重庆市主城区街道地表物中重金属的污染特征

分析了重庆市主城区街道地表物的基本性质及As、Cd、Cr、Cu、Hg，Ni、Pb，Zn等元索的全置、模拟酸雨（pH4．5）的浸出量。结果表明：各功能区中街道地表物的自然组成均以中等粒径的为主；就元素而言，粒径越细对重金属的贡献率越高；就功能区而言．细粒径与中等粒径的颗粒对重金属贡献率较为接近。街道地表物呈碱性，有潜在的有机物污染。重庆市主城区街道地表物重金属元素含量有较大的差异，受人为活动干扰严重的重金属种类为Cr、Cd、Hg、Cu。内梅罗指数评价结果显示除Ni外，其他元素均有不同程度的污染，各功能区均受到重金属的严重污染。重庆市主城区街道地表物中的重金属只与其中的磷素含量显著正相关。

Heavy Metals Contamination of Street Dusts in Core Zone of Chongqing Municipality

In order to study the heavy metals contamination of street dusts in core zone of Chongqing city,the total contents and extracted heavy metal content by simulated acid rain of As,Cd,Cr,Cu,Hg,Ni,Pb,Zn were analyzed,meanwhile,corresponding properties including pH,organic matter(OM),total nitrogen(TN),total phosphorus(TP) and total potassium(TK) were also analyzed.The results showed that: (1) in different functional zone,the medium size particle account for about 50% of the total street dust.The contribution of different size particle to heavy metal content as follows: for different element,the finer the particle,the greater the contribution is,but for different functional zone,the medium size particle almost has the same contribution as the finest particle;(2) the street dust were alkaline and had potential organic pollution;(3) the total heavy metal contents of street dusts in Chongqing had great difference,and the elements seriously influenced by people were Cr,Cd,Hg and Cu;(4) the Nemerow comprehensive index indicated that the street dusts were contaminated by seven kinds of heavy metals except for Ni,while all functional zones were polluted seriously;(5) the total heavy metal contents of street dusts in Chongqing only had remarkably positive correlation with TP.