Studies On Microbial Community And Phosphorus Enrichment Bacteria From The Low Temperature Nitrogen And Phosphorus Removal Process

Microorganism plays a decisive role in the process of the main pollutants in the biological sewage treatment systems. In order to improve the wastewater treatment process, must understand the community structure characteristics in the sewage treatment system. But at present the research of sewage treatment mainly are traditional techniques based on separation purification and cultivation, and it could not satisfy nowadays the research of microbial community which requires accurate and complete.The subject improvement process activated sludge from an anaerobic-anoxic-aerobic denitrification-dephosphorization system, Operation it at14±1℃, The microbial community structure investigated by the molecular biological technology PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis), Optimization PCR and DGGE reaction conditions. Finally isolated efficient function bacteria from the activated sludge in the actuating phase of the low temperature system and identification all the strains.The results show that the improvement A2/O system at14±1℃in stable removal efficiencies procedure on TN TP and COD were both high, the removal of COD was95%TP was90%and TN was80%, the process significant improved the effect of denitrification-dephosphorization.Using molecular biology method to analysis the microbial community structure in the different reaction pool from the improvement A2/O system. Get the following conclution, Each reaction pool have plenty and complex structure microbes, the microbes was inevitably flowed by the flow of the sludge, so the bacteria distribution in the reactor was equable.The sequence was determined through comparison with Genbank:16S rDNA sequences from activated sludge samples were analyzed and classified into six lineages of the bacteria, including Gamma Proteobacterium; Nitrospira sp; Actionbacterium; Betaproteobacteria; Bacilli and Bacteroidetes.The Nitrospira sp and Actionbacterium were the domain bacteria, Bacteroidetes were the advantage bacterium in the anaerobic pool; Gamma Proteobacterium were the advantage bacterium in the anoxic pool; Betaproteobacteria were the advantage bacterium in the aerobic pool. These microbes were the main strains in the low temperature denitrification-dephosphorization system.Separation and screening the circulating stains phosphorus accumulation organism (PAO) and nitrifying when the low temperature system is stable, in order to test the pH,temperature,trace elements and strains blend on the strains and the influence of the removal efficiency. Through experiment, screened out three high efficiency phosphorus accumulation organism, Results show that the optimal temperature for the three strains growth is about15℃, phosphorus removal for all three strains are optimal in7-9condition.Add trace elements or not have no significant effect on the growth of bacter, but has great influence on the phosphorus removel effect. Strains blends did not show obvious advantages with phosphorus removel than single strains. After blends, the best phosphorus removal effect is P1×P3,24hours of phosphorus removal rate is87%,P1×P2、P2×P3effect is poorer,only below30%.Finally, the methods of molecular biology to identification the three phosphate accumulating bacteria and all the three strains belong to Bacilli.