城市超标河流生态增容管控技术体系研究

Study on Enhancing and Controlling System of Ecological Capacity for Exceeded Standard Urban Rivers

针对城市河流生态系统严重退化与水质普遍受到污染的现实,提出了生态增容的理念,分别从底泥环保疏浚、降雨径流污染物浓度削减、城市点源减排、农业面源减排、流域水土保持、河流生态系统健康恢复与维持等方面提出了管控措施。根据区域削减量,预测了遂溪河遂溪县城段的减排效果,COD与氨氮的预测值分别为18.56 mg/L与0.87 mg/L,分别占标准的92.8%及87.0%,满足了Ⅲ类水环境功能要求,这两项指标的允许排放量分别为272.38 t/a、23.60 t/a。通过实施生态增容方案,不但可以使研究水体达到既定的水环境功能,腾出环境容量用于适度发展经济,还可以实现河流健康生态系统的良性循环。

Aiming at the situation of serious degradation and pollution of urban fiver ecosystem, this paper proposed a concept of enhancing and controlling system of ecological capacity, which included contaminated sediment dredging, pollutants concentration reduction from rainfall and run- off, city point sources discharge reduction, agricultural non-point sources discharge reduction, soil and water conservation in river basin, restoration and maintenance of river ecosystem, etc. Based on the reduction amount in the study area, it predicted the discharge reduction effect of the down- town reach of the Suixi River. The estimated values of COD and ammonia nitrogen were 18.56 mg/L and 0.87 mg/L respectively, which were 92.8% and 87.0% of Class III water standard. The amount of discharge limits were 272.38 t of COD and 23.6 t of ammonia nitrogen per year. In general, the implementation of enhancing ecological capacity not only can meet the functional requirements and spare environmental capacity for economic development, but also can promote a virtuous circle of urban fiver ecosystem.