Anaerobic Co-digestion Of Swine Manure With Corn Stover And Microbial Diversity Analysis

As the production of pigs and corn increased,the resource treatment is of great significance to environmental protection of swine manure(SM)and corn stover(CS).This study was conducted in mesophilic(38±1?)with semi continuous anaerobic co-digesting SM after solid-liquid separation and CS for studying the biogas production characteristics and microbial diversity.The main results are as follows.At first,the inoculum was collected in our laboratory which was digestate from anaerobic digestion with only SM.The different VS loadings(2,3 and 4 g-VS L-1 d-1)with different SM to CS ratios(1:0,1:1,2:1 and 1:2)was conducted to study the biogas and methane production.The results showed that biogas productions of 4 g-VS L-1 d-1 VS loading,1:1 and 2:1 ratio of SM/CS were higher than control(VS loading is 4 g-VS L-1 d-1),increased by 2.2% and 9.9%,respectively.The optimal VS loading was 3 g-VS L-1 d-1 based on the VS destroyed biogas production.The duplicated proof test was conducted which VS loading was 3 g-VS L-1 d-1,swine manure to corn stover ratios(1:0,1:1,2:1 and 1:2)to find out the optimal SM/CS ratio.The result showed that when SM to CS was 2:1,the VS destroyed biogas production was the highest,72.56±3.40 m L/g.The microbial diversity analysis of different treatments was conducted for proof test.In phylum level,the dominant microorganisms were Firmicutes,Tenericutes,Bacteroidetes and Euryarchaeota in control group.The dominant microorganisms of Verrucomicrobia,Proteobacteria,Spirochaetae and Cloacimonetes were also concluded in experiment groups except above four phylums.In genus level,biogas and methane production was positive correlation with the abundance of archaea Methanoculleus,negative correlation with the hydrolysis and acid-producing bacteria abundance,Ruminofilibacter,Mobilitalea,Sedimentibacter and Sphaerochaeta.The dominant bacteria were Fastidiosipila,the dominant archaea was Methanoculleus in the optimal group(3-2-1).The above results showed that anaerobic co-digesting swine manure and corn stover could increase biogas production and the optimal VS loading was 3 g-VS L-1 d-1,the optimal swine manure to corn stover ratio was 2:1.The different microbial compositions in different treatments were confirmed in this study.This study can offer some supports of theory and data for the future of large scale semi continuous anaerobic co-digesting swine manure and corn stover.