表面活性剂去除土壤和地下水中LNAPLs作用机制研究  

Removal Mechanism of Light Non-aqueous Phase Liquid from Soil and Groundwater by Surfactant

作　　者：杨建[1] 陈家军[1] 卢毅[1] 

机构地区：[1]北京师范大学环境学院,环境模拟与污染控制国家重点实验室,北京100875

出　　处：《环境科学》2009年第7期2153-2159,共7页Environmental Science

基　　金：国家自然科学基金项目(40772148)

摘　　要：去除多孔介质中滞留的LNAPLs,表面活性剂对LNAPLs的增溶和降低界面张力是关键.在实验测得不同浓度Triton X-100溶液对正十六烷的增溶以及它们之间界面张力的基础上,通过平衡清洗实验和砂柱冲洗实验分析了不同形态正十六烷的产生规律和机制.结果表明,正十六烷溶解能力与Triton X-100浓度成正比,当Triton X-100浓度大于临界胶束浓度CMC时,计算得摩尔增溶比MSR=1.6804,胶束相/水相分配系数对数值lgKmc=1.7158;正十六烷-Triton X-100溶液之间界面张力与Triton X-100浓度成反比,其变化规律符合高斯模型(R2=0.9964);溶解态正十六烷和自由态正十六烷与增溶和降低界面张力分别有较好的对应关系,表明增溶和降低界面张力都对多孔介质中正十六烷去除有影响,其中降低界面张力可以有效增加多孔介质中正十六烷的流动性,在正十六烷去除过程中起主要作用.Surfactant increases solubilization of n-hexadecane and reduces interfacial tension between surfactant and n-hexadecane, which are very important for the removal of residual LNAPLs in porous media. After the solubilization of n-hexadecane and interfacial tension between Triton X-100 solution and n-hexadecane were studied through experiments, the forming rule of different states of n-hexadecane were analyzed through equilibrium washing experiment and sand pillar leaching experiment. The experimental results show that： the dissolving ability was proportional to the concentration of Triton X-100 solution, and MSR = 1.680 4 and lgkmo = 1.715 8 calculated by solubilization of n-hexadecane when Triton X-100 solution concentration was large than CMC. The interfacial tension was inversely proportional to Triton X-100 solution concentration, and the variation was in accord with Gauss model （R^2 = 0.996 4）. Dissolved state and free state n-hexadecane had very good corresponding relation with solubilization and reducing interfacial tension respectively. Both solubilization and reducing interfacial tension could remove n-hexadecane from porous media. Reducing interfacial tension increased the flow ability of n-hexadecane effectively, and it removed most of residual n-hexadecane in soil and groundwater remediation.

关 键 词：TRITON X-100 正十六烷 增溶 界面张力 石英砂 

分 类 号：X53[环境科学与工程—环境工程] X522