苏州河储存式雨水调蓄池水环境质量改善效应分析

Analysis of Water Quality Improvement in Suzhou Creek by Stormwater Detention Tanks

以上海市苏州河环境综合整治二期工程中建设的5座储存式雨水调蓄池为研究对象，探究了单座及多座雨水调蓄池联动运行对苏州河水质的改善效应。模拟结果显示：①雨水调蓄池对河道水质的改善效应随着其容积建造标准的提高而增强，随着水动力的增强而减弱。②5座调蓄池分别单独运行时，在断面平均流速分别为0.50、0.30和0.10m／s的条件下，可使苏州河河口断面最大瞬时COD浓度分别降低（21～92）、（34～139）和（90～264）mg／L，使平均COD浓度分别降低（13～55）、（20～84）和（53～157）mg／L。③5座调蓄池联动使用时，在上述3种水动力条件下，对河口断面最大瞬时COD浓度的削减效应无叠加。④在上述3种水动力条件下，5座调蓄池联动运行可使河1：7断面溢流事件全过程的COD通量浓度分别下降13.2、13.8和14.4mg/L。

Five stormwater detention tanks （SDTs） were built along the Suzhou Creek in central Shanghai for a comprehensive two-stage treatment project. The effects of five SDTs individually or in combination on water quality improvement were studied using SOBEK software. The results showed that： ① The improvement effect of Suzhou Creek water quality increased with the SDT volume design standard, and decreased with the hydrodynamic condition. ②When five SDTs were operated individually at vertical mean velocities of 0.50 m/s, 0.30 m/s and 0. l0 m/s, the maximum instant COD concentrations of the Suzhou Creek at estuary section could be reduced by 21 -92, 34 -139 and 90 -264 mg/L, respectively. The mean COD concentration reductions were 13 -55, 20 -84 and 53 -157 rag/L, respectively at these conditions. ③The maximum instant COD concentration reduction effect did not improve when using five SDTs together. ④ The COD flux concentration at the estuary section in an overflow event could be reduced by 13.2 rag/L, 13.8 mg/L and 14.4 mg/L at three hydrodynamic conditions when using five SDTs together.