Pioneering Biofouling Resistant PES UF Membrane with MnFe2O4/g-C3N4 Nanocomposite: Insight into Mechanisms and Fouling Dynamics

Abstract

The advancement of ultrafiltration (UF) membranes with minimal biofouling ability and outstanding performance is essential for effective water treatment. This study reports the synthesis of graphitic carbon nitride modified with manganese ferrite to produce MnFe2O4/g-C3N4 nanocomposite by thermal treatment and co-precipitation methods. Textural and morphological characterizations confirmed the successful deposition of MnFe2O4 particles on g-C3N4 surface. Polyethersulfone (PES) membranes were constructed containing MnFe2O4/g-C3N4 nanofiller of varying loading (0.5–3 wt.%). The MnFe2O4/g-C3N4/PES membranes executed enhanced physicochemical properties with increasing nanofiller content. Filtration and rejection experiments using pure water, humic acid (HA), and bovine serum albumin (BSA) were performed to evaluate the membranes performance. The M−2 (2 wt.% of MnFe2O4/g-C3N4) membrane revealed the maximum pure water permeability (351.4 LMH), three folds better than the bare membrane. The modified membrane displayed excellent anti-biofouling capabilities, with up to 64 % and 76 % increase in HA and BSA fluxes, respectively and high rejection values (96.5 % HA; 97.2 % BSA). The M−2 membrane demonstrated high flux recovery ratios of 91.1 % for HA and 88.8 % for BSA. The long-term filtration and pH-stability studies suggested exceptional longevity, reusability and efficiency of the membranes, under normal and harsh conditions. Overall, the MnFe2O4/g-C3N4 nanocomposite was regarded as an effective filler for materializing the permeability and anti-biofouling performance of PES-based membranes.