柠檬酸复合淋洗剂对镉污染土壤淋洗效果研究

为了探讨不同组合复合淋洗剂对重金属的淋洗效果,本文以镉污染土壤为材料,采用振荡淋洗的方法研究了CA+CAS和CA+CAS+Na₂S₂O₃组合试剂对镉的去除效果。结果表明,CA+Na₂S₂O₃ 和CA+CAS+Na₂S₂O₃组合对土壤中镉的去除率均较高,且第一次淋洗去除率在80%以上,第二次淋洗最大去除率仅为13.95%,第一次淋洗效果明显高于第二次。CAS的加入可以缓解CA和Na₂S₂O₃对土壤pH、全氮和有效钾等理化性质的影响。从形态上分析,未处理土壤中镉主要以可交换态和可还原态存在,两种形态和达到93.8%。淋洗处理可将土壤中大部分的镉去除,去除率最大可达98.21%,且淋洗后土壤中镉可氧化态和残渣态含量所占比例增加,比例达到50%左右。

Study on leaching effect of citric acid composite reagents for removing Cd from Cd-contaminated soil

In order to explore the leaching effect of different composite eluents on heavy metals, the removal effect of CA+CAS and CA+CAS+Na2S2O3 combined reagents on cadmium contaminated soil was studied by shaking leaching method in this paper. The results showed that both CA+Na2S2O3 and CA+CAS+Na2S2O3 had high leaching rates for cadmium, and the first leaching rate was above 80%. The maximum leaching rate of the second leaching was only 13.95%. The first leaching effect was significantly higher than the second leaching. The addition of CAS can alleviate the effects of CA and Na2S2O3 on soil pH, total nitrogen, available potassium and other physicochemical properties. From the analysis of morphology, cadmium mainly existed in exchangeable form and reducible form in untreated soil, and the two forms reached 93.8%. Leaching treatment can remove most of the cadmium in the soil, the maximum removal rate can reach 98.21%, and the proportion of oxidative form and residue form of cadmium in the soil after leaching increases to about 50%.