重金属复合污染土壤的淋洗修复试验研究

Experimental Study on Leaching Remediation of Heavy Metal Compound Contaminated Soil

为研究重金属复合污染土壤淋洗修复工艺,本文使用柠檬酸作为淋洗剂,对砷、镍、钴、铜等重金属污染土壤进行淋洗处理,考察不同淋洗剂浓度、淋洗土水比、淋洗时间对淋洗效果的影响。试验结果表明,柠檬酸对镍的去除率最高,对钴的去除率次之,对砷和铜的去除率较低。试验确定了最优淋洗剂浓度、最优淋洗土水比和最优淋洗时间等条件,在最优淋洗条件下,淋洗后土壤中各重金属的浓度均低于修复目标值。生石灰和聚丙烯酰胺可用于处理淋洗废水。

In order to study the leaching remediation process of heavy metal compound contaminated soil, citric acid is used as the leaching agent to leach the soil contaminated by arsenic, nickel, cobalt, copper and other heavy metals, and the effects of different leaching agent concentration, the leaching soil-water ratio, and the leaching time on the leaching effect are investigated in this paper. The experimental results show that the removal rate of nickel by citric acid is the highest, the removal rate of cobalt is the second, and the removal rate of arsenic and copper is relatively lower. The optimum leaching agent concentration, the optimum leaching soil-water ratio and the optimum leaching time are determined in this experiment, under the optimal leaching conditions, the concentrations of heavy metals in the soil after leaching are lower than the remediation target value. Quicklime and polyacrylamide can be used to treat leaching wastewater.