Determining binding of polycyclic aromatic hydrocarbons to CTABr micelles using semi-equilibrium dialysis techniques

Abstract

Micellar enhanced ultrafiltration (MEUF) has been shown to be an effective removal technique for a variety of trace contaminants in wastewater, especially for water soluble low molecular weight organic contaminants. In MEUF, contaminants first partition into surfactant micelles prior to removal by ultrafiltration, where the contaminants are below the molecular weight cut-off of the ultrafiltration membrane but the micelles are above the cut-off. Binding constants of selected Polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, phenanthrene, pyrene and fluorene have been determined in order to examine the removal efficiency of MEUF for PAHs with Cetyltrimethylammonium bromide (CTABr) using a semi equilibrium dialysis method. PAHs show strong binding with CTABr because of hydrophobic interactions. Our results enabled us to develop a relationship between binding constant (log KB) and log KOW for neutral compounds, which will be useful for predicting MEUF performance for PAHs removal from waste water. The range of our reported binding constant values are from 2.61 to 5.07.