Zhao Baowei, Zhu Lizhong
School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou, Gansu Province 730070, China.
J Hazard Mater. 2006 Aug 25;136(3):513-9. doi: 10.1016/j.jhazmat.2005.08.036. Epub 2005 Oct 19.
Efforts to remove the dense nonaqueous phase liquids (DNAPLs) in subsurface by mobilizing them face with risks of driving the contaminants deeper into aquifer zones. In this paper, a synergistical solubilization of DNAPLs by mixed nonionic and anionic surfactant, Triton X-100 (TX100) and sodium dodecylbenzene sulfonate (SDBS) in DNAPL/water systems was presented. Given 1:40 phase ratio of DNAPL:water (v/v), mixed TX100-SDBS exhibited significantly synergistical solubilization for the DNAPLs, trichloroethene (TCE), chlorobenzene (CB) and 1,2-dichlorobenzene (1,2-DCB), respectively, when the total surfactant concentration was up to 6000mg/L, i.e. the condition when solubilization by the mixture was better than those attainable with individual components by themselves. The synergistical extents depended on the initial ratios of TX100 to SDBS, the initial surfactant concentrations and the properties of DNAPLs. Given the total surfactant concentration, synergistical extents increased with the fraction of SDBS in mixed surfactant. On the contrary, did with the total surfactant concentration. The solubilization capacity by 3:1, 1:1 and 1:3 of mass ratio of TX100-SDBS were determined and compared with those by single ones. In the view of the mass solubilization ratio (SR), the mixed TX100-SDBS could solubilize more DNAPLs than single SDBS at given surfactant concentration. Reduction in partition of TX100 and synergistic solubilization were responsible for the significant solubilization extent of mixed system. The work presented here demonstrates that mixed nonionic-anionic surfactants would be preferred over the corresponding single surfactants for solubilization remediation of DNAPLs, which could decrease risks of driving the contaminants deeper into aquifers.
通过调动致密非水相液体（DNAPLs）来去除地下水中的这类物质，面临着将污染物驱入含水层更深区域的风险。本文介绍了在DNAPL/水体系中，非离子和阴离子表面活性剂混合物（Triton X-100（TX100）和十二烷基苯磺酸钠（SDBS））对DNAPLs的协同增溶作用。当DNAPL与水的体积比为1:40时，在总表面活性剂浓度高达6000mg/L时，混合的TX100-SDBS对DNAPLs、三氯乙烯（TCE）、氯苯（CB）和1,2-二氯苯（1,2-DCB）分别表现出显著的协同增溶作用，即混合物的增溶效果优于各单一成分单独作用时所能达到的效果。协同程度取决于TX100与SDBS的初始比例、初始表面活性剂浓度以及DNAPLs的性质。在总表面活性剂浓度一定的情况下，协同程度随着混合表面活性剂中SDBS比例的增加而增大。相反，随着总表面活性剂浓度的增加而减小。测定了TX100-SDBS质量比为3:1、1:1和1:3时的增溶能力，并与单一表面活性剂的增溶能力进行了比较。从质量增溶比（SR）来看，在给定表面活性剂浓度下，混合的TX100-SDBS比单一的SDBS能增溶更多的DNAPLs。TX100分配的减少和协同增溶作用是混合体系显著增溶程度的原因。本文的研究表明，对于DNAPLs的增溶修复，混合非离子-阴离子表面活性剂比相应的单一表面活性剂更具优势，这可以降低将污染物驱入含水层更深区域的风险。
