安徽砀山梨园土壤重金属分布特征及污染评价

Heavy Metals Distribution Characteristics and Pollution Assessment in Pear Soils of Dangshan, Anhui Province

以安徽砀山梨园为研究区域,测定土壤重金属元素Cd、Hg、Cu、Zn、As、Pb、Cr含量,采用单因子污染指数法、Nemerow综合污染指数法和潜在生态危害指数法进行污染评价。砀山梨园土壤中Cd、Cu、Zn、As等重金属含量超过安徽省土壤背景值,Hg、Cr含量与背景值基本一致,Pb含量小于背景值;与国内其它地区果园相比,Cu含量较高,Cd、As和Cr含量适中,Hg、Zn和Pb含量较低。以安徽省土壤背景值为评价标准,Cd、Hg、Cu、Zn、As、Cr的单因子污染指数较高,污染比率均超过40%,Nemerow综合污染指数为1.54,达到轻度污染级别,综合潜在生态危害指数为中等潜在生态风险。以农用地土壤污染风险筛选值为评价标准,7种重金属元素单因子污染指数均小于1,Nemerow综合污染指数为0.33,属清洁未受污染水平,潜在生态危害整体表现为低潜在生态风险。

Dangshan pear orchard in Anhui Province was used as the study area to determine the content of soil heavy metal elements Cd,Hg,Cu,Zn,As,Pb,and Cr,the pollution evaluation was carried out by using the single-factor pollution index method,the Nemerow comprehensive pollution index method,and the potential ecological hazard index method.The results showed that the Cd,Cu,Zn and As content in the soil of Dangshan pear orchard exceeded the background value of the soil in Anhui Province,the Hg and Cr content was basically the same as the background value,and the Pb content was less than the background value;compared with the orchards of other regions in China,the Cu content was higher,the Cd,As and Cr content was moderate,and the Hg,Zn and Pb content was lower.Evaluated with the background value of soil in Anhui Province,except for Pb,the single-factor pollution index of the remaining heavy metal elements were close to 1 or greater than 1,with most of the pollution ratios above 40%,and the Nemerow integrated pollution index was 1.54,reaching the mild pollution level,and the combined potential ecological hazard index is medium potential ecological risk.Evaluating the screening value of soil pollution risk of agricultural land,the single-factor pollution index of each heavy metal element is less than 1,and the Nemerow comprehensive pollution index is 0.33,which is a clean and uncontaminated level,and the potential ecological hazards as a whole are characterized by low potential ecological risks.