雨污分流制泵站旱天放江后上游调水对受纳河道水质的影响

Influence of Upstream Water Diversion on Water Quality of Receiving River after Drainage in Dry Weather from Pumping Station of Rain and Sewage Seperate System

旱天放江是造成上海市城区河道污染的主要原因之一。以虬江为研究对象,探究分流制泵站旱天放江后,调水对受纳河道水质的影响。选取放江当天至调水第7 d,分析对比受纳水体上游至下游,各采样断面水体中COD、TP、氨氮以及沉积物中TOC含量的差异。结果表明,放江后和调水连续7 d后,各断面水体中水质检测指标以及沉积物中TOC含量均高于放江前。放江开始至调水第7 d,虬江水体中COD、TP、氨氮含量均呈现先递减后趋向于平稳的趋势,沉积物中TOC含量呈现递增的趋势。受调水作用的影响,上游水体中COD、TP、氨氮以及沉积物中TOC含量均低于下游。

Drainage in dry weather was one of the main sources of pollution in urban rivers of Shanghai.In order to assess effects of water diversion on water quality of the receiving rivers after dry weather discharged from pumping station of separate system,Qiujiang Creek was taken as the research object.The difference between COD,TP,ammonia nitrogen content of the receiving river water and TOC content in sediments from upstream to downstream was analyzed and compared from the day of discharging to the seventh day of water diversion.Results showed that concentration of water quality test indicators in the water and TOC content in sediments after discharging and seven days’water diversion were higher than those before discharge.During the beginning of discharge to the seventh day of water diversion,contents of COD,TP and ammonia nitrogen in the water of Qiujiang Creek decreased first and then tended to be stable,and TOC content in the sediments showed an increasing trend.Under the influence of water diversion,the content of COD,TP,ammonia nitrogen and TOC in upstream water was lower than downstream.