The key to reducing the environmental and human health hazards of heavy metals is to choose proper washing agents to remediate heavy metal-contaminated soil. In this study, ferric nitrate and citric acid (CA) were used to remove Cu, Zn, Pb, and Cd from contaminated soil. The effects of concentration, liquid–solid ratio, and time of the washing processes were investigated. Besides, the effects of ferric nitrate or CA on soil fertility and the potential ecological risk of heavy metals after soil washing were also studied. In ferric nitrate remediation, the optimal removal efficiencies of Cu, Zn, Pb, and Cd were 78.68%, 58.96%, 48.53%, and 80.86%, respectively. On the contrary, in CA remediation, the optimal removal efficiencies of Cu, Zn, Pb, and Cd were 66.59%, 43.10%, 37.95%, and 77.48%, respectively. The washing with both ferric nitrate and CA significantly reduced the potential ecological risk of heavy metals in the soil, whereas ferric nitrate showed better performance in lowering the metal risks than CA. Soil properties had been improved to some extent, including invertase activity, acid phosphatase activity, available phosphorus, and available nitrogen. The washing results showed that ferric nitrate exhibited better performance than CA. This study suggests that ferric nitrate can be considered a suitable agent for washing soil contaminated by heavy metals.

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硝酸铁与柠檬酸洗涤重金属污染土壤的对比研究

减少重金属对环境和人类健康危害的关键是选择合适的洗涤剂来修复重金属污染的土壤。在本研究中，硝酸铁和柠檬酸 (CA) 用于去除受污染土壤中的 Cu、Zn、Pb 和 Cd。研究了浓度、液固比和洗涤过程时间的影响。此外，还研究了硝酸铁或CA对土壤肥力的影响以及土壤冲洗后重金属的潜在生态风险。在硝酸铁修复中，Cu、Zn、Pb和Cd的最佳去除效率分别为78.68%、58.96%、48.53%和80.86%。相反，在CA修复中，Cu、Zn、Pb和Cd的最佳去除效率分别为66.59%、43.10%、37.95%和77.48%。硝酸铁和 CA 的洗涤显着降低了土壤中重金属的潜在生态风险，而硝酸铁在降低金属风险方面表现出比 CA 更好的性能。土壤性质得到一定程度的改善，包括转化酶活性、酸性磷酸酶活性、速效磷和速效氮。洗涤结果表明硝酸铁表现出比CA更好的性能。这项研究表明，硝酸铁可以被认为是清洗被重金属污染的土壤的合适药剂。有效磷和有效氮。洗涤结果表明硝酸铁表现出比CA更好的性能。这项研究表明，硝酸铁可以被认为是清洗被重金属污染的土壤的合适药剂。有效磷和有效氮。洗涤结果表明硝酸铁表现出比CA更好的性能。这项研究表明，硝酸铁可以被认为是清洗被重金属污染的土壤的合适药剂。