道路雨水径流中重金属特征研究进展

Study on the characteristics of heavy metals in road stormwater runoff

为研究不透水道路路面雨水径流中重金属污染现状,从危害程度较大的Fe、Cu、Cd、Zn、Pb、Cr、Ni等7种重金属元素入手,总结了国内外主要城市道路雨水重金属赋存状态、道路沉积物重金属含量及与地表径流出流污染间关系。结果表明,相比于城市道路,高速公路雨水出来存在明显的“二次冲刷效应”,且Pb污染最为严重;城市道路较科教区、生活区和商业区,Zn、Pb出流量显著增大,但各元素均存在“初期效应”;道路沉积物中重金属含量远超出土各城市壤背景值数倍,且污染程度整体上与粒径呈负相关;沉积物是重金属累积的重要载体,也是径流污染源之一,循环关系可描述为:大气悬浮物→道路沉积物→城市土壤→雨洪沉积物。

In order to research the rainfall runoff pollution characteristics of heavy metals on the impervious road,we started from Fe,Cu,Cd,Zn,Pb,Cr,Ni and so on 7 heavy metals and summarized the state of occurrence of heavy metals in major urban roads at home and abroad,content of road sediment heavy metal and the relationship between the flow and runoff pollution.The results show that compared with the urban road,the highway rainwater is an obvious “second scouring effect”,and Pb pollution is the most serious;compared to the region of science and education,residential and commercial,content of Zn and Pb in urban have a significant increases,but they are all accorded with “initial effect” of each element;the content of heavy metal in sediments are far beyond the soil background several times from city to city,and the degree of contamination is negatively correlated with grain size;Sediment is the carrier of heavy metal,also is the main source of runoff pollutants,the circulation relation could be described as:suspended sediment on air→sediments on road→urban soil→sediments in pipes.