西安主城区土壤重金属污染评价

Evaluation of Heavy Metal Pollution in Soil of the Main Urban District in Xi'an

西安城区一体化进程加快,土壤环境资源承受压力巨大,以As、Cd、Cr、Cu、Hg、Ni、Pb、Zn作为评价因子,采用单因子及内梅罗综合污染指数法对西安主城区土壤重金属污染进行评价。结果显示,Cd、Hg、Ni、Zn总超标率分别为40.4%、18.2%、1.0%、2.0%,As、Cr、Cu、Pb未超标;污染程度顺序为Cd>Ni>Hg>Zn>Cu>As>Cr>Pb,其中As、Cr、Pb污染等级为清洁,Cu属尚清洁,Hg、Zn属轻度污染,Cd、Ni属重污染;重污染区分三部分展布于西郊到北郊,其外围中度、轻度污染区及尚清洁区依次呈环状分布,清洁区分布面积广泛。

With As, Cd, Cr, Cu, Hg, Ni, Pb, Zn as evaluation factors, the single factor and Nemerow comprehensive pol-lution index methods are adopted to evaluate heavy metal pollution in soil of the main urban district in Xi＇an. The results show that total excessive rates of Cd、Hg、Ni、Zn are 40. 4%, 18. 2%, 1. 0%, 2. 0%, and As, Cr, Cu, Pb do not exceed the standards. The order of the pollution degree is Cd〉Ni〉Hg〉Zn〉Cu〉As〉Cr〉Pb, among which the As、Cr、Pb are belong to clean, Cu is belong to proximity clean, Hg、Zn are belong to mild pollution, and Cd、Ni are belong to heavy pollution. Heavily polluted areas spread from western suburbs to northern suburbs in three parts, at the periphery of which, moderate pollution areas,light pollution areas and proximity clean zones distribute by annularity in turn, and the clean areas widely distribute.