Zeolite-PAN/PVDF composite nanofiber membranes for highly efficient and selective removal of cationic dyes from wastewater

This study presents a novel composite nanofiber membrane combining polyacrylonitrile/polyvinylidene fluoride (PAN/PVDF) electrospun nanofibers with locally sourced zeolite from Sumatera, Indonesia, for pollutant dye filtration. The Ze-PAN/PVDF composite nanofiber membrane has 100% methylene blue dye rejection even after five filtration cycles with a permeation flux of 185 L m−2 h−1 bar−1. The membrane is highly selective, with 100% dye filtration efficiency for cationic dyes (i.e., methylene blue and crystal violet) vs. 78% and 1% for anionic dyes (i.e., Congo red and methyl orange, respectively). For the cationic dyes, the dye filtration mechanism is mainly governed by electrostatic attraction, while the size exclusion mechanism becomes more dominant for the anionic dyes. Overall, these results demonstrate the potential use of Ze-PAN/PVDF composite nanofiber membrane in wastewater treatment applications.