成都燃煤电厂周围土壤中砷、锑、铅、锌分布特征及污染评价

DISTRIBUTION CHARACTERISTICS AND POLLUTION EVALUATION OF As,Sb,Pb AND Zn IN SOIL AROUND THE COAL-FIRED POWER PLANT IN CHENGDU

系统研究了成都市燃煤电厂周围土壤中As、Sb、Pb和Zn的水平及垂直分布特征,同时利用单因子污染指数法和内梅罗综合污染指数法对土壤污染程度进行了评价.结果表明,上述元素在电厂周围土壤中的含量均具有方向性,As、Sb、Zn呈现出南>西>东>北的特点,而Pb则是南>西>北>东;Zn和Pb的含量随深度增加呈总体下降趋势,而As和Sb的变化却不明显;4种元素的垂向迁移能力为Zn>Pb>As>Sb;电厂周围的4个方向都受到了不同程度的污染,其污染程度为南>西>东>北,各元素的污染程度则是Sb>As>Pb>Zn;研究的区域均属于重度污染等级.

The horizontal and vertical distributions of As,Sb,Pb and Zn in soils around the coal-fired power plant in Chengdu were systematically investigated.The pollution degree was evaluated by single factor and Nemerow comprehensive pollution index.It was found that the contents of the four elements in the selected soils were all direction-dependent and As,Sb,Zn followed the order of southwesteastnorth,while Pb followed the order of southwestnortheast.The contents of Zn and Pb in the soils tended to decrease with increasing depth,while As and Sb did not show such an obvious change.The mobility of these elements in vertical profile increases in the order of： ZnPbAsSb.The soils in all directions were polluted to various degrees,which ranked as follows： southwesteastnorth.The pollution of individual element was in the sequence of SbAsPbZn.All the studied areas were of heavy pollution grade.