华盛顿哥伦比亚特区合流制管网溢流污染治理及长效管控策略的工程经验分析

Engineering Experience Analysis on Pollution Control and Long Term Control Strategy of Combined Sewer Overflows in Washington D.C.

为长效控制华盛顿哥伦比亚特区合流制管网溢流(CSOs)污染问题,华盛顿哥伦比亚特区供排水局(WASA)以流域管控为单元,针对特区内各流域的本底情况和突出问题,按“灰色与绿色”、“地上与地下”、“分散与系统”相结合方式,制定长期有效的管控策略,并借助水力模型和监测手段进行实时监测与评估。结果表明,华盛顿哥伦比亚特区流域内CSOs体积削减了90%~95%,溢流频次削减了95%~100%,溢流污染负荷削减了30%~35%,大肠杆菌数减少了35%~40%,溶解氧含量提高了40%~50%,流域整体水质得到显著提高。这对我国CSOs污染控制技术研究具有很好的借鉴价值,在一些城市的老城区合流制区域提升改造、相关性流域综合治理以及黑臭水体控制与治理方面能起到较好的示范作用。

In order to control the combined sewer overflows(CSOs) pollution in Washington D.C. with a long-term situation, D.C. Water and Sewer Authority(WASA) takes river basin management as a unit, and points at the background and outstanding problems of river basins in Washington D.C. WASA plans long-term effective management strategy on the basis of combination of “gray and green”, “ground and underground”, “separation and concentration”, and carried out real-time monitor and evaluation with the help of hydraulic model and monitoring methods. Result shows that the volume of combined sewer overflow in Washington D.C. is reduced by 90%~95%. The frequency of overflow is reduced by 95%~100%. The pollution load of overflow is reduced by 30%~35%. The number of fecal coliform is reduced by 35%~40%. The content of dissolved oxygen is increased by 40%~50%, and the overall water quality of basin is significantly improved. It has a good reference value for the study of CSOs pollution control techniques at home. It can also play a good demonstration role in the upgrading and reconstruction of confluence system area in some old urban areas, the comprehensive management of relevant river basins and the control and treatment of black and smelly water bodies.