基于京杭运河五牧断面水质达标的水环境容量计算研究

为保证京杭运河五牧断面的水质达标率及水体环境健康,依据《江苏省地表水(环境)功能区划》,综合考虑水文、水体污染来源等因素,对整治范围内入运河的污染源进行概化,通过建立一维水量水质数学模型确定模型参数,计算五牧断面水质达标时各概化排口的允许排污量,进而得到该研究区域的水环境容量,与现状污染物入河量对比,确定污染物削减量,为改善京杭运河水环境质量提供依据。结果表明:确保京杭运河五牧断面水质达标情况下,研究区域近期COD、氨氮、总磷水环境容量分别为47 216t/a、5 376.1 t/a、508.1 t/a,远期COD、氨氮、总磷水环境容量分别为28 977.3 t/a、2319.1 t/a、301.1 t/a。污染物削减率与水质超标率对比二者差距在30%以内,说明水环境容量计算结果基本合理。

Water environment capacity calculation based on water quality standards at Wumu section in the Grand Canal

In order to ensure water quality control rates and the water environmental health of Wumu section in the Grand Canal, according to the water quality target of the surface water(environment) function zonation in Jiangsu province, considering factors such as hydrology , water pollution source, generalized pollution sources of the study area into the canal. Through the establishment of the study area a one-dimensional mathematical model for water quality determines the research area of water quality model parameters, calculated from the allowable discharge amount and water environment capacity of drain outlets when quality reaching the standard in Wumu section. Compared with the amount of present pollutant discharge into account, it calculated the amount of pollutants to be reduced, so as to provide basis for improving water environmental health of the Grand Canal. The results showed that, in order to ensure water quality reaching standard of Wumu section, in the near future the study area water environmental capacity of COD, NH₃-N, TP were 47216, 5376.1 and 508.1 t/a respectively, in the forward water environmental capacity of COD, NH₃-N, TP were 28977.3, 2319.1 and 301.1 t/a respectively. Contrast pollutant reduction rate and the excess rate of water quality which gap within 30%.The calculation results of water environment capacity are reasonable.