基于监测与模型的典型合流制排水系统溢流污染来源解析

Analysis on the source of overflow pollution of typical combined drainage system based on monitoring and model

以北京中心城区某典型合流制分区为研究区,开展自“地表-管网-排口”的全过程监测,基于MIKE URBAN软件构建数值模型,构建一套结合监测与模型的溢流污染解析方法,量化分析不同降雨量级下溢流污染来源。结果表明:管道沉积物、地表径流和生活污水对COD的贡献率分别为43.4%~53.9%、27.4%~27.5%和18.6%~29.2%。中雨流量峰值晚于浓度峰值,大雨反之;两场降雨溢流水质浓度峰值差异小于流量峰值。随着降雨量级及强度增加,地表径流和管道沉积物的污染负荷增加,后者增加量更大。管道沉积物是合流制溢流污染的主要来源,应优先对其进行控制。

Taking a typical combined flow system district in central URBAN area of Beijing as the research area,the whole process monitoring from"surface,pipe network and outlet"was car ried out.A numerical model was constructed based on MIKE URBAN software,and a set of overflow pollution analysis method combining monitoring and model was constructed to quantitatively analyze the sources of overflow pollution under different rainfall levels.The results show that:the contribution rates of pipeline sediment,surface runoff and daily sewage to COD are 43.4%-53.9%,27.4%-27.5%and 18.6%-29.2%,respectively.The peak of moderate rain flow is later than the peak of concentration,and the reverse for heavy rain;The difference of the peak water concentration of the two rainfall overflows is smaller than the peak water flow.With the increase of rainfall level and intensity,the pollution load of surface runoff and pipeline sediment increases,and the latter increases more.Pipeline sediment is the main source of combined overflow pollution,and priority should be given to its control.