农用地土壤重金属环境地球化学基线研究

Environmental Geochemical Baseline of Soil Metallic Elements in Agricultural Soil

摘要: 为探究农用地表层土壤重金属污染受人为活动影响的程度和范围，研究了海盐县表层土壤中As、Cd、Cr、Cu、Hg、Ni、Pb、Zn和Fe等元素分布特征。以Fe为标准因子，采用标准化方法计算了表层土壤重金属元素环境地球化学基线值，基线值为As 7.48 mg/kg、Cd 0.19 mg/kg、Cr 82.06 mg/kg、Cu 33.03 mg/kg、Hg 0.18 mg/kg、Ni 35.18 mg/kg、Pb 31.27 mg/kg和Zn 94.54 mg/kg。应用基线值作为评价因子，采用单因子指数法，评价了研究区表层土壤重金属污染程度，结果显示海盐县农用地范围各重金属元素均有不同程度污染，轻度以上点位污染率依次为Hg (3.63%) > Cd (3.04%) > Cu (1.08%) > As (1.89%) > Zn (0.36%%) > Pb (1.14%)；Cr和Ni无轻度污染。

Abstract: In order to determine the source of exception of heavy mental in agricultural soil, As, Cr, Cd, Cu, Hg, Ni, Pb, Zn and Fe in surface soil samples taken from Haiyan Count, Zhejiang province were detected. With Fe as a canonical factor, the author adopted the standard method to establish environment geochemistry baseline models of above-mentioned eight elements of agricultural soil in the research area. The results show that the environment geochemistry baseline values are As 7.48 mg/kg, Cd 0.19 mg/kg, Cr 82.06 mg/kg, Cu 33.03 mg/kg, Hg 0.18 mg/kg, Ni 35.18 mg/kg, Pb 31.27 mg/kg and Zn 94.54 mg/kg. With baseline value as the major factor, single factor index was adopted to make a systematic assessment on the heavy metal pollution state. Results show that mild to moderate heavy metal pollution is widely existed in surface agricultural soil of Haiyan. Polluted ratio of some minor pollution in descending order is Hg 3.63%, Cd 3.04%, Cu 1.08%, As 1.89%, Zn 0.36% and Pb 1.14%.