上海中心城区合流制排水系统雨天溢流水质研究

Characteristics of Combined Sewer Overflow during Rainfall in Central Area of Shanghai

合流制排水系统雨天溢流已成为上海中心城区河道的主要污染源。为此,重点研究了上海中心城区某合流制排水区域JXB系统雨天污染物溢流的出流过程和污染物的事件平均浓度,并探讨了溢流污染物的初期效应。结果表明,降雨特性对污染物溢流过程的水质影响较大;该区域雨天溢流COD、BOD5、SS、NH3-N的事件平均浓度分别为268、101、110、9.5mg/L,SS浓度明显低于相关研究的结果;分析溢流污染物的初期效应表明,JXB系统排江污染物的初期效应较为显著,其中COD和BOD5的初期效应比SS的显著。

The combined sewer overflow （CSO） pollution during rainfall has become a main pollution source of urban water bodies of Shanghai. The process of pollutant overflow from the JXB sewer system and the event mean concentrations （EMCs） of overflows in Shanghai were studied, and the first flush effects were discussed. It is found that rainfall characters have distinct influence on the characteristics of CSO, and the EMCs of COD, BODs, SS, NH3 - N are 268 mg,/L, 101 rag/L, 110 mg/L and 9.5 mg/L respectively. SS concentration is significantly lower than the results in the studies concerned. From the first flush effect analysis of the CSO, it is found that the pollutants from the JXB sewer system have significant first flush effects, in which the first flush effects for COD and BOD5 are more significant than that for SS.