为探讨植物在土壤重金属污染修复方面的作用，以重庆市郊某蔬菜基地的农田土为试验土壤，研究 Pb、Cd、Hg 单一污染及 Pb＋Cd、Pb＋Hg 复合污染情况下，苎麻吸收、富集及转运相应重金属的能力。结果表明，在单一重金属污染时，苎麻各部位积累的重金属浓度为根＞茎＞叶，对单一重金属的富集效果为 Pb＞Cd＞Hg，转运能力为 Hg＞Pb＞Cd；在 Pb、Cd 复合污染时，土壤中（Pb＋Cd）浓度较小时，苎麻主动吸收占主导，土壤中（Pb＋Cd）浓度较大时，苎麻被动吸收占主导；在 Pb、Hg 复合污染时，Hg 抑制了苎麻地下部分对 Pb 的吸收，同时抑制了 Pb 从根部向地上部分的转移。%In order to probe into the phytoremediation effect of plant on heavy metal pollution,the authors took the farmland at a vegetable base in suburb of Chongqing as experimental soil to research the ability to absorb,accumulate and transfer related heavy metals in the condition with simple pollution of Pb,Cd and Hg and the complicated condition with compound pollution of Pb + Cd and Pb + Hg.The results showed that in simple heavy metal polluted condition,the concentration of heavy metal accumulated at every part of B.nivea was root>stem >leaves,with accumulation effect of single heavy metal Pb>Cd>Hg,and transfer ability Hg>Pb>Cd;in the condition with compound pollution of Pb and Cd,when (Pb+Cd)concentration was less,the positive absorption played the leading role,and when(Pb+ Cd) concentration was more,passive absorption played the leading role;in the condition with compound pollution of Pb and Hg,Hg restricted underground part of B.nivea to absorb Pb,and meanwhile restrict the Pb to be transferred from root to over-ground area.
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