Synergistic Enhancement of PVDF-TiO₂/WO₃ Membranes via Polydopamine Modification for Natural Rubber Wastewater Treatment

Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro, Semarang, 50275, Indonesia

^* Corresponding author: tdkusworo@che.undip.ac.id

Abstract

The rapid growth of the natural rubber industry in Indonesia has intensified the challenges of wastewater treatment, necessitating innovative solutions to address pollutants like COD, phenol, and NH₃-N. This study investigates the synergistic enhancement of PVDF-TiO²/WO₃ membranes through polydopamine (PDA) modification for efficient natural rubber wastewater treatment. The membranes were fabricated via dry-wet phase inversion and dip-coating methods, with TiO₂/WO₃ nanoparticles incorporated to improve photocatalytic activity under visible light. PDA coating further enhanced hydrophilicity, antifouling properties, and mechanical strength. Characterization via SEM, FTIR, and mechanical testing revealed that the PDA-modified membrane (M-05) exhibited superior porosity (73.88%), pore size (14.76 nm), and flexibility (134.3% elongation) compared to unmodified membranes. Under visible-light irradiation, M-05 demonstrated stable flux (120 L/m²·h) and high rejection rates for NH₃-N (95.11%), COD (90%), and phenol (85%), attributed to the synergistic effects of TiO₂/WO₃ photocatalysis and PDA’s hydrophilic surface. The membrane system reduced fouling and extended operational longevity, aligning with SDG 6 (Clean Water) and SDG 12 (Responsible Production). This study highlights the potential of membrane photocatalytic for sustainable industrial wastewater treatment, offering a scalable solution for pollutant degradation and water reuse in rubber processing.