Experimental Data and Modeling for Surfactant Micelles, HOCs, and Soil

Abstract

Experimental data are compared with results from a model developed for nonionic surfactant solubilization of hydrophobic organic compounds (HOCs) in soil/aqueous systems. The model parameters that describe each of the major physicochemical processes affecting sorption and micellar uptake of both nonionic surfactant and hydrophobic organic compounds can be characterized with values obtained independently from separate experiments involving aqueous, soil, or soil/ aqueous systems. The experimental data presented in this paper demonstrate that the modeling approach is reasonably valid for several nonionic surfactants. It is also shown that treating a soil with successive surfactant washings results in greater removal of HOC than a single washing with the same total mass of surfactant. An inverse method is evaluated with experimental data. This method permits the determination of a ratio of the values of two of the model parameters from gross experimental data such that if one parameter is measured the other can be calculated.