采用室内序批实验研究4种Tween系列非离子表面活性剂对人工污染东北黑土中几种典型多环芳烃(PAHs)化合物蒽、菲、萘和芴的增溶和洗脱特性,表面活性剂在土壤上的吸附损失以及几种助表面活性剂对PAHs洗脱效率的促进效果。结果表明,Tween系列表面活性剂均能大幅度增加PAHs的水溶解度,具有较好的增溶能力,其中Tween80对PAHs的增溶效果最佳,其次为Tween60。4种表面活性剂均能不同程度地洗脱土壤中的PAHs,且洗脱率随着表面活性剂浓度的增加而增大。表面活性剂对土壤中菲的洗脱效果最好,浓度为4 000mg/L时的菲去除率在60%-80%之间。比较各表面活性剂的洗脱能力发现,表面活性剂对土壤中PAHs的洗脱能力大小顺序为Tween80〉Tween60〉Tween40〉Tween20。各表面活性剂在黑土中的吸附等温线均为近似S形,Tween60和Tween80在土壤中的吸附损失(1 300-1 400mg/kg)低于Tween20和Twen40(1 600-1 700mg/kg)。作为助表面活性剂,加入一定浓度的正丙醇、正丁醇和正己醇会促进Tween80对PAHs的洗脱作用,其促进效果大小顺序为正丙醇〉正丁醇〉正己醇。
The elution of polycyclic aromatic hydrocarbons(PAHs)from contaminated black soils had been examined using Tween series surfactants in a laboratory.The results of the solubilization experiment indicated that the solubility of PAHs in water could be greatly enhanced by Tween series surfactants,and the most effective surfactant for water solubility enhancing of PAHs at surfactants concentration above the critical micelle concentration(CMC)was Tween80.All surfactants were effective on removal of PAHs from black soil,and the removal rates of PAHs increased gradually with the increase of concentration of surfactants.The highest removal rate of 60% ~80% was observed for phenanthrene,and the least efficiency was observed for fluorene.The sequence of removal rates of PAHs from the soil was Tween80 Tween60 Tween40Tween20.The adsorption isotherms of surfactants in black soil were S-shape,and the adsorption of Tween80 and Tween60 to soil was weaker than that of Tween40 and Tween20.The efficiency of cosurfactants for improving PAHs solubilization capacity was as:n-propanolbutanoln-hexanol.