柠檬酸淋洗修复河南某冶炼厂周边Pb污染土壤

Remediation of Pb-polluted Soils around a Smelter in Henan Province by Oscillating Washing with Citric Acid

以河南某冶炼厂周边Pb污染土壤为研究对象,采用震荡淋洗技术对其进行修复试验研究,探讨了柠檬酸浓度、液固比、淋洗温度、淋洗时间对土壤中Pb去除率的影响,并对土壤修复前后的理化性质进行了对比分析。在柠檬酸浓度为0.4 mol/L、液固比为10:1、淋洗温度为25℃、淋洗时间为24 h时的淋洗条件下,此时Pb的去除率达到72.73%。土壤修复前后理化性质分析结果表明:修复前后土壤的矿物组成基本没有变化,但土壤的粒度组成略有变细,并且土壤中部分养分的存在一定的流失。本研究为今后铅污染土壤规模化修复提供了参考。

In this work, intermittent oscillating washing tests were conducted to remediate Pb-contaminated soils, which was collected from around a metallurgical industry in Henan province. The concentration of CA, liquid-solid ratio, leaching time and temperature were chosen to research the optimal conditions. The results indicated that the Pb removal rate was 72.73% with CA concentration of 0.4 mol/L, L/S=10:1, washing temperature of 25 ℃, washing time of 24 h. The results of physical and chemical properties analysis before and after soil remediation showed that the mineral composition of soil was basically unchanged, but the size composition of soil was slightly finer, and some nutrients in the soil were lost. This study provides reference for large-scale remediation of contaminated soils in the future.