Key Laboratory on Soil Environment and Waste Reuse in Agriculture of Guangdong Higher Education Institutes, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China.
School of Environmental and Life Sciences, University of Newcastle (Australia) Singapore, 6 Temasek Blvd, Singapore, 038986, Singapore.
Environ Geochem Health. 2019 Oct;41(5):2081-2091. doi: 10.1007/s10653-019-00259-w. Epub 2019 Mar 5.
This study evaluated the feasibility of combining potassium chloride (KCl) leaching and electrokinetic (EK) treatment for the remediation of cadmium (Cd) and other metals from contaminated soils. KCl leaching was compared at three concentrations (0.2%, 0.5%, and 1% KCl). EK treatment was conducted separately to migrate the metals in the topsoil to the subsoil. The combined approach using KCl leaching before or after EK treatment was compared. For the single vertical EK treatment, the removal of Cd, lead (Pb), copper (Cu) and zinc (Zn) from the topsoil (0-20 cm) was 9.38%, 4.80%, 0.95%, and 10.81%, respectively. KCl leaching at 1% KCl removed 84.06% Cd, 9.95% Pb, 4.34% Cu, and 19.93% Zn from the topsoil, with higher removal efficiency than that of the 0.2% and 0.5% KCl leaching treatments. By combining the KCl leaching and EK treatment, the removal efficiency of heavy metals improved, in particular for the 1% KCl + EK treatment, where the removal rate of Cd, Pb, Cu, and Zn from the upper surface soil reached 97.79%, 17.69%, 14.37%, and 41.96%, respectively. Correspondingly, the soil Cd content decreased from 4 to 0.21 mg/kg, and was below the Chinese standard limit of 0.3 mg/kg soil. These results indicate that 1% KCl + EK treatment is a good combination technique to mitigate Cd pollution from contaminated soils used for growing rice and leafy vegetables.
本研究评估了氯化钾 (KCl) 浸出和电动 (EK) 处理相结合修复污染土壤中镉 (Cd) 和其他金属的可行性。比较了三种浓度（0.2%、0.5%和 1% KCl）的 KCl 浸出。EK 处理分别进行，以使金属从表土迁移到底土。比较了 KCl 浸出前或后与 EK 处理相结合的方法。对于单一垂直 EK 处理，从表土（0-20 cm）中去除 Cd、铅 (Pb)、铜 (Cu) 和锌 (Zn) 的去除率分别为 9.38%、4.80%、0.95%和 10.81%。1% KCl 的 KCl 浸出从表土中去除了 84.06%的 Cd、9.95%的 Pb、4.34%的 Cu 和 19.93%的 Zn，去除效率高于 0.2%和 0.5% KCl 浸出处理。通过结合 KCl 浸出和 EK 处理，重金属的去除效率得到提高，特别是对于 1% KCl+EK 处理，Cd、Pb、Cu 和 Zn 从上表土中的去除率分别达到 97.79%、17.69%、14.37%和 41.96%。相应地，土壤 Cd 含量从 4 降至 0.21mg/kg，低于中国土壤 0.3mg/kg 的标准限值。这些结果表明，1% KCl+EK 处理是一种从用于种植水稻和叶菜类蔬菜的污染土壤中减轻 Cd 污染的良好组合技术。
