Decoration of polyethersulfone membranes with zinc oxide nanoparticles for efficient treatment of food dyes

Abstract

Unmonitored food dyes (FDs) spoilage to water bodies is deteriorating the ecosystem in many regions of the planet, meanwhile, water streams tainted with FDs can significantly impact human health. Consequently, the fabrication of new materials is crucial to the eradication of FDs from aqueous solutions in a selective manner. A current study conducted a methodical investigation for optimizing the design fabricating of a novel nanocomposite membrane comprised of various zinc oxide nanoparticles (ZnO NPs) (0.05, 0.1, 0.3, 0.5, and 1 wt%) and polyethersulfone (PES) (20, 21, 22, and 23 wt%) content. Besides, determining their impact on the nano-filtration (NF) membranes performance for the FDs elimination, tartrazine AR (TZ-AR) and fast green FCF (FG-FCF). Comprehensive characterization was implemented to probe the characteristics of fabricated NF membranes. De-colorization from the water via PES and PES/ZnO membranes harnessed distinct three proposed mechanisms: wettability, electrostatic, and size exclusion. According to the results, there has been a discernible improvement in the overall performance of the ZnO-containing membranes. The rejection characteristics of FDs improved by up to 92.69 % for TZ-AR and 97.5 % for FG-FCF when harnessing ZnO content to 1 wt% in the PES membrane. However, water permeation peaked at 0.3 wt% NPs, and then began to diminish at 0.5 and 1 wt% NPs. Meanwhile, rejection surged to 96.06 % TZ-AR and 99.15 % FG-FCF when PES content was 23 wt%. Moreover, a flux recovery ratio has significantly enhanced while fouling behavior manifested a diminished compared to pure PES membranes. These results implied that optimizing the fabricated PES/ZnO nanocomposite membranes could be a viable way to impart desirable membrane traits for targeted applications with a manipulated permeation-separation trade-off.