基于反硝化除磷的低温启动与稳定运行的中试试验

Pilot Study on Start-up and Stable Operation at Low Temperature Based on Denitrifying Phosphorus Removal

为了解反硝化聚磷菌(DPAOs)的脱氮除磷特性,以实际生活污水为研究对象,在低温(6~16)℃下采用改良UCT工艺开展了中试规模(20m^3)的反硝化除磷试验研究.结果表明,当T为6~12℃,HRT为20h,SRT为35d改良UCT工艺可成功启动并稳定运行.稳定运行时,系统能保持60%±5%的脱氮率,80%±5%的除磷率,其中COD、NH4^+4-N、总氮(TN)和总磷(TP)出水浓度分别为20、5、11和0.5mg·L^-1,可达到《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A排放标准.为进一步考察该系统脱氮除磷特性,增大好氧池到缺氧池回流比至150%,待系统稳定后,系统可获得较高的脱氮除磷率,其中脱氮率为80%±10%,除磷率为90%±5%.其中,缺氧池反硝化除磷的作用占总生物除磷的80%±4%,COD、NH4^+-N、总氮(TN)和总磷(TP)平均出水浓度分别为19.55、0.1、7.8和0.15mg·L^-1,可达到京标A排放标准.

In order to understand the denitrifying and phosphorus removal characteristics of denitrifying phosphate-accumulating organisms (DPAOs),a pilot scale (20 m^3 ) denitrifying and phosphorus removal experiment was carried out using a modified University of Cape Town (UCT) process at low temperatures of (6-16)℃.The test results show that at such temperatures,the hydraulic retention time (HRT) is 20 h and the solids retention time (SRT) is 35 days,and the modified UCT process can start up successfully and run steadily.When running steadily,the system can maintain nitrogen and phosphorus removal rates of 60%± 5% and 80%± 5%,respectively.The effluent concentrations of chemical oxygen demand (COD),ammonium nitrogen (NH4^+-N),total nitrogen (TN),and total phosphorus (TP) were 20,5,11,and 0.5 mg·L^-1,respectively,which meet the first A emission standard of“Pollutant Discharge Standard for Urban Sewage Treatment Plant”(GB 18918-2002 ).In order to further investigate the characteristics of nitrogen and phosphorus removal in the system,the reflux ratio from the aerobic tank to the anoxic tank was increased to 150%.After the system was stabilized,it obtained higher nitrogen and phosphorus removal rates of 80%± 10% and 90%± 5%, respectively.Among them,denitrifying phosphorus removal in the anoxic tank accounted for 80%± 4% of the total biological phosphorus removal.The average effluent concentrations of COD,NH4^+-N,TN,and TP were 19.55,0.1,7.8,and 0.15 mg·L^-1, respectively,which meet the Beijing Standard A discharge standard.