title: Cysteine-Functionalized Chitosan Magnetic Nano-Based Particles for the Recovery of Light and Heavy Rare Earth Metals: Uptake Kinetics and Sorption Isotherms.
abstract: Cysteine-functionalized chitosan magnetic nano-based particles were synthesized for the sorption of light and heavy rare earth (RE) metal ions (La(III), Nd(III) and Yb(III)). The structural, surface, and magnetic properties of nano-sized sorbent were investigated by elemental analysis, FTIR, XRD, TEM and VSM (vibrating sample magnetometry). Experimental data show that the pseudo second-order rate equation fits the kinetic profiles well, while sorption isotherms are described by the Langmuir model. Thermodynamic constants (ΔG°, ΔH°) demonstrate the spontaneous and endothermic nature of sorption. Yb(III) (heavy RE) was selectively sorbed while light RE metal ions La(III) and Nd(III) were concentrated/enriched in the solution. Cationic species RE(III) in aqueous solution can be adsorbed by the combination of chelating and anion-exchange mechanisms. The sorbent can be efficiently regenerated using acidified thiourea.
authors.affiliation: Ecole des mines d'Alès, Centre des Matériaux des Mines d'Alès, 6 avenue de Clavières, F-30319 Alès cedex, France. galhoum_nma@yahoo.com.|Nuclear Materials Authority, P.O. Box 530, El-Maadi, Cairo, Egypt. galhoum_nma@yahoo.com.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Galhoum
authors.affiliation: Nuclear Materials Authority, P.O. Box 530, El-Maadi, Cairo, Egypt. mahfouznma@yahoo.com.
authors.forename: Mohammad G
authors.initials: MG
authors.lastname: Mafhouz
authors.affiliation: Chemistry Department, Faculty of Science, Ain Shams University, P.O. Box 11566 Ain Shams, Egypt. sayedth@sci.asu.edu.eg.
authors.forename: Sayed T
authors.initials: ST
authors.lastname: Abdel-Rehem
authors.affiliation: Nuclear Materials Authority, P.O. Box 530, El-Maadi, Cairo, Egypt. g_nabawia@hotmail.com.
authors.forename: Nabawia A
authors.initials: NA
authors.lastname: Gomaa
authors.affiliation: Chemistry Department, Faculty of Science, Menoufia University, P.O. Box 32511 Shebin El-Kom, Egypt. asemali2010@yahoo.com.
authors.forename: Asem A
authors.initials: AA
authors.lastname: Atia
authors.affiliation: Nuclear Materials Authority, P.O. Box 530, El-Maadi, Cairo, Egypt. thierry.vincent@mines-ales.fr.
authors.forename: Thierry
authors.initials: T
authors.lastname: Vincent
authors.affiliation: Nuclear Materials Authority, P.O. Box 530, El-Maadi, Cairo, Egypt. eric.guibal@mines-ales.fr.
authors.forename: Eric
authors.initials: E
authors.lastname: Guibal
keywords: cysteine-grafting; magnetic chitosan nanocomposites; rare earth metals; sorption isotherms; thermodynamics; uptake kinetics