Polysaccharide-based adsorbents prepared in ionic liquid with high performance for removing Pb(II) from aqueous systems

Késsily B Rufato; Vitor C Almeida; Matt J Kipper; Adley F Rubira; Alessandro F Martins; Edvani C Muniz

doi:10.1016/j.carbpol.2019.03.095

Polysaccharide-based adsorbents prepared in ionic liquid with high performance for removing Pb(II) from aqueous systems

Carbohydr Polym. 2019 Jul 1:215:272-279. doi: 10.1016/j.carbpol.2019.03.095. Epub 2019 Mar 28.

Authors

Késsily B Rufato¹, Vitor C Almeida², Matt J Kipper³, Adley F Rubira², Alessandro F Martins⁴, Edvani C Muniz²

Affiliations

¹ Department of Chemical, State University of Maringá (UEM), 5790 Colombo Av., 87020-900 Maringá, PR, Brazil; Laboratory of Materials, Macromolecules and Composites, Federal University of Technology (UTFPR), 86812-460 Apucarana, PR, Brazil.
² Department of Chemical, State University of Maringá (UEM), 5790 Colombo Av., 87020-900 Maringá, PR, Brazil.
³ Department of Chemical and Biological Engineering, Colorado State University, 1370, Campus Delivery, Fort Collins, CO, USA.
⁴ Laboratory of Materials, Macromolecules and Composites, Federal University of Technology (UTFPR), 86812-460 Apucarana, PR, Brazil; Department of Chemical and Biological Engineering, Colorado State University, 1370, Campus Delivery, Fort Collins, CO, USA. Electronic address: afmartins@utfpr.edu.br.

PMID: 30981354
DOI: 10.1016/j.carbpol.2019.03.095

Abstract

Alginate/chitosan (ALG/CHT) and alginate/N,N-dimethyl chitosan (ALG/DMC) polyelectrolyte complex (PEC)-based adsorbents with high capacities for removing Pb(II) from aqueous systems are produced in [1-hydrogen-3-methylimidazolium hydrogen sulfate ionic liquid ([Hmim][HSO₄^-]). The [Hmim][HSO₄^-] is recovered, characterized by ¹H NMR and reused to yield novel polysaccharide-based adsorbents. As-obtained PEC materials are characterized through infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and Zeta potential measurements. Kinetic and equilibrium adsorption studies reveal that the pseudo-second-order Kinetic, as well as the Redlich-Peterson isotherm, provide the best fits for the experimental data, respectively. CHT/ALG and DMC/ALG adsorbents promoted maximum adsorption capacities (q_m) of 529.4 mg g^-1 and 560.2 mg g^-1, respectively. After adsorption, the materials are characterized by infrared spectroscopy and X-ray photoelectron spectroscopy, confirming that the chemisorption prevails upon Pb(II) removal. Also, PECs produced in the recovered [Hmim][HSO₄^-] have good capacities for removing Pb(II) ions from aqueous systems as well. This study showed that the [Hmim][HSO₄^-] is an alternative solvent to prepare novel and eco-friendly PEC-based adsorbents.

Keywords: Adsorption; Alginate; Chitosan; Chitosan derivative; Ionic liquid; Lead.