高速公路路面雨水径流有机污染物赋存状态研究

Partitioning fraction of organic pollutants in expressway stormwater runoff

选择南京机场高速公路禄口高架桥段,对14场降雨径流进行了监测分析,探讨了雨水径流中溶解态和颗粒态COD的出流规律、事件平均浓度(EMC)、赋存比例及其影响因素.结果表明,若初期降雨强度大,冲刷作用显著,径流初期出流COD以颗粒态为主,后期以溶解态为主;若初期降雨强度小,溶解效应强,出流COD则以溶解态为主.就14场降雨的EMC中值而言,颗粒态COD约为溶解态COD的2倍;颗粒态COD受降雨特性影响的权重降序排列为:前期晴天数>最大降雨强度>降雨量和降雨历时;溶解态COD受降雨特性影响的权重降序排列为:最大降雨强度>降雨历时和降雨量>前期晴天数.

Based on monitoring and analysis of 14 rainfall-runoff events on Lukou overpass of Nanjing Airport Expressway, the effluent regularity, event mean concentration （EMC） and occurrence percentage of both solution-state and granular-state COD in runoff, as well as their influential factors were explored. With large initial rainfall intensity, the scouring action was evident and the effluent COD was dominated by granular state and then by solution state in the later stage, while with small initial rainfall intensity, the solution effect was evident and the effluent COD was dominated by solution state. In terms of the median EMC in the runoff of the 14 rainfall events, the granular-state COD was around 2 times as high as the solution-state COD. The descending order for influence weights of rainfall characters on granular-state COD was as follows： antecedent days of dry weather 〉 maximum rainfall intensity 〉 rainall volume and durtion of rainfall. The descending order for influence weights of rainfall characters on solution-state COD was as follows： maximum rainfall intensity 〉 durtion of rainfall and rainfall volume 〉 antecedent days of dry weather.