Development of Asymmetric Low Pressure Reverse Osmosis-Surfactants Membrane: Effect of Surfactant Types and Concentration

Abstract

The effect of surfactants that are cationic (Cetyl trimethylammonium bromide (CTAB)), anionic (Sodium Dodecyl Sulphate (SDS)) and non-ionic (Triton X-100) on performance, morphologies and molecular orientation of Polysulfone (PSF) low pressure reverse osmosis (LPRO) membrane were addressed. The experimental data showed that the increasing of 0.5 wt% in surfactant concentration produced higher pure water permeation (PWP) and flux. At 2.5 wt% of SDS, the LPRO membranes achieved the highest PWP of about  64.42 L/m2 × h while 3.0 wt% of CTAB demonstrated the highest flux of 55.28 L/m2 × h. Analysis from morphological results found
that the optimal performance at 89.6 % rejection was produced by the membrane with 2 wt% SDS which is a good promoter for the fine morphological structures of the membrane, thus producing fine spectrum of molecular orientation factor.