephalosporin C (CPC) production in solid-state fermentation (SSF), using sugarcane bagasse as inert support, impregnated with liquid medium. Methods and Results: Solid-state fermentation using different initial pH values, buffer and nutrient concentrations were performed. Results revealed pH as a key parameter in CPC SSF, as it hampered the antibiotic production not only above 7.8, but also under 6.4. Using initial pH lower than 6.8 and PB in the solid medium, it was possible to keep pH within the production range, increase the production period (from 1 to 3 days) and hence the CPC yield from 468 to 3200 mu g gdm(-1) (g(-1) of dry matter). Conclusion: Parameters that help to keep pH in adequate values for CPC production in SSF, such as initial pH, buffering system and nutrient concentration, can greatly increase the production time and CPC yields in this fermentation technique. Significance and Impact of the Study: This is the first work on CPC production on impregnated support, and the only one revealing pH as a key parameter; it is also shown that high nutrient concentration can improve CPC yields in SSF as long as pH is kept under control.
Sugar bagasse was converted into an anion-exchanger through grafting acrylamide using (NH4)2Fe(SO4)2/H2O2 as initiator in an aqueous system, followed by reacting with ethylenediamine and hydrochloric acid. The effects of the grafting conditions such as monomer concentration, temperature, reaction time on the degree of grafting were investigated. The ion exchange capacity of the sugar bagasse base anion-exchange fiber (SB-IEF) was up to 3.70 mmol/g. Application of the SB-IEF in sugar decolorization was evaluated. Compared with commercial strong basic anion exchange resin (AIER) and strong basic anion exchange fiber (AIEF), SB-IEF showed the highest static decolorization capacity for sugar colorants (decolorization degree 71.40\%), followed by AIEF (decolorization degree 68.74\%) and AIER (decolorization degree 31.40\%) at the same operating conditions. The dynamic decolorization results indicated that SB-IEF showed larger processing volume than AIER and AIEF. SB-IEF with higher grafting degree would have a higher decolorization degree. When 200 mL 2\% brown granulated sugar solution was treated with 1 g SB-IEF (grafting degree 82\%), 80\% decolorization degree could be achieved. The research results may provide a recyclable route for the comprehensive utilization of by-products of sucrose industry. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Due to the environmental concerns and the potential hazards and risks posed by chromium (VI), its removal from aquatic habitats has become a serious demand. In this paper, novel modifications were employed to increase the adsorption performance of Cr (VI) using activated carbon (AC) derived from sugarcane bagasse activated with phosphoric acid. AC was consequently modified with triethoxysilane propylamine and diethylene triamine as silica (Si) and nitrogen (N) sources, respectively. SEM-EDX, N-2 adsorption isotherms and FTIR analyses were performed to characterize the adsorbents. Equilibrium adsorption behavior of Cr(VI) ions with respect to varying in surface characteristics of resulting materials was investigated using Langmuir, Freundlich and Temkin isotherms. Kinetic and thermodynamic studies of Cr(VI) adsorption over AC, Si@AC and Si-N@AC were carried out. Freundlich model described the adsorption isotherm of AC and Si-N@AC severally, suggesting that the Cr(VI) removal was multi-layer adsorption. However, Langmuir model satisfied with adsorption of Cr (VI) over Si@AC. Pseudo-second order model fitted well the adsorption suggesting the chemical interaction. As a result of doping AC with Si and N, high adsorption capacities obtained at pH 2 and 30(o)C were to be 268 and 233 mg/g for Si@AC and Si-N@AC which are especially superior compared to others in literature.
For the efficient production of lignocellulosic ethanol, a technology of recycling yeast cells at a high-solid load was developed. The yeast Saccharomyces cerevisiae TJ14 grew up to 5.0 x 10(7) cells/mL at 39 degrees C during the simultaneous saccharification and fermentation of hydrothermally pretreated rice straw. By exploiting the viability of the cells, a portion of the fermentation residue was recycled, yielding 52.3 g/L ethanol (90.3\% yield) at 1.12 g/(L.h) in six batches. This result is attributable to the maintenance of a viable cell count (cells/mL) on the order of 10(7). In accordance with this principle, the effects of low-cost nutrients on yeast recycling were elucidated, where 0.125\% corn steep liquor was deemed sufficient for fermenting rice straw and empty fruit bunch hydrolysates. The supplementation of sugarcane molasses into bagasse was found to be a practical approach, resulting in 63.5-67.7 g/L ethanol and 5.3 x 10(6)-4.4 x 10(7) cells/mL in six batches. Here, we describe that the high cell-growth potential in industrially relevant media minimizes the retention of lignocellulosic residues in subsequent batches, thus eliminating the problematic operations in yeast recycling. (C) 2018 Elsevier B.V. All rights reserved.
A biodegradable polymer composite containing lignin from sugarcane bagasse and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was produced and characterized in terms of its thermal, morphological, and mechanical properties. For comparison with the properties of the composites, the properties of the isolated composite components (lignin and PHBV) were also determined. The characterizations were carried out by Fourier transformed infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and mechanical properties. In the micrograph images, no physical contact between filler and matrix was verified. The thermal decomposition profiles of composites depend on the lignin/PHBV proportions, and their residual mass increased as a function of lignin amount. Higher temperatures were necessary to promote PHBV crystallization in the presence of lignin. However, the crystalline degree of composites was not affected by the lignin. The results obtained in the mechanical tests showed that the lignin addition caused a decrease of mechanical properties.
