双桥河流域水环境容量及污染负荷分配研究

Study on water environment capacity and pollution load distribution in Shuangqiao river basin

安徽双桥河是巢湖的主要入湖河流之一,其水质长期处于劣V类,直接威胁居民饮水安全。基于双桥河流域现状特征,本研究以化学需氧量(COD)、氨氮(NH_3-N)、总磷(TP)为主要污染因子,利用一维水质模型核算双桥河流域水环境容量.研究表明,流域内COD、NH_3-N及TP的环境容量分别为-755.7t/a、38.42t/a、-3.438t/a.同时,根据污染负荷分配(TMDL)原理,依据污染负荷贡献率,开展流域内各污染源负荷总量分配,并分别制定点源与面源污染负荷削减方案.结果表明,流域内NH3-N的点源、面源负荷比分别为50.53%、48.66%.其中,点源的城镇生活削减为17.59t/a,面源的农村生活、分散式畜禽养殖、集中式畜禽养殖、农业面源、城市地表径流、垃圾渗滤液、水产养殖削减量分别为16.6t/a、0.45t/a、0.47t/a、1.63t/a、0.04t/a、0.13t/a、0.41t/a.本研究结果为双桥河流域全面实施水质目标管理体系奠定基础,同时为基础资料相近的小流域水质模拟提供借鉴和技术支撑.

The Shuangqiao river in Anhui Province is one of the main rivers entering to Chao-hu Lake.The water quality of the Shuangqiao river has long been inferior to Grade V,which directly threatens the safety of drinking water for residents.The water environment capacity of Shuangqiao river basin was calculated using one-dimensional water quality model based on the current characteristics.The study showed that the environmental capacity of COD,NH3-N and TP of the basin were-755.7 t/a,38.42 t/a,and-3.438 t/a,respectively.According to the Waste Load Allocations(TMDL)principle,the total load distribution of the various pollution sources within the basin was completed,and the point source and non-point source pollution load reduction plans was formulated based on the contribution rate of the pollution load,respectively,which built a foundation for the full implementation of the water quality objective management system in Shuangqiao river basin,and provided reference and technical support for the water quality simulation of small watersheds with similar basic data.