小飞扬草(Euphobia thymifolia L.)对土壤Cr Cd N i复合污染的反应和积累特征研究

Responses of Euphobia thymifolia L.to the Soil Complex Pollution of Cr,Cd and Ni

针对目前植物修复中对Cr、Cd、N i复合污染的超富集杂草类植物缺乏的状况,采用盆栽试验方法,研究了小飞扬草(Euphobia thym ifoliaL.)对3种重金属的积累特性以及重金属复合污染对植物生长的影响。结果表明,小飞扬草在低浓度组合下对Cr、Cd、N i的富集系数最大值均>1,分别为1.54、3.93、5.68,且能同时富集Cd、N i,具备了作为超富集植物的特征;3种重金属在小飞扬草内的迁移率大小顺序为Cd>Cr>N i;小飞扬草能耐受Cr、Cd、N i复合污染,可作为尾矿废弃地植被重建到修复过程中的优先选择植物。

In order to find plants that can restore ruined mine beds polluted by heavy metals,pot experiments was conducted to study the hyperaccumulative characteristics for Cr,Cd and Ni in Euphobia thymifolia L.The plant was grown under the complex polluted conditions by Cr,Cd and Ni.The aboveground biomass of Euphobia thymifolia L.increased with the increase of addition Cd,but reduced with the increase of addition Cr;while,adding Ni showed no significant effects.The analysis for the concentration of metals showed that the uptake of one heavy metal by plant was affected by the other heavy metals as well as itself.The maximum enrichment coefficients of Cr,Cd and Ni in the aboveground of Euphobia thymifolia L.were all more than 1,being 3.93,5.68 and 1.54,respectively.Correspondingly,the concentration of Cr in the plant was highest(77.23 mg·kg^(-1)) under the treatment of Cr,Cd and Ni levels being 50,10 and 20mg·kg^(-1),respectively,and Cd and Ni was highest(19.65 and 112.36 mg·kg^(-1)) at Cr,Cd and Ni levels of 100,5 and 20 mg·kg^(-1).The ratios of the heavy metals concentrations accumulated in the plants to those in common plants averagely ranged 10~50,which implied Euphobia thymifolia L.possessed the characteristics of hyperaccumulators and seemed to be a good pioneer plant in infertile mines.