Department of Civil & Environmental Engineering, Lehigh University, 1 West Packer Avenue, Bethlehem, PA 18015, USA.
Water Res. 2013 Sep 1;47(13):4612-20. doi: 10.1016/j.watres.2013.04.062. Epub 2013 May 17.
Recent studies have suggested that the ability of a surfactant to enhance the bioavailability of hydrophobic organic compounds (HOC) requires the formation of surfactant hemi-micelles on the bacterial cell surface and subsequent partitioning of HOC into the hemi-micelles. However, the studies did not provide direct evidence of HOC partitioning into surfactant hemi-micelles on the bacterial cell surface. In this study, direct evidence is provided to demonstrate that the nonionic surfactant Brij 30 forms hemi-micelles on the bacterial cell surface and that phenanthrene sorption at the bacterial surface is enhanced by the surfactant. These results are in agreement with the current theory describing surfactant-enhanced HOC bioavailability. This enhanced bioavailability is put into context with microbial kinetics and system partitioning processes, and it is demonstrated that the addition of surfactant can enhance, have no effect, or inhibit HOC biodegradation depending upon surfactant concentration and microbial growth rate. Understanding these non-linear relationships between surfactant-enhanced HOC bioavailability, biodegradation kinetics, and system partitioning will assist in the design and implementation of surfactant-enhanced bioremediation programs.
最近的研究表明，表面活性剂增强疏水性有机化合物（HOC）生物利用度的能力需要在细菌表面形成表面活性剂半胶束，随后将 HOC 分配到半胶束中。然而，这些研究并没有提供 HOC 分配到细菌表面的表面活性剂半胶束中的直接证据。在本研究中，提供了直接证据证明非离子表面活性剂 Brij 30 在细菌表面形成半胶束，并且表面活性剂增强了蒽在细菌表面的吸附。这些结果与描述表面活性剂增强 HOC 生物利用度的当前理论一致。将这种增强的生物利用度与微生物动力学和系统分配过程联系起来，并证明表面活性剂的添加可以根据表面活性剂浓度和微生物生长速率增强、没有影响或抑制 HOC 生物降解。了解表面活性剂增强的 HOC 生物利用度、生物降解动力学和系统分配之间的这些非线性关系将有助于设计和实施表面活性剂增强的生物修复计划。
