无患子皂苷对土壤重金属Cr的淋洗修复

Removal of chromium contaminated soil by washing technology using Sapindus saponin

为修复日益严重的重金属污染土壤,采用无患子皂苷对土壤进行批次淋洗实验,考察了无患子皂苷浓度、淋洗时间、p H、提取次数对去除重金属Cr的影响。实验结果表明:浓度为21 g/L的无患子皂苷溶液对Cr的去除效果最好,去除率达到32.05%;随着淋洗时间、提取次数的增加,Cr的去除率也随之增加;降低无患子皂苷的p H值有利于去除重金属Cr。重金属形态变化分析结果表明,无患子皂苷可以较为有效去除弱酸提取态以及可还原态的金属,降低了金属存在于环境中的风险。

In order to remediate heavy metal contaminated soil, the washing process in a batch ex-periment was conducted to investigate the performance of Sapindus saponin on chromium removal from soil. The effects of Sapindus saponin concentration,contact time,solution pH,extraction times on chromium removal rate were studied. The results showed that the removal efficiency reached 32. 05% when using 21 g/L Sapindus saponins solution as extractant. With the increase of contact time and extraction times, and decrease of solution pH, the removal rate of chromium increased. The results of speciation study showed that Sapindus saponins could effectively remove the acid ex-tractable and reducible fractions of chromium, and reduce metal risk in the environment.