MICROFILTRATION OF LONG-CHAIN CARBOXYLATES - RELATIONSHIP BETWEEN REJECTION AND MICELLIZATION

Membrane transfer of anionic detergents (sodium carboxylates) has been investigated. Membranes used were Membralox membranes made of alumina . Rejection of surfactants on 0.1 and 0.2 mum membranes appeared stron gly correlated to their ability to micellize. The mechanism of rejecti on could involve multilayer adsorption of carboxylates on membranes an d formation of cylindrical micelles near the membranes. The increase o f tangential flow velocity or the use of sequential backflush led to a reduction of fouling and the lowering of soap rejection on 0.1 and 0. 2 mum standard membranes. In new kinds of membranes made of other meta llic oxides, high rejections of micellized carboxylates were associate d with low fouling levels. They seemed to be particularly relevant to achieve separation of anionic detergents.