Sulfated chitosan/PVA absorbent membrane for removal of copper and nickel ions from aqueous solutions-Fabrication and sorption studies

Novel absorbents for the removal of Cu2+ and Ni2+ ions from aqueous solutions were prepared from solution cast sulfated chitosan/polyvinyl alcohol membranes (SCS/PVA) and their properties were investigated. FTIR, SEM, XRD and TGA analyses were used to determine membrane structure. The effect of environmental parameters on absorption was studied, including pH, contact time, temperature and the initial concentration of Ni2+ and Cu2+ ions. Freundlich and Langmuir absorption isotherms were fitted to experimental data and a pseudo-second order rate equation was employed to model the kinetics of uptake for several copper and nickel ion concentrations. The results indicate that the affinity of an SCS/PVA membrane for Cu2+ ions was higher than that for Ni2+ ions. The study demonstrated that the SCS/PVA system can be utilized as highly efficient sorbents, to extract Ni2+ and Cu2+ from aqueous feed solutions.