复合淋洗剂对镉污染土壤的淋洗效果

[目的]探讨复合淋洗剂对重金属的淋洗效果。[方法]以镉污染土壤为材料,采用振荡淋洗法研究了CA+CaCl_2、CA+FeCl_3及CA+CaCl_2+FeCl_3组合试剂对土壤中镉的去除效果。[结果]几种试剂在组合条件下对镉的去除率均要高于单一试剂淋洗的去除率,且CA+FeCl_3对土壤中镉的去除效果最好,去除率为86.31%~89.61%。从淋洗前后的镉有效态含量来看,CA+FeCl_3(3∶1)中镉有效态含量最高,达1.794μg/L。形态分析结果表明,经淋洗剂淋洗后,土壤中的可交换态镉大部分被淋洗出来,其所占比例大大降低,可氧化态和残渣态含量比例增加,土壤中活性态镉减少,生物毒性大大降低。[结论]CA+FeCl_3(3∶1)对土壤中镉的去除效果最好,去除率达89.61%。

Leaching Effects of Compound Eluent on Cadmium Contaminated Soil

[Objective] To study the leaching effect of complex eluent on heavy metals.[Method] With cadmium contaminated soil as the material,the removal of cadmium in soil by CA + CaCl2,CA + FeCl3 and CA + CaCl2 + FeCl3 combination reagent was studied by oscillating elution method.[Result] The results showed that the removal rate of cadmium by several reagents in combination was higher than that by single reagent.CA + FeCl3 had the best effect on cadmium removal in soil,and the removal rate was 86.31％-89.61％.The effective content of cadmium in CA + FeCl3 (3∶1) was the highest,reaching 1.794 μg/L,according to the available cadmium content before and after leaching.Morphological analysis results showed that the spray lotion after leaching in soil exchangeable cadmium were mostly leached out,its proportion was greatly reduced,oxidizable and residual content was increased,the activity of cadmium in the soil decreased,the biological toxicity was greatly reduced.[Conclusion] CA + FeCl3 (3∶1) had the best removal efficiency of cadmium in soil,and the removal rate was 89.61％.