title: Adsorption of nickel and copper onto natural iron oxide-coated sand from aqueous solutions: study in single and binary systems.
abstract: Natural iron oxide-coated sand (NCS), extracted from the iron ore located in North-West of Tunisia, was employed to investigate its capacity to remove copper and nickel from aqueous solutions. The aim of this work was to characterize the considered sorbent (NCS) and to assess the possibility of removing nickel and copper from aqueous solutions by this sorbent. The effects of agitation time, pH, initial metal ion concentration and temperature on the removal of these metals were studied. In order to study the sorption isotherm, two equilibrium models, the Freundlich and Langmuir isotherms, were analyzed. The effect of solution pH on the adsorption onto NCS was studied in the pH range from 2 to 7 and 2 to 9 for copper and nickel respectively. The adsorption was endothermic and the computation of the parameters, DeltaH degrees, DeltaS degrees and DeltaG degrees, indicated that the interactions were thermodynamically favourable. Experiments with Cu and Ni adsorption measured together showed that Cu severely interfered with Ni adsorption to the NCS and vice versa under the conditions of the two coexisted ions adsorption.
authors.affiliation: Laboratoire Eau Energie et Environnement, département de génie géologique, Ecole Nationale d'Ingénieurs de Sfax, BP W 3038 Sfax, Tunisia. nesrine.boujelben@tunet.tn
authors.forename: N
authors.initials: N
authors.lastname: Boujelben
authors.forename: J
authors.initials: J
authors.lastname: Bouzid
authors.forename: Z
authors.initials: Z
authors.lastname: Elouear
mesh_terms: D000327:Adsorption; D003300:Copper / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D009532:Nickel / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D012996:Solutions; D013696:Temperature; D013816:Thermodynamics; D013997:Time Factors
chemical_list: D005290:Ferric Compounds; D012996:Solutions; C000499:ferric oxide; D012822:Silicon Dioxide; D003300:Copper; D009532:Nickel