BACKGROUNDThe present study explored the effect of garlic and/or eucalypt oils on biogas production during in vitro ruminal fermentation of four agro industry byproducts. For this, 0-180mg oil L-1 incubation medium was added and gas volumes were recorded from 2 to 48h of incubation. Dry matter substrate degradability and neutral as well as acid detergent fibre were determined after 72h. RESULTSGas production and nutrient degradability was oil type dependent. The oils enhanced (P<0.05) biogas and asymptotic biogas production for corn stalks and oat straw, although no effect was observed on asymptotic biogas production for sorghum straw and sugarcane bagasse. Addition of both oils decreased (P<0.05) fermentation pH for corn stalks, sorghum straw and oat straw and also increased (P<0.05) dry matter degradability for all four byproducts. Neutral detergent fibre degradability for all byproducts was higher (P<0.05) with garlic oil. Eucalypt oil, however, decreased (P<0.05) neutral detergent fibre degradability for sugarcane bagasse and corn stalks, although only weak effects were observed for sorghum and oat straws. CONCLUSIONWith respect to ruminal biogas production, the addition of garlic oil showed better environmental effects than the addition of eucalypt oil and increasing oil concentrations resulted in enhanced fermentation characteristics. (c) 2018 Society of Chemical Industry
The consolidation of the biorefinery concept has the potential to contribute to the sustainable development of agro-industrial regions, particularly in developing countries. The industrial symbiosis (IS) approach can leverage this potential through industrial cooperation, fostering new businesses, innovation and job creation coupled with reduced environmental impacts. We argue that coupling the biorefinery concept and the IS approach would invigorate traditionally agricultural regions, relying on endogenous vocation to promote sustainability. The purpose of this study is to examine the potential for development of an agro-industrial symbiosis network (ISN) from the construction of a biorefinery in the Norte Fluminense region (Brazil) - a region that has become highly dependent on oil \& gas revenues but still has a tradition in agriculture and agro-industry. In this paper, we present the scenario analysis performed to design the agro ISN and an initial quantification of potential benefits. Four scenarios were developed (reference, short, mid and long terms) with the support of a synergy matrix and material flow analysis. Eighteen waste streams were identified and sixteen were addressed through the scenarios. In the long-term scenario, 14 productive activities could compose the agro-industrial symbiosis network, 8 of them as newcomers. ``Quick-wins{''
Representative samples of soft, low density, group 1 (rice straw, rice hulls, sugarcane bagasse) and hard, high density, group 2 agricultural by-products (pecan shells) were converted into granular activated carbons (GACs). GACs were produced from group 1 and 2 materials by physical activation or from group 2 materials by chemical activation. Carbons were evaluated for their physical (hardness, bulk density), chemical (ash, conductivity, pH), surface (total surface area), and adsorption properties (molasses color removal, sugar decolorization) and compared with two commercial reference carbons. The results show that the type of by-product, binder, and activation method determine the properties of GACs. Regardless of the binder, sugarcane bagasse showed a better potential than rice straw or rice hulls as precursor of GACs with the desirable properties of a sugar decolorizing carbon. Pecan shells produced GACs that were closest to the reference carbons in terms of all the properties investigated. (C) 1999 Elsevier Science Ltd. All rights reserved.
Generally the concrete is weak in tensile as well as flexural strength which are some basic strength properties of any structure. Steel fiber can be potentially used in the concrete to improve its structural strength. Use of steel fiber in the concrete will also reduce the steel reinforcement requirements at later stage. Concrete was prepared in the present research work in which sugarcane bagasse ash was used to substitute cement to minimize cement use and thereby reduce construction costs. In this work concrete beams \& cylinders were cast in various proportions of SCBA like 5\%, 10\%, 15\%, and 20\%. This combination was further enhanced by adding steel fiber by volume in percentages like 0.5\%, 1\%, and 1.5\%. The beams \& cylinders were prepared using this combination and tested at different curing ages, such as 7-days, 28days, 56-days and 90-days. At such ages, concrete properties such as flexural strength and split tensile strength were analyzed. In this study it is clearly evident that use of steel fibers are improve the tensile strength of concrete but in combination of SCBA with 10 \% replacement of cement gives the best result in case of flexural strength. Copyright (c) 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Sustainable Materials and Practices for Built Environment.
This paper reports comparative study of two chemical techniques (viz, dilute acid/alkali treatment) and two physical techniques (viz, hot water bath and autoclaving) coupled with sonication, termed as sono-hybrid techniques, for hydrolysis of rice straw. The efficacy of each sono-hybrid technique was assessed on the basis of total sugar and reducing sugar release. The system of biomass pretreatment is revealed to be mass transfer controlled. Higher sugar release is obtained during dilute acid treatment than dilute alkali treatment. Autoclaving alone was found to increase sugar release marginally as compared to hot water bath. Sonication of the biomass solution after autoclaving and stirring resulted in significant rise of sugar release, which is attributed to strong convection generated during sonication that assists effective transport of sugar molecules. Discrimination between individual contributions of ultrasound and cavitation to mass transfer enhancement reveals that contribution of ultrasound (through micro-streaming) is higher. Micro-turbulence as well as acoustic waves generated by cavitation did not contribute much to enhancing of mass transfer in the system. (C) 2013 Elsevier B.V. All rights reserved.
