used by several authors to denote ''micellar enhanced ultra-Micellar extraction coupled with ultrafiltration techniques repfiltration'' processes (20).
resents a potentially attractive tool for the removal of different
The advantage of using micelles instead of polyelectrokinds of contaminants from waste waters. Even though most inlytes may be found in the large variety of surfactants comdustrial streams to be treated contain large amounts of electrolytes, mercially available, with all kinds of different properties, very little is known about the behavior of micellar solutions in and also in their ability to solubilize hydrophobic substances ultrafiltration when large amounts of salts are present. This paper such as extractant molecules (21,22) or synergistic agents is concerned with an investigation of two cationic surfactants (cet- (23). On the other hand one cannot ignore the drawbacks yltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC)) and one anionic surfactant (sodium dodecylsul-of micellar systems for practical applications. The major fate (SDS)) in the presence of several salts occurring in specific drawback is due to the existence of monomeric surfactant industrial processes (carbonates and hydrogenocarbonates, ni-(at a concentration close to the cmc), which is not retained trites, nitrates). The ultrafiltration behavior of these systems, with by the membranes. Biodegradable surfactants or low cmc individual salt concentrations up to 0.9 M, is studied from the surfactants can be considered in order to solve this problem. viewpoint of the fluxes obtained, the amount of surfactant leakage In addition, most studies reported so far, with a few excepand of the membrane ''gel point.'' Two types of polymeric memtions, were concerned with surfactant solutions with low branes with molecular weight cutoff of 10,000 Da are considered metal ion content, whereas the industrial streams to be (cellulose and polysulfone), which show significantly different betreated often contain also large amounts of electrolytes. This haviors.