西安市兴庆宫公园土壤中重金属含量研究及污染评价

Concentration Determination and Contamination Evaluation for Heavy Metals in Soil of Xingqing Park in Xi'an

通过对西安市兴庆宫公园表层土壤的取样调查,分析了Cu、Zn、Cd、Cr及Pb等5种重金属的含量及形态分布特征,并对其综合污染状况及潜在生态风险进行分析与评价。结果显示,兴庆宫公园的表层土壤呈碱性,并含有较多有机质;土壤中Cu、Zn、Cd、Cr及Pb平均含量分别为29.89 mg/kg、55.28 mg/kg、0.169 mg/kg、66.71 mg/kg和43.59mg/kg;土壤中Cu、Zn、Cd、Cr及Pb化学形态均以残渣态为主;整个公园土壤内梅罗污染指数为2.29,土壤重金属综合污染已经达到中度污染;整个公园潜在生态风险指数平均值为73.89,生态风险等级为轻微。

Heavy metal concentration and chemical speciation of Cu, Zn, Cd, Cr and Pb were analyzed from the surface soil samples taken from the Xingqing Park in Xi＇ an, and the heavy metal pollution level and the potential ecological risk were evaluated by Nemero pollution index and Hakanson potential ecological risk index. The result showed that the soil appeared alkaline and contained plenty of organic matter, and the average concentrations of Cu, Zn, Cd, Cr and Pb were 29.89mg/kg, 55.28 mg/kg, 0. 169mg/kg, 66.71mg/kg and 43.59 mg/kg respectively. The chemical speciation of Cu, Zn, Cd, Cr and Pb mainly existed in residual form. The average Nemero index was 2.29, indicating the soil had been moderately polluted by heavy metals. And the average potential ecological risk index was 73.89, indicating the soil presented a slight ecological risk.