选择南京市区3处不同类型屋面(沥青屋面、瓦屋面、混凝土屋面),对7场降雨径流事件进行了监测分析,重点探讨了屋面雨水径流中污染物的出流规律、事件平均浓度(EMC).结果表明,对于降雨量大、降雨强度大的降雨事件,初期污染物浓度较高,整个出流过程污染物浓度随降雨历时呈前高后低的变化趋势;对于降雨量小、降雨强度小的降雨事件污染物浓度没有明显降低趋势;降雨强度大、具有明显降雨峰值的降雨事件中污染物出流存在“二次冲刷”现象.EMC的计算结果表明,屋面径流TN,COD的污染严重,3种屋面的TN以及沥青、混凝土屋面COD超出了《地表水环境质量标准》V类标准限值,瓦屋面和沥青屋面的TP也超出了Ⅲ类标准限值;SS和TP浓度排序:瓦屋面＞沥青屋面＞混凝土屋面,COD,TN的浓度排序为:沥青屋面＞混凝土屋面＞瓦屋面;受屋面类型、降雨特性和当地大气状况的影响,本研究与国内外同类研究存在一定的差异.%The water quality of roof rain-runoff were monitored during 7 rainfall runoff events occurred on different types of roof (asphalt roof, tile roof, concrete roof) in Nanjing. Discharge rule of pollution and event mean concentrations (EMC) were evaluated. When the rainfall and rainfall intensity was heavy, the concentrations of pollutants in the initial runoff were higher, and were lower in the later runoff; otherwise, the concentrations of pollutants in the runoff were around a value and decreased slightly. Security flush effect exists in the events with heavy rainfall and intensity peak. The EMCs showed that the pollution extent of TN and COD were serious. Paniculate TN EMCs of three type roofs and COD EMCs of asphalt roof, concrete roof exceeded the class Ⅳ standard values of the "surface water environmental quality standard ". TP EMCs of asphalt roof, tile roof exceeded the class Ⅲ standard values. The sequence of the concentrations of SS, TP were: tile roof > asphalt roof > concrete roof; for COD and TN: asphalt roof > concrete roof > tile roof. By roofing type, rainfall characteristics and the influence of the local atmospheric conditions, there were certain differences between this study and other similar research at domestic or foreign.
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