基于流域的深圳市现状及未来污染负荷分析

Analysis of Current and Future Typical River Pollutants in Shenzhen Based on Basin

文章研究采用时间序列分析法、最小二乘法、综合方法等分析了深圳市各流域现状污染和水环境容量,并预测了各流域未来污染和水环境容量。结果表明深圳市9个流域中,废污水排放量密度和污染负荷密度呈现出西部流域高、东部流域低的趋势,深圳河流域最大、大亚湾流域最小。深圳河流域现状年和2035年污水排放量密度分别为212.32和282.85万t/(km^2·a),大亚湾流域分别为7.68和10.46万t/(km^2·a);深圳河流域现状年和2035年COD污染负荷密度分别为141.83和79.34 t/(km^2·a),氨氮分别为14.93和1.40 t/(km^2·a),总磷分别为1.96和1.10 t/(km^2·a),总氮分别为24.88和2.33 t/(km^2·a);大亚湾流域现状年和2035年COD污染负荷密度分别为8.93和4.86 t/(km^2·a),氨氮分别为0.93和0.06 t/(km^2·a),总磷分别为0.13和0.07 t/(km^2·a),总氮分别为1.55和0.14 t/(km^2·a)。现状年按照各流域需要达到地表水Ⅴ类水计算,雨季1个流域和旱季6个流域即使不排放污水,COD、氨氮、总磷仍超过水环境容量;2035年按照各流域需要达到地表水Ⅳ类水计算,雨季1个流域和旱季7个流域即使不排放污水,COD、氨氮、总磷仍超过水环境容量。未来污水排放量密度增加的情况下,通过雨污100%分流和污水排放标准达到地表水Ⅳ类水等能使污染负荷密度大幅降低,但是旱季污染负荷仍大于水环境容量,未来需要继续提高污水排放标准或者实施河流补水。研究可为深圳市打造高品质的水环境提供科学依据和战略预判。

This study used the time series analysis method,least squares method,and comprehensive methods to analyze the current and future pollution and water environment capacity of each basin in Shenzhen.The results showed that within the nine basins in Shenzhen,the wastewater discharge density and pollution load density turned to be higher in western basin and lower in the eastern basin,with the maximum in the Shenzhen River basin and the minimum in the Dayawan basin.The current and predicted(in 2035)wastewater discharge density were estimated to be 2.12 and 2.82 million t/(km^2·a)for Shenzhen River basin,while they were 0.077 and 0.105 million t/(km^2·a)for the Dayawan basin.The current and predicted(in2035)COD,ammonia nitrogen,total phosphorus,and total nitrogen in Shenzhen river were 141.83 and 79.34,14.93 and 1.40,1.96 and 1.10,24.88 and 2.33 t/(km^2·a),respectively.As for the Dayawan basin,the current and predicted(in 2035)COD,ammonia nitrogen,total phosphorus and total nitrogen were 8.93 and 4.86,0.93 and 0.06,0.13 and 0.07,1.55 and 0.14 t/(km^2·a),respectively.If the current water quality was to meet the national surface water classⅤstandard,even if no sewage was discharged,the COD,ammonia nitrogen and total phosphorus in one basin in the rainy seasons and six basins in the dry seasons still exceed the water environmental capacity.As for the proposed national surface water classⅣstandards in 2035,even if no sewage was discharged,the COD,ammonia nitrogen and total phosphorus in one basin in the rainy seasons and seven basins in the dry seasons still exceed the water environmental capacity.In the case of increasing sewage discharge density in the future,even if the future measures that rain and pollutants are 100%diverted,and the sewage discharge standard satisfies surface water classⅣthat can greatly reduce the pollution load density,the pollution load in the dry seasons is still greater than the water environment capacity.Therefore,it is necessary to improve the discharge standard of sewage treatment plants,or carry out river water replenishment.This research can provide a scientific basis and strategic prediction for highquality water environment development in Shen Zhen.