滇池河流降雨径流资源利用的技术途径

根据城市污水土地处理慢速渗滤等工艺的去除率BOD₅和COD_Cr分别为84.3%和82.5%,TP、KN和NH_3-N分别为94.9%、85.8%和89.4%,SS也高达58.4%。保证这类生态工程终年稳定运行的核心问题是:处理出水水质稳定和处理水量的稳定。影响稳定的主要因素有作物非用水季节(收获和栽种)的水量调节系统、雨季稳定运行和高去除率的处理工艺、适应慢速土地处理的气候和土壤等环境条件以及水量平衡调节与管理的有效保证。集水区域内实行分区管理的截流和改善下垫面排水调控能力的水利工程,配合使用灌溉型慢速土地处理(SR)或植物生长淹没床(VSB)湿地资源化利用与处理系统等生态工程处理工艺,是实现降雨径流资源化利用的主要技术保证。

Technical Approach to Resources Utilization of Rainfall Runoff in Rivers of Dianchi Lake Watershed

Based on the results of land treatment demonstration project which were conducted in Kunming and Chuxiong cities of Yunan province at various periods,the removal rates of BOD5, CODCr,TP,KN,NH3-N and suspended solid (SS) by using Slow Rate land treatment (SR) system for municipal wastewater was 84.3%,82.5%,94.9%,85.8%,89.4% and 58.4%,respectively.The core skills for ensuring steady operation of this ecological project all the year round are the stabilities of effluent quality and quantity.The main factors relating to stabilities of both include water regulation system in seasons when no water required for crop growth (harvesting and seeding),the treatment techniques relating to rainy season steady operation in and high removal rates,environmental factors such as weather and soil conditions suitable for slow rate infiltration land treatment (SR) operation, and the effective guarantees of water balance regulation and management.The most important technical guarantees for resources utilization of rainfall runoff are the implementation of sectionalized interception management in catchment areas and hydraulic engineering which can improve regulation capability of underlying surface drainage in combination with the use of ecological techniques such as slow rate land treatment (SR) for crop irrigation type or wetland for vegetated submerged bed (VSB), etc. As pollutants from outside sources were not effectively controlled in Dianchi lake catchment water pollution control,the most important approach to control river pollution is to reduce water quantity of surface runoff entering river in rainy season and water quality improvement,to make use of treated wastewater of rain water and rainfall runoff as a resource,and to make the renovated clean water enter into planned specific rivers or drainage channels to supplement eco-water use of Dianchi Lake.