NTA强化印度芥菜修复Cd、Pb污染土及重金属渗漏特征

Effect of Brassica juncea L. Extraction and the Leakage Characteristics of Cd-and Pb-Contaminated Soil in NTA Treatment

针对可降解螯合剂强化植物提取修复过程中重金属渗漏研究的薄弱环节,以印度芥菜提取修复Cd、Pb污染土为背景,通过植物栽培-降雨淋滤实验,研究NTA的强化植物提取效果,以及在降雨条件下的重金属渗漏特征,结果表明:NTA对印度芥菜生物量影响不显著,印度芥菜生物量主要受重金属污染类型影响,Pb对印度芥菜的生长抑制作用最大;NTA对Cd、Pb单一与复合3种类型污染土中印度芥菜的重金属富集、转移以及地上部提取量均表现出不同程度促进作用,对Pb单一污染土重金属提取促进作用最强;添加NTA大幅提高重金属的渗漏,且酸雨条件下渗漏风险进一步加大。重金属渗漏随降雨量的增加呈线性下降趋势。

Research about heavy metal leakage in biodegradable chelator induced phytoextraction is a weak link. Heavy metal leakage characteristics for NTA-induced Brassica juncea L. extraction and remediation of Cd- and Pb- contaminated soil was studied through the plant cultivation-rainfall leaching experiment. The results showed that the effect of NTA on the biomass of the Brassica juncea L. was not significant, while it was mainly affected by the heavy metal pollution type, and the growth inhibition effect of the Pb was greatest. In NTA treatment, the bioconcentration factor, translocation factor and the heavy metal uptake of the shoot of Brassica juncea L. have increased in all three types of contaminated soil(Cd- and Pb- contaminated soil, Cd-Pb co-contaminated soil), especially in Pb-contaminated soil. The addition of the NTA greatly improved the leakage of the heavy metal and further increased under the acid rain condition. The leakage of heavy metal decreases linearly with the increase of rainfall.