利用Na_2S_2O_3溶液萃取和回收污染土壤中的重金属

通过对比试验研究了Na2S2O3萃取液中重金属的分离效果并将其应用于修复土壤污染。结果表明,Na2S2O3溶液能有效地萃取土壤中重金属,Na2S能沉淀分离Na2S2O3溶液中的Cu、Hg,其效率均达99%以上。连续萃取能提高污染土壤中重金属的去除率,回收的Na2S2O3连续使用6次,损失约6%,土壤中Cu和Hg累积去除率分别达64.6%、75.1%。得到的硫化物沉淀含有很高的重金属,能很方便地处理或回收。

Extracting and Recovering the Heavy Metals from Contaminated Soils with Na2S2O3 Solution

The technique of separating heavy metals in Na2S2O3 solution was studied and used for remediation of soils pollution.Na2S2O3 solution could effectively extract the heavy metals from soil.Na2S could separate sedimentarily Cu,Hg in Na2S2O3 solution with efficiency both over 99%;The accumulative removal rates of Cu and Hg in soils reached 60.4% and 75.1%,respectively.After successive use of recovered Na2S2O3 for six times,Na2S2O3 losses were about 6%.The sulfide precipitates obtained had high concentrations of heavy metals and could be treated or recovered conveniently.