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

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.