Cellulosic Waste Research Articles

Performance of single substrate in sulphate reducing bioreactor for the treatment of acid mine drainage

The focus of this study is to investigate efficiency of the sulphate reducing passive bioreactors for the treatment of acid mine drainage. The performance of locally available substrates (manures, woodchips, millet fodders and sugarcane waste) were examined for the treatment of acid mine drainage. The manures showed efficient removal of metals and other pollutants. With cow manure, buffalo manure and goat manure pH increased from initial 2.70 to 6.25, 7.10 and 7.50. All cellulosic wastes also raised pH in a range of 4.83–5.32. Significant reduction was observed in Eh, acidity and sulphate concentration also. It was observed that: 51.49–99.32% of Fe, 84.95–99.97% of Cu, 35.11–99.78% of Zn, 17.87–99.14% of Ni, 63.55–99.02% of Co and 12.68–73.86% of Mn were removed in maximum retention period of 10days. Thus manures can be cost effective as a single substrate in a passive treatment method for removal of metals from AMD in bioreactors. Also chemical makeup of substrate provided an insight on the ability of sulphate reduction and metal removal.

DEVELOPMENT OF MICROORGANISMS FOR CELLULOSE-BIOFUEL CONSOLIDATED BIOPROCESSINGS: METABOLIC ENGINEERS' TRICKS

Cellulose waste biomass is the most abundant and attractive substrate for “biorefinery strategies” that are aimed to produce high-value products (e.g. solvents, fuels, building blocks) by economically and environmentally sustainable fermentation processes. However, cellulose is highly recalcitrant to biodegradation and its conversion by biotechnological strategies currently requires economically inefficient multistep industrial processes. The need for dedicated cellulase production continues to be a major constraint to cost-effective processing of cellulosic biomass.Research efforts have been aimed at developing recombinant microorganisms with suitable characteristics for single step biomass fermentation (consolidated bioprocessing, CBP). Two paradigms have been applied for such, so far unsuccessful, attempts: a) “native cellulolytic strategies”, aimed at conferring high-value product properties to natural cellulolytic microorganisms; b) “recombinant cellulolytic strategies”, aimed to confer cellulolytic ability to microorganisms exhibiting high product yields and titers.By starting from the description of natural enzyme systems for plant biomass degradation and natural metabolic pathways for some of the most valuable product (i.e. butanol, ethanol, and hydrogen) biosynthesis, this review describes state-of-the-art bottlenecks and solutions for the development of recombinant microbial strains for cellulosic biofuel CBP by metabolic engineering. Complexed cellulases (i.e. cellulosomes) benefit from stronger proximity effects and show enhanced synergy on insoluble substrates (i.e. crystalline cellulose) with respect to free enzymes. For this reason, special attention was held on strategies involving cellulosome/designer cellulosome-bearing recombinant microorganisms.

A Comparative Study on the Waste Cotton Textiles Dissolved in the Solution of ZnCl<sub>2</sub> and LiBr

Cellulose dissolution is one of the core issue of the process of the waste cellulose recycling. This paper study the dissolution process of the waste cotton textiles in the solution of ZnCl2 and LiBr, found that the ZnCl2 solution is more suitable for the cellulose dissolution, it is a very important significance for the recycling of cellulose in salt dissolution system.

Isolation and screening of thermophilic cellulolytic bacteria from compost piles

Cellulose, a major polysaccharide found in agricultural residues and industrial and municipal wastes. In the present study thermophilic cellulolytic microorganisms were isolated. The isolates were tested for their cellulytic activity. The enzyme production from potent isolates was optimised using cellulose basal broth medium. Activity of partially purified enzyme was determined. The most potent thermophilic cellulolytic isolates were identified as Bacillus subtilis. The crude cellulase enzyme concentrated at 80-85% ammonium sulfate produced highest zone of hydrolysis. The enzymatic degradation of cellulose waste has been suggested as a feasible alternative for the conversion of lignocelluloses substrate into fermentable sugars and application for biofuel production. Scientific World, Vol. 10, No. 10, July 2012 p43-46 DOI: http://dx.doi.org/10.3126/sw.v10i10.6861

IMPROVEMENT OF RECYCLED PAPER’S PROPERTIES FOR THE PRODUCTION OF BRAILLE PAPER BY IMPREGNATION WITH LOW GRADE CELLULOSE ACETATE: OPTIMIZATION USING RESPONSE SURFACE METHODOLOGY (RSM)

