Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing 100044, China.
Beijing Water Science and Technology Institute, Beijing 100048, China.
Int J Environ Res Public Health. 2019 Apr 28;16(9):1503. doi: 10.3390/ijerph16091503.
Combined sewer overflow (CSO) pollution poses a serious threat to the urban water environment and is more severe in old urban areas. This research uses the old urban area in the sponge city pilot area in Tongzhou District, Beijing, as the study area. The United States Environmental Protection Agency (USEPA) storm water management model (SWMM) was used to establish the hydrologic and hydraulic model of this area. The model parameters were calibrated and validated based on the measured rainfall and runoff data. The results show that the Nash-Sutcliffe efficiency coefficient for calibration and validation is more than 0.74. Thirty-two sets of systematic CSO control schemes are formulated, which include the "gray (includes the pipes, pumps, ditches, and detention ponds engineered by people to manage stormwater) strategy" and "gray-green strategies", and the regularity of CSO control for "low impact development (LID) facilities at the source", "intercepting sewer pipes at the midway", and "storage tank at the end", are quantitatively analyzed. The results show that the LID facility has an average annual reduction rate of 22% for the CSO frequency and 35% to 49% for the CSO volume. The retrofitting of intercepting sewer pipes has an average annual reduction rate of 11% for the CSO frequency and 4% to 15% for the CSO volume, and the storage tank has an average annual reduction rate from 3% to 36% for the CSO volume; furthermore, the reduction rate decreases with the increase in the CSO volume reduction rate by LID facilities. When the CSO control target is stricter, the control effect of the "end" segment is more obvious, but the control efficiency is lower. By studying the variability of the storage tank volume under different control targets, it can be concluded that it is reasonable to set the CSO control target because the number of overflow events does not exceed four times per year for the study area.
合流制污水溢流（CSO）污染对城市水环境构成严重威胁，在旧城区尤为严重。本研究以北京市通州区海绵城市试点区的旧城区为研究区域，采用美国环保署（USEPA）雨水管理模型（SWMM）建立了该区域的水文水力模型。根据实测降雨和径流数据对模型参数进行了率定和验证，校准和验证的纳什效率系数大于 0.74。制定了 32 套系统的 CSO 控制方案，包括“灰色（包括由人管理雨水的管道、泵、沟渠和蓄水池）策略”和“灰色-绿色策略”，并定量分析了“源头低影响开发（LID）设施”、“中途截流污水管”和“末端储水池”的 CSO 控制规律。结果表明，LID 设施对 CSO 频率的平均年减排率为 22%，对 CSO 体积的平均年减排率为 35%至 49%；截流污水管的改造对 CSO 频率的平均年减排率为 11%，对 CSO 体积的平均年减排率为 4%至 15%，储水池对 CSO 体积的平均年减排率为 3%至 36%；此外，随着 LID 设施对 CSO 体积减排率的增加，减排率降低。当 CSO 控制目标更严格时，“末端”段的控制效果更为明显，但控制效率较低。通过研究不同控制目标下储水池体积的变化，可以得出结论，由于研究区域的溢流事件每年不超过 4 次，因此设定 CSO 控制目标是合理的。
