State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Department of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; School of Environment & Natural Resources, Renmin University of China, Beijing, 100872, China.
J Environ Manage. 2022 Feb 1;303:114268. doi: 10.1016/j.jenvman.2021.114268. Epub 2021 Dec 8.
Significant management needs raised in urban sewer system to facilitate urban resilience to rainstorm. The work investigated the effects of temporal evolution of rainfall on hydrograph and pollutant discharge of CSO over an intensive observation period of 12 months, with special attention to differences in temporal scale for supporting management decision making. The characteristics of rainfall in different temporal scales helped overflow-risk identification and assessment. Prolonged dry seasons over 112 days in the CSO monitored year 2018 increased the sediment buildup in the pipes. The built sediment was mostly flushed out to overflow (and the treatment facility) by initial rainfall during 47 h. Following CSO hydraulics and pollutant discharge follows initial peak patterns which responded to rainfall patterns. Results of Redundancy analysis and network analysis showed that the combined effects of rainfall, urbanization, and sediments as "CSO troika" are the driving forces for CSO pollutants in the long-term. The improved characterization of CSO events and the associated pollutants has refined our understanding of how overflow hydrograph and pollutant discharge responds to rainfall temporally, which methodology supported decision making in the combining source/process control with terminal management for facilizing urban resilience.
城市排水系统需要大量管理工作以提高城市应对暴雨的韧性。本研究在为期 12 个月的强化观测期间，调查了降雨的时间演变对合流制污水溢流（CSO）的水文和污染物排放的影响，特别关注了支持管理决策制定的时间尺度差异。不同时间尺度的降雨特征有助于识别和评估溢流水险。在 2018 年监测到的 CSO 中，长达 112 天的旱季增加了管道中的沉积物堆积。在最初的 47 小时降雨中，大部分堆积的沉积物被冲出管道（和处理设施）。CSO 水力和污染物排放遵循初始峰值模式，这与降雨模式相对应。冗余分析和网络分析的结果表明，降雨、城市化和沉积物作为“CSO 铁三角”的综合影响是 CSO 污染物的长期驱动力。对 CSO 事件及其相关污染物的特征描述的改进，深化了我们对溢流水文和污染物排放如何随时间响应降雨的理解，该方法支持了在源头/过程控制与终端管理相结合的情况下进行决策，以促进城市的弹性。
