【摘要】 研究了某遗留锌冶炼场地土壤中重金属的污染特征，结合模拟实验探讨了土壤中针铁矿对Cd迁移的影响机制。结果表明，锌冶炼场地土壤中As、Cd、Cu、Hg、Pb几何均值依次为15.9、1.52、62.1、0.108和167 mg/kg, Cd含量均值为湖南省土壤背景值的11.7倍。场地土壤中Cd具有较强的迁移性，下渗迁移可达6 m甚至更深。随机森林模型分析结果表明，土壤中Cd迁移主要受针铁矿和粉砂影响。土壤中针铁矿可以吸附Cd并进行迁移，淋滤液pH值和离子强度明显影响土壤中针铁矿对Cd的迁移作用。当淋滤液pH=6、离子强度1 mmol/L时，37.6%的Cd随针铁矿携带下渗迁移。通过调控土壤pH值和盐基离子浓度改变土壤中针铁矿对Cd迁移的影响，可以实现锌冶炼场地土壤中Cd等重金属污染的风险管控。更多还原

【Abstract】 The pollution of heavy metals in the soil of a zinc smelting site was analyzed, and the influence mechanism of goethite on cadmium migration in the soil was discussed by performing simulation experiments. The results show that the geometric mean values of As, Cd, Cu, Hg and Pb in zinc smelting site soil are 15.9 mg/kg, 1.52 mg/kg, 62.1 mg/kg, 0.108 mg/kg and 167 mg/kg respectively. The average content of Cd is 11.7 times the general value of soil in Hunan Province. It is shown that Cd in the soil has strong migration, and can be infiltrated down to the depth of 6 m or more of the soil. The results of stochastic forest model analysis show that Cd migration in the soil is mainly affected by goethite and silt. Cd in the soil can be adsorbed by goethite and then migrated. The pH value and ionic strength of leachate obviously affect the migration of Cd by goethite in the soil. When the pH of leachate is 6 and the ionic strength is 1 mmol/L, 37.6% of Cd in the soil can be migrated by goethite. Adjusting the pH value and salt ions concentration of soil can change the migration of Cd by goethite in the soil. As a result, the risk of pollution by heavy metals such as Cd in the soil of zinc smelting site can be controlled.更多还原