This study presents the production of novel oleogels via circular valorisation of food industry side streams. Sugarcane molasses and soybean processing side streams (i.e. soybean cake) were employed as fermentation feedstocks for the production of microbial oil. Fed-batch bioreactor fermentations carried out by the oleaginous yeast Rhodosporidium toruloides led to the production of 36.9 g/L total dry weight with an intracellular oil content of 49.8\% (w/w) and 89.4 mu g/g carotenoids. The carotenoid-rich microbial oil and soybean oil were evaluated as base oils for the production of wax-based oleogels. The wax esters, used as oleogelators, were produced via enzymatic catalysis, using microbial oil or soybean fatty acid distillate as raw materials. All oleogels presented a gel-like behaviour (G' > G `'). However, the highest G' was determined for the oleogel produced from soybean oil and microbial oil-wax esters, which indicated a stronger network. Thermal analysis showed that this oleogel had a melting temperature profile up to 35 degrees C, which is favorable for applications in the confectionery industry. Also, texture analysis demonstrated that soybean oil-microbial oil wax oleogel was stable (1.9-2.2 N) within 30-days storage period. This study showed the potential of novel oleogels production through the development of bioprocesses based on the valorisation of various renewable resources.
The objective of the present study was to determine the effect of urea-lime treatment on nutritive value and rumen degradability of rice straw by using the nylon-bag technique. Straw was assigned to treatments according to a 2 x 3 x 5 factorial arrangement in a completely randomised design. Factor A comprised two storage times (10 and 20 days), Factor B comprised three levels of lime addition (0\%, 1\% and 2\%) and Factor C comprised five levels of urea treatment (1\%, 2\%, 3\%, 4\% and 5\%). Two ruminal fistulated beef steers (410 +/- 10 kg) were used to determine in situ DM degradability. The results showed that increasing the urea treatment level increased crude protein and organic matter concentrations, while concentrations of neutral detergent fibre and acid detergent fibre decreased linearly with an increasing lime treatment level (P < 0.05). Moreover, urea and lime treatment increased the soluble fractions at time zero (a), insoluble degradability fractions (b), rate of degradation (c), potential degradability (a+b) and the effective degradability of DM (P < 0.05). Furthermore, rice-straw treatment at 20 days showed a better straw chemical composition and rumen degradability (P < 0.05) than that at 10 days. In conclusion, treatment with urea and lime improved the quality and ruminal degradability of rice straw. The present study suggested that urea treatment can improve the nutritional value of rice straw, especially, treatment with 3\% urea together with 2\% lime.
Anaerobic co-digestion (AcoD) of food waste (FW) and lignocellulose waste is a promising technology for methane production. This work investigated the methane generation from AcoD of FW, sugarcane leaves (SLs), and cow dung (CD) under mesophilic conditions in a batch test. As for AcoD of two feedstocks (SL and FW or CD and FW), introduction of SL and CD (25\%, volatile solid (VS) basis) showed slight improvement in methane production from FW. In contrast, positive synergistic effect (synergy index = 1.03-1.14 > 1) was observed in all the AcoD reactors of the three feedstocks (SL, CD, and FW). The optimum mixing ratio of FW:SL:CD (VS basis) was 85:11.25:3.75 with a synergy index of 1.07, achieving a methane yield rate and methane content of 297.16 mL/g VS and 73.26\%, respectively. This group cumulative methane production was an improvement of 110.45 and 444.72\% higher than mono-digestion of SL and CD. The biodegradability, soluble chemical oxygen demand (SCOD), and VS removal rate were 56.44, 44.55 and 55.38\%, respectively. The optimum results indicated that AcoD of FW, SL, and CD have higher potentials for energy recovery and provided forceful scientific evidence for their energy utilization.
The lignocellulosic biomass comprises three main components: cellulose, hemicellulose, and lignin. Degradation and conversion of these three components are attractive to biotechnology. This study aimed to prospect fungal lignocellulolytic enzymes with potential industrial applications, produced through a temporal analysis using Hymenaea courbaril and Tamarindus indica seeds as carbon sources. alpha-L-arabinofuranosidase, acetyl xylan esterase, endo-1,5-alpha-L-arabinanase, beta-D-galactosidase, beta-D-glucosidase, beta-glucanase, beta-D-xylosidase, cellobiohydrolase, endoglucanase, lichenase, mannanase, polygalacturonase, endo-1,4-beta-xylanase, and xyloglucanase activities were determined. The enzymes were produced for eight filamentous fungi: Aspergillus fumigatus, Trametes hirsuta, Lasiodiplodia sp., two strains of Trichoderma longibrachiatum, Neocosmospora perseae, Fusarium sp. and Thermothelomyces thermophilus. The best producers concerning enzymatic activity were T. thermophilus and T. longibrachiatum. The optimal conditions for enzyme production were the media supplemented with tamarind seeds, under agitation, for 72 h. This analysis was essential to demonstrate that cultivation conditions, static and under agitation, exert strong influences on the production of several enzymes produced by different fungi. The kind of sugarcane, pretreatment used, microorganisms, and carbon sources proved limiting sugar profile factors.
