Novel delafossite-AgFeO2 decorated cellulose acetate ultrafiltration membrane for efficient water purification

Abstract In this study, we explored the overall enhancement of cellulose acetate (CA) UF performance (i.e., permeation, antifouling, antibacterial, and dye rejection properties) through incorporation of AgFeO 2 nanoparticles (NPs) in the membrane matrix. The prepared nanocomposite membranes featured an asymmetric, sponge-like structure with random distribution of AgFeO 2 NPs. This developed morphology altered the intrinsic characteristics compared with the neat CA membrane. For instance, the nanocomposite membrane (M5) containing 8 wt% (of AgFeO 2 NPs possessed the lowest contact angle (42.68°), and the highest negative zeta potential of -24.9 mV. This was reflected on the pure water permeability (PWP) and bovine serum albumin (BSA) permeability (4.813 LMH·bar⁻ 1 and 4.37 LMH·bar⁻ 1 , respectively). In experiments for BSA, MB, and CV dye rejection, the same membrane achieved rejection rates of 51.1%, 64.4%, and 93.7%, respectively. In addition, this membrane showed excellent reusability, as indicated by a high flux recovery ratio (FRR) of 94.12% after three cycles and a low total fouling ratio, with a significant portion being reversible fouling and reduced hydraulic resistance. Strong antibacterial performance and filtration efficiency against S. aureus and E. coli is another additional asset of this membrane. In summary, AgFeO 2 NPs served as effective modifier for CA UF membrane, enhancing its permeation, antifouling, antibacterial, and dye removal capabilities without compromising the rejection performance. Graphical Abstract