天水苹果园土壤重金属污染调查与评价

Evaluation of the Concentration of Heavy Metals in Apple Orchard Soils in Tianshui Area

以天水苹果园表层土壤（0-20cm）为调查对象，对土壤中重金属Zn、Cu、Pb、Cr和CA的含量进行测定，运用单项污染指数法、内梅罗综合污染指数和潜在生态危害指数法对土壤健康状况进行评价．结果表明：Zn、Cu、Pb、Cr、CA平均值分别为77．39，23．03，23．62，61．49，0．072mg／kg，除Cu和CA以外，其他三种元素均超过甘肃省土壤背景值；单项污染指数评价结果显示，土壤中Zn、Pb、Cr为轻度污染，目前尚无Cu、CA污染；天水果园土壤重金属潜在生态危害轻微．

The contents of soil heavy metals（Zn, Cu, Pb, Cr and Cd） and their pollution were investigated by sampling the topsoil （0-20 cm） from apple orchards in Tianshui area. The pollution of heavy metals was evaluated by using single factor pollution index and potential ecological. Results showed that the mean concentration of heavy metals Zn,Cu, Pb, Cr and Cd were 77. 39,23. 03,23. 62,61.49 and 0. 072 mg/kg, respectively. The Zn,Pb and Cr contents were higher, while the Cu and Cd were lower than the background level of heavy metals of Gansu. Zn, Pb and Cr were light pollution, and for Cu, Cd all samples were no-pollution. The evaluation showed that the potential ecological hazard of Tianshui apple orchards was in slight pollution.