Characteristics And Functions Of Microbial Community In Anaerobic Active Sludge Of ABR System For Treating Oil-Field Wastewater

High-throughput sequencing technologies and traditional separation culture method were carried out for studing on the structure and functions of microbial communities of anaerobic active sludge in the anaerobic ABR and SBR processing system.First,the high-throughput sequencing analysis was used for revealing the change of the microbial community structure and function in oil extraction wastewater,ABR active sludge and effluent.38118 high quality bacteria 16 s rRNA gene sequences and 41147 fungi the ITS sequences effectively were obtained from oil extraction wastewater,ABR active sludge and ABR effluent Bacteria mainly belongs to the four phylums and 180 genus,respectively is Proteobacteria(45.9%),Firmicutes(11.6%),Bacteroidetes(8.1%)and Thermotogae(6.2%).View of bacteria belong to the level of genus of community composition,is include of Desulfovibrio(2.3%),Thermovirga(1.9%),Marinobacterium(1.8%),Thiomicrospira(0.7%)and Methylophaga(0.7%).Fungi in the ABR pool mainly comes from the three phylums,respectively is Ascomycota(62.31%),Basidiomycota(19.4%)and Zygomycota(3.73%).The Ascomycota plays a main role in the whole sludge system.The diversity of fungi in the level of genus is significantly higher than in bacteria.In addition to unclassified fungi,fungi mainly included of Aspergillus,Alternaria and Cryptococcus.Then,the traditional separation methods was used to separate of facultative anaerobic microbes in ABR activated sludge.To analysis oil anaerobic degradation flora diversity in the ABR system,we screened high efficient degradation facultative anaerobic bacteria strains of oil extraction wastewater.Isolation and purification 11 facultative anaerobic bacteria strains in ABR activated sludge.Most of the strains on the Phylogenetic closely associated with bacillus genus and its related genera,among them two strains belong to bacillus genus,three strains belong to Paenibacillus,4 strains belong to Brevibacillus.The other two strains of bacteria I2 and WHM respectively belong to Tepidiphilus and Psychrobacter.By optimizing degradation conditions and oil extraction wastewater TOC and petroleum degradation experiments,on the one hand,to explore the best influence conditions of facultative anaerobic microbial degradation of oil extraction wastewater,the results show that the optimal reaction temperature is 50?,the best inoculation amount is1%,the best response time is 24h.On the other hand,understanding the degradation characteristics of 11 bacteria strains for oil extraction wastewater,the results showed that strain F2,Q3,WH1 and I2 can degrade the TOC in oil extraction wastewater and also can remove the oil component in the wastewater,thus it can be used to build engineering bacterium for actual wastewater treatment.Finally,to understand the composition and function of the anaerobic bacteria,the methods of traditional separation was used in screening by strict anaerobic bacteria in the ABR activated sludge.Through traditional cultivation method,8 strictly anaerobic bacteria strains were isolated from ABR pool.Then through the morphological and molecular identification,the results showed that ABR-1 is Asaccharospora irregularis bacterium,ABR-2 is Clostridium perfringens,ABR-3 and ABR-8 are Clostridium bifermentans,ABR-4 is Clostridium sordellii,ABR-5 is Sporolactobacillus terrae,ABR-6 and ABR-7similarited as Clostridium uliginosum CK55~T and Clostridium tetanomorphum DSM 4474~T were 98.48%and 96.96%respectively.Eight strains of function is closely related to the metabolism and lipid metabolism in oil field wastewater.