Fabrication of MWCNTs-polysulfone composite membranes and its application in the removal of bisphenol A

To explore the efficient removal of dissolved organic pollutant molecules from water, multi-walled carbon nanotubes (MWCNTs)-polysulfone (PSF) composite membranes with high CNTs hybrid content were fabricated, and the adsorption and ultrafiltration behaviors towards bisphenol A (BPA) were explored in this study. The MWCNTs-PSF composite membranes were composed of a dense top surface and a porous bulk layer with MWCNTs separately embedding in or hanging on the polymer matrix. The pore size of the top surface centralized in 30-70 nm. The pure water flux of MWCNTs-PSF membranes was found to be variable in accordance with the surface pore size. The adsorption capacity of membranes towards BPA from water was remarkably enhanced by the composite of MWCNTs, and the maximum adsorption capacity of M-CNT15 was more than twice of that of M-PSF. In the filtration process, the MWCNTs-PSF composite membranes exhibited obviously superior retaining capacities to the neat PSF membrane. The M-CNT15 membrane maintained 20% rejection to BPA molecules in steady-state, comparison to nearly zero rejection of M-PSF under the same operating conditions.