Performance enhancement of ultrafiltration membrane via simple deposition of polymer-based modifiers

Abstract

Ultrafiltration (UF) membrane is extensively utilized in water treatment for the removal of colloidal particles, dissolved organic matters and microorganisms. These colloidal particles and organic matters are prone to being adsorbed on membrane surface known as membrane fouling, which increases operational costs and lowers down membrane efficiency. In this work, a group of synthesized hydrophilic random copolymers and homopolymer were utilized to enhance PES UF membrane performance by a simple deposition of a thin layer. Despite the increased intrinsic resistance as a result of the thin modification layer, higher pure water permeability and recovery rate were observed for the modified Polyethersulfone (PES) membrane during Bovine Serum Albumin (BSA) fouling test in comparison to the virgin membrane. Moreover, the stability of the adsorbed polymer layers was evaluated by a cyclic fouling test and chemical cleaning endurance assessment. The membrane surface morphology and topography were characterized by field emission scanning electron microscopy (FESEM) and atom force microscope (AFM). The chemical composition before and after clcylic fouling test and chemical cleaning were studied with attenuated total reflectance fourier transform infrared (ATR-FTIR) spectroscopy. The results show that the random copolymer modified membrane exhibited average 26 % rises in water permeability compared with the virgin PES UF membrane when 0.5 wt% BSA solution was used as feed. The stable permeability and flux recovery rate during the cyclic study with chemical cleaning suggest good affinity of the newly synthesized random copolymer with the PES membrane and water. This strategy successfully enhanced the UF membrane anti-fouling performance.