不同螯合剂诱导下黑麦草对铅污染土壤的修复效果研究

Remediation Effect of Ryegrass on Lead Contaminated Soil Induced by Different Chelators

[目的]探究3种土壤螯合剂作用下黑麦草对Pb^(2+)的富集作用和转运效果。[方法]通过盆栽试验,研究乙二胺四乙酸(EDTA)、氯化铁(FeCl_(3))和柠檬酸(CA)3种螯合剂对黑麦草修复不同浓度铅污染土壤的修复效果。[结果]黑麦草对Pb^(2+)有良好的耐受性和富集作用,低浓度(≤500 mg/kg)Pb^(2+)促进黑麦草生长,高浓度(≥1000 mg/kg)Pb^(2+)抑制黑麦草生长。EDTA作用下,黑麦草对不同浓度Pb^(2+)污染土壤均有良好的富集作用;FeCl_(3)作用下,黑麦草对高浓度Pb^(2+)污染土壤的耐受性和富集作用最好;CA作用下,黑麦草对低浓度Pb^(2+)污染土壤的富集作用最好。[结论]施用EDTA和FeCl_(3)后,能显著促进Pb^(2+)从黑麦草根部向茎叶部位转移,从而提高污染场地土壤修复效果。

[Ovjective]To explore the enrichment effect and translocation effect of Pb^(2+)by ryegrass under the action of three soil chelators.[Method]The remediation effect of ethylene diamine tetraacetic acid(EDTA),ferric chloride(FeCl_(3))and citric acid(CA)on ryegrass remediation of lead-contaminated soil at different concentrations was investigated by pot experiments.[Result]The ryegrass showed good tolerance and enrichment to Pb^(2+).Low concentrations(≤500 mg/kg)of Pb^(2+)promoted the growth of ryegrass and high concentrations(≥1000 mg/kg)of Pb^(2+)inhibited the growth of ryegrass.The action of EDTA,ryegrass showed good enrichment to different concentrations of Pb^(2+)contaminated soil,under the action of FeCl_(3),ryegrass had the best tolerance and enrichment to the soil polluted by high concentration of Pb^(2+),and under the action of CA,ryegrass had the best enrichment effect on the soil contaminated with low concentration of Pb^(2+).[Conclusion]The application of EDTA and FeCl_(3) significantly promoted the transfer of Pb^(2+)from ryegrass roots to stem and leaf parts,thus improving the remediation effect of contaminated site soil.