UV-grafted green ZnO/bentonite nanocomposites on PES membranes for enhanced pharmaceutical wastewater treatment and antibacterial activity

Dadari, S ORCID: 0000-0002-6643-064X, Shirvani, B, Fadaei, Z, Ghaemi, N, Rajabi, H ORCID: 0000-0001-9078-7393 and Bridgeman, J ORCID: 0000-0001-8348-5004 (2026) UV-grafted green ZnO/bentonite nanocomposites on PES membranes for enhanced pharmaceutical wastewater treatment and antibacterial activity Chemical Engineering Science, 321. p. 122984. ISSN 0009-2509, 1873-4405

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Abstract

Pharmaceutical residues in wastewater pose a significant global threat due to their persistence and their role in contributing to antimicrobial resistance. This study presents a novel, sustainable nanofiltration membrane designed for advanced treatment of pharmaceutical wastewater. We utilized an eco-friendly UV-grafting technique to immobilize green-synthesized zinc oxide nanoparticles, anchored on acid-activated bentonite (ZnO-NPs/AAB), onto the surface of a polyethersulfone (PES) membrane. This approach is the first to combine these specific green components and fabrication methods. The resulting multifunctional membranes demonstrated significantly improved hydrophilicity, antifouling properties, and filtration performance. Characterisation by FTIR and EDAX confirmed successful surface modification. The optimized membrane, M2, UV-grafted with 0.06 wt% ZnO-NPs/AAB achieved outstanding removal efficiencies for amoxicillin trihydrate and cephalexin monohydrate (>99 %) and high degradation of organic pollutants from real pharmaceutical wastewater, with COD removal exceeding 92 % under visible light. Moreover, the membrane displayed potent antibacterial activity (>96 % inhibition of E. coli and S. aureus), highlighting strong resistance to biofouling. Enhanced performance results from the synergy of photocatalysis, adsorption, size exclusion, and electrostatic interactions. This work presents a scalable and environmentally responsible approach for fabricating high-performance membranes that simultaneously address both chemical and microbial contaminants in wastewater.

Item Type:	Article
Uncontrolled Keywords:	ZnO/bentonite, Nano-photocatalyst, Nanofiltration, Co-existing pollutants, Pharmaceutical wastewater, Antibacterial performance
Divisions:	Faculty of Science & Engineering Faculty of Science & Engineering > School of Engineering Faculty of Science & Engineering > School of Engineering > Civil and Environmental Engineering
Depositing User:	Symplectic Admin
Date Deposited:	03 Dec 2025 14:52
Last Modified:	28 Feb 2026 11:04
DOI:	10.1016/j.ces.2025.122984
Open Access URL:	https://doi.org/10.1016/j.ces.2025.122984
Related Websites:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3195818
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