城区雨水管网径流污染特征研究

以新乡市城区屋面作为汇水区域,开展试验对雨水管网中场次降雨径流水文水质过程进行研究,可为有效利用城市雨水、控制非点源污染等提供依据。水质指标包括SS、COD和TN。结果表明:水质指标中SS、COD变化趋势基本一致,随着降雨过程的持续浓度逐渐降低并趋于一个稳定值;TN随着雨量的累积浓度逐渐降低,但在降雨结束前有反弹趋势;指标标准差率呈SS>COD>TN的趋势;径流初期屋面冲刷效应明显,初期径流量可定义为前1³mm的降雨量;径流中SS与COD、TN之间的相关性较好,在控制径流污染时可采取措施同时去除;径流污染物直接通过城区排水管网汇入受纳水体后对其水质影响较大,尤以SS、COD的变化最为明显。

Research on pollution characteristics of runoff of rain pipeline in urban

Taking urban roof as the catchment area in Xinxiang City, the paper researched the hydrology and water quality process of each rainfall event so as to provide the basis for effective use of urban rainfall and control of non-point source pollution. The samples includes the contents of SS, COD and TN. The results show that the variation trend of pollutant index SS, COD in runoff is similar and tends to a steady value.the contents gradually decrease and reach a stable value with the duration of rainfall.With the accumulation of rainfall, the change amplitude of TN gradually reduce, but which has a rebound and increase tendency before the end of rain. The standard deviation rate of water quality indicator is in the order of SS>COD>TN. The first flush of roof runoff is clear, and the initial runoff amount is equivalent to former 1~3mm rainfall. The correlation between SS and COD, TN in runoff is good. It shows that the similar measures can be taken to remove them in controlling the runoff pollution. That the runoff pollutants flow into the receiving water body directly through urban drainage pipes has an important effect on its quality. The change of SS and COD is obvious.