Research On The Optimization Of An Aerobic Fermentation Conditions And The Agricultural-Use Of The Remains

China is a large agricultural country with abundant biomass energy; strong promotion of biogas technology can not only improve the rural living environment, but also can provide people with clean energy. In this experiment, we use the rural common animal manure and wheat straw as fermenting materials to study their gas producing characteristics under different conditions in order to ascertain the optimal fermenting raw material and fermentation condition. At the same time I aslo evaluate the agricultural-use of fermentation residue so as to provide a theoretical basis for promotion of biogas technology in rural areas and resources recycling.Use self-designed biogas fermentation device, select the wheat straw, corn straw, pig manure and cow dung four types of fermentation raw material to study different ratios, inoculum concentrations and single-factor of material concentration's impacts on the fermentation process as well as the three factors'synthesizes impact on fermentation process. At the same time, detect the content of nutrition element in plants and heavy metal content in biogas fermentative residue. In the light of the standards of agricultural assessment, Conclusions are as follows:(1)When Livestock manure and straw were mixed fermented the ratio of the best dry material mass were as follows, pig manure∶corn stalks equals 2:1, cow dung∶corn stalks equals 1∶1, pig manure: wheat straw equals 3∶1, cow dung∶wheat straw equals 1∶1. When temperature changes a lot, especially the daily average decrease of 3～6℃above, is often affects gas production. higher, severely, steady temperature is benefit for fermentation. Under low temperature (11～30℃), the average temperature is 20.5℃, it is suitable to use the cow dung mixed with straw as fermenting materials。Its gas production is stabler and higher than using pig manure mixed with straw as fermenting materials. When under higher temperature(18～39℃), the average temperature is 28.2℃,the capability of gas production used pig manure mixed with straw as fermenting materials is higher than that used cow dung mixed with straw as fermenting materials.(2)Increase the fermentation raw material concentration can increase gas production, but the utilization rate of fermentation of raw materials shows an upward trend then a downward trend as the increasing of the fermentation raw material concentration. So it is not suitable to increase gas production by increasing the concentration of raw materials simply. It's better to choose the 10% fermenting raw materials, accord both gas production and utilization raw materials. When the concentration of fermenting materials is 10% is the best. This can both provide adequate gas production and upgrade the utilization rate of fermenting materials to conserve resources.(3)Inoculum concentration's influence on the methane gas production is significant. Increase Inoculation concentration good for the reaction when the inoculum concentration is 6%. When the inoculum concentration reaches more than 30%, the methane fermentation system boot faster, variation range of pH is smaller and gas production is stable. But the experimental group whose material inoculation is higher than 30% are equal in gas production. So when the inoculum concentration equals to 30% is the best. At this time, It can not only economize raw materials, but also produce gas efficiently.(4)The combination that pig manure mixed with wheat straw on anaerobic fermentation produce gas mostly is A (raw material configuration) is 2:1, B (materials concentration) is 6%; C (inoculum concentration) is 30%. COD degradation rate of the best combination was A (raw material configuration) is 1:1, B (raw material concentration) is 6%, C (inoculum concentration) is 30%. In the study of the three factors, The most significant factor affect anaerobic fermentation used pig manure and wheat straw is the inoculum concentration; appropriate amount of inoculum can make the system contains enough highly active anaerobic microbial gas production as soon as possible to enhance gas production.(5)The methane fermentation residue and the methane fermentation residual include rich plant nutrition element. Its heavy metal content respectively achieves in the irrigation water agricultural use standard and the agricultural use sludge the pollutant control standard. Meanwhile the biogas slurry can be a good agricultural liquid manure, and the residue can be used as base fertilizer for agricultural use.