Rejection of Caffeine and Carbamazepine by surface coated PVDF hollow-fiber membrane system

摘要

This research investigates surface coated ultrafiltration (UF) polyvinylidene fluoride (PVDF) hollow fiber membrane for the removal of organic micropollutants (OMPs) in water. Coating of PVDF membranes with Poly (1-phenylethene-1,2-diyl) - Polystyrene solution through physical adsorption was carried out under two modes, ‘dipped’ and ‘sprayed’. The performance of the coated membrane in the rejection of model organic micropollutants, caffeine and carbamazepine spiked in deionised water (at 300 g/L and 500 g/L), correlated with the coating methods used. Dipped coated membrane showed a better removal of recalcitrant hydrophobic carbamazepine compared to the ‘sprayed’ coated membrane; while for both methods of coating, removal of caffeine was relatively insignificant. Inferably, hydrophobic interaction and size exclusion may be the major removal mechanism involved in the rejection by the coated membranes. The coating layer potentially enhanced reduction of pore size with resulting effect on membrane permeability and providing more sites for possible hydrophobic interaction.