电动-化学淋溶联合修复铀污染土壤

Electrokinetic and Chemical Eluviation Combined Remediation of Uranium Contaminated Soil

矿山周围土壤放射性污染问题对生态环境及人体健康构成威胁,亟需对铀污染土壤展开高效修复技术研究。以某铀矿区的放射性污染土壤为研究对象,探究不同淋溶剂类型、淋溶剂浓度、液固比及复合淋溶剂配比去除铀的最佳工艺参数。结果表明:化学淋溶剂对铀污染土壤中铀的去除性能存在明显的差异,表现为无机酸(48.70%)>有机酸(31.91%)>螯合剂(23.31%)>无机盐(17.26%)。复合淋溶剂及电动化学淋溶法的联合使用可有效提高污染土壤中铀的去除率,其中,在电压30 V、柠檬酸+氯化铁复合浓度0.1 mol/L+7.5 g/L、液固比5 mL/g、温度25℃的最佳条件下,污染土壤中铀的平均去除率达59.75%,较单一化学淋溶提高了13.37个百分点。

The problem of radioactive contamination of the soil around the mine poses a threat to the ecological environment and human health,and it is urgent to study the efficient remediation technology of uranium contaminated soil.Taking the radioactive contaminated soil in a uranium mining area as the research object to explore the optimal process parameters for uranium removal with different leaching solvent types,leaching solvent concentrations,liquid-solid ratio and compound leaching solvent ratio.The results show that there are significant differences in the removal performance of uranium from uranium contaminated soil by chemical leaching solvents,which is inorganic acid(48.70%)>organic acid(31.91%)>chelating agent(23.31%)>inorganic salts(17.26%).The combined use of composite leaching solvent and electrochemical leaching method can effectively improve the removal rate of uranium in contaminated soil,in which the average removal rate of uranium in contaminated soil is 59.75%,which is 13.37 percentage points higher than that of single chemical leaching under the optimal parameters of voltage of 30 V,composite concentration of citric acid+ferric chloride of 0.1 mol/L+7.5 g/L,liquid-solid ratio of 5 mL/g and temperature of 25℃.