超大型污水厂超水量负荷高效能运行研究

Study on High-efficiency Operation of Super-large Wastewater Treatment Plant with Excess Water Load

摘要:

以上海某超大型污水厂作为研究对象，开展了1.4倍超水量负荷高效能运行试验，考察了污水厂在夏季汛期超水量负荷条件下的过流能力和生物处理系统效能。试验时长为37 h，污水厂进水水力平均负荷为设计处理量的1.418倍，最高瞬时水力负荷达1.803倍，进水COD、NH4+-N、TN和TP浓度分别维持在250、20、25、4.5 mg/L以下，出水COD、NH4+-N、TN和TP浓度分别在25、0.2、8、0.2 mg/L以下，出水水质满足一级A排放标准。1.4倍超水量负荷对污水厂预处理、生物处理、二沉池等工艺段过流能力影响不大，对中间提升泵房前池液位有一定影响，污水厂设施设备运行情况整体稳定。结果表明，在夏季汛期，污水厂可实现短期内在1.4倍超水量负荷下安全稳定运行，能够初步应对汛期进水流量突增情况，最大程度的减少汛期污水溢流。

Abstract:

Taking a super-large wastewater treatment plant (WWTP) in Shanghai as the research object, the high-efficiency operation test of 1.4 times excess water load is carried out to inspect the discharge capacity and the biological treatment system efficiency of WWTP under the condition of excess water load in summer flood season. The duration of the experiment is 37 h. The average inflow hydraulic load of the WWTP is 1.418 times of the designed treatment capacity. The highest hydraulic load is 1.803 times instantly. The COD, NH4+-N, TN and TP concentrations of the influent are kept below 250，20，25，4.5 mg/L respectively. The COD, NH4+-N, TN and TP concentrations of the effluent are below 25，0.2，8， 0.2 mg/L respectively. The effluent quality meets the first-class A discharge standard. 1.4 times the excess water load has little effect on the discharge capacity of the pretreatment, biological treatment and secondary sedimentation tank of WWTP, but has a certain impact on the liquid level of the tank in the front of the intermediate lifting pump house. The operation of facilities and equipment in WWTP is stable as a whole. The results show that in the summer flood season, the safe and stable operation of WWTP can be realized in the short term under 1.4 times excess water load, which can preliminarily cope with the sudden increase of influent flow in flood season, and reduce the overflow of sewage in flood season to the greatest extent.