This study investigated the amendment of sugarcane bagasse biochar (SCBB) on soil fertility, crop yield, and nutrient loss in two different-textured soils under sugarcane (Saccharum spp.) production. Eleven megagrams per hectare of freshly incorporated biochar increased yield of plant cane by 22\% in light-texture soil (LS) and 12\% in heavy-textured soil (HS). Although the overall yield of the ratoon crop was lower, the biochar treatment produced 20 and 14\% higher yields than the control at the LS and HS sites, respectively. Biochar increased soil carbon (C-soil) across LS and HS sites by 15\% and decreased the soil C/N ratio by 19\%. Over the two growing seasons and sites, cumulative runoff volume, and loads of NO3--N, PO4-3-P, biological oxygen demand (BOD5), total organic C (TOC), and total suspended solids (TSS) were reduced by 33, 35, 39, 25, 24, and 54\% with biochar. Calcium and K losses in runoff were also reduced by 43 and 24\% with biochar. It reduced NH4+-N leaching in LS and HS soils over the two growing seasons by 33-167\% and 66-81\%, respectively, and reduced PO4-3-P leaching by 45-57\% in HS over 2 yr. Although biochar is not considered a fertilizer, SCBB acted as a source of nutrients, increasing soil fertility and crop yield. It also reduced nutrient losses during heavy rain events typical of the subtropical climate of Louisiana.
Lignocellulosic biomass is a promising substrate for biogas production. However, its recalcitrant structure limits conversion efficiency. This study aims to design a microbial consortium (MC) capable of producing the cellulolytic enzyme and exploring the taxonomic and genetic aspects of lignocellulose degradation. A diverse range of lignocellulolytic bacteria and degrading enzymes from various habitats were enriched for a known KKU-MC1. The KKU-MC1 was found to be abundant in Bacteroidetes (51\%), Proteobacteria (29\%), Firmicutes (10\%), and other phyla (8\% unknown, 0.4\% unclassified, 0.6\% archaea, and the remaining 1\% other bacteria with low predominance). Carbohydrate-active enzyme (CAZyme) annotation revealed that the genera Bacteroides,Ruminiclostridium,Enterococcus, and Parabacteroides encoded a diverse set of cellulose and hemicellulose degradation enzymes. Furthermore, the gene families associated with lignin deconstruction were more abundant in the Pseudomonas genera. Subsequently, the effects of MC on methane production from various biomasses were studied in two ways: bioaugmentation and pre-hydrolysis. Methane yield (MY) of pre-hydrolysis cassava bagasse (CB), Napier grass (NG), and sugarcane bagasse (SB) with KKU-MC1 for 5 days improved by 38-56\% compared to non-prehydrolysis substrates, while MY of prehydrolysed filter cake (FC) for 15 days improved by 56\% compared to raw FC. The MY of CB, NG, and SB (at 4\% initial volatile solid concentration (IVC)) with KKU-MC1 augmentation improved by 29-42\% compared to the non-augmentation treatment. FC (1\% IVC) had 17\% higher MY than the non-augmentation treatment. These findings demonstrated that KKU-MC1 released the cellulolytic enzyme capable of decomposing various lignocellulosic biomasses, resulting in increased biogas production.
To improve the reliability of the industrial systems, the main requirement is to identify the most expected failures and to minimize the effects of such failures. This can be achieved through availability evaluation of the systems of the industry. Here, the performance analysis of molasses (by-product of sugarcane) making system is carried out. The system consists of four subsystems, namely: Crystallizer, C-fore worker, C-after Worker and Melter. Functioning of these subsystems is in series and within subsystems have different working configurations. Equations associated with the system model are developed and solved to get the state probabilities by using supplementary variable technique. A particular case is also considered to show the availability and expected behavior of the molasses making system. Numerical results are obtained to explain the effect of subsystems working behavior.
Mycelial growth of two strains of the mushroom Lentinula edodes (IE-40 and IE-105) was evaluated on barley straw, corn cob, corn stover, rice bran, bracts of pineapple crown, coffee husk, sugarcane bagasse and sugarcane leaves. The last four substrates were chosen for mushroom production essays. A mixture of coffee husks, coffee pulp and sorghum,grains was used as spawn. The substrates were sterilised and inoculated, under aseptic conditions, in plastic bags. The bags were incubated at 25 degrees C in darkness. There was no development of primordia in the coffee husks. In the other substrates, primordia were observed between 30 and 62 days. Both strains, IE-40 and IE-105, showed their highest production in sugarcane bagasse, with biological efficiencies of 130-133 \%, followed by 83-98 \% in sugarcane leaves and 36-37 \% in bracts of pineapple crown. ((C) Inra/Elsevier, Paris.).
Lignocellulosic biorefining for producing biofuels poses technical challenges. It is usually conducted over a long time using heat, making it energy intensive. In this study, we lowered the energy consumption of this process through an optimized enzyme and pretreatment strategy. First, the dominant mutant M137E/N269G of Bispora sp. MEY-1 XYL10C\_Delta N was obtained by directed evolution with high catalytic efficiency (970 mL/s center dot mg) and specific activity (2090 U/mg) at 37 degrees C, and thermostability was improved (T50 increased by 5 degrees C). After pretreatment with seawater immersion following steam explosion, bagasse was co-treated with cellulase and M137E/N269G under mild conditions (37 degrees C), the resulting highest yield of fermentable sugars reached 219 mu mol/g of bagasse, 46\% higher than that of the non-seawater treatment group, with the highest degree of synergy of 2.0. Pretreatment with seawater following steam explosion and synergistic hydrolysis through high activity xylanase and cellulase helped to achieve low energy degradation of lignocellulosic biomass.
