Separation Efficiency of Epoxified-Polyethersulfone Blend Membrane for Chromium Removal

Abstract

A microporous bisphenol A diglycidyl ether (DGEBA) epoxified-polyethersulfone (PES) blend membrane (EPES membrane) was prepared through dry-wet phase inversion. This study attempts to correlate the changes in membrane physical and chemical properties when the EPES membranes were exposed to different durations of dry-phase inversion, towards the separation efficiency of carcinogen chromium (VI). Field emission scanning electron microscopy (FESEM) and porometer analysis revealed a small but not significant change of the physical structures of the EPES membranes at different durations of dry-phase inversion that are applied. On the other hand, in terms of chemical properties, both Fourier transform infrared spectroscopy and contact angle measurement demonstrated enhanced membrane hydrophilicity when a longer period of dry phase inversion was imposed during membrane synthesis. The EPES membrane synthesized through 1 h of dry phase inversion showed the most balanced high rejection and permeation performances at 88.84 ± 0.18 % removal of Cr (VI) ions with minimum membrane fouling at a steady permeation flux of 11.27 ± 0.35 L/m2h. From the result, EPES blend membranes revealed good potential in the removal of carcinogen Cr (VI) without jeopardizing the membrane permeation flux.