烷基糖苷对土壤中重金属的去除研究

Removal of Heavy Metals from Soil by Alkyl Polyglycoside

通过振荡分离实验研究了烷基糖苷(APG)对土壤中Cu、Zn、Pb和Cd的去除作用,考察了烷基糖苷淋洗液的pH值、浓度、离子强度等对重金属去除率的影响,并对烷基糖苷处理前后土壤中重金属的形态进行了分析。结果显示,烷基糖苷对土壤中重金属的去除率受淋洗液pH值的影响且随淋洗液浓度的增加上升,当烷基糖苷淋洗液的pH为5.2、浓度为85 g/L时,土壤中Cd、Cu、Pb和Zn的去除率分别达到了77.7%、40.5%、24.5%和20.0%。溶液离子强度的变化对Cu、Zn、Pb的去除影响不大,但Cd的去除率随NaCl溶液浓度的升高增大。比较APG处理前后土壤中重金属的形态发现,APG对离子交换态和碳酸盐结合态重金属的去除效果最好,表明经APG洗脱,可有效降低土壤中重金属的毒性和生物可利用性。

Batch experiments were done to evaluate the performance of alkyl polyglycoside（APG） for removal of heavy metals from contaminated soil.Effects of pH value,concentration of APG and ionic strength on the desorption of heavy metals from soil by AGP washing were investigated.Speciations of heavy metals in the soil were also identified before and after APG treatment.Results indicated that a high concentration of APG solution and pH condition about 5 was contributed to a better removal efficiency of heavy metals.The maximum removal efficiencies for cadmium,copper,lead and zinc were reached to 77.7%,40.5%,24.5% and 20.0% respectively,by using 85 g/L APG solution washing at pH 5.2.Concentration of NaCl solution had a positive influence on the desorption of Cd,but almost no efforts on those of Cu,Zn and Pb.Comparing the speciation transformation of heavy metals in the soil before and after APG treatments,it was found that heavy metals in exchangeable and carbonated fractions could be more easily washed away.As a result,the toxicity and bio-reusability of metals in sol were significantly decreased after APG washing.