反硝化聚磷菌的培养富集及处理生活污水的稳定运行

Cultivation and enrichment of denitrifying phosphorus removal system for treating domestic sewage

在厌氧-好氧交替运行的序批式反应器(sequencing batch reactor,SBR)中,以C/P比大于50的实际生活污水为进水,成功驯化富集聚磷菌,平均厌氧释磷量为15 mg·L^-1,出水PO4^3--P浓度稳定小于0.5 mg·L^-1。在系统运行的第74 d调整运行模式为厌氧-缺氧-好氧,在缺氧开始时短期投加NO3^--N配水以驯化培养反硝化聚磷菌。保持系统内NO3^--N浓度不变,在进水COD浓度为250 mg·L^-1时,反硝化除磷效果最佳,平均反硝化除磷量占除磷量的比为87.1%。不同pH下反硝化除磷速率的小试证明,在pH=7.0时得到最大的比吸磷速率2.1 mg P·(g VSS·h)^-1。此时调整NO3--N进水为另一个全程硝化反应器的出水,并加大排水比增加缺氧初的进水量使得反应器内缺氧时的pH接近7.0,与未改变pH时对比表明前者在缺氧段反硝化除磷速率加快。反应器共运行160 d,稳定完成COD的去除与反硝化除磷过程。

Phosphate accumulating organisms(PAOs)has been enriched successfully in an anaerobic-aerobic sequencing batch reactor(AO-SBR)with the influent of the domestic sewage with C/P ratio greater than 50.The average anaerobic phosphorus release amount was 15 mg·L^-1.The concentration of effluent PO4^3--P was less than0.5 mg·L^-1.On the 74 th day,the operation mode was adjusted to anaerobic-anoxic-aerobic,and NO3^--N was added at the beginning of anoxic zone to enrich the denitrifying phosphorus accumulating bacteria(DPB).The best efficiency of denitrifying phosphorus removal performance were acquired when the influent COD concentration was 250 mg·L^-1 and the NO3^--N concentration was constant in the system.Meanwhile the ratio of average denitrifying phosphorus removal to phosphorus removal was 87.1%.Anoxic pH effect tests showed that the rate of denitrifying phosphorus removal is related to the pH value,DPB preferred higher pH for phosphorus removal,and the maximum specific phosphorus removal rate of 2.1 mg P·(g VSS·h)^-1 is obtained at pH=7.0.In the subsequent experiments,NO3^--N was supplied from the effluent reactor and drainage ratio was increased.These methods ensured that the pH of the anaerobic reactor was closed to 7.0.The comparison with the unadjusted stage showed that the rate of denitrifying phosphorus removal increased.The reactor was operated for 160 days,and the COD removal and denitrifying phosphorus removal process were stably completed.