Analysis Of Prokaryotic Microbial Community In Pigs Treated By IC Reactor

Swine wastewater with solid-liquid mixed, large discharge, high content of organic matter and P, N element, carrying large amounts of pathogenic bacteria, eggs and heavy metal elements make it quite difficult to deal with. Usually a combination of aerobic and anaerobic process could make it harmless treatment and energy recovery. IC reactor has characteristics with higher COD degradation rate, smaller HRT and strong shock resistance and so on, which is one of the most efficient means of modern organic wastewater treatment in the field of anaerobic treatment. The IC reactor applied to swine wastewater treatment has only just started, and some encouraging progress has been made in the treatment effect. But the study of prokaryotic microbial community characteristics and functions of the granular sludge acclimation in swine wastewater is still blank. Based on the above facts, this paper uses self-designed IC reactor to do the swine wastewater treatment, the main research contents including study on the effect of different ratios of height to diameter IC reactors in the swine wastewater treatment, which is to investigate the influence of height to diameter ratio and OLR on the IC reactor treatment effect and the composition, structure and function of prokaryotic microbial community of activated sludge and granular sludge in the IC reactor with different height to diameter ratio were studied, which is to investigate the influence of height to diameter ratio and OLR on the prokaryotic microbial community diversity and community dynamics of the activated sludge and granular sludge of IC reactor with different height to diameter ratios. Research results are as follows:(1) The treatment efficiency of IC reactor with height to diameter ratio of 6:1 was higer than that of height to diameter ratio of 10:1 when the OLR is lower than 4.09kgCOD/(m3.d), but less than it when the OLR is more than 4.09kgCOD/(m3.d). During the stable operation of this two IC reactor, the optimal influent COD concentration was 8183.30mg/L with HRT of 48 h, whose OLR reached to 4.09kgCOD/(m3.d) and COD removal rates reached to 95.34% and 95.50% for IC reactors with height to diameter ratio of 6:1 and 10:1 respectively. The optimal HRT was 12 h when the influent COD concentration is about 8000mg/L, whose OLR reached to 19.50 kgCOD/(m3.d) and COD removal rates reached to 88.45% and 89.56% for IC reactors with height to diameter ratio of 6:1 and 10:1 respectively. The optimal influent COD concentration was 15685.07mg/L when the HRT was 12 h, whose OLR reached to 31.37 kgCOD/(m3.d) and COD removal rates reached to 85.57% and 88.49% for IC reactors with height to diameter ratio of 6:1 and 10:1 respectively. These two IC reactor of OLR could be up to 35.89 kgCOD/(m3.d) and at this time of the COD removal rate could be maintained at around 80%. It could be seen from the experimental results that the influence of the ratio of height to diameter on the IC reactor treatment effect is less than that of OLR.(2) 16 S rRNA gene technology was used to conducted a in-depth research on the prokaryotic microbial community diversity of the start sludge and granular sludge(the OLR of 31.37 kgCOD /(m3.d)) of these two different ratio of height to diameter IC reactor. The results show that bacterial and archaeal community is rich in both of the start sludge and granular sludge of these two IC reactors, and bacterial community is much richer. The predominant groups were Firmicutes, Bacteroides, Proteobacteria and Euryarchaeota. The predominant bacterial gunus were Clostridium, Syntrophomonas and Syntrophus. The predominant archaea gunus were Methanosaeta and Methanosarcina. Combined IC reactor operating parameters analysis shows that OLR and the ratio of height to diameter have a significant effect on the types, quantity and function of the prokaryotic microbial community which plays the main degradation function.