水葱对镉的超富集作用及其用于植物修复的潜力

摘要

野外观察与研究发现水葱(Scirpus tabernaemontani G.)可以耐受土壤中高浓度的重金属污染,并对镉有很高的生物富集量.实验室水培试验研究了两个主要因素,营养液pH值以及镉含量,对其生物量以及镉富集效果的影响.结果表明,水葱可耐受的高浓度Cd(30 mg/L)和大范围pH值变化(3.7～7.7).当营养液pH值为4.7,Cd含量为25 mg/L时,水葱富集的Cd达到最大值:地上部分264.71 mg/kg,地下部分234.39 mg/kg,平均转运系数1.13.这显示了它用于植物修复镉污染土壤的巨大潜力.%Cadmium phytoextraction can be economically feasible only when the developed systems high biomass plant can accumulate greater than 100 mg/kg Cd on dry weight.In this experiment,Scirpus tabernaemontani,a perennial herb,was used to demonstrate its capability at accumulating Cd,more than 280 mg/kg Cd in its above-ground parts.This hydroponics experiment showed the effects of two factors,solution pH and medium Cd concentration,on the plant biomass growth and Cd-extraction in 30 days.The herb could bear high level of Cd(30 mg/L)and widespread pH value shifting.The highest Cd-extractions are 264.71 mg/kg(above-ground parts)and 234.39 mg/kg(underground parts),with the average translation coefficient 1.13.It demonstrated the potential of this herb for phytoremediation.