一种重金属铬污染土壤修复技术研究

A Study of Methodology on Restoring the Soil Contaminated by the Heavy Metal Chromium

本研究以两步法（淋洗法加电势迁移法）对受重金属铬污染的土壤进行的修复。实验分两个阶段进行,前期筛选出淋洗时间和淋洗剂用量,电压梯度以及电极处的p H作为变量,通过控制变量实验和正交实验得出可靠结果。结果表明,淋洗时间为72小时,淋洗剂用量为1500m L时土壤中的重金属铬得到较好的去除。在电场离子电势迁移中,对铬迁移速率的影响从电压梯度,阳极p H到阴极p H依次递减。阴极p H可不控制,阳极p H在3~5范围内,电场梯度为1.5 V/cm时土壤中的铬去除率达到最高。

The study is using a novel method called Two-step methodology which included Showering and Electro-kinetic remediation periods to restore the soil contaminated by the heavy metal Chromium. The experiment is dived into two phases and it selects the best showering time, the best showering does as well as the voltage gradient and the pH of the electric poles as variables. By using control variable method and orthogonal experiments, the study come out with a reliable conclusion. The results demonstrate that under 72-hour washing time and 1500 mL washing does the Chromium in the soil can be removed perfectly. Subsequently in the electro-kinetic remediation period, the influence on the Chromium removal rate is declining as the following sequence： the electric field gradient, anolyte pH and catholyte pH. The removal rate of the Chromium can reach to the peak in this condition： the catholyte pH is out of control, the anolyte pH should be control under 3-5 and the electric field gradient arrived 1.5 v/cm.