College of Resources and Environmental Engineering, Wuhan University of Science and Technology, Hubei, People's Republic of China.
Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources, Wuhan University of Science and Technology, Wuhan, People's Republic of China.
Environ Technol. 2024 Jan;45(4):705-715. doi: 10.1080/09593330.2022.2121179. Epub 2022 Sep 16.
Soil leaching remediation has attracted extensive attention because of its good removal effect, short operation period and stable removal effect of heavy metals. The key to reduce the harm of heavy metal contaminated soil to the environment and human health is to use appropriate leachate to repair heavy metal contaminated soil. In this study, citric acid (CA), iron nitrate (Fe(NO)) and polyepoxysuccinic acid (PESA) with different concentrations were used as research reagents to explore the best combination of leaching effects of heavy metals (Cu, Zn, Pb, Cd) in contaminated soil. The effects of concentration of eluent, liquid to solid ratio and leaching time on leaching efficiency of heavy metals and the changes of soil physical and chemical properties before and after leaching were studied. The results showed that 0.5 mol/L CA and 0.05 mol/L PESA were combined according to the volume ratio of 7:3, and the leaching effect was the best when the liquid-solid ratio was 15 and the leaching time was 240 min. Under the optimal leaching condition, the four heavy metals in the soil had significant removal effects, and the removal rates were, respectively, 86.06% Cu, Zn 74.55%, Pb 67.88% and Cd 91.63%. The X-ray spectrum and Fourier infrared spectrum analysis of soil before and after leaching showed that CA-PESA combined leaching had little effect on soil structure change. This study provided theoretical support for the development and application of suitable leaching agents for the remediation of heavy metal-contaminated soil.
土壤淋洗修复因其去除效果好、操作周期短、重金属去除效果稳定而受到广泛关注。减少重金属污染土壤对环境和人体健康危害的关键是使用适当的淋洗剂修复重金属污染土壤。本研究以柠檬酸（CA）、硝酸铁（Fe（NO 3 ） 3 ）和聚环氧琥珀酸（PESA）为研究试剂，研究了不同浓度的淋洗剂对污染土壤中重金属（Cu、Zn、Pb、Cd）淋洗效果的最佳组合。研究了淋洗剂浓度、液固比和淋洗时间对重金属淋洗效率的影响以及淋洗前后土壤物理化学性质的变化。结果表明，0.5 mol/L CA 和 0.05 mol/L PESA 按体积比 7:3 组合，液固比为 15，淋洗时间为 240 min 时淋洗效果最佳。在最优淋洗条件下，土壤中的四种重金属均有明显去除效果，去除率分别为 86.06% Cu、Zn 74.55%、Pb 67.88%和 Cd 91.63%。淋洗前后土壤的 X 射线能谱和傅里叶变换红外光谱分析表明，CA-PESA 联合淋洗对土壤结构变化影响较小。本研究为开发和应用适合重金属污染土壤修复的淋洗剂提供了理论支持。