Paper dust is a kind of cellulosic waste that is generated by converting operations in paper mills. It was derived to a low-grade cellulose acetate in this study. Papers made from recycled fiber were then impregnated with the resultant cellulose acetate. Effects of impregnation conditions on the paper properties were statistically investigated by employing central composite design (CCD) based response surface methodology (RSM). Four response variables, namely density, burst index, smoothness, and rate of surface wettability were analyzed. Polynomial estimation model of each response was developed as functions of three independent variables, which are pressing temperature (T), dipping time (D), and concentration of cellulose acetate (C). The paper which was impregnated based on the calculated optimum condition (T: 163 °C, D: 2.8 minutes, and C: 2.7 percent), possessed a density of 0.5450 g/cm3, rate of surface wettability of 0.012°/s, burst index of 2.84 kPa m2/g, and paper smoothness of 475 mL/min. There was no significant difference between the experimental values and the predicted values calculated from estimation models. The cellulose acetate impregnated Braille papers made from recycled fibre was found to have better properties than those of commercial Braille paper in terms of rate of surface wettability and burst index.

Production of cellulase by immobilized whole cells of Haloarcula

Halophilic Archaea are adapted to a life in the extreme conditions and some of them are capable of growth on cellulosic waste as carbon and energy source by producing cellulase enzyme. The production of cellulase using free and immobilized cells of halophilic archaeal strain Haloarcula 2TK2 isolated from Tuzkoy Salt Mine and capable of producing cellulose was studied. The cells were cultured in a liquid medium containing 2.5 M NaCl to obtain the maximum cellulase activity and immobilized on agarose or polyacrylamide or alginate. Optimal salt dependence of free and immobilized cells of Haloarcula 2TK2 was established and the effects of pH and temperature were investigated. Immobilization to Na-alginate enhanced the enzymatic activity of the haloarchaeal cells when compared to free cells and other polymeric supports. From the results obtained it is reasonable to infer that decomposition of plant polymers into simpler end products does occur at high salinities and cellulase producing haloarchael cells may be potentially utilized for the treatment of hypersaline waste water to remove cellulose.

In vitro Cellulose Rich Organic Material Degradation by Cellulolytic Streptomyces albospinus (MTCC 8768)

Aims: Cellulosic biomass is the only foreseeable sustainable source of fuels and is also one of the dominating waste materials in nature resulting from human activities. Keeping in view the environmental problems like disposal of large volumes of cellulosic wastes and shortage of fossil fuel in the world, the main aim of the present investigation was to characterize and study the cellulolytic activity of Streptomyces albospinus (MTCC 8768), isolated from municipal wastes, on natural cellulosic substrates viz. straw powder, wood powder and finely grated vegetable peels. Methodology and Result: Stanier's Basal broth with 100 mg of each of the substrates was inoculated separately with S. albospinus (MTCC No. 8768) and incubated at 37 °C for 8 days. The cellulosic substrates were reweighed at an interval of 2 days and the difference between the initial weight and the final weight gave the amount of substrates degraded by the isolate. It was observed that maximum degradation was observed in the grated vegetable peels (64 mg) followed by straw powder (38 mg) and wood powder (28 mg) over a period of 8 days. Conclusion, significance and impact of study: By the selection of efficient cellulolytic microorganisms and cost� effective operational techniques, the production of useful end products from the biodegradation of the low cost enormous stock of cellulose in nature can be very beneficial.

Utilization of cellulosic wastes in textile and garment industries. I. Synthesis and grafting characterization of carboxymethyl cellulose from knitted rag

AbstractCarboxymethyl cellulose (CMC) was synthesized from knitted rags, a cellulosic wastes of textile and garment industries, in aqueous ethanolic sodium hydroxide and subsequently mono‐chloroacetic acid reaction medium. A low substituted to high substituted products was obtained from single step up to seven steps carboxymethylation of cellulose. In this way, it was possible to produce low cost and different grades or substituted carboxymethylation derivatives of cellulose. Solubility, degree of substitution (DS), CMC content, and molecular weight of CMC were increased gradually with the increase of the number of reaction steps, although fourth step attained optimal. The DS of CMC from one to seven reaction steps was 0.91–2.84, respectively. Similarly, CMC content and molecular weight of CMC were 72.60%–85.00% and 153,886–252,231, respectively. Grafting of CMC film with methyl methacrylate (MMA) improved strength properties, but it decreased moisture content due to the incorporation of hydrophobic MMA monomer. The prepared CMC, when applied as sizing agent to cotton fabric, was deposited on the fabric surface through bond formation making it smooth without any crack or rupture. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Utilization of Cellulosic Wastes in Textile and Garment Industries: 2. Synthesis and Characterization of Cellulose Acetate from Knitted Rag

