清远市区菜地土壤重金属污染情况调查与评价

Investigation and evaluation of heavy metal contamination of vegetable soil in Qingyuan City

目的了解清远市区菜地土壤中重金属污染情况。方法对清远市区113个主要菜地的土壤进行取样,样品湿式消解法后,用原子吸收光谱仪（AAS）对铅、镉、铜和铬4种元素进行分析。采用单因子污染指数和多因子综合污染指数法进行评价。结果清远市区菜地土壤主要污染是镉和铜,超标率分别是18.6%和6.2%,铅和铬没有超标。铜为轻度污染,镉为重度污染。113个菜地土壤重金属综合污染指数在0.18~4.33之间,有11.5%的土壤综合污染指数大于1。结论清远市区部分菜地中土壤已受重金属污染,相关部门应该采取措施防止污染进一步扩散。

[Objective]To understand the conditions of the heavy metal pollution in the vegetable soil of Qingyuan City.[Methods]The samples were collected from 113 vegetable fields in Qingyuan City. After the samples were treated with wet digestion,the contents of lead,cadmium,copper and chromium were analyzed by atomic absorption spectrophotometer（AAS）.The conditions were evaluated by single factor pollution index and synthetic pollution index.[Results]The main contamination was caused by cadmium and copper in Qingyuan City, whose excessive rate was 18.6% and 6.2%, respectively. The lead and chromium was not higher than the standard. The degree of copper pollution was slight, that of cadmium was severe. The synthetic pollution index was between 0.18-4.33 in 113 vegetable fields. The synthetic pollution index of 11.5% of the fields was greater than 1. [Conclusion]Some vegetable fields have been polluted by heavy metal in Qingyuan City. The related departments should take measures to prevent the further spread of pollution.