The aim of this work was to synthesize carboxymethyl cellulose (CMC) and produce CMC films from the cellulose of palm bunch and bagasse agricultural waste. The effect of various amounts of H2O2(0-40\%v/v) during delignification on the properties of cellulose, CMC, and CMC films was studied. As the H(2)O(2)content increased, yield and the lignin content of the cellulose from palm bunch and bagasse decreased, whereas lightness (L{*
Lignin biodegradation is an attractive approach for producing value- added products. These valuable products are produced by the processing and refining of lignocellulosic residues. A set of ligninolytic enzymes including lignin peroxidase (LiP), manganese-dependent peroxidase (MnP), and laccase (Lac) were individually produced from Ganoderma lucidum, Trametes versicolor, and Pleurotus ostreatus. Solid state fermentation under pre-optimized culture conditions with varying ratios of enzymes were used for the delignification of lignocellulosic biomass residues. The fungal enzymes were purified in four steps including ammonium sulfate precipitation, dialysis, ion exchange chromatography, and gel filtration chromatography. The purified enzymes were subsequently used in varying ratios (with each containing 200 U/mL) for the delignification of wheat straw, sugarcane bagasse, and rice straw. The consortium of enzymes caused the removal of 58.5\%, 46\%, and 52\% of the lignin from the wheat straw, sugarcane bagasse, and rice straw, respectively, at LiP: MnP: Lac ratios of 1: 2: 2, 1: 1: 2, and 2: 1: 2. The best delignification was observed in wheat straw (58.5\%), exposing 76.54\% cellulose content. The results suggested that the ligninolytic enzymes are effective catalysts for the selective partial delignification of lignocellulosic biomass residues. After delignification these lignocellulosic residues could be utilized as cost-effective substrates for the production of enzymes, biofuels, and other industrially significant products.
Second-generation ethanol process uses lignocellulose, but a pre-treatment is required to degrade lignin before saccharification. Biological pre-treatment, using phenoloxidases, represents a cheap and eco-friendly option. Mould contamination can be overcome by heat pre-conditioning of substrates. Pasteurisation can be a mild and sustainable option. A 5-level response-surface experimental design was performed to test the effect of different time and temperatures on lignocellulolytic activities and substrate dephenolisation. Substrate microbial communities were characterised via catabolic profiles to determine functional diversity changes after pasteurisation. Temperatures ranging from 70 to 75 degrees C and time from 5 to 10 h led to the highest laccase activities and 30\% of substrate dephenolisation was achieved while avoiding mould contamination. The per cent of O-Alkyl (polysaccharides) did not vary significantly, meaning that polysaccharides were not extensively consumed. Microbial communities were less catabolically diversified (H' = 1.2) but more active (AWCD = 0.9) and could degrade polysaccharides. (C) 2020 Published by Elsevier Ltd.
Lignocellulosic biomass is a promising bioprocess substrate for the production of biofuels and biomaterials. This study modeled and optimized the production of xylose and glucose from sugarcane leaves subjected to hybrid pretreatment of HCl and moist heat and, it examined the dynamics of hydrogen biofuel production from these substrates at a semi pilot scale. The response surface methodology was used to optimize the hybrid pretreatment within the ranges of 4-10\%, 60-100 degrees C and 60-240 min for HCl concentration, temperature and process time respectively. The coefficients of determination (R-2) of 0.99 and 0.93 were obtained for xylose and glucose models respectively indicating the suitability of the models to navigate the optimization space. Process optimization predicted Xylose and glucose yields of 8.92 g/l and 1.68 g/l on a hybrid pretreatment of 5.28\% HCl for 187 min at 94.94 degrees C. Experimental validation yielded xylose and glucose of 8.6 g/l and 1.78 g/l. Biohydrogen production on these optimized substrates in 13L bioreactor showed a peak hydrogen fraction of 26.73\% at the 30th hour, and hydrogen yield of 248.05 ml H-2 g(-1) of fermentable sugar. These findings demonstrate that sugarcane leaves which are usually burnt during harvesting can be an excellent renewable source of fermentable sugars for the production of biofuels such as hydrogen. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
In this study, barley straw was treated by subcritical water (sCW) and pressurized aqueous ethanol (PAE) (20-100\% v/v ethanol) at 180-220 degrees C, 50-200 bar, 5 mL/min, for 40 min. The optimum condition to obtain monosaccharides was using sCW at 200 degrees C, 50 bar for 40 min with the highest contents of xylose (48.63 +/- 2.95 mg/g barley straw) followed by glucose (17.85 +/- 1.01 mg/g barley straw) and arabinose (7.20 +/- 1.15 mg/g barley straw). The highest content of total phenolics in the hydrolysates (75.38 +/- 1.43 mg GAE/g straw) and lignin removed in the residue (7.5\% lignin left) were achieved by PAE (60\%) at 220 degrees C, 50 bar, for 40 min, resulting in 88.43\% of cellulose in the residue. In addition, the use of PAE treatments at higher ethanol con-centrations significantly reduced the formation of inhibitors such as 5-HMF and furfural. Furthermore, PAE hydrolysates had antioxidant activity values in the range of 23.87-82.62 mM FeSO4/g straw.
Bacillus atrophaeus' spores are used in the preparation of bioindicators to monitor the dry heat, ethylene oxide, and plasma sterilization processes and in tests to assess sterilizing products. Earlier production methods involved culture in chemically defined medium to support sporulation with the disadvantage of requiring an extended period of time (14 days) besides high cost of substrates. The effect of cultivation conditions by solid-state fermentation (SSF) was investigated aiming at improving the cost-productivity relation. Initial SSF parameters such as the type of substrate were tested. Process optimization was carried out using factorial experimental designs and response surface methodology in which the influence of different variables-particle size, moisture content, incubation time, pH, inoculum size, calcium sources, and medium composition-was studied. The results have suggested that soybean molasses and sugarcane bagasse are potential substrate and support, respectively, contributing to a 5-day reduction in incubation time. Variables which presented significant effects and optimum values were mean particle size (1.0 mm), moisture content (93\%), initial substrate pH (8.0), and water as a solution base. The high-yield spore production was about 3 logs higher than the control and no significant difference in dry heat resistance was observed.
