湖南株洲市土壤重金属分布特征及污染评价

Distribution and pollution assessments of heavy metals in soils in Zhuzhou, Hunan

对株洲市土壤重金属Cu、Pb、Zn、Cd、Cr、Hg、As污染现状进行了调查与评价。结果表明:①株洲市60个样品中Cd已达到重度污染程度,污染严重;Cu、Hg、As处于中度污染;Pb、Zn、Cr属于轻度污染。内梅罗综合污染指数也已达重污染。②不同土地利用类型土壤中各重金属含量由高到低变化如下:Cu、Zn、Cr为水田→菜地→旱地;Pb、Hg、As为旱地→水田→菜地;Cd为菜地→旱地→水田。③不同土壤类型中各重金属含量由高到低变化如下:Zn、Cd、As为潮土→粘土→红壤;Pb、Hg为粘土→潮土→红壤;Cr为红壤→潮土→粘土;Cu为潮土→红壤→粘土。

Investigation and assessments of pollutions of heavy metals such as Cu, Pb, Zn, Cd, Cr, Hg and As in Zhuzhou City were carried out. The results show the following： （1） The Cd pollution of all the 60 samples from Zhuzhou City has been heavy, the pollution of Cu, Hg and As is moderate, and the pollution of Pb, Zn and Cr is shght. The Nemerow comprehensive pollution index also shows heavy pollution. （2） The heavy metal contents in soils of different land use types decrease as follows： the Cu, Zn, and Cr contents decrease from paddy field→ vegetable field→dry land; Pb, Hg and As, dry land-→paddy field→vegetable field; and Cd, vegetable field→dry land→paddy field. （3） The heavy metals content with different soil types from high to low is as follows： The contents of various heavy metals in different soil types decrease as follows： the contents of Zn, Cd and As decrease from sandy Chao soil→clay soil→red soil; Pb and Hg, clay soil→sandy Chao soil→red soil; Cr, red soil→sandy Chao soil-→clay soil; Cu, sandy Chao soil-→red soil→clay soil.