中文摘要：

通过平行运行3个分别以O2、NO3^-、NO2^-为电子受体的SBR除磷系统，探讨了反硝化除磷区别于好氧除磷的工艺特征及其内在微生物竞争机制．NO2-不会对经驯化后反硝化聚磷菌（DPAO）的缺氧吸磷产生直接抑制作用，但其作为反硝化除磷电子受体的效能远低于NO3^-；具备利用NO3^-而缺乏NO2^-反硝化酶系的DPAO（DPAO5）流失及聚糖菌（GAO）增殖是根本原因．而NO3^-是一种高效电子受体，其反硝化除磷效能与以O2为受体的好氧除磷系统相当，两者在除磷计量学和功能菌群构成上十分接近．作为聚磷菌（PAO）的竞争者，GAO在3个研究系统中均大量存在．基于对不同电子受体的利用能力，PAO包含P0、PN、Pn、PNn、PON、PONn等6个种类．PON和PONn等兼性PAO是生物除磷的主体，其在污泥中比例越高，系统的除磷负荷也越大，即SBRa〉SBRn5〉SBRn3.

英文摘要：

By parallel operation of three phosphorus removal systems （SBR） using different electron acceptors of O2, NO3^- and NO2^- , process characteristics and inherent competition mechanism of microorganisms were discussed. Although NO2^- had no direct inhibition on anoxic phosphorus uptake after the DPAO cultivation, system performance was still much lower than that with NO3^- as electron acceptor. And it ultimately resulted from the washout of the group of DPAO （ DPAO5 ） that lacked the ability to denitrify NO2^- and the enhanced GAO growth in the system. Being the efficient electron acceptor, NO3^- or O2 supplying SBRs removed phosphorus smoothly and comparatively, in viewpoint of stiochoimetry and constitution of functional bacteria. In all three test systems, mass of GAO was present to exhaust limited organics with PAO population. Moreover, total PAO could be divided into 6 distinct groups, i.e., P0, PN, Pn, PNn, PON and PoNn, based on the abilities of utilizing different electron acceptors. And facuhative PAO of PoN and PoNn were found as the main contributors for the phosphorus removal. The higher ratio they accounted in sludge, the more capacity the system possessed to remove phosphorus, i.e., SBR0 〉 SBRn5 〉 SBRn3.