Characteristics Of Transformation Form On Carbon And Nitrogen In Anaerobic Digestion Using Chicken Manure Mediated By Biochar

Current application research of biochar mainly focuses on soil improvement, sewage treatment, environmental restoration, and other fields. However, there are few reports about biochar application to anaerobic digestion.In addition, the effect of carbon and nitrogen on anaerobic digestion temporarily stays in the simple field of carbon nitrogen ratio, namely simple comparison between carbon and nitrogen content, and it is not yet clear that what kind of specific carbon, nitrogen, makes bigger influence on the anaerobic digestion. C source material is very important in anaerobic fermentation, and it is synthesis raw materials of fermented product. C/N has a great influence on biogas fermentation, and decides biogas production and its quantity. In anaerobic digestion, carbon is transformed into methane and carbon dioxide under the action of methanogenesis, and carbon content in the fermented liquid has a downtrend, leading to C/N falling continuously and forming ammonia that produces inhibitory effect on the normal proceeding of anaerobic digestion. Biochar has developed pore structure, large specific surface area, strong stability and adsorption. carbon content is extremely rich in biochar, and it can improve C/N of fermentation raw material.As one of the important elements in anaerobic fermentation, nitrogen makes huge change.With self-designed anaerobic digestion test equipment adding biochar to chicken manure, anaerobic digestion experiments of three factors and three levels was conducted in this study: in the biological carbon content of 2.5%, 5.0%, 7.5%; 20, 40, 60 mesh by biochar size, quantity of measured carbon, nitrogen form content, biogas production, CH4 content of nitrogen form, CO2 and H2 S content when sampling 20%, 25% and 25%. Carbon nitrogen forms in different inoculum dynamic change rule with different biochar addition amounts, different particle size of biochar, different inoculums addition amounts was explored, the relationship between measured carbon, nitrogen form data and gas properties was analyzed, and specific carbon nitrogen forms affect gas properties was attempted to be confirmed.The main research contents and results of this paper are as follows:(1)The biochar mediated form of chicken manure anaerobic digestion carbon conversion and gas properties. Studies show that adding biochar had significant effect on carbon form and its content in digested chicken manure wastewater. Carbon in digested chicken manure wastewater system may be transformed through two ways: first, volatilize as gaseous form; Second, conversion to CH4 under the action of anaerobic digestion. Organic carbon content in the test reduced by 717.8 mg/L, inorganic carbon content decreased by 229.5 mg/L, total carbon equivalent to a 12.51% reduction decreased by 947.3 mg/L.TOC content, TC content, NPOC content, and IC content decrease with extended anaerobic digestion time, and reduced by 11.79%, 6.02%, 9.29% and 11.79% respectively at the end of anaerobic digestion. Between the carbon form are significant or extremely significant correlation. In anaerobic digestion, the change of different carbon forms maked non-significant influence on CH4 content, CO2 and H2 S content.(2)The biochar mediated form of chicken manure anaerobic digestion nitrogen conversion and gas properties.. Studies show that adding biochar had significant effect on nitrogen form and its content in digested chicken manure wastewater. Adding biochar chicken manure total nitrogen decreased significantly in the anaerobic digestion system, compared to before the test after test of various nitrogen forms total reduced 1557.34 mg/L, equivalent to a 59.35% reduction in.TKN, NH4+-N and NO3--N, NO2--N and DIN are decrease with anaerobic digestion time, at the end of the anaerobic digestion was reduced by 59.35%, 76.19%, 0.77%, 59.35% and 24.66%;TON increased with the extension of anaerobic digestion time, increased by 5.06%.NH4+-N is still as the main body in the anaerobic digestion liquid nitrogen in a form, but the decreasing trend is also very significant, on the one hand, NH4+-N in under the action of anaerobic digestion to NH3 volatilization, on the other hand is transformed into NO3--N.N decrease mainly through NH4+-N volatile.Between the nitrogen form are significant or extremely significant correlation. In anaerobic digestion, the change of different nitrogen forms maked non-significant influence on CH4 content, CO2 and H2 S content.