title: Nickel adsorption by magnetic alginate microcapsules containing an extractant.
abstract: The adsorption of heavy metals on biomaterials was investigated by studying the potential of alginate microcapsules containing an extractant (Cyanex 272) and magnetic nanoparticles (gamma-Fe2O3) for the adsorption of nickel (II) from aqueous solutions. A two-stage kinetics behaviour was observed with 70% of the maximum sorption capacity achieved within 8 h. An increase in nickel removal with increase in pH occurred, the maximum uptake capacity being around 0.42 mmol g-1 at pH 8. The adsorption isotherm (pH about 5.3) was obtained in a wide range of initial nickel concentrations; the experimental data were fitted by a Langmuir model and the qmax value was estimated to be 0.52 mmol g-1. Moreover, including magnetic particles in the microcapsules allowed easy isolation of the beads from the aqueous solutions after the sorption process. Magnetic microcapsules are then suitable for the development of efficient biosorbents for removal and recovery of heavy metals from wastewater using magnetic separation.
authors.affiliation: Laboratoire Liquides Ioniques et Interfaces chargées (LI2C) case 63, Université Pierre et Marie Curie-Paris 6, CNRS UMR 7612, 4 place Jussieu 75252 PARIS France.
authors.forename: Audrey-Flore
authors.initials: AF
authors.lastname: Ngomsik
authors.forename: Agnès
authors.initials: A
authors.lastname: Bee
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Siaugue
authors.forename: Valérie
authors.initials: V
authors.lastname: Cabuil
authors.forename: Gérard
authors.initials: G
authors.lastname: Cote
mesh_terms: D000327:Adsorption; D000464:Alginates / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis; D007474:Ion Exchange; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry*; D009532:Nickel / Q000493:pharmacokinetics*; D009943:Organophosphorus Compounds / Q000737:chemistry; D014877:Water Pollution, Chemical; D018508:Water Purification / Q000379:methods*
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D007220:Industrial Waste; D009943:Organophosphorus Compounds; C044965:trioctyl phosphine oxide; D009532:Nickel; D020723:Glucuronic Acid