Research On Affecting Performance And Bacterial Diversity Of Biological Aerated Filter For Municipal Wastewater Treatment

In this paper, the Biological Aerated Filter (BAF) which was used in Qingdao Maidao sewage treatment plant was studied to analyze its treatment efficiency in treating typical municipal sewage which mainly composed of domestic sewage.First, focused on the influence of different operating conditions and process parameters on the performance of biological aerated filter purify effectiveness;Then, With the help of molecular ecology techniques, such as PCR, with constructing 16S rDNA gene library, bacteria diversity of BAF filter surface biofilm in Qingdao Maidao sewage treatment plant was analyzed by phylogenetic; Finally, BAF kinetics models of removing organic was given.BAF was used in Qingdao Maidao Wastewater Treatment Plant for municipal wastewater treatment, major pollutants COD,NH3-N and SS removal rates of the annual average was 58.8%,56.2% and 67.6%, respectively. Processing performance and stability, the effluent indexes are better than the I-B criteria specified in Discharge Standard of Pollution for Municipal Wastewater Treatment Plant(GB18198-2002),shows that the process has a good capacity of sewage treatment.Research on Affecting Performance of Biological Aerated Filter for Municipal Wastewater Treatment, the results showed that when COD and NH3-N in influent were between 60-260mg/L and 22-65 mg/L, respectively, the optimum hydraulic loading was between 2.5-3.2m3/(m2h),the optimum COD loading in influent was between 2.2-3.3kg/(m3d),and the optimum NH3-N loading was between 0.4-0.8kg/(m3 d).The optimum gas to liquid ratio was 5:1.The optimum temperature was between 15-28℃. The removal rate was negatively related to COD and NH3-N loading in influent.BAF bacterial diversity within the biofilm surface was studied;the results show that the dominant microorganisms of the filter surface areβ-proteobacteria, y-proteobacteria and bacteroidetes.Order of dominance isβ-proteobacterium sp. (accounting for 38.6%),γ-proteobacterium sp.(accounting for 18.2%),bacteroidetes sp. (accounting for 13.6%),α-proteobacterium sp.(accounting for 9.1%), 8-proteobacterium sp. and Nitrospirae sp.(each accounting for 4.5%),Firmicutes sp. (accounting for 2.3%),while there are still 9.1% of unknown groups.In the BAF, Pseudomonas,Sphaerotilus,Xanthomonas and Flavobacterium are dominant microorganisms to remove organic pollutants,Nitrosomonas sp.are advantage nitrosation bacteria, Nitrospira sp.are advantage nitrification bacteria, Hyphomicrobium and Comamonas sp.are advantage denitrifying bacteria.26 OUT phylotypes received from sequencing were analyzed with MEGA, the result also demonstrated that the bacterium on the filter surface in Biological Aerated Filter (BAF) have great diversity.The kinetic model of removing organic of Biological Aerated Filter can be obtained through analyzing removal kinetic model of organic esterase:...