Development of high flux nanofiltration membrane using para-amino benzoate ferroxane nanoparticle for enhanced antifouling behavior and dye removal

Abstract

In this work, para-amino benzoate ferroxane nanoparticle (PABFNP) was employed as a key functional nanoparticle to improve the polyethersulfone (PES) nanofiltration membrane, and PABFNPs blended with PES (PES/PABFNPs) nanofiltration membranes were thus prepared via phase inversion method. PABFNPs may have good compatibility with PES polymer due to intermolecular attractions including hydrogen bonding between −OH and –NH2 of PABFNPs with SO of PES. Therefore, the stable bonding between hydrophilic PABFNPs and PES leads to PES nanofiltration membrane of exceptionally high performance. The effects of PABFNPs blending ratio on the chemical structure, hydrophilicity, surface morphology, zeta potential, and antifouling behavior of the membrane samples were evaluated. The salt rejection of the PES/PABFNPs membranes was also examined. With an increase in PABFNPs blending ratio up to 0.25wt.% with PABFNP0.25 membrane, surface hydrophilicity and pure water flux were strongly increased and then decreased owing to the agglomeration of PABFNPs in the PES matrix. PABFNP0.25 membrane was found to have the lowest irreversible fouling ratio of 1 %, the highest flux recovery ratio value of 99 % and excellent long-term pH stability. The pure water flux of PABFNP0.25 membrane was 64.2kg/m2h with a high rejection for dye (99 % for Direct Red 16 and 98.42 % Methylene blue). Moreover, the algal dye rejection test was carried out to investigate the rejection performance of the PES/PABFNPs membranes towards the mixture of pollutants. As a result, by addition of PABFNPs at lower blending ratio, the membrane with satisfying antifouling behavior, long-term pH stability, and nanofiltration performance was prepared.