A/O交替运行钢渣基复合滤料生物滤池处理模拟生活污水脱氮除磷特性

利用两级钢渣基复合滤料生物滤池(SSMBF)构建厌氧/好氧(A/O)交替运行工艺系统.在单池HRT=2h,A/O交替周期48h,厌氧DO=0.2~0.5mg/L,好氧DO=3~5mg/L,T=23~27℃的运行条件下,考察了SSMBF系统对模拟生活污水(pH=6.8~7.5,COD=260~330mg/L,NH4+-N=35~40mg/L,PO43--P=9~11mg/L)的处理效果,分析了其氨氮和磷去除特性.结果表明,两级A/O交替SSMBF系统具有良好的生活污水处理能力,对氨氮、磷和COD的去除率分别为95%、40%~60%和83.3%,出水氨氮、磷和COD浓度分别为0.5mg/L?3~6mg/L和50mg/L.在厌氧/好氧交替周期为48h的工况下,SSMBF系统的氨氧化菌和聚磷菌分别可在10h和8h恢复最佳活性.SEM?EDS表征和污染物去除特性分析结果显示,A/O交替运行SSMBF系统充分发挥了钢渣基复合滤料的离子和碱度释放特性,通过聚磷菌的厌氧释磷效应,在厌氧SSMBF中诱导促进了生物-结晶协同除磷,结晶产物为以羟基磷灰石为主的磷酸盐化合物.

Characteristics of nitrogen and phosphorus removal from artificially synthesized domestic wastewater in an alternating A/O biological filter with steel slag media

Under hydraulic retention time (HRT) of 2h, A/O alternating interval of 48h, temperature of 23~27℃, dissolved oxygen concentration (DO) of 0.2~0.5mg/L in anaerobic stage and 3~5mg/L in aerobic stage, two steel slag media biological filters (SSMBFs) were carried out and operated in alternating anaerobic/aerobic (A/O) mode to investigate characteristics of nitrogen and phosphorus removal from artificially synthesized domestic wastewater with influent quality of pH 6.8~7.5, COD 260~330mg/L, NH4+-N 35~40mg/L and PO43--P 9~11mg/L. The results showed that the alternating A/O-SSMBFs performed a promising performance for wastewater treatment, as well as the NH4+-N, PO43--P and COD could be removed more than 95%, 40%~60% and 83.3% respectively, and the effluent concentrations of NH4+-N, PO43--P and COD decreased to 0.5mg/L, 3~6mg/L and 50mg/L respectively. It was also observed that the biological activity of ammonia oxidizing bacteria (AOB) and phosphorus accumulating bacteria (PAOs) could be recovered in 10 hours and 8 hours respectively, while the SSMBF alternating converted operational mode every 48h from anaerobic to aerobic or on the contrary. The SEM and EDS characterization of crystals formed on the media surface and analysis of pollution removal character revealed that the phosphorus in an alternating A/O-SSMBFs system could be removed by both biological oxidization and crystallization. Because the steel slag media could release alkalinity and ion as well as the PAOs could release phosphorus under the anaerobic environment, the phosphorus removal by crystallization had been enhanced in this system. The principal constituent of crystalline substance was hydroxyapatite.