螯合剂在重金属污染土壤修复中应用研究进展

Application of chelants in remediation of heavy metals-contaminated soil

螯合剂在重金属污染土壤修复中具有重要的作用。文章结合国内外的研究成果和最新研究进展,从螯合剂对重金属的活化效率及其影响因素、螯合剂在土壤中风险评价、生物可降解性螯合剂S,S-EDDS在化学淋洗修复和植物修复中的应用等几个方面论述了国内外螯合剂的研究现状,总结了在螯合剂应用研究中存在的问题,同时指出必须对螯合剂对重金属在土壤中的存在形态的影响以及螯合剂对矿物元素的作用,螯合剂与污染土壤组分作用的微观机理等进行深入的研究。

Chelants play an important role in the remediation of heavy metal-contaminated soil as they can affect the desorption and solution of heavy metals from soil particles evidently. Recent research on the application of chelants to the remediation of heavy metal-polluted soil were summarized, including their action efficiency and factors affecting their efficiency, risk assessment of them, and the development of the application of biodegradable chelant S,S-EDDS in remediation research. The efficiency of the chelants was affected by their properties, the soils type and the plants. Conditions such as proportions of chelants to target heavy metals, pH value of the chelants solution also influenced the efficiency of the applied chlants. Potential risk presented by addition of chelants into soil was around the leaching of the chelants together with the chelated metals, persistence of synthetical chelants and their toxicity to organism. It was also proposed that the variation of the speciation of the heavy metals and the dissolution of mineral elements exerted by the chelants should be given more attention. The micro-interaction between chelants and soil components should also be considered.