氟污染土壤的阳极强化电动力学修复研究

在不同电解电压及阳极电解液浓度下，对土壤氟在电动力学作用下的迁移特征及其影响因素进行了研究，分析了利用阳极强化电动力学技术修复氟污染土壤的可行性.结果表明，1.0 V/cm电解电压下，当阳极电解液为去离子水时，氟在阴、阳极电解液中的累积量分别为8.2 mg和47.7 mg，土壤氟的去除率仅为8.8%.而阳极强化电动力学作用能够有效促进土壤中氟化物的迁移，1.0、 1.5、 2.0 V/cm电解电压下，阳极电解液为0.02 mol/L的氢氧化钠溶液时，土壤氟的去除率分别为25.9%、 31.2%、 47.3%；当阳极电解液浓度升高为0.1 mol/L时，土壤氟的去除率分别为55.4%、 61.1%、 73.0%.电迁移是其主要的作用机制，电渗析也对氟在土壤中的移动产生影响.电解电压及电解液浓度是影响氟去除效率的主要因素.可以采用适当的阳极强化电动力学技术对氟污染土壤进行修复.

Fluorine-contaminated Soils

An experimental study was carried out in order to determine the characteristics of migration and its influencing factor of soil fluorine in the electrokinetic process under different applied voltage and concentration of anolyte. The feasibility of anolyte enhanced on electrokinetic remediation of fluorine-contaminated soil was analyzed. The results show that when deionized water is used as anolyte with the 1.0 V/cm voltage gradient, the cumulative mass of fluorine in catholyte and anolyte are 8.2 mg and 47.7 mg respectively and the removal rate of fluorine is only 8.8%. Anolyte enhanced electrokinetic process can promote effectively the migration of fluoride in soil. When 0.02 mol/L NaOH solution is employed as the anolyte, the removal rates are 25.9%, 31.2% and 47.3% with 1.0, 1.5 and 2.0 V/cm voltage gradient respectively. As the concentration of anolyte increased to 0.1 mol/L, the removal rates are 55.4%, 61.1% and 73.0%. The electromigration is the main transport mechanism and the electroosmotic flow has an effect on the migration of fluorine in soil. The voltage gradient and the concentration of anolyte are the main factors influencing the removal rate of fluorine in soil. Appropriate anolyte enhanced electrokinetic method can be applied to remediate fluorine from contaminated soil.