A Study On The Independence Of Anaerobic Biodegradation Of Organic Fraction Of Municipal Solid Waste

The anaerobic degradation process of landfill is a complex multi-substrate process that is entirely possible to be influenced by other components.This study was formulated to evaluate the independence of anaerobic biodegradation of oganic waste in municipal solid waste such as food waste,paper waste and yard waste of individual and mixing at different ratios to investigate methane production?L₀,m³ CH₄/ton wet waste?and methane generation rate constant?k,1/yr?,and then quantitatively evaluate whether there is mutual interference among the components and their influence on L₀ and k of each single component so as to analyze whether the interaction of each component has influence on their respective biodegradation processs.In this study,the organic components of municipal solid waste?food waste,newspaper and yard waste?including single component substrate as well as the multi-component that was mixed in proportion were selected to evaluate the effects of different inoculum on different substrates to perform the bacth experiments of mesophilic anaerobic digestion.The results are as follows:?1?In the case of anaerobic sludge and leachate as inoculum,the calculated values of food waste+newspaper,food waste+yard waste,food waste+newspaper+yard waste were both lower than the measured value to some extent,but there is a significant difference only under the condition of food waste+newspaper+yard waste with anaerobic sludge as inoculum.?2?According to the fitting results of the calculated value curve and the measured curve of three experimental groups?food waste+newspaper,food waste+yard waste+food waste+newspaper+yard waste?using the first-order kinetic model,the results of food waste+newspaper with anaerobic sludge and all experimental groups with leachate show that there are significant differences between methane generation rate constant.Thus,it can be assumed that under the experimental conditions of this study,which uses a highly dilute solution of the anaerobic sludge and leachate as inoculum,methane generation rate constant of multi-component substrate appear to promote the process,but it seems to related to the original of inoculum and substrate to some extent.?3?In this study,the distribution of bacterial community structure were mainly Firmicutes and Bacteroidetes.When the inoculum was anaerobic sludge,though methanocorpusculum and methanosaeta was the dominant methanogens,the coexistence of acetoclastic and hydrogenotrophic groups was observed,whereas methanoculleus and methanosarcina were the dominant methanogens when the inoculum is leachate.The two experimental groups showed completely different distribution of microbial community structure.The same results were obtained through Fisher's exact test.The distribution of bacterial and methanogenic community structures in all substrate samples was generally related to the source of the inoculum.