Department of Civil Engineering, Carnegie Mellon University, Pittsburg, PA 15213, USA.
Biotechnol Bioeng. 1992 Dec 20;40(11):1367-80. doi: 10.1002/bit.260401111.
The solubilization and mineralization of (14)C-phenanthrene in soil-water systems was examined with several commercially available surface-active agents, viz., an alkyl ethoxylate C(12)E(4); two alkylphenol ethoxylate surfactants: C(8)PE(9.5) and C(9)PE(10.5); two sorbitan ethoxylate surfactants: the sorbitan monolaurate (Tween 20) and the sorbitan monooleate (Tween 80); two pairs of nonionic ethoxylate surfactant mixtures: C(12)E(4)/C(12)E(23) at a 1:1 ratio, and C(12-15)E(3)/C(12-15)E(9) at a 1:3 ratio; and two surfactants possessing relatively high critical micelle concentration (CMC) values and low aggregation numbers: CHAPS and octyglucoside. Surface tension experiments were performed to evaluate surfactant sorption onto soil and the surfactant doses required to attain the CMC in the soil-water systems. Surfactant solubilization of (14)C-phenanthrene commenced with the onset of micellization. The addition of surface-active agents was observed not to be beneficial to the microbial mineralization of phenanthrene in the soil-water systems and, for supra-CMC surfactant doses, phenanthrene mineralization was completely inhibited for all the surfactants tested. A comparison of solubilization, surface tension, and mineralization data confirms that the inhibitory effect on microbial degradation of phenanthrene is related to the CMC of the surfactant in the presence of soil. Additional tests demonstrated the recovery of mineralization upon dilution of surfactant concentration to sub-CMC levels, and a relatively high exit rate for phenanthrene from micelles. These tests suggest that the inhibitory effect is probably related to a reversible physiological surfactant micelle-bacteria interaction, possibly through partial complexing or release of membrane material with disrupting membrane lamellar structure. This study indicates that nonionic surfactant solubilization of sorbed hydrophobic organic compounds from soil may not be beneficial for the concomitant enhancement of soil bioremediation. Additional work is needed to address physicochemical processes for bioavailability enhancement, and effects of solubilizing agents on microorganisms for remediation and treatment of hydrophobic organic compounds and nonaqueous phase liquids.
用几种市售的表面活性剂研究了土壤-水体系中（14）C-菲的增溶和矿化作用，这些表面活性剂分别为：一种烷基乙氧基化物 C（12）E（4）；两种烷基酚乙氧基化物表面活性剂：C（8）PE（9.5）和 C（9）PE（10.5）；两种山梨糖醇乙氧基化物表面活性剂：失水山梨糖醇单月桂酸酯（吐温 20）和失水山梨糖醇单油酸酯（吐温 80）；两对非离子乙氧基化物表面活性剂混合物：C（12）E（4）/C（12）E（23），比例为 1:1，和 C（12-15）E（3）/C（12-15）E（9），比例为 1:3；以及两种具有相对较高临界胶束浓度（CMC）值和低聚集数的表面活性剂：CHAPS 和辛基葡萄糖苷。进行表面张力实验以评估表面活性剂在土壤上的吸附以及在土壤-水体系中达到 CMC 所需的表面活性剂剂量。（14）C-菲的增溶作用始于胶束化的开始。添加表面活性剂并没有有益于土壤-水体系中菲的微生物矿化，并且对于超 CMC 表面活性剂剂量，所有测试的表面活性剂都完全抑制了菲的矿化。增溶、表面张力和矿化数据的比较证实，对菲微生物降解的抑制作用与土壤中表面活性剂的 CMC 有关。进一步的测试表明，在将表面活性剂浓度稀释至亚 CMC 水平后，矿化作用得到恢复，并且菲从胶束中快速释放。这些测试表明，抑制作用可能与表面活性剂胶束-细菌之间的可逆生理相互作用有关，可能是通过与破坏膜层状结构的膜材料的部分络合或释放有关。本研究表明，非离子表面活性剂从土壤中增溶被吸附的疏水性有机化合物可能不利于同时增强土壤生物修复。需要进一步的工作来解决生物有效性增强的物理化学过程，以及增溶剂对微生物的影响，以修复和处理疏水性有机化合物和非水相液体。
