水电能源科学

为明晰城市屋面和道路雨水径流中颗粒态和溶解态典型污染物的初期冲刷特征，科学合理确定初期弃流量(V_FF),以北京市某典型水泥屋面和沥青道路径流为例，采用M(V)曲线评估颗粒态和溶解态污染物初期冲刷特征，即通过计算次降雨事件中指定径流增量的污染物平均浓度来评估水质变化确定，量化其V_FF,并评价相应径流污染总量控制效果。结果表明，沥青道路径流颗粒态和溶解态的化学需氧量(COD)和磷的污染水平显著高于水泥屋面(p<0.05),但颗粒态和溶解态氮并未呈现这一显著差异；水泥屋面径流中颗粒态污染物呈现更强的初期冲刷现象，但沥青道路径流溶解态污染物初期冲刷现象更强；除初期冲刷程度较弱的污染指标外，COD、总氮(TN)和总磷(TP)与其颗粒态或溶解态指标的V_FF存在明显差异；按照现行国家标准要求进行初期雨水3 mm弃流，水泥屋面、沥青道路可分别实现(65.26±32.40)%、(65.43±23.81)%的SS污染总量控制率及(58.17±32.49)%、(59.06±31.48)%的COD污染总量控制率，如基于实际监测数据识别的V_FF进行弃流，将获得更高的径流污染控制效果。研究结果可为城市径流污染中实施颗粒态和溶解态污染物的针对性控制策略与方法提供一定参考。

To clarify the first flush characteristics of particulate and dissolved pollutants in urban roof and road runoff and to scientifically determine the first flush volume(V_FF), this study investigated the typical cement roof and asphalt road runoff in Beijing using the M(V) curve method. The approach involved calculating average pollutant concentrations in specified runoff increments during rainfall events to assess water quality variations, quantify V_FF, and evaluate corresponding runoff pollution control effectiveness. The results show that the pollution levels of particulate and dissolved chemical oxygen demand(COD) and phosphorus in runoff from asphalt road are significantly higher than those from cement roof(p<0.05), but no such significant difference is observed for particulate and dissolved nitrogen. Particulate pollutants in cement roof runoff exhibit a stronger first flush phenomenon, whereas the first flush phenomenon of dissolved pollutants is more pronounced in asphalt road runoff. Except for the pollution indicators with weaker first flush phenomenon, there are significant differences between V_FF of COD, total nitrogen(TN), and total phosphorus(TP) and their particulate or dissolved indicators. According to the current national standard, the first 3 mm of runoff shall be discarded, cement roof and asphalt road can achieve SS pollution control rates of(65.26±32.40)% and(65.43±23.81)%, respectively, and COD pollution control rates of(58.17±32.49)% and(59.06±31.48)%, respectively. Higher runoff pollution control results will be obtained if V_FF is determined based on actual monitoring data. The findings will provide reference for implementing targeted control strategies and methods for particulate and dissolved pollutants in urban stormwater runoff.