玉带溪流域合流制片区截污方案溢流污染特征分析OACSTPCD

In order to clarify the overflow pollution characteristics and overflow control effects of different interception schemes in the combined area of Yudai River Basin,the upstream area of the northern branch of Yudai River is selected as the study area,and a drainage system model is constructed.Under different rainfall levels throughout the year,a comparative study between end interception and interception diversion schemes of the combined area is conducted on the overflow pollution characteristics indices.The results show that the interception diversion scheme is generally superior to the end interception scheme in terms of overflow frequency,total overflow amount,overflow duration,average overflow flow rate,peak overflow flow rate,and overflow pollution load.Under different rainfall levels throughout the year,the overflow reduction rate of the end interception scheme is 12.9％to 77.5％,and of the interception diversion scheme is 40.6％to 98.8％.In terms of the overflow pollution load reduction,when the rainfall level is moderate or heavy,the end interception scheme has a reduction rate of more than 64％on the three pollutants(chemical oxygen demand,ammonia nitrogen,and total phosphorus),and the reduction rate of interception diversion scheme is as large as 89％;when the rainfall level is heavy and above,the reduction rate of overflow pollution load of the end interception scheme is less than 50％,and the reduction rate of the interception diversion scheme reaches more than 60％.Therefore,analyzing and studying the characteristics of overflow pollution is beneficial for mastering the pollutant discharge patterns and overflow reduction effects of different interception schemes,and has guiding significance for economically and effectively controlling combined overflow pollution.