宝鸡北部黄土覆盖区耕地土壤重金属污染特征及评价

Characteristics and Evaluation of Heavy Metal Pollution in Arable Soil of Loess Covered Area in Northern Baoji

采集宝鸡市北部黄土覆盖区公路、工厂附近等21个点位的耕地土壤样品,对其Cu、Pb、Zn、Cr和Cd五种重金属元素的含量进行了测定。综合使用单因子指数法、综合指数法、地积累指数法、潜在生态风险法和模糊数学评价法,对其土壤质量进行了分析评价。研究结果表明:该区耕地均受到不同程度的重金属污染; Cd、Pb和Zn元素的含量已超过土壤环境质量二级标准,Cu和Cr元素的含量未达到超标水平; 5种重金属的污染程度顺序为Cd>Pb>Zn>Cu>Cr。

The arable soil samples were collected from 21 locations of loess covered area in northern Baoji, and their Cu, Pb, Zn, Cr and Cd contents were determined. The quality of these arable soil samples were analyzed and evaluated by comprehensively using the methods of single-factor pollution index, comprehensive pollution index, geoaccumulation index, potential ecological risk index, and fuzzy mathematics evaluation. The study results indicated that the cultivated land in this area had been inordinately contaminated by above-mentioned heavy metal elements. The contents of Cd, Pb and Zn elements had exceeded the secondary standards in “Soil Environmental Quality Standard”, and the contents of Cu and Cr elements did not reach the standard. The order of the pollution levels of five heavy metal elements was Cd〉Pb〉Zn〉Cu〉Cr.