复合淋洗剂对土壤中铬的淋洗规律

采用静态实验方法， 考虑研究成本及环保要求， 选用价格低廉且生物可降解的柠檬酸、 酒石酸、 水、 鼠李糖脂、 草酸及富里酸6种淋洗剂， 对高质量比Cr污染土壤进行淋洗修复. 首先考察土壤中不同陈化时间Cr对淋洗效果的影响； 其次筛选淋洗剂并优化淋洗条件； 最后考察多种复配淋洗组合， 确定最佳复配淋洗剂. 结果表明： Cr陈化时间对总Cr去除率的影响较小， 而对Cr（Ⅵ）去除率影响明显； 不同淋洗剂对总Cr和Cr（Ⅵ）淋洗效果不同， 草酸和柠檬酸均可有效去除总Cr和Cr（Ⅵ）； 对总Cr和Cr（Ⅵ）去除最优的淋洗条件是0.5 mol/L草酸或柠檬酸、m(固)∶V(液）=1∶10, 淋洗1次； 在最优淋洗条件下， 对土壤重金属Cr的去除效果较好.

Leaching Law of Chromium in Soil by Compound Leaching Agent

Using static experiment method, considering the research cost and environmental protection requirements, six kinds of low-cost and biodegradable leaching agents of citric acid, oxalic acid, fulvic acid, water, rhamnolipid, and tartaric acid were elected to leach and repair high mass ratio Cr contaminated soil. Firstly, the effects of different aging time of Cr in soil on the leaching efficiency were investigated. Secondly, the leaching agent was screened and the leaching conditions were optimized. Finally, a variety of mixed leaching combinations were investigated to determine the best leaching agent combinations. The results show that the Cr aging time has little effects on the total Cr removal rates, but has significant effects on the removal rates of Cr（Ⅵ）. Different leaching agents have different leaching effects on total Cr and Cr（Ⅵ）, but oxalic acid and citric acid can effectively remove total Cr and Cr（Ⅵ）. The optimal leaching condition of removing total Cr and Cr（Ⅵ）is 0.5 mol/L of oxalic acid or citric acid, m(solid)∶V(liquid)=1∶10, and leaching one time. Under the optimal leaching condition, the removal effect on Cr in soil is better.