title: Bionanocomposites based on layered silicates and cationic starch as eco-friendly adsorbents for hexavalent chromium removal.
abstract: Functional bionanocomposites based on two layered silicates, the commercial montmorillonite known as Cloisite®Na and a natural bentonite from Algeria, were prepared by intercalation of cationic starch, synthesized with two different degrees of substitution, 0.85 and 0.55. After characterization of the prepared bionanocomposites by XRD and zeta potential measurements, batch studies were conducted to evaluate the adsorption capacity of hexavalent chromium anions from aqueous solution. The adsorption isotherms, adsorption kinetics, and the effect of pH on the process were studied. The removal efficiency was evaluated in the presence of competing anions such as NO3(-), ClO4(-), SO4(2-) and Cl(-). In order to regenerate the adsorbent for its repeated use, the regeneration process was studied in two different extractant solutions, 0.1 M NaCl at pH 10 and 0.28 M Na2CO3 at pH 12.
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, CSIC, C/Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain. eduardo@icmm.csic.es.
authors.forename: Yamina
authors.initials: Y
authors.lastname: Koriche
authors.forename: Margarita
authors.initials: M
authors.lastname: Darder
authors.forename: Pilar
authors.initials: P
authors.lastname: Aranda
authors.forename: Saida
authors.initials: S
authors.lastname: Semsari
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ruiz-Hitzky
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D002857:Chromium / Q000302:isolation & purification*; D053761:Nanocomposites / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods
chemical_list: D002412:Cations; D014874:Water Pollutants, Chemical; D002857:Chromium; D001546:Bentonite; C074702:chromium hexavalent ion; D013213:Starch