东江源地表水污染优先控制治理分析

Monitoring and Analysis of Water Pollution in Dongjiang Headwater Area

将东江源沿线18个水环境功能区划分成寻乌控制单元、安远控制单元和定南控制单元,2011~2012年间进行东江源地表水水质监测和污染负荷核算,结果表明,影响最广的主要污染源包括农业面源污染、城镇化加剧的区域生活污染和矿产企业工业点源污染,东江源地表水水质污染趋重,污染物以COD、氨氮和总氮为主,这些污染物指标均值分别为21.86mg·L^-1、0.90mg·L^-1、0.96mg·L^-1,污染负荷分别达1 235.9t·a^-1、622.8t·a^-1和3 361.8t·a^-1;筛选确定了寻乌、定南控制单元2个优先治理单元,以及寻乌县石排下游、定南下历河砂头下游2个重点监控点。其中寻乌控制单元主要污染物的年污染输出最大,分别占东江源流域的56.5%、51.5%、44.9%;安远控制单元的水质监测和年污染负荷量相对较低;定南控制单元主要污染物指标分别为26.4mg·L^-1、1.41mg·L^-1和1.13mg·L^-1,劣Ⅴ类水质的功能区2个,数量最多。

Based on the three divisions of Xunwu control unit, Anyuan control unit and Dingnan control unit from the 18 water function parts of the Dongjiang headwater area, the water quality monitoring and the calculation of water pollution load were made during 2011-2012. The results show that surface water pollution has got more serious, caused by the most extensive main pollution source of agricultural non-point source pollution, urbanization intensified regional domestic pollution and the industrial point source pollution dominated from rare earth mineral. The main pollutants are COD, NH3-N and TN, respectively accounting for 21.86mg/L, 0.90mg/L, 0.96mg/L, and their pollutant load of 1 235.9t/a, 622.8t/a and 3 361.8 t/a.