Study On Succession And Function Of Microbial Community During The Operation Periodin IC Anaerobic Reactor

The pharmaceutical wastewater contains complex composition,high salinity,poor biodegradability,high COD content and high chromaticity,which is one of the recognized refractory degradation industrial wastewater.This paper study the start-up and operation period of IC anaerobic reactor for pharmaceutical wastewater treatment,reveal the changes of microbial community structure in the operation period and the relationship with functional bacteria,and further study the relationship between microbial community structure and environmental factors,in order to provide technical and theoretical support for biological treatment and system control of pharmaceutical wastewater.In this study,the start-up and operation period of IC anaerobic reactor for pharmaceutical wastewater treatment was studied as follows:?1?The removal rate of pharmaceutical wastewater treatment during the operation period and start-up process of IC anaerobic reactor was studied.The anaerobic sludge in IC reactor was acclimated by pharmaceutical wastewater concentration gradient.After the successful start-up of IC reactor,the effluent quality is good,the removal rate of COD was stable at about 65%,the removal rate of SO₄^2-was stable at about 73%,and the influent ammonia nitrogen is low than effluent ammonia nitrogen.?2?The change of microbial community diversity during the operation period was studied.16383 bacteria effective sequence and 22372 archaea effective sequence were obtained from the sludge samples by using high-throughput sequencing.Sample2 and sample 4 have highest Shannon-Wiener index in bacteria and archaea level,respectively,indicating these two samples have the highest bacterial diversity and archaeal diversity in all samples.?3?The composition of microbial community structure of IC anaerobic reactor was studied in bacterial and archaeal level.During the operation period of IC reactor,the dominant bacterial phylum were Proteobacteria,Chloroflexi and Bacteroidetes,the dominant bacteria genera were norank_fAnaerolineaceae,Truepera,Mesotoga,Tepidiphilus,norank_fRhodobacteraceae,Ottowi and norank_f<sub>Lentimicrobiaceae,the dominant archaeal phyla was Euryarchaeota,the dominant archaeal genus was Methanomethylovorans.?4?The effects of environmental factors on microbial community structure were studied by CCA analysis.The results show that influent COD,ammonia nitrogen,sulfate and p H are important factors for affecting microbial community structure,influent COD,ammonia nitrogen and sulfate were positively correlated with Thermotogae,Bacteroidetes and Firmicutes,Proteobacteria,Tepidiphilus,norank_f<sub>Lentimicrobiaceae etc.;influent p H was positively correlated with Gemmatimonadetes,WS6,Actinobacteria,Truepera,and Methanosaeta.