n this study, nanocomposite polyethersulfone (PES) membranes were engineered to reduce biofouling during wastewater treatment. Green bio-graphene (bG) was synthesized via liquid-phase exfoliation of graphite in the presence of chitosan, enhancing its antimicrobial properties. Three antimicrobial agents—bG, α-amylase, and lysozyme—were incorporated into the PES casting solution, and the process was optimized using the phase inversion method to maximize antimicrobial efficacy.

The biocatalytic performance of the optimized membranes was then evaluated. Enzyme reusability tests showed that α-amylase retained approximately 42% of its activity after eight cycles, while lysozyme activity significantly declined. Storage stability tests revealed that the membranes maintained over 60% of their catalytic activity after three weeks and exhibited strong antibacterial activity for up to two weeks.
The biocatalytic nanocomposite membranes exhibited higher anti-biofouling and antimicrobial performance than the neat PES membrane, ensuring stable performance in challenging wastewater environments.