Ultrafiltration of SDS solutions using polymeric membranes

The objective of the study was to investigate the influence of membrane material, membrane cut-off, transmembrane pressure and surface active agent concentration on transport and separation properties of ultrafiltration membranes. Intersep Nadir membranes, made of polyethersulfone, polysulfone, regenerated cellulose, cellulose acetate and polyamide were used in experiments. The applied pressure varied from 0.05 to 0.20 MPa. The concentration of sodium dodecyl sulphate (SDS) in model solutions was below its critical micelle concentration (in the range of 5-600 g / m3). It was found that membranes made of regenerated cellulose and cellulose acetate were less susceptible to fouling than polysulfone and polyamide ones. With increasing membrane cut-off, the value of fouling index decreased. It was also observed that membrane permeability and SDS rejection deteriorated with an increase in SDS concentrations in the tested solutions. The SDS separation efficiency varied from 15 to 80%.