Novel composite membranes for simultaneous catalytic degradation of organic contaminants and adsorption of heavy metal ions

Novel composite membranes are successfully developed for simultaneous adsorption of heavy metal ions and catalytic degradation of organic contaminants by blending polydopamine-coated ferroferric oxide (Fe3O4@PDA) nanoparticles in polyethersulfone (PES) matrix via liquid-induced phase separation (LIPS) method. The permeabilities of the as-fabricated composite membranes are significantly improved by introducing Fe3O4@PDA nanoparticles, because the hydrophilic coating on the surface of Fe3O4@PDA nanoparticles enables to generate more microporous structures between the PES matrix and nanoparticles during the LIPS process. The composite membrane containing 20 wt% Fe3O4@PDA nanoparticles shows water flux as high as 2640 L.m(-2).h(-1).bar(-1), which is six times larger than that of PES blank membrane. The composite membranes exhibit efficient and repeatable performances for simultaneous adsorptive removal of heavy metal ions and catalytic degradation of organic contaminants based on the mechanism of Fenton-like reaction. The proposed composite membranes with multifunction of simultaneous catalytic degradation of organic contaminants and adsorption of heavy metal ions provide a new pathway to deal with some hard-to-be-treated wastewaters from papermaking, leather, textile printing-dyeing industries, and so on. Furthermore, the proposed one-step strategy for fabricating composite membranes with both large permeability and high separation efficiency in this work is easy to be scaled up.