Modified waste sugarcane bagasse (SCB) was prepared to remove cationic dyes: methylene blue and rhodamine B from aqueous solution by using a continuous mode. Effects of flow rate on adsorption of the two dyes in fixed bed column were studied. Competitive adsorption kinetics of the two dyes in binary system was investigated in detail. Results showed that the adsorption capacities of the modified sorbent for methylene blue and rhodamine B in one component system were 1.7 and 0.4 mmol g(-1), respectively. Competitive adsorption process in the binary system could be divided into three phases: free adsorption, substitution adsorption and adsorption equilibrium. 0.19 mmol of rhodamine B absorbed was replaced by 0.35 mmol of methylene blue in the second phase. Simple modified Yoon-Nelson model was used to predict the adsorption kinetics for the first time. The obtained adsorption rate constants for the two dyes in the three phases both followed the order: phase I > phase III > phase II, demonstrating that substitution adsorption phase is the rate determining step. Desorption experiment showed that the loaded two dyes could be separated and recycled by using the mixture solution of HCl (0.1 mol L-1) and ethanol as eluent. The prepared fixed bed column had great potential in industrial wastewater treatment. (C) 2019 Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
The phthalation of bagasse was comparatively investigated with the isolated three main components in 1-allyl-3-methylidazium chloride (AmimCl) to reveal the reaction behavior of bagasse. In the present study, the reaction behavior of hemicelluloses during the homogeneous phthalation was extensively explored. The phthalation degree of hemicellulosic samples ranged from 16.37\% to 52.14\%. The reaction priority on the main and side chains of hemicelluloses were revealed by the changes of monosaccharide contents upon phthalation. The results indicated that side-chains of hemicelluloses were more easily phthalated than main-chains, and the phthalation of secondary hydroxyl groups on uronic acids was more difficult than that on neutral sugars. C-13 NMR and HSQC analyses suggested the similar reactivity of the secondary hydroxyls at C-2 and C-3 positions in anhydroxylose units. These results provide more detailed understanding of the homogenous modification of lignocellulose. (C) 2016 Elsevier Ltd. All rights reserved.
Fungal delignification can be a feasible process to pretreat biomass for bioethanol production if its performance is improved in terms of efficiency through a few modifications. The aim of this study was to enhance the biodelignification pretreatment of rice straw using laccase in the presence of ionic liquid (1-Allyl-3-methylimidazolium chloride, {[
The performance of two laboratory scale biofilters, packed with pressmud (BF1) and sugarcane bagasse (BF2), was evaluated for gas phase ethylacetate removal under various operating conditions. Biofilters were inoculated with mixed culture obtained from pharmaceutical wastewater sludge. Experiments were carried out at different flow rates (0.03, 0.06, 0.09 and 0.12 m(3) h(-1)) and inlet ethylacetate concentrations (0.2, 0.4, 0.6 and 1.2 gm(-3)). Maximum removal efficiency (RE) of 100\% and 98\% was achieved at an inlet concentration of 0.2 gm(-3) and gas flow rate of 0.03 m(3) h(-1) in BF1 and BF2, respectively. A maximum elimination capacity (EC) of 66.6 gm(-3) h(-1) and 64.1 gm(3) h(-1) was obtained in BF1 and BF2, respectively, at an inlet concentration of 0.8 gm(-3) and a gas flow rate of 0.12 m(3) h(-1). The kinetics of biofiltration of ethylacetate was studied by using Ottengraf and van den Oever model. The kinetic modelling gives an insight into the mechanism of biofiltration. The modified Ottengraf model, which was also tested, demonstrated good agreement between calculated and experimental data.
Given their potential for biological nitrogen fixation, legumes used as green manure are an alternative source of nitrogen to crops, and can supplement or even replace mineral nitrogen fertilization. The utilization of nitrogen by sugarcane (Saccharum spp.) fertilized with sunn hemp (Crotalaria juncea L.) and ammonium sulphate (AS) was evaluated using the N-15 tracer technique. Amounts of 195.8 kg and 70 kg N per hectare, respectively, of sunn hemp and AS were added in the following treatments: without green manure and without AS; without green manure, with AS -N-15; with green manure-N-15 and with AS; with green manure-N-15, without AS; with green manure and with AS-N-15. Four samples from the leaves +3 were collected and 2 in of the sugar cane row were harvested to estimate crop yield. The results for N contents (g kg(-1)), isotopic abundance of N (atoms \% N-15) in leaf +3 samples, and sugarcane productivity were used to calculate cumulative N, nitrogen in the plant derived from the fertilizer-Ndff (\% and kg ha(-1)), as well as percent recovery of fertilizer N (R\%). Sugarcane was analysed and pol and total recovered sugar calculated. The highest Ndff percentages were observed eight months after sugarcane planting for treatments containing green manure without mineral N, and green manure with mineral N, at 15.3 and 18.4\%, respectively. The best nitrogen recovery was observed during harvest, 18 months after planting; the treatment containing mineral fertilizer showed 34.4\% recovery, while the sum between mineral N plus green manure N showed 40.0\%. Treatments containing green manure plus mineral N changed soil attributes, by increasing Ca and Mg contents, sum of bases, pH, and base saturation, and decreasing potential acidity. In the plant, those treatments increased Ca and K contents.
