ULTRAFILTRATION AND MICROFILTRATION OF SURFACTANT DISPERSIONS - AN EVALUATION OF PUBLISHED RESEARCH

A critial review of literature on the separation of surfactants from aqueous streams by membrane processes is given. These processes are ultrafiltration (UF), miceller enhanced ultrafiltration (MEUF), and reverse osmosis (RO). The factors which affect the permeate flux and rejection of the surfactant and/or electrolyte are considered in detail. With the exception of MEUF studies, most of the published work on surfactant separation lacks input from surfactant and interface science. These studies indicate that the fouling (gel) layer on the membrane and within the pores essentially controls the permeate flux and rejection characteristics of the separation system. It is therefore essential to understand the physical-chemical nature of the gel layer which is probably a direct result of surfactant and electrolyte concentrations and temperature on the surfactant phase behaviour. The present review also indicates that the mechanism of water and/or surfactant transport through the membrane and gel layer has not been considered.