応用水文 = Applied hydrology

Lignocellulosic biomass (LCB) is the most abundantly available bioresource amounting to about a global yield of up to 1.3 billion tons per year. The hydrolysis of LCB results in the release of various reducing sugars which are highly valued in the production of biofuels such as bioethanol and biogas, various organic acids, phenols, and aldehydes. The majority of LCB is composed of biological polymers such as cellulose, hemicellulose and lignin, which are strongly associated with each other by covalent and hydrogen bonds thus forming a highly recalcitrant structure. The presence of lignin renders the bio-polymeric structure highly resistant to solubilization thereby inhibiting the hydrolysis of cellulose and hemicellulose which presents a significant challenge for the isolation of the respective bio-polymeric components. This has led to extensive research in the development of various pretreatment techniques utilizing various physical, chemical, physicochemical and biological approaches which are specifically tailored towards the source biomaterial and its application. The objective of this review is to discuss the various pretreatment strategies currently in use and provide an overview of their utilization for the isolation of high-value bio-polymeric components. The article further discusses the advantages and disadvantages of the various pretreatment methodologies as well as addresses the role of various key factors that are likely to have a significant impact on the pretreatment and digestibility of LCB.

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Recent Trends in the Pretreatment of Lignocellulosic Biomass for Value-Added Products

Protection of environment is of immediate concern and this can only be achieved by avoiding the use of chemicals for fuel production. Lignocellulosic waste is becoming popular as a feedstock for biofuel production. The can be converted into usable form for biofuel production by using a suitable pretreatment method. Different pretreatment methods have been used by researchers which are physical, chemical, physico-chemical, biological and combined pretreatments. Evidently chemical pretreatment is found to be more expensive as a large amount of chemicals are used for pretreating the lignocellulosic substrate. It has been shown that combined pretreatments are more effective as compared to single pretreatment and there is an extensive scope of combinations which can also be applied in future. Recent review critically discusses and compares different pretreatment methods, biomass resources, chemical composition of different agricultural biomass and the use of this biomass for bioenergy generation. Various pretreatment processes used for bio-hydrogen, bio-methane, bio-ethanol, bio-methanol bio-butanol and bio-diesel production are also discussed.

Pretreatment of lignocellulosic wastes for biofuel production: A critical review

Environmental hazards: Assessing risk and reducing disaster

Current perspective on pretreatment technologies using lignocellulosic biomass: An emerging biorefinery concept

Effect of microwave pretreatment of mixed culture on biohydrogen production from waste of sweet produced from Benincasa hispida

The present study focuses on the production of biohydrogen by the process of anaerobic degradation. Vegetable wastes (VW) were used to produce biohydrogen using heat pretreated mixed inoculum taken from cow dung so that the methanogenic activity can inhibit and also eliminate the non spore forming bacteria too. Inoculum was pretreated by heating in the temperature range of 50–100 °C. Maximum biohydrogen produced when inoculum was pretreated at 100 °C was 98.80 % of the total gas. The amount of the hydrogen produced was 3.44 ml H2/gm dried VW and COD removal efficiency was 81.3 %. Only 17.7 % hydrogen was produced in the untreated inoculum and COD removal efficiency was 36 %. Each batch reactor was operated for 25 days and renewed thereafter, the working volume of the each batch reactor was 800 ml and the 20 % inoculum was used for the reactor set up. The heat pretreatment of the inoculum hence enhanced the biohydrogen production.

Effect of Heat Pretreated Consortia on Fermentative Biohydrogen Production from Vegetable Waste

Ultrasonic assisted petha waste water pretreatment of rice straw for optimum production of methane and ethanol using mixed microbial culture

Objectives: To evaluate the efficacy of N,N'-dichloro-bis (2,4,6-trichlorophenyl] urea, known as CC2 in lipophilic and hydrophilic formulations as a decontaminant against massive dose of sulphur mustard (SM) and investigate its toxic effects on various haematological, biochemical, histological and physiological parameters. Methods: CC2 was prepared as a 20% ointment in petroleum jelly and as a hydrophilic suspension in hydroxypropyl cellulose or gum acacia, and evaluated for its decontamination efficacy against a massive dose of SM in mice and rats. Various haematological, biochemical, histological and physiological variables were studied for safety evaluation of CC2 by administering 2.0 g.kg - 1 orally. Results: CC2 was stable in lipophilic and hydrophilic formulations by active chlorine assay and was able to decontaminate SM immediately by gas chromatographic technique. In animal experiments hydrophilic formulations of GC2 was found to be an effective decontaminant compared to lipophilic ointment. The hydrophilic formulations were able to protect mice (114 fold LD 5 0 ) and rats (48 fold LD 5 0 ) when decontaminated 30 sec post dermal application of SM. CC2 in a dose of 2.0 g.kg - 1 orally, did not change significantly any of the haematological and biochemical parameter, 24 h after administration. Histological observation of vital organs did not reveal any toxicity of CC2. Respiratory variables like tidal volume and frequency were not changed in unanaesthetised rats given a dose of 2.0 g.kg - 1 orally. Cardiovascular parameters viz., heart rate, mean arterial blood pressure, left ventricular end diastolic pressure, and arterial systolic and diastolic pressures were also not changed in anaesthetised rats given a dose of 2.0 g.kg - 1 orally. Conclusion: High decontamination efficacy against SM, good stability and extremely low toxicity make hydrophilic formulation of CC2 a favourable and preferred personal decontaminant.

Radhika Singh

Papers

Pretreatment of lignocellulosic wastes for biofuel production: A critical review

Effect of microwave pretreatment of mixed culture on biohydrogen production from waste of sweet produced from Benincasa hispida

Effect of Heat Pretreated Consortia on Fermentative Biohydrogen Production from Vegetable Waste

Ultrasonic assisted petha waste water pretreatment of rice straw for optimum production of methane and ethanol using mixed microbial culture

Acute toxicity studies of CC2: An effective chemical decontaminant of sulphur mustard in hydrophilic formulation