螯合剂使用对商陆修复Cd、Cu污染土壤的影响

Effect of Chelating Agent on Remediation of Cd and Cu Contaminated Soil by Phytolacca

为探索不同螯合剂混施对重金属Cd、Cu污染土壤的修复效果,通过盆栽试验,研究了3种螯合剂(EDTANa2、CA、TA)单施及混施作用对商陆生长与吸收土壤中Cd、Cu的影响。结果表明:3种螯合剂单施及混施均能促进商陆的生长,其促进效果为EDTA-Na2+CA>EDTA-Na2+TA>CA+TA>EDTA-Na2>CA>TA。不同螯合诱导处理商陆植株地上部实验中,对于Cd,EDTA-Na2处理效果最好,对照空白处理提高了34.42%,其次是EDTA-Na2+CA,对照空白处理提高了29.5%;对于Cu而言,EDTA-Na2+CA效果最好,对照空白处理提高了22.89%。商陆能有效去除土壤中的Cd,而对Cu的修复效果不佳。螯合剂的加入在不同程度上增加了土壤重金属水溶性有效态的含量,效果以EDTA-Na2的单施和EDTA-Na2+CA混施最佳。因此,在螯合诱导植物修复技术的工程实践运用中,EDTA-Na2和CA的混合添加,可以有效减少EDTA-Na2的使用量,降低二次污染。

In order to explore the use of different chelating agents to repair heavy metal Cd and Cu contaminated soil,apot experiment was conducted to study the effects of three chelating agents(EDTA-Na2,citric acid,tartaric acid)alone and in combination on the Radix Phytolaccae growth and absorption of Cd and Cu in soil.The result shows that the three chelating agents could promote the growth of Radix Phytolaccae by single and mixed application.The promoting effect was EDTA-Na2+citric acid>EDTA-Na2+tartaric acid>citric acid+tartaric acid>EDTA-Na2≈citric acid>tartaric acid.Different chelating induction treatments for aboveground parts of Radix Phytolaccae,EDTA-Na2 treatment was the best for Cd,which was increased by 34.42%,followed by EDTA-Na2+citric acid,which was increased by 29.5%.For Cu,EDTA-Na2+citric acid had the best effect,increasing by 22.89%.Phytolacca acinosa can remove Cd in soil effectively and the remediation effect of Cu is not well.The addition of chelating agent increases the water-soluble effective state of heavy metals in soil to different extents,and the effect is best by single application and mixed application of EDTA-Na2.Therefore,in the engineering practice of chelation-induced phytoremediation technology,the mixed addition of EDTA-Na2 and citric acid can reduce the amount of use of EDTA-Na2 effectively and reduce secondary pollution.