Smart enzyme-MOF hybrid membranes for emerging pollutant removal with enhanced stability and antifouling performance: Experimental insights and machine learning-driven performance prediction

A bio-functional membrane system was developed by immobilizing Aspergillus oryzae peroxidase and ZIF-8 within a polyvinylidene fluoride (PVDF) matrix, with ABTS acting as a redox mediator to enhance the catalytic oxidation of ibuprofen, an emerging contaminant. The enzyme-activated membrane (P/ZIF-8/ABTS/PVDF) achieved an initial ibuprofen removal efficiency of 80% and maintained catalytic activity over repeated cycles. Superior antifouling performance was demonstrated, with a water flux recovery ratio of 86% and significantly reduced irreversible fouling compared to pristine PVDF and ZIF-8/PVDF membranes. Analysis of Ibuprofen degradation by-products revealed that they were primarily generated through natural enzymatic pathways and were less toxic than ibuprofen. The P@PVDF/ZIF-8/ABTS/H₂O₂ membrane also exhibited outstanding degradation efficiency when tested with both synthetic and real municipal wastewater spiked with several emerging contaminants, including ibuprofen. Removal efficiencies for most contaminants ranged from 93% to 98%. Additionally, machine learning models were applied to predict membrane removal and flux, demonstrating strong performance with maximum R² values of 0.92 and 0.96, respectively. The findings highlight the potential of flexible enzyme-activated membranes as a sustainable strategy for wastewater treatment and provide valuable insights for the development of next-generation membrane-based purification technologies.