Fabrication of eggshell derived hydroxyapatite polymer composite membrane for efficient removal of thorium ions from aqueous solutions

Abstract

A novel eggshell-derived hydroxyapatite polymer composite membrane was fabricated to explore its efficiency in the elimination of Th(IV) metal ions from water bodies. Membrane fabrication was carried out by two stage process in which, at first hydroxyapatite (Hap) was derived from eggshell and the minerals thus obtained were used as filler in Poly vinyl alcohol (PVA) - Poly vinyl pyrrolidone (PVP) based polymer membrane. Structural and morphological studies of PVA-PVP-Hap membrane were carried out by analyzing Fourier transform IR spectra (FTIR), X-Ray diffraction spectra (XRD), Scanning electron microscope-energy dispersive X-ray images (SEM-EDX) etc. Water uptake capacity and ion exchange capacity were determined for membrane characterization. Optimization studies were performed for the elimination of Th(IV) metal from polluted water. Regeneration studies also proved that the membrane can be used upto 4 cycles of operation with less than 5% loss in performance using ethanol as eluent for the desorption of this pollutant from the membrane. © 2020 Elsevier Ltd.