The Study On Promoting Anaerobic Digestion By Novel Electron Flow Contronl

Methane production by anaerobic digestion of is one of the most important strategies to mitigate the energy crisis through biomass energy.Therefore,this study was mainly focusing on the acetogenesis stage and methanogenesis stage which are the two crucial restrictive stages of the four stages,Utilizing sodium acetate as the only carbon source in the whole process,Geobacter sulfurreducens and granular activated carbon（GAC）were amended in the propose of promoting methanogenic process through electron transfer.The amount of CH₄ production,CH₄ production rate,acetate degradtion rate,SMP,FISH,qPCR,high-throughput sequencing,SEM were employed to reveal the influence of external conditions and mechanism during methanogenesis process.The CH₄ production rate of Geobacter sulfurreducens amended treatment in the experimental group increased from 0.094mmol/d to 0.15mmol/d,and the lag phase was shortened from 4 days to 1 day.FISH was used to determine the integration of introduced G.sulfurreducens and bioaugmented methanogens.According to the fluorescence intensity,FISH quantified analysis showed that the biomass of G.sulfurreducens in experimental sample is 80%more than the control.Additionally,G.sulfurreducens was spatially gathering more intense with methanogens which implied the potential for biological connection.The 16S rRNA gene high-throughput sequencing showed thatgenus of Methanobacterium was increased 45%and Geobacter were also detected in test group.Therefore,The results indicated that Methanobacterium were the key methanogens related with the Geobacter bioaugmentation.Adding granular activated carbon（GAC）to different temperature anaerobic digestion system,the rate of CH₄ production increased by 50%at 55℃and decreased 42%at35℃.It is supposed that the increase of methane production lead to CH₄ production increased or not biomass by qPCR.The 16S rRNA gene high-throughput sequencing was conducted to analyze that the relative abundance of Methanosarcinaceae increase about 31%.Nothing known exoelectrogenic were found in 55℃,So we supposed that there were other unknown exoelectrogenic to submit electronic to methanogens,and thought the direct interspecies electron transfer process is the main involved.