Removal of lead (II) ions from water using chitosan/polyester crosslinked spheres derived from chitosan and glycerol-based polyester

The present study reports development of eco-friendly polymeric spheres derived from crosslinking of chitosan (CTS) with different polyesters. The polyesters were synthesized via polycondensation reaction of maleic anhydride with 1,4-butadiol and glycerol, potential renewable chemical, as hydroxyl sources. The structures of the prepared polyesters and the crosslinking of CTS/polyester spheres were confirmed by Fourier transform infrared spectroscopy. Crosslinking of CTS with polyesters enhances the structure and the stability of CTS-based spheres in aqueous media, but decreases its hydrophilicity. The obtained spheres were employed for adsorption of lead ions (Pb2+) from aqueous solutions. The batch adsorption experiments were evaluated to investigate the effect of glycerol-loading on adsorption of Pb2+ ions. The results indicated that the amount of adsorbed (Pb2+) ions was increased with time and operating temperature. The maximum 83.5% removal efficiency of Pb2+ ions from aqueous solution was achieved at pH= 5.0. The experimental data was described with the Langmuir and Freundlich isotherm models, whereas the Freundlich model showed the best fit of the data.