广州市典型社区单元面源污染初期冲刷效应

First flush effect of non-point source pollution in Guangzhou typical community unit

为了向初期雨水截留控制提供基础数据,研究广州市社区单元面源污染初始冲刷效应,采集并分析研究区域中3场降雨道路、屋顶和绿地径流的污染物情况,利用无量纲累积曲线、初期冲刷系数及质量初期冲刷强度指数MFF对径流污染物BOD_5、COD_(Cr)、TSS、NH_3-N、TP、TN的初期冲刷效应进行定性分析和定量分析。结果表明,绿地和屋顶比道路更易发生初期冲刷效应,且冲刷强度一般比道路强,而绿地在连续降雨后初期冲刷效应更加明显;各种初期冲刷污染物中,TN初期冲刷效应更为显著,TP和NH_3-N次之;采用MFF指数法可以得到较为可靠的定量化结果,建议采用该方法作为初始冲刷效应分析方法。

In order to provide basic data for initial rainfall interception control,the first flush effect of non-point source pollution in Guangzhou community unit was studied in this paper. The runoff pollutants at road,roof and greenbelt during three rainfall events in the study area were collected and analyzed. The dimensionless cumulative curve,the first flush coefficient and MFF index were used respectively to do quantitative analysis and qualitative analysis of the first flush effect of runoff pollutants such as BOD_5,COD_(Cr),TSS,NH_3-N,TP and TN. The results showed that the first flush at greenbelt and roof occurred more easily and had more intensity than that at road,and the first flush at greenbelt is more obvious after successive rains. Among the various pollutants in the first flush,the first flush effect of TN is more obvious,and TP and NH_3-N take the second place. The more reliable quantitative results can be obtained by the MFF index method,and it is recommended to be the analysis method of the first flush effect.