城市住宅小区路面径流污染特征分析

Analysis of Characteristics of Road Runoff Pollution in Urban Residential Areas

为了解城市住宅小区路面径流不同时期的水质特性,以北京市某住宅小区路面径流为例,结合降雨量、降雨历时的同步观测,分析了小、中、大、大暴雨4场降雨中总悬浮颗粒物(TSS)、化学需氧量(COD)、总氮(TN)、总磷(TP)浓度和浊度随时间的变化,并将场次降雨分为前20、20~60、60 min后三个时期,对三个时期内污染物浓度进行差异性和相关性分析。结果表明,该小区路面径流的TSS、COD、TN、TP次降雨径流平均浓度介于32.3~74.3、45.0~90.1、1.3~8.0、0.37~0.49 mg/L之间,浊度为9.9~21.0 NTU,除小雨外,其他三种降雨时路面污染较为严重。4场降雨的前20 min,COD、TN、浊度、TP均与TSS有同源性,其中COD、TN受雨强影响较大;20~60 min,TSS、浊度及TN、TP有同源性,其中COD、TSS、浊度受雨强影响较为显著;60 min后,TP、浊度、TSS两两之间及TN、TP均有同源性,其中TSS、TN均受雨强影响较大。

To investigate the characteristics of water quality in different periods of road runoff in urban residential areas,the road runoff of a residential district in Beijing was selected as the research object.The concentration variations of total suspended solid(TSS),chemical oxygen demand(COD),total nitrogen(TN),total phosphorus(TP)and turbidity were analyzed along with time under the small,medium,heavy and intense rainfall events.The rainfall times were divided into three periods,namely the initial 20 min,20-60 min and the last 60 min,and the difference and correlation of pollutant concentrations in the three periods were analyzed.The results show that the event mean concentration(EMC)of TSS,COD,TN,TP and turbidity of road runoff were between 32.3-74.3 mg/L,45.0-90.1 mg/L,1.3-8.0 mg/L,0.37-0.49 mg/L and 9.9-21.0 NTU,respectively.Except small rainfall,the road pollutions were much serious for the other three rainfall events.During the initial 20 min,COD,TN,turbidity and TP had homology with TSS,among which COD and TN were greatly affected by rainfall intensity.At 20-60 min,TSS and turbidity had homology,so did TN and TP,among which COD,TSS and turbidity were significantly affected by rainfall intensity.After 60 min,TP,turbidity and TSS were homologous,like TN and TP,among which TSS and TN were greatly affected by rainfall intensity.