Comparative Performance of CNF/rGO/WO ₃ Composite Membrane for Photo‐Filtration of Water Containing Cationic and Anionic Dyes

Abstract

ABSTRACT The increasing discharge of wastewater from various textile industries poses significant environmental pollution and human health challenges worldwide. This work presents the comparative performance in removing cationic and anionic organic pollutants from water using CNF‐embaded rGO/WO 3 ‐3 composite membrane. Membranes were fabricated by a solution casting method, and their photodegradation and photo‐filtration performance under visible light was assessed using methyl orange (MO) and methylene blue (MB) as model pollutants. The composite membrane demonstrated higher degradation efficiency for MB with a removal of 99.5% and a flux of 138.5 L.m −2 .h −1 .bar −1 , compared to 95% and 106.34 L.m −2 .h −1 .bar −1 for MO. This superior performance is attributed to stronger surface affinity between MB and the negatively charged membrane. Photocatalytic degradation was completed within 40 min for MB and 160 min for MO. The membrane also demonstrated excellent reusability and durability. After five cycles of repeated use, it retained 72% degradation efficiency for MB (flux: 124.16 L.m −2 .h −1 .bar −1 ) and 80% for MO (flux: 41.79 L.m −2 .h −1 .bar −1 ), showing minimal decline in performance. Overall, our CNF/rGO/WO 3 ‐3 composite membrane offers a simple, green, and efficient approach for the removal of cationic and anionic organic pollutants from water, with a strong potential for real wastewater treatment and other environmental remediation applications.