Extraction of organic components from wastewater by pervaporation

Abstract

In the run of the last decades the coming up of new technologies as well as new needs has increased the interest in wastewater treatment. This study concerns the synthetic membrane development; synthesis of polymers for membrane preparation and the extraction of volatile organic components in aqueous media by pervaporation through polydimethylsiloxane, which is the most frequently used polymer material for the active layer of pervaporation for the extraction of organic compounds from wastewater. This elastomer has some special characteristics: high hydrophobicity, high permeability, good thermal and mechanical resistance and easy manufacture of the active layer on asymmetric substrate. The elastomer is a cross-linked material in which the degree of cross-linking and the structure of the network theoretically depends uniquely on the chemical structure. In this work we study the influence of some parameters of the preparation procedure on the membrane properties. Sorption of ethyl acetate, an aroma model, in pure state and in aqueous solution of different concentrating was performed and analysed. The curing was also carried out at different temperatures. The membrane physical properties (density, shore hardness and elasticity) were determined. Finally, in order to predict quantitatively the solvent contents in the membrane at the upstream face in pervaporation flux, we used floury, Huggins approach which appears to be valid in its simplified form.