广州城市路面径流COD污染特征分析

Case study analysis of the characteristic features of COD pollution in urban road runoff,Guangzhou

2006年4—7月,通过在广州市两条交通主干线上设点监测、采样分析,对城市路面径流COD污染特征进行分析。结果表明,市区和郊区路面径流COD浓度均超过《污水综合排放标准》规定的二级排放阈值;城市不同地区的COD负荷有较大差异,市区路面径流COD浓度高于郊区,COD污染物质积累速度高于郊区;雨前干燥期是路面COD物质积累的重要影响因子;路面径流中COD浓度随降雨-径流过程呈现规律性变化,且径流COD与SS浓度具有显著相关关系;城市路面径流COD存在初期冲刷现象。

The present paper is actually a case study analysis of the characteristic features of COD pollution in the urban road runoff, Guangzhou. For our research purpose, we have done field-monitoring and field-research data-sampling and-collecting activities in two sampling sites in a period from February to July in 2006. Then, a detailed analysis and careful discussion has been done with the sampling data concerning the pollution load and characteristic features in urban road runoff situation in Guangzhou. The results of our case study and analysis show： （1） both the COD concentrations in downtown and suburban areas of the city exceed the Tier II standard by Integrated WastewaterDischarged Standard （GB 8978--1996 in China）; （2） there exists a great difference with COD concentrations between the downtown and suburban areas, with that much higher in downtown than that in the suburbs, what＇ s more, the cumulative rate of pollutants in downtown is far exceeded that in suburb; （3） ADP proves to be one of the most serious factors to cumulative COD concentration; （4） with the process of rainfall-flow, COD concentration in road runoffs tends to fluctuate regularly, there turns to be an obvious correlation between COD and SS concentration in the urban road runoffs; （5） there proves to exist a ＂First Flush＂ phenomenon on COD load in road runoff.