Comparison of Remediation Mechanism of Heavy Metal–Contaminated Soil by Combined Leaching and Two-Step Leaching

Soil contaminated by heavy metals, which is widespread in the world, has the characteristics of persistence and potential, so it is urgent to repair the soil contaminated by heavy metals and reduce the content of heavy metals in the soil. The remediation technology of heavy metal–contaminated soil has developed rapidly, and the remediation of soil leaching has attracted wide attention due to its short operation period and stable effect. Therefore, it is necessary to systematically summarize the current progress. In this paper, the present situation of heavy metal–contaminated soil and the research progress of heavy metal–contaminated soil remediation were summarized first, and then, the combined leaching method and the two-step leaching method of soil remediation technology were comprehensively evaluated and analyzed. Comparing the selected spray lotion, a chelating agent-chelating agent compound with optimal leaching effect, exploring its action principle and elution repair mechanism, is found, and due to different kinds of chelating agent chelating ability, chelating agent distribution can effectively complement the chelating properties. Therefore, this paper will contribute to a comprehensive and in-depth understanding of soil leaching remediation technology for heavy metal–contaminated sites and provide certain references for the development of heavy metal soil leaching remediation technology and the reasonable selection of leaching agents for heavy metal–contaminated soil.