Biomass-based porous carbon has attracted much attentionof researchersdue to its wide range of raw materials, low cost, and other advantages.It has been also widely used in energy storage devices such as lithium-ionbatteries. The carbonization process and final morphology of biomassare indirectly affected by the surface modification and structureoptimization of the original biomass. The focus of this study is toprepare porous carbon, which can be used as an electrode materialof a lithium-ion battery by surface modification and structure regulationof biomass pretreatment. In this study, the method of H2O2-assisted hydrothermal treatment was used to preparea kind of bagasse based porous carbon materials that can be used inlithium-ion batteries. The reaction process of H2O2 and bagasse under hydrothermal conditions was explored anddescribed. The results showed that H2O2 promotedthe hydrolysis and oxidation of lignocellulose in bagasse and thesmall molecules obtained from lignocellulose hydrolysis under hydrothermalconditions would be repolymerized to form carbon spheres. The preparedcarbon material was applied to the lithium-ion battery. Under a currentdensity of 0.1 A g(-1), the specific capacity of 891mAh g(-1) in the first cycle was displayed, and aspecific capacity of 453 mAh g(-1) was maintainedafter 150 cycles. At the same time, it showed a good rate performance.After 10 cycles at current densities of 0.1, 0.2, 0.5, 1, 2, and 5A g(-1), the specific capacities of 545, 421, 307,245, 195, and 133 mAh g(-1) were obtained. All theraw materials and products used in this experiment are harmless tothe environment, which has certain guiding significance for the structuralregulation and green synthesis of lignocellulosic biomass-derivedcarbon materials.
Zirconia nanorods have been successfully synthesized from local zircon-based Zr(OH)(4) precursors through a facile precursor-templating method assisted by sugarcane bagasse based-nano cellulose as the one-dimensional (1D) structure directing template. However, the 1D structure arrangement of the zirconia precursors by the cellulose template during synthesis undergoes at selective precursor pHs. The final products of zirconia consist of the t-metastable and the m-phases, exhibit microstructures of nanorods and elongated agglomerates, and reveal large specific surface areas. (C) 2019 The Ceramic Society of Japan. All rights reserved.
Herein, we report a new strategy for the simultaneous degradation of lignocellulosic biomass and bioelectricity generation using a novel three-chamber microbial fuel cell (MFC). Oscillatoria annae, a freshwater cyanobacterium, was used for the hydrolysis of cellulose to glucose. The electrocatalytic activity of the coculture of Acetobacter aceti and Gluconobacter roseus was used to oxidize the glucose for current generation in the MFC. Carbon felt was used as the anode and cathode material. Lignocellulosic materials such as sugarcane bagasse and corn cob were used as substrates. The performances of the MFC with two different substrates were analyzed by polarization studies, coulombic efficiency, percentage of COD removal and internal resistance. The three-chamber MFC produced a maximum power output of 8.78 W/m(3) at 20.95 A/m(3) and 6.73 W/m(3) at 17.28 A/m(3) with sugarcane bagasse and corn cob as substrates, respectively.
A major obstacle in the bioproduction of metabolites of industrial interest is the high cost of the culture medium. Obtaining two bioproducts simultaneously (lipids and carotenoids) by Rhodo-torula mucilaginosa can solve part of this problem. However, reconciling two metabolites is a challenge since the nutritional needs of yeasts for one metabolite (lipid) are often not the same as those for another (carotenoids). The use of co-products can minimize the cost of the process when they substitute a commercial medium. And the success of simultaneous bioproduction can be achieved using a strategy of experimental planning that combines sugarcane molasses (25 g/L to 55 g/L) and cassava wastewater (20 g/L to 50 g/L), optimizing and adding value to the process. In this study, 7.94 g/L of lipids were produced with an accumulation in dry mass of 48.14\% and 2958.32 mu g/L (168.08 mu g/g) of volumetric and specific carotenoids concentration. In addition, in an experiment using ammonium sulfate (3 g/L) as an activator, there was an increase of 94.46\% and 81.16\% in the production of specific and volumetric carotenoids, respectively. In the gas chromatographic analysis, oleic (73.67\%), palmitic (20.23\%) and linoleic (4.01\%) acids were found. Our studies demonstrated the strategic viability of simultaneously obtaining lipids and carotenoids through an ideal combination of co-products from cheap renewable sources, making it possible to reduce the costs of processing in bioreactors.
