| Through the new rural construction, housing conditions and living conditions of rural residents have been greatly improved. However, due to the infrastructure, such as up and down the water pipes, waste treatment and disposal measure is not in place, causing new environmental problems. In this paper forcus on laboratory studies on some problems exiting in mixed organic waste anaerobic fermentation device in order to provide some theoretical guidance for the anaerobic fermentation of mixed raw material. Anaerobic fermentation refers to under anaerobic conditions, the use of natural microorganisms or microbial inoculation, convert the organic matter into carbon dioxide and methane gas. The method has some advantages like low energy consumption, less sludge, recyclable of energy. In developed countries, especially in Europe actively developed and used in recent years, it is one of the future directions of organic solid waste disposal.Based on the existing research, on the basis of cow dung, biogas, straw, fruit and vegetable waste, sewage mixture as a fermentation substrate studied the change of TP gas production characteristics under different temperatures in the design of their own small-scale biogas device. The results showed the same growth trend at different temperatures of water-soluble phosphorus, under the condition of temperature (52 ℃) of a water-soluble phosphorus greater growth; under lower temperature (30 ℃/ 37 ℃) conditions the daily gas production and gas production accumulation are significantly higher than the total volume of high temperature and room temperature (22 ℃) in the experimental group, the water-soluble phosphorus and gas production cumulative trend consistent. At high temperatures, the water-soluble phosphorus and gas production cumulative trend trend is opposite; at room temperature, more water-soluble phosphorus accumulation. Biogas generation, medium temperature (30 ℃/ 37 ℃) under the conditions, CH4 has accounted for the main component; at a high temperature (52 ℃) conditions, CH4 and CO2 content is basically the same. From the solid volume reduction effect, the temperature (37 ℃) better, TS reduction rate of 58.15%, VS reduce the rate of 74.59%. The pH value of different temperature system is basically kept constant, which shows that the buffering function of the system is good.The degradation of straw is limiting step of anaerobic fermentation, aiming at this problem, this paper contains leaf in the soil sample can get 10 strains screening, separation and purification of lignin degradation strains. With strong capacity of producing lignin peroxidase two strains, remember to A62, A61. A62 strain degradation enzyme activity is relatively high. Experiments of strain A62 growth curve was determined, draw strain A62 time range of each growth stage. Gram staining showed that strain A62 belongs to bacterium of positive of change orchid family name. Lignin peroxidase enzyme production conditions of optimization show that the most appropriate production strains A62 lignin peroxidase (temperature, pH, carbon source, nitrogen source,35 ℃, respectively,8, lactose, peptone. The experiment measured highest lignin peroxidase enzyme activity of 46.2 U/mL. Strain A62 degradation of lignin, the results show that under different conditions, the pH value of 8, culture temperature of 35 ℃, in 0.02 mol/L (N) peptone as the nitrogen source, the strain the ability to degrade lignin strongest.Mixed anaerobic fermentation of raw materials is a very complex process, how efficient volume reduction at the same time get a higher quality of biogas has been a research direction, anaerobic fermentation technology at the same time meet the requirements of the energy shortage and environmental protection. This article only on these two issues conducted experiments to explore; to study in the future will filter out lignin-degrading bacteria after the expansion is applied to the actual anaerobic fermentation system to obtain efficient degradation process at the same time get more methane. |
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