Cheng K Y, Wong J W C
Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, PR China.
Environ Technol. 2006 Aug;27(8):835-44. doi: 10.1080/09593332708618695.
The present study examined the effects of four surfactants, including three non-ionic surfactants (Tween 80, Triton X-100 and Brij 35) and an anionic surfactant SDS on the solubilization and distribution of phenanthrene (Phe) and pyrene (Pyr) in soil-water systems. All four surfactants could enhance the solubilization of Phe and Pyr in aqueous phase linearly when surfactant concentrations exceeded their respective critical micelle concentrations (CMC). Molar solubilization ratio (MSR) which indicated surfactant's solubilization capacity for Phe and Pyr, was highest for Tween 80 for both PAHs, and SDS had the lowest among the four surfactants, while Triton X-100 and Brij 35 had about the same MSR for both PAHs. Moreover, all the surfactants could provide a strong micelle partitioning phase for the more hydrophobic Pyr than Phe as revealed by their high micelle--aqueous phase partition coefficient, K(mc). Batch desorption studies also demonstrated that Tween 80 had the best capacity for the desorption of both Phe and Pyr in the soil-water systems, and followed by Triton X-100 and Brij 35, while SDS seems to have no positive effect on the desorption of PAHs probably due to its relatively high CMC value. Therefore, from the application standpoint, the results obtained in this study suggest that Tween 80 would be the most suitable candidate among the four surfactants in improving solubilization and desorption of PAHs in soil-water system, which are believed to be the prerequisites for successful bioremediation technology for PAH contaminated soil.
本研究考察了四种表面活性剂，包括三种非离子表面活性剂（吐温80、曲拉通X-100和Brij 35）和一种阴离子表面活性剂十二烷基硫酸钠（SDS）对菲（Phe）和芘（Pyr）在土壤-水体系中的增溶作用及分布情况。当表面活性剂浓度超过各自的临界胶束浓度（CMC）时，所有四种表面活性剂均可线性增强菲和芘在水相中的增溶作用。摩尔增溶比（MSR）表明表面活性剂对菲和芘的增溶能力，对于两种多环芳烃（PAHs）而言，吐温80的MSR最高，SDS在四种表面活性剂中最低，而曲拉通X-100和Brij 35对两种PAHs的MSR大致相同。此外，所有表面活性剂均能为疏水性更强的芘提供比菲更强的胶束分配相，这可由它们较高的胶束-水相分配系数K(mc)看出。批次解吸研究还表明，吐温80在土壤-水体系中对菲和芘的解吸能力最佳，其次是曲拉通X-100和Brij 35，而SDS似乎对PAHs的解吸没有积极影响，这可能是由于其相对较高的CMC值。因此，从应用角度来看，本研究结果表明，在改善土壤-水体系中PAHs的增溶和解吸方面，吐温80是四种表面活性剂中最合适的选择，而增溶和解吸被认为是PAH污染土壤成功生物修复技术的前提条件。
