title: Sorption of Cr(VI) onto natural iron and aluminum (oxy)hydroxides: effects of pH, ionic strength and initial concentration.
abstract: The aim of this work is to study the performances of removal of hexavalent chromium from aqueous solution by three different oxy-hydroxides: hematite, goethite and alpha-alumina. Batch experiments were conducted to measure the effects on adsorption of Cr(VI) of different parameters such as pH of the medium, ionic strength, and initial concentration. Results showed that the adsorption of Cr(VI) depends strongly on the pH, but is independent of ionic strength for hematite and goethite. For alpha-alumina, adsorption is strongly dependent on pH values and ionic strength. Equilibrium studies showed that Cr(VI) had a high affinity in an acidic medium, but decreased as solution pH increased. Equilibrium isotherms were measured experimentally. Results were analyzed by the Langmuir and Freundlich equations using linearized correlation coefficient at room temperature. The characteristic parameters for each isotherm have been determined. Langmuir equation was found to fit the equilibrium data for Cr(VI) adsorption.
authors.affiliation: Département de Chimie, Laboratoire de Radiochimie, Sciences Analytiques et Environnement, Université de Nice Sophia Antipolis, 28 Avenue Valrose-Faculté des Sciences, 06108 Nice Cedex 02, France. o.ajouyed@hotmail.com
authors.forename: Omar
authors.initials: O
authors.lastname: Ajouyed
authors.forename: Charlotte
authors.initials: C
authors.lastname: Hurel
authors.forename: Mohammed
authors.initials: M
authors.lastname: Ammari
authors.forename: Laïla
authors.initials: L
authors.lastname: Ben Allal
authors.forename: Nicolas
authors.initials: N
authors.lastname: Marmier
mesh_terms: D000327:Adsorption; D000536:Aluminum Hydroxide / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D009994:Osmolar Concentration
chemical_list: D002857:Chromium; D000536:Aluminum Hydroxide; D007501:Iron