Cellulose acetate (CA) was synthesized from knitted rag, a cellulosic waste of Textile and Garment industries, in the glacial acetic acid, and subsequently acetic anhydride (Ac2O) in presence of concentrated H2SO4 reaction medium. A low to high substitution products were obtained from single step up to seven steps acetylation of cellulose. In this way, it was possible to produce low cost and different grades or substituted acetylation derivatives of cellulose. The synthesized CA was characterized and investigation of its physical characteristics was done. Solubility, acetyl content, acetic acid content, degree of substitution, and molecular weight of CA increased gradually with the increase of the number of reaction steps attaining optimum value at the fourth step. The acetyl and acetic acid content of CA were increased from 39.95 % to 44.25 %, and from 55.73 % to 61.73 % respectively. Similarly, degree of substitution and molecular weight of CA were increased from 2.47 to 2.94, and from 74,249 to 121,437 respectively.

Development of Functional Adsorbent From Textile Cotton Waste by Radiation Induced Grafting Process: Equilibrium and Kinetic Studies of Acid Dye Adsorption

An environment benign-aqueous solvent based-single step-radiation induced grafting process was used to graft Poly(vinylbenzyltrimethyl ammonium) chloride (PVBT) onto cellulosic cotton textile waste to transform it into a valuable cationic adsorbent (PVBT-g-Cellulose). The PVBT-g-Cellulose adsorbent was characterized by grafting yield determination, elemental analysis, scanning electron microscope (SEM), and fourier transformed infrared (FTIR) spectroscopy. The PVBT-g-Cellulose adsorbent, investigated for the removal of model dyes from manufactured solutions, exhibited equilibrium adsorption capacities of ∼540 mg/g, ∼474 mg/g, and ∼122 mg/g for acid blue 25(AB25), acid yellow 99(AY99), and acid blue 74(AB74), respectively. The degree of agreement between the adsorption isotherm models and experimental data followed the order: Langmuir-Freundlich>Redlich-Peterson>Langmuir>Freundlich. The kinetic adsorption data was found to be in close agreement with pseudo-second order kinetic model. The elution percentage of as high as ∼95% could be achieved for AB25 using a suitable eluent.

Dynamic behavior analysis of carboxymethylcellulose hydrolysis in a chemostat

At the present time cellulosic waste substrates is a subject of global relevance because is an alternative source for biofuel production, the complex nature of this substrate and the presence of microorganisms for its biodegradation may result in complex dynamics which are important to understand why in many cases could have negative effects in the productivity process. In this paper dynamical behavior analysis of a chemostat model was carried out for two unstructured kinetic growth models (Luong and Han-Levenspiel), choosing as study case the carboxymethylcellulose hydrolysis by Cellulomonas cellulans, where differences related with multiplicity of steady states, hysteresis, periodicity and unstable operating regions were pointed out.

Purification and Characterization of Thermostable Alkaline Cellulase from Marine Bacterium Bacillus licheniformis AU01 by Utilizing Cellulosic Wastes

The present study was aimed to produce cellu- lase from Bacillus licheniformis AU01 by utilizing major cellulosic wastes. Among the cellulosic wastes tested, rice bran and peptone were found to be the best carbon and nitrogen source for production of cellulase (188 U ml -1 ). Through multi step purification an 8.66 fold purified protein with a specific activity of 620.8 U mg -1 was achieved with the molecular weight of 37 kDa. The optimum temperature and pH for CMCase activity was determined as 50 C and 9 respectively and more than 80 % activity retained at tem- perature 80 C and pH 12.0. The cellulase purified from present study was stable even in the presence of various cationic, anionic and commercial detergents. These remarkable qualities such as thermostability, pH stability and compatibility with detergents will make this cellulase as a potential candidate for industrial applications.

Fermentative bioenergy production from distillers grains using mixed microflora

The feasibility of hydrogen production from distillers grains substrate, an industrial cellulosic waste, was investigated. A substrate concentration of 80 g/L gave the maximum production at 50 °C and pH of 6.0 using sewage sludge. Four controllable factors with three levels: seed sludge (two sewage sludges and cow dung), temperature (40, 50, and 60 °C), pH (6, 7 and 8) and seed pretreatment (none, heat, and acid) were selected in Taguchi experimental design to optimize fermentation conditions. The peak hydrogen and ethanol productions were found with heat-treated cow dung seed, substrate concentration 80 g/L, 50 °C and pH 6. The peak hydrogen production rate and hydrogen yield were 7.9 mmol H2/L/d and 0.40 mmol H2/g-COD respectively whereas the peak ethanol production was 3050 mg COD/L and rate 0.22 g EtOH/L/d. A total bioenergy yield of 41 J/g substrate was obtained which was 21% and 79% from hydrogen and ethanol respectively.

