【摘要】 通过对合肥市4种不同类型下垫面27场降雨径流和自然降雨水样中SS、COD、TN和TP水质指标的分析,探讨了草地、屋面、校内路面和校外道路降雨径流污染物历时变化规律及初期冲刷效应,比较了不同类型下垫面降雨径流和自然降雨水样中污染物浓度分布的差异,计算了场次降雨径流污染物的事件平均浓度.结果表明,不同下垫面降雨径流污染物浓度随时间变化的规律相似,且大多存在初期冲刷现象,一般在降雨初期污染物浓度较高,随着降雨历时的延长污染物浓度呈下降趋势,并趋于平稳;不同下垫面降雨径流和自然降雨水样中TN污染负荷较高,大气湿沉降对降雨径流中TN的贡献很大;校外道路降雨径流水样中SS、COD、TN和TP浓度的变化范围冬半年大于夏半年,不同下垫面条件对降雨径流中污染物EMC的影响存在差异.更多还原

【Abstract】 Water samples from different underlying surface conditions,including grassplot,top of building,road in campus and road outside campus,were collected from 27 rainfall events in Hefei City.SS,COD,TN and TP were analyzed and compared.The study illustrated the time-varying regularity,the first flush effect,and the even mean concentrations of rainfall runoff pollutants on different underlying surface conditions.Results showed that contamination concentrations were commonly higher at the initial stage,while decreased with prolonging of the rainfall time and gradually became stable at the later stage.TN loading was high in rainfall runoff under both different underlying surface conditions and natural rainfall,indicating that atmospheric wet deposition contributed a lot to the TN of rainfall runoff.Variation of SS,COD,TN and TP in the road runoff outside campus were wider in the period from October 2009 to March 2010 than those in the period from April to September 2010.EMCs in the rainfall runoff depended greatly on different underlying surface conditions.更多还原