Partitioning of Hydrophobic Organic Compounds to Sorbed Surfactants. 1. Experimental Studies
Partitioning of two hydrophobic organic compounds (HOCs), phenanthrene and naphthalene, to surfactant micelles, kaolinite, and sorbed surfactants was studied to provide further insight on (1) the effectiveness of using sorbed surfactants to remove HOCs from water and (2) the feasibility of surfactant-enhanced remediation (SER) for contaminated subsurface systems. Sorbed surfactant partition coefficients, Kss, showed a strong dependence on the surfactant sorption isotherms:  at low sorbed surfactant levels Kss values were at their highest and then decreased with increasing surfactant sorption densities. Kss values for SDS were always larger than the corresponding micellar partition coefficient (Kmic) values; for Tween 80, however, Kss values were higher than Kmic values only at the lower sorbed surfactant densities. HOC distributions between the immobile and mobile phases varied with surfactant dose because of the competition between sorbed and micellar surfactants for HOC partitioning:  distribution coeff...