Effect of mixing on enzymatic hydrolysis of cardboard waste: Saccharification yield and subsequent separation of the solid residue using a pressure filter

Cellulosic wastes, from sources such as low-quality cardboard and paper, are regarded as potential feedstocks for bioethanol production. One pathway from these cellulosic materials to ethanol is saccharification (hydrolysis) followed by fermentation. Saccharification is commonly performed using enzymes that are able to cleave the cellulosic structure to smaller units, preferably to glucose monomers. During the hydrolysis, mixing conditions have a considerable impact on the performance of the enzymes. Thus mixing conditions in the hydrolysis tank can also influence the downstream operations and, consequently, the overall economy of the bioethanol process. In this experimental study, four types of impeller, at different hydrolysis conditions were used. The effect of mixing on the glucose yield and on the filtration characteristics of the hydrolysate was evaluated. It was shown that not only the sugar yield depended on the mixing conditions: the effect on the solid–liquid separation step was even more significant.

Estimating evolution of [formula omitted] during methanization of cellulosic waste based on stoichiometric chemical reactions, microbial dynamics and stable carbon isotope fractionation

A change in δ13CH4 during mesophilic methanization of cellulosic waste (paper and cardboard) was described using a mathematical model based on stoichiometric chemical reactions, microbial dynamics and the equation for the 13C isotope accumulation in products including isotope fractionation. In this study, experimental data, previously obtained by Qu et al. (2009), was used to model metabolic pathways of cellulose transformation. A significant change in δ13CH4 occurred in time during cellulosic waste methanization which was in accordance with the model. It was explained by the change in input of acetoclastic and hydrogenotrophic methanogenesis as well as by fractionation of stable carbon isotopes 13C and 12C which was much higher for hydrogenotrophic methanogenesis when compared to acetoclastic methanogenesis.

Combination of Sorbents and Modification of Its Constituents to Enhance the Mopping Ability of Chemically Modified and Unmodified Biological Wastes on Crude Oil and Its Lower Fractions

Protein wastes (feathers, goat hair) and cellulosic wastes (corn cob, coconut husks) were collected, washed with detergent solution, thoroughly rinsed and sun dried for 2 days before drying in an oven and then ground, half of ground material was carbonized at a maximum temperature of 500?C after mixing with H2SO4.The carbonized parts were pulverized; both carbonized and uncarbonized sorbents were sieved into two particle sizes of 325 μm and 625 μm using mechanical sieve.1.5 g protein wastes and cellulosic wastes were each used to mop up spilled crude oil, diesel, kerosene and petrol (separately before combining) by encasing them in a sac like boom of 2cm x 2cm x 1cm dimension so as to determine the efficacy of waste sorbents in cleaning hydrocarbon spills. Results of Tables 1(a)-4(a), 1(b)-4(b) and 5-8 shows that the sorbents mopped, desorbed and retained an average of more than 500%, 350% and 300% of their weight of the hydrocarbon sorbates within average of 90 mins contact time, the volume of sorbates mopped up increased significantly when equal weight of activated and unactivated sorbents were combined, the results of equal combination of activated and unactivated sorbents at each particle size and contact time were compared with that of calculated values, high percentage retention observed were a function of mechanism of absorption/adsorption. Each sorbent have a distinct feature that enhances its mopping ability. Large volumes of the hydrocarbon liquids were recovered by mere pressing, the sorbates were mopped up in the order; crude oil > diesel > kerosene > petrol. Protein sorbents with oleophilic and aqua phobic properties absorbed more of all the hydrocarbon liquids than cellulosic sorbents at any particle size and contact, the later tend to be more abundant and therefore cost effective; it was observed that both carbonized and uncarbonized sorbents are good hydrocarbon mops and therefore good alternative to synthetic polyurethane foam already in use. Combination, particle size, activation of sorbents, contact time, viscosity and chain length of hydrocarbon determined the amount of sorbates absorbed/adsorbed, recovered or retained. The residual leachable oil (kerosene) in the sorbents were below 5% and does not constitute serious environmental menace when left in an open dump to decay being biodegradable waste, but a brighter application is that the waste sorbent can be used in making logs as alternative to fire wood or in making particle board for furniture.

