铜污染旱地红壤的络合诱导植物修复作用

Chelate-induced phytoextraction of copper contaminated upland red soil.

研究EDTA和低分子量有机酸对污染旱地红壤Cu形态变化及金属忍耐 富集型植物印度芥菜生长和Cu吸收的影响 ,以探讨Cu污染土壤的有机络合诱导植物吸取修复作用 .结果表明 ,在芥菜营养生长旺盛期施用EDTA可显著提高土壤Cu的活性 ,土壤水浸提态Cu和交换态Cu均显著上升 ;这种活化效应随外加Cu浓度的上升和EDTA用量的增加而增大 ;柠檬酸和苹果酸对土壤Cu的活化效应小 ,只对水浸提态Cu略有影响 ;EDTA可显著增加芥菜茎叶、根的Cu浓度和吸收量 .等摩尔量柠檬酸和苹果酸对土壤铜形态变化和芥菜Cu吸收没有显著作用 .

A copper spiked red soil was used in pot experiment to study the effects of EDTA and low molecule weight organic acids on Cu speciation in soil,and Cu uptake by Brassica juncea.The results showed that the mobility of Cu in soil was improved obviously when EDTA was added at the vigorous growth stage.Both water extractable and exchangeable Cu concentration increased significantly following EDTA addition.Citric acid and malic acid only had an effect on water extractable Cu,and no effect on Cu uptake by the plant.EDTA significantly increased the concentration of Cu in plant leaves and roots,and the Cu uptake by Brassica juncea.All of these indicated the chelate induced phytoextraction.