Fabrication of polyether sulfone-laser induced graphene composite electroconductive membrane and its application in biofouling control and chromium removal

Abstract

Polymeric membranes used in water purification face challenges due to high-pressure requirements, fouling propensity, and permeability-selectivity trade-offs. Electroconductive membranes (ECMs) can deal with these challenges and have the potential to improve the performance and lifetime of membranes using a low electric potential. In the present work, robust ultrafiltration (UF) ECMs were fabricated using polyether sulfone (PES) and laser-induced graphene (LIG) through the phase inversion process. LIG is a conductive material with electrochemical and catalytic activity fabricated directly on a polymeric substrate with a CO2 laser in a chemical-free single-step process. The fabricated ECMs were optimized with PES concentration and membrane thickness, can perform reduction, precipitation, and filtration simultaneously. These ECMs have a permeability ranging from 450 to 200 LMH bar−1 with BSA rejection of ∼60 % and FRR up to ∼90 %. The electrochemically enhanced Cr(VI) removal reached ∼94 % by applying a low electrical potential. Furthermore, in the biofouling experiments, the attached live biomass was reduced by ∼67 % for fabricated ECMs compared to the pristine membrane. The results showed the anti-biofouling potential of fabricated ECMs, which can be further enhanced using their electrochemical activity. These new-generation ECMs have immense potential for dealing with permeability-selectivity trade-offs, enhancing pollutant removal, and antifouling applications with low applied potential.