前置A2NSBR系统硝化和反硝化除磷的特性

Nitrification and denitrifying phosphorus removal performance in the pre-A2 NSBR system

以处理实际低C/N生活污水的前置A2NSBR系统为研究对象,考察系统内生物膜的硝化特性和活性污泥的反硝化除磷特性.试验研究了有机物和NO2^--N浓度对生物膜硝化性能的影响,以及不同电子受体浓度对反硝化吸磷速率的影响.结果测得硝化速率为11.3mgNH4^+-N/(L·h),在填充率40%的条件下容积负荷为0.27kgNH4+-N/(m3·d),有机物的存在会对硝化有抑制,但是系统表现出了良好的抗有机负荷冲击能力,硝化速率为9.72mg NH4^+-N/(L·h).NO2^--N处理对AOB活性几乎无影响,对NOB活性抑制作用明显,当NO2^--N浓度为400mg/L时,NOB活性仅为1.63%,几乎接近完全被抑制.根据本次不同电子受体条件下除磷批次试验的结果,好氧吸磷速率为17.62mg P/(g VSS·h),以NO3--N为电子受体的缺氧吸磷速率是12.94mg P/(g VSS·h),从而可知缺氧聚磷菌占总聚磷菌的比例大约是73.4%,其中在NO2^--N浓度为30mg/L出现吸磷抑制,当NO2^--N和NO3^--N共存时,NO2--N在初始浓度为15mg/L便出现吸磷抑制.

Biofilm nitrification and activated sludge denitrifying phosphorus removal performance were investigated in the pre-A2 NSBR system,which treated real low carbon to nitrogen(C/N)ratio domestic sewage.The effect of organic substance and NO2^--N concentration on the biofilm nitrification performance,and different electronic acceptors on the denitrifying phosphorus uptake rate were studied.Results indicated that nitrification rate was 11.3 mgNH4+-N/(L·h),the ammonia volume loading was 0.27 kgNH4^+-N/(m3·d)under the filling rate of 40%,the nitrification performance was inhibited by organic substance,but the system showed a good nitrification rate of 9.72 mg NH4^+-N/(L·h)when organics presented.NO2^--N treatment exhibited little effect on the AOB activity but obvious effect on the NOB activity,the NOB activity was almost completely inhibited(only 1.63%)when NO2^--N concentration was 400mg/L.According to the phosphorus uptake rate experiment under different electronic acceptors,the phosphorus uptake rate under oxygen and NO3^--N was 17.62mg P/(g VSS·h)and 12.94mg P/(g VSS·h),respectively,anoxic phosphate accumulating organisms(PAOs)occupied 73.4%of the total PAOs,phosphorus uptake performance was inhibited when the NO2^--N concentration was 30mg/L,and phosphorus uptake performance was inhibited when the NO2^--N concentration was 15mg/L under the condition of NO2^--N and NO3^--N coexisted.