High flux polysulfone/nano-zirconia composite microfiltration membranes containing water channels for wastewater treatment

Polysulfone (PSF)/nano-zirconia (nano-ZrO₂) composite microfiltration membranes with hydrophilic water channels were fabricated via non-solvent-induced phase separation (NIPS) and reinforced with a polyphenylene sulfide (PPS) woven substrate for efficient and chemically robust filtration. The composite membrane exhibited a bicontinuous phase structure, where nano-ZrO₂ particles were distributed and organized to form water channels, thereby facilitating water molecule transport, as confirmed by SEM, AFM, and TEM measurements and molecular dynamics simulations. The composite membrane achieved over 98% rejection of 0.2-μm-diameter microspheres and nearly 100% rejection of 0.5-μm-diameter microspheres, respectively, as well as a > 6.4 log reduction value (LRV) against E. coli, while the permeability of the membrane was as high as 11.1 L m⁻² h⁻¹ kPa⁻¹, which was 2.5-times higher than that of commercially available counterparts. The membrane also maintained 97.0% rejection after 720 h in 1 mol/L KOH and 100% rejection after 720 h in 0.1 mol/L HCl, indicating strong potential for industrial wastewater treatment.