Abstract: The chemical compositions of Manihot esculenta crantz(M. utilissima Pohl)stalks were investigated, the contents of phenolic hydroxyl group and UV spectra of lignin were determined by ultraviolet-visible spectrophotometer. The result showed that the chemical compositions of Manihot esculenta crantz(M. utilissima Pohl)stalks were as follows: ashes 4.97%, cold water extraction 12.04%, hot water extraction 12.57%, 1% sodium hydroxide solution extraction 34.16%, benzene-alcohol solution extraction 4.20%, nitric acid-alcohol cellulose 35.86%, holo-cellulose 72.62%, pentosan 19.20%, acid-soluble lignin 2.51%, acid-insoluble lignin 26.10%, organic solvent-soluble lignin 1.07%, pectin content is 0.02%; it can be used as a non-wood renewable source of natural products.Phenolic hydroxyl content of organic solvent-soluble lignin and acid-insoluble lignin are 1.245 mmol·g-1 and 0.261mmol·g-1 respectively; the maximum absorption wavelength of organic solvent-soluble lignin and acid-soluble lignin in the UV region is near to 205 nm and 280 nm, but shifts to long wavelength or short wavelength with the nature of the different solvents.
Abstract: In this paper, W-doped rutile titania was prepared by low temperature hydrolysis using Tetrabutyl titanate. Powers were characterized by XRD、DRS、PL. At 1073K, Doped concentration have been in a certain range, Tungsten could be doped into the lattice of rutile TiO2 in the way of replacement, which would cause no change in rutile TiO2 crystalline state with sunlight as the light source, pH=2.0, catalyst concentration was 1.0g.L-1, concentration of methyl orange was 5.0mg.L-1. It has been shown that Tungsten doped TiO2 powders(1.0%,1073K) has been the most photodegradation efficiency, and the degradation efficiency was 96.8% after 12h.
Abstract: The effects of the dosage of enzyme, liquid/solid ratio, reaction temperature, PH value and reaction time on enzymolysis and saccharification of bagasse pith were studied. The results showed that the optimum conditions of enzymatic hydrolysis of cellulase were PH 5.0,the dosage of enzyme 0.005g/g (oven dry pulp), liquid/solid ratio 35:1, 50°C and s 60h. The changes of bagasse pith during reacting were analyzed through HPLC and FIRT, it were found that the content of xylose increased and improve the yield of reducing sugar in hyrolysis by double-enzymatic(cellulase and lxyanase). The results of FTIR analysis showed that new chemical construction and functional groups were not generated.
Abstract: The solubility of 8-hydroxyquinoline lead, lead diethyldithiocarbamate, 8-hydroxyquinoline mercury and mercury diethyldithiocarbamate in supercritical carbon dioxide under different supercritical conditions was investigated by using supercritical extraction device. It was measured ranged from 308.15K to 328.15K for supercritical temperature, and 10 MPa to 30MPa for pressure. The solubility data of metal complexes were correlated and a mathematical model was put forward from a viewpoint of solvent association theory compared to Chrastil’s model. The results showed that SA model gives fairly good agreement with the experiment data.
Abstract: We investigated the influence of amendment of charcoals derived from rice residues at 250, 450 and 850 °C on the sorption and desorption behaviors of carbofuran in a soil using a batch equilibrium method. The crop residues derived charcoals at 850 °C had higher sorption capacity than those prepared at 250 and 450 °C. Amendment of the charcoal material (<1%) prepared at 250 °C had no obvious effects on pesticide sorption in soils. The soils amended with the charcoal materials had higher sorption capacity than the original soil, and the nonlinearity of sorption of carbofuran on the amended soils increased with the content of charcoal, especially for those amended with the charcoal obtained at 850 °C. Sorption-desorption hysteresis occurred for all treatments including the control.
Abstract: As we know, agricultural waste like rice husk & straw etc., are produced a lot from the rice paddy special caution is needed in order to prevent the resulting serious environment pollution. Due to lack of practical additive influence of RDF production in the present, the present research will be involved in forming parameters of temperature, pressure etc. in addition to ameliorate strength and thermal performance test of the RDF product by the additive. The optimal condition of manufacture technique will be concluded and suggested for the reference of processes in the practical plant establishment.
Abstract: The effect of the reaction time, the amount of enzyme, the reaction temperature and the pH value system, also the substrate size on bagasse pulp cellulose hydrolysis in the rate of reducing sugar was studied. And the optimum conditions response was researched. Under these conditions, we also studied the percent conversion of reducing sugar, and analyzed the changes of crystallinity after the bagasse pulp cellulose hydrolysis.
Abstract: The tungsten carbide catalysts supported on carbon nanotubes were prepared by the temperature-programmed reduction, and there were used as catalysts for the hydrogenation of cellulose. The optimum synthesis and reactive conditions were investigated. The results show that the WC loading was 40%, the catalyst calcination temperature was 773K, the reduction temperature was 1073K. The conversion rate of cellulose could reach 84.5%, and the yield of sorbitol was 45.9%. The WC/CNTs catalysts show high catalytic activities and higher selectivity towards sorbitol in crystal cellulose hydrogenation.
Abstract: One-stage Autothermal Thermophilic Aerobic Digestion was autonomously designed to treat municipal sludges. By the way of batch operation experiment, the influence of removal rates of volatile suspended solids(VSS), total suspended solids(TSS), auto-rise temperature, and COD concentration, volatile fatty acid concentration of sludge, were investigated respectively. The results showed that a large part of reactor temperature was in thermophilic statues at 56°C-60°C during sludge digestion period; Municipal sludges treated have achieved stabilization standard of 503 articles of EPA while removal rates of VSS and TSS at 38.9% and 31% respectively for 360h retention time. Resulting from micro-organisms hydrolysis reaction, total COD concentration of sludge supernatant (SCOD) was increased firstly and then dropped afterward during the process of digestion while total COD concentration of solid phase of sludge(TCOD) still fall down with removal rate of TCOD at 35.6% for 360h retention time. A sum of concentration of volatile fatty acid(VFA) was accumulated gradually in the sludge supernatant at 2745mg/L for 360h retention time because of micro-aerobic situation in the beginning of digestion process, and can be use as the carbon sources for wastewater treatment process.
Abstract: The combustion characteristics of coal and biomass blends with adding adsorbing sulfur agent was investigated using thermogravimetric analyzer. The results indicated that the combustion process of the blends were similar to that of pure coal and biomass, which there were two apparent weight-loss peaks--one for volatile burning and another for char burning. The combustion stages could be divided into the dewatering period, volatilization and burning, char burning and burnout. Nevertheless, the combustion characteristics of blends varied with the biomass blending ratio and Ca/S ratio. Due to the increase of biomass blending ratio, the volatile matter content of blends increased, which leaded to the increase of peak value for volatile burning stage. In this stage, due to the lower reaction temperature, less SO2 was produced and the reaction to CaO was slower. With the progress proceeding, char began to be burned and large heat was released and the adsorbing sulfur reactions were becoming stronger. Although the mass of blends reduced fastly, the mass of CaSO3 and CaSO4 increased compared to CaO, Which leaded to a wider temperature range of weight-loss for the char burning period. At the same linear temperature gradient, an increase of Ca/S decreased the temperature of volatilization and char burning, and the residue was increased due to more CaO additive. Therefore, the appropriate ratio of Ca/S was necessary to improve the combustion and adsorbing sulfur efficiency. In this study, a basic kinetics analysis for coal and biomass blends is provided. The kinetics parameters reveal that the combustion process of coal and biomass blends with adding absorbing sulfur agent can be described by a first order reaction equation.