甘肃省白银市区土壤环境质量评价

对白银市区土壤中Cu、Pb、Zn、Cd、Hg的分布、存在形式和在水体中的含量进行分析,认为该区土壤、水体已受到Cu、Pb、Zn、Cd、Hg等重金属污染.按国家土壤环境质量标准,白银市土壤中Cd的环境质量均未达到Ⅰ级标准,Ⅲ级、Ⅳ级污染面积占研究区面积的82.39％,污染比较严重；Hg、Pb、Zn、Cu的Ⅲ级及其以上污染区面积分别占研究区的7.35％、5.59％、14.67％、5.71％.通过2000年与2007年白银市土壤重金属元素背景值对比发现,Cu、Pb、Zn、Cd、Hg的污染增速明显,并有逐渐扩大的趋势.对Cu、Pb、Zn、Cd、Hg的成因来源进行了初步探讨,认为有色金属冶炼、加工和重化工是主要污染源,其次为燃煤、生活垃圾及汽车尾气排放.

AN ASSESSMENT OF THE SOIL ENVIRONMENTAL QUALITY IN THE DOWNTOWN AREA OF BAIYIN CITY,GANSU PROVINCE

The distribution and modes of occurrence of Cu, Pb, Zn, Cd and Hg in the soil and their content in the water were analyzed in this paper. It is found that the soil and water of the study area have been heavily polluted by Cu, Pb, Zn, Cd, Hg and other heavy metals. According to the National Environmental Quality Standards for Soil, no places in Baiyin has attained grade I of quality of Cd in surface soil, while places of grade m, Ⅳ account for 82.39% of the study area, so Cd pollution is very serious. The percentages of grade Ⅲand above grade Ⅲof quality of Hg, Pb, Zn and Cu account for 7.35%, 5.59%, 14.67% and 5.71% respectively. A comparison of the average content of heavy metal elements between 2000 and 2007 in Baiyin City reveals that the growth rate of Cu, Pb, Zn, Cd, Hg contamination was significantly and gradually growing. An investigation was made on the sources of Cu, Pb, Zn, Cd and Hg, which shows that the major sources of pollution are non-ferrous metal smelting, processing and heavy chemical industry, followed by coal, garbage and car exhaust emissions.