Butanol production from renewable resources has been increasingly investigated over the past decade, mostly for its use as a liquid biofuel for road transportation, since its energy density is higher than that of ethanol and it may be used in gasoline driven engines with practically no changes, but also for use as a feedstock in the chemical industry. Most of the research concerning butanol production focuses on the ABE process (fermentation of sugars into a mixture of acetone, butanol and ethanol), which has several drawbacks regarding microorganism performance and product inhibition. An alternative to ABE fermentation, ethanol catalytic conversion to butanol can produce a higher quality product with less retrofitting than ABE in existing ethanol producing facilities. There are different types of catalysts for the chemical conversion of ethanol to butanol being developed in laboratory scale, but their actual use in a sugarcane processing plant has never before been assessed. Butanol production from ethanol in a sugarcane biorefinexy, using data from the literature, was assessed in this study; different technological alternatives (catalytic routes) were evaluated through computer simulation in Aspen Plus (including production of electricity, sugar, ethanol and other products) and economic and environmental impacts were assessed. Results indicate that vapor-phase catalysis presents higher potential for industrial implementation, and commercialization of butanol for use as a chemical feedstock has an economic performance similar to that of current, optimized first generation sugarcane distilleries, but can potentially contribute to cost reduction that will allow commercialization of butanol as a fuel in the future. (C) 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
The present study investigates fluid mechanical properties of cellulosic feedstocks relevant to flow through (FT) pretreatment for biological conversion of cellulosic biomass. The results inform identifying conditions for which FT pretreatment can be implemented in a practical context. Measurements of pressure drop across packed beds, viscous compaction and water absorption are reported for milled and not milled sugarcane bagasse, switchgrass and poplar, and important factors impacting viscous flow are deduced. Using biomass knife-milled to pass through a 2 mmsieve, the observed pressure drop was highest for bagasse, intermediate for switchgrass and lowest for poplar. The highest pressure drop was associated with the presence of more fine particles, greater viscous compaction and the degree of water absorption. Using bagasse without particle size reduction, the instability of the reactor during pretreatment above 140 kg/m(3) sets an upper bound on the allowable concentration for continuous stable flow. (C) 2014 Published by Elsevier Ltd.
In order to establish a cost-effective biorefinery in Moroccan sugar plants, the use of sugarcane bagasse and beet pulp to produce bioethanol is considered as a promising option. In fact, lately this efficient way of biomass conversion into bioethanol, which is a cleaner source of energy, has received a lot of interest. In this context, the main objective of the present paper is to conduct a comparative study between the most investigated processes of producing bioethanol from lignocellulosic biomass. This study has considered the technical, economical, and environmental criteria to select the most efficient processes for a large scale production. For each step of the studied process, the most efficient options have been selected. In the pretreatment step, the use of dilute sulfuric acid was selected as the best option followed by steam explosion method. In the hydrolysis step, dilute sulfuric acid was also adopted. Concerning the following step, co-culture fermentation using a respiratory mutant of Saccharomyces cereuisiae and Pichia stipitis has been found to give the best result. In the last step, conventional distillation process coupled with pervaporation has been chosen as the best way to produce high purity anhydrous ethanol; while molecular sieves and extractive distillation in dividing-wall columns using ethylene glycol was also considered as promising alternatives of the pervaporation process. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
The effects of the exogenous fibrolytic enzyme (ENZ) commercial preparation Dyadic (R) xylanase PLUS (Dyadic International, Inc., Jupiter, USA), containing endo-1,4-beta-D-xylanase, on ruminal fermentation of maize stover, oat straw, and sugarcane bagasse were examined using the in vitro gas production (GP) technique. The ENZ commercial preparation was added at 0 (control), 60 (low), 120 (medium), and 240 (high) mu g/g dry matter of substrate, and at two times of application (direct addition just before fermentation or with a 72-h pre-incubation before fermentation). Ruminal GP volumes were recorded at 2, 4, 6, 8, 10, 12, 14, 24, and 48 h of incubation, and substrate degradability and concentration of fermentation end-products (volatile fatty acids, ammonia, methane) in the cultures were determined at 48 h of incubation. Increased (P < 0.05) GP volume was observed in fibrous feeds treated with ENZ compared with untreated substrates. The pre-incubation vs the direct addition of ENZ resulted in greater GP volume (P < 0.05) with the three tested feeds. Enzyme addition decreased (P < 0.05) rumen pH compared to control when maize stover and sugarcane bagasse were incubated. Ammonia-N and total volatile fatty acids (VFA) were not affected (P > 0.05) by ENZ application in maize stover and oat straw. However, total and individual VFA concentrations, and CH4 and CO2 volumes were greater (P < 0.05) when sugarcane bagasse was incubated with 240 mu g ENZ/g (P < 0.05). It can be concluded that the application of endo-1,4-beta-D-xylanase enhances rumen fermentation of roughages, although the magnitude of the effects depends on the fibrous substrate fermented, the time of application, and the amount of enzyme added.
Dilute-acid hydrolysis pretreatment of sugarcane bagasse resulted in release of 48\% (18.4 g/L) of the xylan in the hemicellulose fraction into the hydrolysate as monomeric xylose. In order to enhance the recuperation of this monomer, a post-hydrolysis stage consisted of thermal treatment was carried out. This treatment resulted in an increase in xylose release of 62\% (23.5 g/L) of the hemicellulose fraction. Original and post-hydrolysates were concentrated to the same levels of monomeric xylose in the fermentor feed. During the fermentation process, cellular growth was observed to be higher in the post-hydrolysate (3.5 g/L, Y(x/s) = 0.075 g cells/g xylose) than in the original hydrolysate (2.9 g/L, Y(x/s) = 0.068 g cells/g xylose). The post-treated hydrolysate required less concentration of sugars resulting in a lower concentration of fermentation inhibitors, which were formed primarily in the dilute acid hydrolysis step. Post-hydrolysis step led to a high xylose-xylitol conversion efficiency of 76\% (0.7 g xylitol/g xylose) and volumetric productivity of 0.68 g xylitol/L h when compared to 71\% (0.65 g xylitol/g xylose and productivity of 0.61 g xylitol/L h) for the original hemicellulosic hydrolysate.