Application of Chemically Modified and Unmodified Waste Biological Sorbents in Treatment of Wastewater

Protein wastes (feathers, goat hair) and cellulosic wastes (corn cob, coconut husks) were collected and washed with detergent solution, thoroughly rinsed and sun dried for 2 days before drying in an oven, and then ground. One-half of ground material was carbonized at a maximum temperature of 500°C after mixing with H2SO4. The carbonized parts were pulverized; both carbonized and uncarbonized sorbents were sieved into two particle sizes of 325 and 625 μm using mechanical sieve. Sorbents of a given particle size were packed into glass column.Then, textile wastewater that had its physicochemical parameters previously determined was eluted into each glass column and a contact time of 60 and 120 mins was allowed before analysis. Results showed 48.15–99.98 percentage reduction of , EC, Cl−, BOD, COD, DO, TSS, and TDS, 34.67–99.93 percentage reduction of , EC, Cl−, BOD, COD, DO, TSS, and TDS, 52.83–97.95 percentage reduction of Pb2+, Ni2+, Cr3+and Mn2+and 34.59–94.87 percentage reduction of Pb2+, Ni2+, Cr3+and Mn2+. Carbonization, small particle, size and longer contact time enhanced the sorption capabilities of the sorbents. These show that protein and cellulosic wastes can be used to detoxify wastewater.

STATISTICAL OPTIMISATION OF ETHANOL PRODUCTION FROM A CELLULOSIC MIXTURE BASED ON PAPER RESIDUES

Lignocellulosic biomass can be used to produce ethanol. The bioconversion process of waste cellulosic materials to ethanol involves two steps: hydrolysis of cellulose to produce reducing sugars, and the fermentation of sugars to ethanol. The response surface methodology (RSM) based on the 2 factorial Central Composite Design (CCD) was applied to optimize the biotechnological conditions of the enzymatic saccharification of the substrate and ethanol production from a mixture of three waste cellulosic materials, i.e. office paper, newspaper and cardboard in ration of 1:1:1 (w/w). The control sample yielded 4.3 kg ethanol from 100 kg cellulosic waste materials and subsequent to the statistical optimization, the efficiency of the bioprocess was increased almost 2.65-fold, obtaining 11.04 kg ethanol from 100 kg cellulosic waste materials.

Recycling of Cellulosic Fibers by Enzymatic Process

In this research, enzymatic treatment as an environmental friendly process has been used for recycling process of old cellulosic wastes such as cotton, viscose, and lyocell. Cellulase hydrolyses cellulosic chains and shortens cellulosic fibers. This study investigates to detect the optimum enzyme concentration and time of treatments for suitable changes of length and weight loss. The main purposes of this article are shortening of cellulosic fibers and evaluating of enzymatic treatment in different kind of cellulosic fibers. According to the data of experiments, with the increase of enzyme concentration and the treatment time, the length and weight loss percentage of the cellulosic fibers has been decreased. The length and weight loss percentage of treated viscose is more than that of lyocell and cotton fibers. Optimized condition, reaction time, and enzyme concentration have been determined by mean length of treated cellulosic samples. Suitable longitudinal distribution of fiber for papermaking industries is in the range of 0 to 4 mm. Optimum enzyme concentration and treatment time for recycling cotton, lyocell, and viscose fibers are 2% and 48 h for cotton and lyocell and 0.5% and 48 h for viscose, respectively. According to the data of experiment, the length of treated fibers is appropriate for its usage as a raw material in papermaking industries.

Characterization of cellulosic wastes and gasification products from chicken farms

The current article focuses on gasification as a primary disposal solution for cellulosic wastes derived from chicken farms, and the possibility to recover energy from this process. Wood shavings and chicken litter were characterized with a view to establishing their thermal parameters, compositional natures and calorific values. The main products obtained from the gasification of chicken litter, namely, producer gas, bio-oil and char, were also analysed in order to establish their potential as energy sources. The experimental protocol included bomb calorimetry, pyrolysis combustion flow calorimetry (PCFC), thermo-gravimetric analyses (TGA), differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, elemental analyses, X-ray diffraction (XRD), mineral content analyses and gas chromatography. The mass and energy balances of the gasification unit were also estimated. The results obtained confirmed that gasification is a viable method of chicken litter disposal. In addition to this, it is also possible to recover some energy from the process. However, energy content in the gas-phase was relatively low. This might be due to the low energy efficiency (19.6%) of the gasification unit, which could be improved by changing the operation parameters.