Development of a bio-based sorbent media for the removal of nickel ions from aqueous solutions

•A low cost bio-based sorbent media was synthesized using chitosan.•The media was used for the removal of nickel ions from aqueous solutions.•Adsorption kinetics follow a pseudo-second order model.•Langmuir isotherm best fitted adsorption data.•Adsorption of nickel on nanofibers is spontaneous with an endothermic nature.

The objective of this study is to develop a low cost bio-based sorbent for the removal of nickel ions from aqueous solutions. Chitosan/Polyethylene oxide (Cs/PEO) nanofibers were prepared by electrospinning technique and characterized. Batch adsorption experiments were then carried out to investigate the effect of contact time and Cs/PEO mass ratio on adsorption efficiency of nickel ions. Results indicate that a maximum nickel adsorption (qm) of 227.27 mg/g was achieved at 75 °C. Pseudo-first order, pseudo-second order, and intraparticle diffusion kinetic models were used to fit kinetic adsorption data. Batch adsorption equilibrium tests were also carried out at different temperatures. Langmuir, Freundlich, Redlich-Peterson and Dubinin-Radushkevich models were fitted to experimental data. It was found that the pseudo-second order and the Langmuir models provided a high degree of correlation (R2 > 0.99) with experimental data. Adsorption was then assumed to be a spontaneous endothermic chemical process.