Incorporation of graphene oxide nanosheets into polyethersulfone membranes to improve their separation performance and antifouling characteristics for Congo red removal.

Due to worldwide shortage of water sources and, on the other hand, producing a huge amount of contaminated industrial wastewater, there is an urgent need to provide proper treatment processes such as fast-growing membrane ones. In this study, some nanocomposite nanofilter membranes, as a promising solution for this goal, were fabricated by incorporation of graphene oxide (GO) nanosheets into polyethersulfone (PES) membrane matrix and polyvinylpyrrolidone (PVP) via the method of non-solvent-induced phase separation (NIPS) to dedicate them higher separation performance and a higher antifouling tendency. The produced GO nanosheets and the prepared membranes' structure were evaluated by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and atomic force microscopy (AFM) analysis. Then, the separation performance and antifouling characteristics of the prepared pristine and nanocomposite membranes were evaluated at 3 bar, 27°C, and Congo red (CR) dye concentrations of 50, 100, and 200 ppm. The observations revealed that the incorporation of GO nanosheets into the polymer matrix of PES-PVP increases the permeation flux, rejection of CR, and flux recovery ratio (FRR) to the maximum values of 276.4 L/m .h, 99.5%, and 92.4%, respectively, at 0.4 wt.% loading of GO nanosheets as an optimum filler loading. PRACTITIONER POINTS: Graphene oxide nanosheets were prepared and uniformly incorporated in the polyethersulfone porous membrane. The nanocomposite membranes revealed higher separation performance, that is, permeation flux and dye rejection as 282.5 L/m .h and 99.5% at 0.4 wt.% loading of GO nanosheets. Flux recovery ratio of the nanocomposite membrane, as their antifouling character, also increased as 92.4%, as the GO nanosheets were incorporated by 0.4 wt.%.