A2/O工艺缺氧池中反硝化聚磷菌的比例、特性研究及菌株鉴定

用释磷/聚磷装置和微生物筛选、分离方法研究A2/O工艺缺氧池污泥,确定缺氧池中反硝化聚磷菌(DPB)的比例,筛选、分离得反硝化聚磷单菌株且对单菌株聚磷特性进行研究.结果表明,缺氧池中DPB占聚磷菌(PAO)的比例约为21.5%.从缺氧池分离得到的肠杆菌科、气单胞菌属和假单胞菌属都是DPB,而不动杆菌属仅是好氧PAO,葡萄球菌属和微球菌属仅是一种专职的反硝化菌.反应过程中同时存在O2和NO3时,肠杆菌科优先利用水中的O2进行聚磷;在缺氧环境中,肠杆菌科在COD为30mg/L时的聚磷效果优于COD为180 mg/L时的聚磷效果.可见DPB的反硝化和聚磷的特性与电子受体的存在形式和COD有密切关系.因此,改良传统A2/O工艺和研发同步反硝化聚磷装置时,必须控制缺氧反硝化聚磷单元中混合液的DO和COD.

Denitrifying phosphate accumulating bacteria in the anoxic reactor of an A2/O wastewater treatment system

Many denitrifying phosphate accumulating bacteria(DPB) were found in the anoxic bioreactor mixed liquor of an A2/O wastewater treatment system in southern China.The DPBs accounted for about 21.5% of total phosphate accumulating organisms(PAO) present.Enterobacteriaceae sp.,Aeromonas sp.and Pseudomonas sp.were DPBs;Acinetobacter sp.was a PAO;Staphylococcus sp.and Micrococcus sp.were strictly denitrifying bacteria.The nature of electronic acceptor and/or the amount of organic matters present in the reactor affected the denitrification and phosphorus accumulation characteristics of DPB;Enterobacteriaceae sp.consumed oxygen first when oxygen and nitrate were both present,and under anoxic conditions,accumulated more phosphorus at a lower COD(30 vs.180 mg/L).Proper control of dissolved oxygen and COD of the anoxic mixed liquor was necessary for improving performance of a conventional A2/O treatment system.