基于河道纳污能力的北运河城市副中心段合流制溢流污染控制研究

针对北运河北京城市副中心段合流制溢流污染问题,采用监测和模拟手段,以出口断面受纳水体水质不恶化为管理目标,计算了场次溢流事件河道纳污能力,提出了将超标频次作为合流制溢流控制指标,并与以溢流频次作为合流制溢流控制指标进行了对比。结果表明,2013—2017年各排口年均溢流频次为7~9次,平均场次溢流量14.27万m3；2017年降雨19场,溢流10次,均超过河道纳污能力；分别以超标频次和溢流频次为控制指标,投入产出比最佳的频次为3次,实现该目标所需的调蓄规模分别为18116m3、13899m3,年溢流体积控制率可达52%和44%,溢流污染负荷控制率可达59%和51%；以超标频次为合流制溢流控制指标,兼具水量和水质控制意义,可利用受纳水体自净能力,降低工程规模。

Research on pollution control of combined sewer overflow in Beijing Municipal Administrative Center section of North Canal based on the ability to decontamination of the river

Aiming at the serious problem of confluence overflow pollution in Beijing sub-center section of the North Canal, this paper calculated the river pollution carrying capacity of the overflow event by means of monitoring and simulation and selected the non-deterioration of the water quality of the receiving water body in the outlet cross section as the management goal. The frequency of exceeding standard was taken as the CSO control index and the results were compared with those taking the overflow frequency as the CSO control index. The results show that the average annual overflow frequency of each outlet from 2013 to 2017 is 7 to 9, and the average overflow volume is 0.142.7 million m3. There were 19 rains, of which 10 overflowed in 2017. All overflow events exceeded the receiving capacity of the river water body. Taking the overflow frequency and exceeding standard frequency as CSO control indexes, the input-output ratio was the best when the valued of frequency was set as 3 times. The corresponding regulation and storage volumes were 18.116 m3 and 13.899 m3 respectively, the control rate of annual overflow volume can reach 52% and 44%, and the load control rate of overflow pollution can reach 59% and 51%. Using the exceeding standard frequency as the control index can make full use of the water environment capacity, reduce the scale of CSO treatment project, and enrich the engineering measures.