A Pd-anchored poly(vinyl chloride-co-maleic acid monoamide)/poly(vinyl chloride) ultrafiltration membrane for the efficient degradation of 4-nitrophenol

Abstract

An ultrafiltration (UF) membrane was prepared using a blend of poly(vinyl chloride) (PVC) and low molecular weight poly(vinyl chloride-co-maleic acid monoamide) (PVMA), demonstrating a significantly improved filtration flux. For example, the water flux of the membrane fabricated with PVMA/PVC (50/50 wt%/wt%) was boosted to 691.67 L m⁻² h⁻¹vs. 64.66 L m⁻² h⁻¹ for the pure PVC membrane, while the porosity of the UF membranes was 88.6% vs. 74.7%, respectively. Employing immobilized palladium nanoparticles as a catalyst, the Pd-PVMA/PVC membrane offered an efficiency as high as 99.0%, which remained greater than 97.0% over three cycles at a filtration flux of 208.75 L m⁻² h⁻¹ for the degradation of 4-nitrophenol (4-NP). The catalytic reaction exhibited first-order kinetics and the apparent kinetic reaction constant was as high as 2.65 × 10⁻³ s⁻¹ at a relatively low Pd nanoparticle loading. In this study, we developed a simple method to prepare PVC UF membranes with high water flux and efficiency for the removal of 4-NP by coupling the catalytic and separation processes.