Fabrication & Characterization of Graphene oxide incorporated Polymeric Membranes for Water Treatment

Abstract

Considering the significance of potable water for the welfare of people, and its growing demand owing to hiking global population, expanding economies and industrialization; development of cost-effective, efficient water treatment technologies has become a need of the hour. The drawbacks of the conventional water disinfection methods have led to an increasing market-share of membrane filtration in water treatment technologies. However, advances in membrane materials are required to improve the properties and performance of existing membranes. The present work is focused on the synthesis of graphene oxide (GO) via a simplified Hummer’s method and its incorporation (0.25, 5 and 1 wt% of polymer) in polyether sulfone; to fabricate mixed matrix membranes with enhanced water flux, hydrophilicity and water retaining capacity in addition to antibacterial properties. Synthesized GO was characterized by XRD, FTIR and SEM. Membranes were fabricated via phase inversion method. The effect of varying concentrations of GO filler on morphology, wettability, water retention, flux and antibacterial properties of the membranes was investigated. Antibacterial activity of GO and GO-PES membranes was tested against Salmonella typhi – causative agent of typhoid. Graphene oxide incorporated membranes exhibited increase in porosity, wettability, higher flux and formation of lateral finger-like channels with increasing GO loading. 0.5 wt% GO loaded membrane showed highest water flux, lowest contact angle and. Increasing the GO loading from 0.5 wt% to 1 wt% resulted in flux decline and decrease in hydrophilicity, this can be attributed to the agglomeration of GO with higher loading. For antibacterial activity against S. typhi, GO-PES membranes with 1wt% GO loading gave the most significant activity i.e. 69.4% reduction in Salmonella typhi cell count. It can be deduced from the results that membranes with 0.5 wt% GO loading are optimal for use in water treatment and disinfection.