Response Of Sewage Sludge Microbial Communities To Carbon Source Supplementary And Effects Of Nityogen And Phosphorus Removal

Adding external carbon source has become one of the solutions in the process of low C/N sewage treatment, in which lacks of carbon source. When the carbon source in the sewage can meet the demand for nitrogen and phosphorus removal itself, if immediately stop the carbon source supplementary, the efficiency will become worse. So after stopping adding the external carbon, how to recover the system becomes an urgent problem in sewage treatment process. Based on the A2/O of activated sludge process, through adding Sodium Acetate as external carbon, the paper has studied the response of sewage sludge microbial communities to carbon source supplementary and effects of nitrogen and phosphorus removal and come up with the theory for the system recovery after stopping adding external carbon, and provide a new concept for the sewage treatment.The results showed that:(1) Microbial community structure of carbon source supplement system in anoxic and anaerobic aerobic section are changed, the microbial population abundance of each section of the reactor system improvement. Research shows that:the anaerobic and anoxic dominant bacteria increased from7to14, aerobic bacteria increased from4to8.(2) Stopping supplementary carbon source, microbial community structure of anaerobic, anoxic and aerobic section are changed, the microbial population abundance of each section of the reactor system by reducing the number of bacteria, microbial significantly reduced. Research shows that:stop the added carbon source, dominant bacteria in each section of the reactor in the system are reduced from14to10, some bacteria band optical density decreased significantly, that a decrease in the number of microorganism.(3) Decreasing carbon source supplement process, each reactor change group structure of bacteria is not obvious, species richness and species of microorganisms have remained stable. Research shows that:decreasing supplementary carbon source, the number of bacteria in each reactor remain unchanged, flora band optical density unchanged, indicate that microbial number remained stable.(4) Decreasing the amount of additional carbon source, system of COD, NH4+-N, TN and TP removal efficiency are stable. Research shows that:supplementary carbon source is gradually reduced as50%,40%,30%,20%,10%every30days, the average effluent concentration of COD, NH4+-N, TN, TP are:29.27mg/L,3.70mg/L,12.84mg/L,0.96mg/L, removal rate are84.23%,90.57%,70.86%,75.32%, the effluent concentrations of COD, NH4+-N, TN can achieve 《urban sewage treatment plant pollutant discharge standard》(GB18918-2002) the First Grage A Standard, TP concentration achieves B standard.