常州市湖塘纺织工业园降雨径流污染负荷分析

我国当前以实现分流制为规划指导原则,分流制下工业园区雨水径流污染对水环境存在较大潜在影响。在此背景下采用SWMM软件模拟降雨和实地调研相结合的方法,分析湖塘园区降雨径流的污染负荷。结果表明:0.25年一遇的降雨径流质量浓度峰值ρ(TN)=6.01 mg/L,ρ(TP)=0.02 mg/L,ρ(COD)=125.21 mg/L,该降雨重现期下的TN和COD浓度均远劣于GB 3838—2002《地表水环境质量标准》的Ⅴ类水标准;随着降雨重现期增大,径流污染物浓度峰值会进一步提高。排入受纳水体采菱港的污染物总量比例:径流中TN占园区总TN(径流+点源)排放量的25.9%,径流中TP占4.4%,COD占28.0%,COD、TN径流污染量占整个园区污染总量的比重较大。结合湖塘园区排水系统的实地调研,建议加强园区初期雨水截留、推广园区中水回用和推进园区与企业排口设置规范化,以有效降低园区雨水径流对周边水环境的影响。

Analysis of rainfall-runoff pollution load of Hutang textile industrial park in Changzhou City

Separate drainage system has been used as the guideline for drainage system planning in China, and the rainfall-runoff pollution in industrial parks with separate drainage systems has potential impacts on the water environment. In this study, the rainfall-runoff pollution load of the Hutang textile industrial park was analyzed through simulation of rainfall with the SWMM software and field research. The results show that the peak values of TN, TP, and COD concentrations in runoff during the rainfall with a return period of 0. 25 year were 6. 01 mg/L, 0. 02 mg/L, and 125. 21 mg/L, respectively. The TN and COD concentrations were evidently lower than the grade V level according to the Environmental Quality Standards for Surface Water(GB3838-2002). With the increase of the rainfall return period, the peak values of pollutant concentrations in the runoff would increase. Of the pollutants discharging into Cailing Port, the TN amount accounted for 25. 9% of the total TN emissions, the TP and COD amounts accounted for 4. 4% and 28. 0%, respectively. The TN and COD amounts in the runoff accounted for large proportions in the Hutang textile industrial park. Based on the drainage field survey in the Hutang textile industrial park, some suggestions are proposed, which include strengthening interception of the early-period runoff, promoting water reuse in the park and standard setup of wastewater outfalls in the park and enterprises, in order to reduce the rainfall-runoff impacts on the surrounding water environment.