Study On Dry Anaerobic Fermentation Of Kitchen Waste-Sludge And Its Microbiological Mechanism

For wet anaerobic digestion technology and dry anaerobic fermentation of individual materials,there are often problems such as low organic load rate,easy acidification,low gas production efficiency and poor stability in practical applications.In this study,the kitchen waste(referred to as kitchen waste)and dewatered sludge(referred to as sludge)were the main research objects,and the dry anaerobic fermentation method was adopted to determine the optimum solid content of dry anaerobic fermentation under the established conditions.Mix the ratio of the best materials and study the microbial mechanism of combined anaerobic fermentation of kitchen waste and dewatered sludge.For dry anaerobic fermentation,the solid content is an important indicator for the raw materials.In this paper,the batch biochemical methanogenic potential test(BMP)batch experiment is conducted to study the mixed dry anaerobic fermentation of kitchen waste and dewatered sludge.The same VS ratio(VS ratio of 1:1),different solid content(TS,15%,20%,25%,respectively),medium-temperature(37 ° C)dry anaerobic fermentation,methanogenic efficiency(methane production rate,The effects of methane production,stability(VFAs accumulation,pH ternary buffer system),the results show that the dry anaerobic fermentation combined fermentation solid content has little effect on methanogenesis,the reactor is relatively stable under the three conditions.There is no acidification,but when the TS is 15%,the gas production is relatively more;when the TS is 25%,the organic matter conversion rate is the highest.Research on kitchen waste and dewatered sludge under the same TS(TS is 20%)combined with dry anaerobic fermentation with different mixing ratios(sludge VS: kitchen waste VS is 0:1,1:3,1: respectively)1,2:1)by BMP.The effect of methanogenic efficiency(methane production rate,methanogenesis),stability(VFAs accumulation,pH ternary buffer system)on medium temperature(37 ° C)dry anaerobic fermentation,determine the appropriate mixing ratio The results show that the reactors in each group can run stably,and the ratio of dewatered sludge and kitchen waste is 0:1,the gas production effect is the best;the appropriate amount of dewatered sludge can effectively improve the VFA caused by the excessive hydrolysis rate in the early stage.Accumulation is conducive to system stability,and proper adjustment of alkalinity is conducive to increasing cumulative methane production.Select the sample corresponding to the desired fermentation time point.0.2 mL of each sample was used for DNA extraction using FastDNA Spin Kit for Soil(MP Biomedicals).It can be seen from the microbial community structure diagram that under the condition that the gas production is not much different and the reactor system is relatively stable,the solid content has little effect on the microbial community structure during dry anaerobic fermentation;with the anaerobic reaction process,The dominant bacteria in the functional flora are changed from acetic acid utilization to hydrogen utilization;when the mixture ratio of dewatered sludge and kitchen waste is 0:1,the bacterial community structure is relatively stable;mixed fermentation with appropriate adjustment of alkalinity is more helpful.The stability of archaeal community structure.Analysis of microbial colonies showed a correlation with time series.