陕西省渭南市郊区土壤重金属污染评价

Assessment of Heavy Metal Pollution in the Suburbs of Weinan City in Shaanxi Province

于2012年对渭南市郊区两两不相邻的菜地、麦地、柿子地、花椒地、荒地和林地土壤重金属进行测定,并运用单因子指数法、内梅罗综合污染指数法、潜在生态危害指数法以及参照最大容许极限值对几种不同土地利用类型中重金属污染现状进行分析。结果表明,在渭南市郊区土壤重金属污染中,主要污染因子为Ni,其次是Cr、Cu和Pb,没有超过土壤重金属背景值的是Zn。最终得出渭南市郊区综合污染指数和潜在生态危害指数分别为3.49和60.57,其评价结果表明,渭南市属于重污染和轻微生态风险。对渭南市郊区土壤重金属含量纵向分析得出,Ni和Cu在地表中的含量都比较高,Cr在各种地表和深度下的污染都比较严重,这与地表污染情况类似;在麦子根系可下扎深度内,土壤重金属尤其是Cr污染严重,因此应加强对土壤重金属污染的治理。

Taking Weinan city of Shaanxi province as researched area, soil heavy metal of the pairwise nonadjacent vegetable, wheat, persimmon, pepper, wasteland and forest in suburb in 2012 was measured, and their pollution status was analyzed by using single factor index method, Nemerow index method, potential ecological risk index method and reference of the allowable limit value of heavy metal. The results showed that the main pollution factor was Ni, followed by Cr, Cu and Pb, and Zn did not exceed the heavy metal background value of the soil in the suburb of Weinan City. Finally, the com- prehensive pollution index and potential ecological risk index were 3.49 and 60.57 respectively, and the evaluation results showed that Weinan city belonged to grade of heavy pollution and slight ecological risk. The results of longitudinal analysis of soil heavy metal content in Weinan city suburb showed that, Ni and Cu content were high, and Cr pollution in all kinds of ground and depth were serious, which was similar to the surface pollution; in plunge depth of wheat roots, soil heavy metals especially Cr pollution was serious. Therefore, we should strengthen the governance of soil heavy metal pollution.