Fabrication of ultra-permeable membranes with antibiofouling capability by incorporating bifunctionalized zeolite
Résumé
Poor water permeance and biofouling significantly limit the application of nanofiltration (NF) membranes in wastewater treatment and seawater desalination. Herein, bifunctionalized FAU-Ag-OH zeolites, featuring abundant hydroxyl groups and silver ions on their surface, were designed and incorporated into polyamide (PA) layer of a thin-film nanocomposite (TFN) membrane, effectively enhancing the antibiofouling properties and water permeance of membrane. The plentiful hydroxyl groups and well-dispersed silver ions on the bifunctionalized FAU-Ag-OH zeolites impart the membrane with more negative surface charge, increased hydrophilicity, and superior antibiofouling property. Additionally, the doped FAU-Ag-OH zeolites can retard the diffusion of piperazine during interfacial polymerization (IP) process and have improved chemical compatibility with polymers, which results in desirable membrane structure. Consequently, the optimal M–0.05 membrane containing FAU-Ag-OH zeolites exhibited a 2.3-fold increase in water permeance (18.8 ± 2.0 L m−2 h−1 bar−1) and enhanced antibiofouling ability (with antibacterial efficiency up to 95.4 % and flux recovery ratio up to 85 %) compared with the TFC membrane. The successful fabrication of such membrane with enhanced antibiofouling properties and improved water permeance is expected to promote the application of NF membranes in water treatment.