title: Adsorption-regeneration by heterogeneous Fenton process using modified carbon and clay materials for removal of indigo blue.
abstract: Indigo blue dye is mainly used in dyeing of denim clothes and its presence in water bodies could have adverse effects on the aquatic system; for this reason, the objective of this study was to promote the removal of indigo blue dye from aqueous solutions by iron and copper electrochemically modified clay and activated carbon and the saturated materials were regenerated by a Fenton-like process. Montmorillonite clay was modified at pH 2 and 7; activated carbon at pH 2 and pH of the system. The elemental X-ray dispersive spectroscopy analysis showed that the optimum pH for modification of montmorillonite with iron and copper was 7 and for activated carbon was 2. The dye used in this work was characterized by infrared. Unmodified and modified clay samples showed the highest removal efficiencies of the dye (90-100%) in the pH interval from 2 to 10 whereas the removal efficiencies decrease as pH increases for samples modified at pH 2. Unmodified clay and copper-modified activated carbon at pH 2 were the most efficient activated materials for the removal of the dye. The adsorption kinetics data of all materials were best adjusted to the pseudo-second-order model, indicating a chemisorption mechanism and the adsorption isotherms data showed that the materials have a heterogeneous surface. The iron-modified clay could be regenerated by a photo-Fenton-like process through four adsorption-regeneration cycles, with 90% removal efficiency.
authors.affiliation: a Departamento de Química , Instituto Nacional de Investigaciones Nucleares (ININ) , Ocoyoacac , Estado de México , México.|b Facultad de Ingeniería , Centro Interamericano de Recursos del Agua (CIRA), Universidad Autónoma del Estado de México, Unidad San Cayetano , Toluca , Estado de México , México.
authors.forename: Perla Tatiana
authors.initials: PT
authors.lastname: Almazán-Sánchez
authors.affiliation: a Departamento de Química , Instituto Nacional de Investigaciones Nucleares (ININ) , Ocoyoacac , Estado de México , México.
authors.forename: Marcos J
authors.initials: MJ
authors.lastname: Solache-Ríos
authors.affiliation: b Facultad de Ingeniería , Centro Interamericano de Recursos del Agua (CIRA), Universidad Autónoma del Estado de México, Unidad San Cayetano , Toluca , Estado de México , México.
authors.forename: Ivonne
authors.initials: I
authors.lastname: Linares-Hernández
authors.affiliation: b Facultad de Ingeniería , Centro Interamericano de Recursos del Agua (CIRA), Universidad Autónoma del Estado de México, Unidad San Cayetano , Toluca , Estado de México , México.
authors.forename: Verónica
authors.initials: V
authors.lastname: Martínez-Miranda
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates; D001546:Bentonite / Q000737:chemistry; D002244:Carbon; D002606:Charcoal / Q000737:chemistry; D000077215:Clay; D006861:Hydrogen Peroxide; D007203:Indigo Carmine / Q000032:analysis / Q000737:chemistry*; D007501:Iron; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D000538:Aluminum Silicates; C045076:Fenton's reagent; D014874:Water Pollutants, Chemical; D001546:Bentonite; D002606:Charcoal; D002244:Carbon; D006861:Hydrogen Peroxide; D007203:Indigo Carmine; D007501:Iron; D000077215:Clay
keywords: Indigo blue; activated carbon; adsorption; heterogeneous Fenton; montmorillonite