Integration of Hydrophilic COOH and ZnO/Fe<sub>3</sub>O<sub>4</sub> into PA-TFN Membranes for Enhanced Pb(II) Removal and Antifouling

Abstract

Carboxylic (COOH) functionalized zinc oxide and iron oxide (COOH-ZnO@Fe 3 O 4 ) composites were used in this study to modify polyamide thin film composite membranes. The resultant membranes exhibit improved water permeability, greater antifouling qualities, robust stability for repeated usage, and enhanced rejection of Pb 2+ metal ions compared to the unmodified membrane. In contrast to the unmodified PA-TFC membrane, which had an 82.36±0.01% Pb 2+ removal efficiency, a contact angle of 82.36°±0.01, a flux recovery ratio of 33.6%, and a water permeation flux of 3.3 L·m⁻²·h⁻¹, the membrane containing 1.5% of the COOH-ZnOFe 3 O 4 composite, for instance, achieved a 97.6±0.35% Pb 2+ removal efficiency, a lower contact angle of 58°±1.86, a higher flux recovery ratio of 86.3%, and a higher water permeation flux of 10.23 L·m⁻²·h⁻¹. Additionally, by combining ZnO, Fe 3 O 4 nanoparticles, and COOH groups from sodium polyacrylate as additives to the PA layer, the modified membranes demonstrated improved performance relative to the other membranes.