Study On The Efficiency Of Biological Nitrogen And Phosphorus Removal And Microbial Diversity In Compand Ferric Enzymatic Activated Sludge

Water Eutrophication has focused by people all over the world,controling andtreating nitrogen and phosphorus pollution is the essential way to cure it. In allwastewater treatment plants,microbes are the main carriers of sewage purification andplay a crucial key on biological nitrogen phosphorus removal, so different communitystructures cause different phosphorus removal efficiency.Ferric enzymatic activatedsludge biological nitrogen and phosphorus removal technology is through ferric iongetting involved into microbial biochemical reactions and energy metabolism,strengthen ferric ion participate in the electron transfer and the role of enzymaticreaction activator to enhance the efficiency of biological nitrogen and phosphorusremoval, and resolve the inherent contradictions and bottlenecks of biologicalnitrogen and phosphorus removal systems from the source, providing a new idea forthe development of efficient deep nitrogen and phosphorus removaltechnology.Taking actual sewage as the research object and using molecular biologymeans of16S rDNA cloned library method,by conventional activated sludge contrasttest, the difference on the efficiency of biological nitrogen and phosphorus removal,microbial community structure and function between compound ferric enzymaticactivated sudge system and conventional activated sludge system were researched inthis study,analysing the principle of ferric enzymatic activated sludge biologicalnitrogen and phosphorus removal from the view points of the micro-structure toreveal its reaction mechanism of biological nitrogen and phosphorus removal and laya theoretical foundation for the biological mechanism of ferric enzymatic activatedsludge biological nitrogen and phosphorus removal technology.The research about the impact of the reaction temperature on microbial activityand the efficiency of nitrification between conventional activated sludge andcompound ferric enzymatic activated sudge system showed that: the nitrificationability and the microbial activity were restricted in the low temperature in twosystems. But at the same conditions of temperature, the nitrification ability, microbial activity and the efficiency of biological nitrogen and phosphorus removal of ferricenzymatic activated sudge system were superior significantly than those ofconventional activated sludge system. When the reaction temperature were20℃,16℃,12℃and8℃,the the specific nitrification rates of ferric enzymaticactivated sudge system and conventional activated sludge system were2.55,2.51,2.27,1.39mgNH3-N/(gVSS*h) and2.46,2.07,1.73,0.33mgNH3-N/(gVSS*h)respectively. Ferric enzymatic activated sludge have conspicuous nitrification abilityof resisting low temperature changes;Low temperature had impacts of differentdegrees on the sludge structure and microbes of two activated sludge, but sludgestructure and microbes of ferric enzymatic activated sludge were more stable thanthose of conventional activated sludge.In the pure culture conditions,the microbial population samples of two activatedsludge systems were identified by BIOLOG and16S rDNA cloning library method.33bacterial strains were separated from two activated sludge samples.These bacterialstrains were identified as five lineages of the domain bacterias: Alphaproteobacteria,Betaproteobacteria, Gammaproteobacteria, Firmicutes and Actinonobacteria.Thesubclass of the Proteobacteria,especially β,γ-proteobacteria was predominated in twoactivated sludge systems. But Acidovorax sp.,Burkholderia thailandensis andComamonas sp.were separated only in compound ferric enzymatic activated sudgesystem.Chromobacterium sp.was separated only in conventional activated sludgesystem.In the mixed cultivating conditions,the microbial population samples of twoactivated sludge systems were identified by16S rDNA cloning library method.Theresults showed that:(1)The bacterial strains separated mainly included Proteobacteria,Bacteroides,Firmicutes and Candidate division TM7.(2)The differences of microbialcomponents in two activated sludge systems:γ-proteobacteria and Bacteroides werepredominated in compound ferric enzymatic activated sudge system. Bacteroides andγ-proteobacteria were predominated in conventional activated sludge system. Thauerasp.,Comamonas sp.,Uncultured gamma proteobacterium,Gerbacter pelophilus,Flavobacterium ferrugineum and Uncultured Bacteroidetes bacterium were separated only in compound ferric enzymatic activated sudge system. Compound ferricenzymatic activated sudge system showed more rich biodiversity. Ferric ion had animpact on the microbial community structure, function diversity and biologicalnitrogen and phosphorus removal effects to a certain extent in compound ferricenzymatic activated sudge.