阿拉尔枣园土壤重金属含量测定及污染评价

为调查阿拉尔枣园土壤重金属污染状况,以新疆阿拉尔团场的红枣园间土壤为研究对象,对24个红枣枣园的土壤进行采集。采用火焰原子吸收分光光度法测定了枣园土壤样品中的Cd,Pb,Cr,Cu和Zn 5种重金属含量,以《土壤环境质量标准》(GB 15618-1995)二级为标准,运用尼梅罗综合污染指数法进行评价。结果表明,24个土壤样点中的Cu,Pb,Cr,Zn和Cd平均含量分别为30.54,85.99,71.09,77.29,4.62 mg/kg,均大于新疆土壤背景值,Cu,Cr,Pb和Zn2+污染等级均为无污染、安全无风险,符合国家二级土壤标准。但是存在Cd污染,分别有54.17%,8.33%,37.5%的采样点处于轻度、中度和重度污染,需要进行特别的关注。土壤重金属综合污染指数P平均值为3.36,属于中度污染状态,Cd是最主要污染指数贡献因子。

In order to investigate the soil heavy metal pollution in the Alar jujube field, the soil samples were col- lected from the 24 jujube gardens in Alar, Xinjiang. By using flame atomic absorption spectrophotometry, 5 kinds of heavy metals, Cd, Pb, Cr, Cu and Zn content of the soil samples were determined according to secondary standard of the soil environment quality standard （GB 15618-1995）, and were evaluated with the Nemerow Syn- thetical Pollution Index method. The results show that Cu, Pb, Cr, Cu and Zinc average content of the 24 soil sample are： 30.54 mg/kg, 85.99 mg/kg, 71.09 mg/kg, 77.29 mg/kg and 4.62 mg/kg respectively, all of which were greater than the soil background values in Xinjiang. Cu, Cr, Pb and Zn2＋ pollution levels are pollution-free, safe and risk-free, conforms to the national secondary standard of soil. However, there is Cd pollution, with 45.83 percent, 8.33 percent and 45.83 percent of the sample points in light, moderate and severe pollution, which re- quires special attention. The potential comprehensive pollution index of soil heavy metals is 3.36, which is moder- ately polluted. Cd is the most important factor contributing to pollution index.