Novel polyethersulfone mixed matrix adsorptive nanofiltration membrane fabricated from embedding zinc oxide coated by polyaniline

Novel mixed matrix polymeric membranes were prepared by incorporating self-produced zinc oxide coated by polyaniline (ZnO-PANI) nanoparticles into polyethersulfone (PES) matrix using phase inversion method. Nanoparticles were synthesized, characterized and incorporated in PES matrix with loadings from 0.05 to 0.6 wt %. ZnO-PANI demonstrated effectiveness as a low-cost adsorbent, especially at a loading of 0.2 wt%. ZnO-PANI was used for adsorbing total phenolic compounds (TPC) from olive leaf extract (OLE) at different initial adsorbate concentration (49.92-466.59 mg/L) and pH (2-6). ZnO-PANI proved to be an effective and low-cost adsorbent to remove TPC from OLE. Langmuir model described the adsorption of TPC better than Freundlich model. Effect of incorporated nanoparticles on membranes morphology and hydrophilic properties studied using contact angle measurement, water content, membrane pore size and porosity, SEM, FTIR and pure water flux. Prepared membranes showed a significant increment in porosity, pore size and hydrophilicity by addition of ZnO-PANI in the casting solution up to 0.2 wt%. This led to a considerable improvement in permeability, which decreased with higher additive concentration. During OLE filtration tests (10-30 bar) using bare PES and 0.2 wt % ZnO-PANI/PES membranes, 0.2 wt% ZnO-PANI/PES showed the highest permeate flux and good TPC rejection (83-87%). Bare PES exhibited impressive TPC value rejections (85-92%) and better fouling resistance. Using 0.2 wt% ZnO-PANI achieved a balanced permeate flux and TPC rejection. The research emphasizes the practical applicability of these membranes in various industries due to their enhanced efficacy in removing phenolic compounds from natural extracts, offering a balanced approach between permeate flux and TPC rejection.