Preparation of CS/PVA/POP Nanofiber Membranes and Adsorption Behavior for Hg(II) Ions

Abstract

Chitosan (CS) and polyvinyl alcohol (PVA) nanofiber membranes were synthesized via electrospinning and used as supporting materials for powdered porous organic polymer (POP). These membranes were then crosslinked with glutaraldehyde, resulting in nanofiber membranes (CS/PVA/POP) as an efficient adsorbent for Hg(II) ions. Characterization using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy showed that the membranes effectively removed up to 92.9% of mercury ions at optimal conditions, with an adsorption capacity of 116.1 mg/g. The adsorption data fit well with the Langmuir isotherm and pseudo-second-order kinetic models. The efficient uptake of mercury ions was attributed to chemisorption involving active groups (C=S, -NH2, -OH), facilitated by mechanisms such as chelation, complexation, or electron exchange. The CS/PVA/POP nanofiber membranes demonstrated significant advantages in adsorption capacity, economic viability, and recyclability, providing an effective solution to mercury pollution in water.