Electrospun nanofiber membrane of PEO/Chitosan for the adsorption of nickel, cadmium, lead and copper ions from aqueous solution

Abstract

Poly ethylene oxide (PEO)/Chitosan nanofiber membrane was prepared by the electrospinning technique; afterward, the potential of the prepared nanofiber membrane for adsorption of nickel (Ni), cadmium (Cd), lead (Pb) and copper (Cu) from aqueous solution was investigated. The applied voltage, tip-collector distance and solution flow rate of electrospinning process were 20kV, 13.5cm and 0.5mLh−1 respectively. The prepared nanofibers were characterized by Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM) and Brunauer–Emmert–Teller (BET) analysis. Based on results, the homogeneous electrospun nanofibers with the average diameter and surface area of 98nm and 312.2m2g−1 were obtained respectively. Then, the adsorption experiments were carried out to investigate the effect of different adsorption parameters such as contact time, initial concentration and temperature in a batch system. The sorption selectivity of lead, copper, cadmium and nickel onto the membrane was in order of Pb(II)<Cd(II)<Cu(II)<Ni(II). The kinetic data of metal ions were analyzed by pseudo-first-order and pseudo-second-order kinetic models. Three isotherm models namely Freundlich, Langmuir and Dubinin–Radushkevich were applied to describe the equilibrium data of metal ions. The calculated thermodynamic parameters (ΔG∘, ΔH∘ and ΔS∘) showed that the adsorption of metal ions onto the PEO/Chitosan nanofiber membrane was feasible, spontaneous and endothermic. The reusability of nanofiber membrane for the removal of different metal ions was also determined after five sorption–desorption cycles.