A novel thin film nanocomposite forward osmosis membrane modified with zwitterionic GO-g-PSBMA with high fouling resistance and heavy metal ions rejection

In the current investigation, a zwitterion-modified graphene oxide (GO-g-PSBMA) nanofiller was prepared using the atom transfer radical polymerization (ATRP) method and embedded into the polyamide (PA) active layer of the forward osmosis (FO) membranes to remove the Cu2 + and Ni2+ ions effectively. The synthesized GO-gPSBMA was analyzed using SEM, EDS, FTIR, and XRD methods. The successful incorporation of nanofiller and its significant impact on membrane morphology was definitively confirmed through a variety of analytical methods. Additionally, the effects of incorporating GO-g-PSBMA on FO performance and the anti-fouling properties of the modified membranes were examined. Incorporating 200 ppm of GO-g-PSBMA enhanced water permeability by 120 % compared to the bare TFC membrane while maintaining the same salt rejection. The best-performing membrane (TFN-GOZW200) exhibited high rejection of Cu2+ (99.2 %) and Ni2+ (97.5 %) ions at a feed concentration of 500 ppm. The anti-fouling experiment presented the high fouling resistance of zwitterionic-modified TFN membranes. The performance improvement of PA thin film could be ascribed to the merits of GO nanosheets and zwitterionic polymers. The synthesized TFN membrane is a promising option for effectively removing heavy metal ions from wastewater, with low antifouling potential.