synthesis of polysulfone/go@ws2 nanocomposite nanofiltration membranes for the removal of anionic and cationic dyes from wastewater

Industrial dyes are one of the major pollutants for surface and underground water reserves. in this study, polysulfone (ps) membranes were prepared by the phase inversion method, and then nanoparticles of tungsten disulfide (ws2), graphene oxide (go), and go@ws2 nanohybrid were used to synthesize nanocomposite membranes with different weight fractions of nanoparticles. prepared nanocomposite membranes were characterized by different analysis methods, including x-ray diffraction, water contact angle measurement, gravimetric porosity analysis, field emission scanning electron microscopy coupled with energy dispersive spectroscopy, and elemental mapping analysis. then, the performance of the synthesized membranes for the removal of methylene blue and congo red dyes from synthetic wastewater was studied. it was found that increasing the nanoparticles led to an increase in water flux through the membrane and dye rejection. finally, the best-performing membrane was found to be the membrane containing 0.3 w/w% of go@ws2 nanohybrid, for which methylene blue and congo red rejection percentages of 63.25 and 67.26 were reported, respectively. rejection of dye was increased by decreasing water contact angle with ps/ go@ws2 0.3% having the lowest contact angle of about 61°. estimation of pore sizes of the membranes showed that they decreased by increasing the amount of nanomaterial, which was the lowest for ps/go@ws2 0.3% membrane. also, calculated pore sizes proved that the prepared membranes are in the category of nanofiltration membranes.