北京市城市非点源污染特征的研究

通过监测降雨径流水质,研究了北京市城市非点源污染的特征。结果表明,北京市城市地表径流水排入任何地表水体都会对其造成污染,且城市地表径流水的大部分水质指标已经达到了污水综合排放的三级标准,因此,我们对待城市地表径流水应该如对待污水一样处理。对于TN、TP、CODCr、BOD5浓度,路面径流要高于屋顶径流,而对于SS浓度,屋顶径流高于路面径流。总磷TP颗粒吸附态的污染物对总污染物的贡献最大,对于路面径流高达83.1%,对于屋顶径流为68.6%,其次是CODCr,总氮TN的颗粒吸附态的贡献较低。通过沉积或过滤去除城市地表径流中的悬浮颗粒物,可以提高城市地表径流的水质。所有污染物随降雨过程变化的总体趋势为雨水初期径流污染物浓度很高,随降雨历时的延长,污染物浓度逐渐下降并趋于稳定。初期径流危害较大。

Study on characterization of urban runoff pollution in Beijing

In this research,we studied the characterization of urban runoff pollution in Beijing through measuring water quality of urban runoff.Results showed that if going into any surface water,urban runoff of Beijing would pollute it. And most indexes of water quality of urban runoff already reached third-level standard of integrated wastewater discharge.Concentrations of TN,TP,COD_(Cr),BOD_5 of street runoff were higher than that of roof runoff and concentrations of SS of street runoff were lower than that of roof runoff.Percentage of TP linked to particles was the largest,which in street runoff was 83.1%,and which in roof runoff was 68.6%.Percentage of COD_(Cr) linked to particles was the second large,and percentage of TN linked to particles was lower relatively.Suspended solids removal,through settling or filtration,would cause an important reduction of pollutants loads in all types of runoff.The trend of change of all pollutants followed the time of rain was that concentrations of pollutants in early runoff were higher,and by the extend of time of rain,concentrations of pollutants descended gradually and approached to the stabilization.Early runoff was very harmful.