title: Adsorption of anionic and cationic dyes on activated carbon from aqueous solutions: equilibrium and kinetics.
abstract: Activated carbon was utilized as adsorbent to remove anionic dye, Orange II (OII), and cationic dye, Methylene blue (MB), from aqueous solutions by adsorption. Batch experiments were conducted to study the effects of temperature (30-65 degrees C), initial concentration of adsorbate (300-500 mg L(-1)) and pH (3.0-9.0) on dyes adsorption. Equilibrium adsorption isotherms and kinetics were investigated. The equilibrium experimental data were analyzed by the Langmuir, Freundlich, Toth and Redlich-Peterson models. The kinetic data obtained with different carbon mass were analyzed using a pseudo-first order, pseudo-second order, intraparticle diffusion, Bangham and Chien-Clayton equations. The best results were achieved with the Langmuir isotherm equilibrium model and with the pseudo-second order kinetic model. The activated carbon was found to be very effective as adsorbent for MB and OII from aqueous solutions.
authors.affiliation: Grupo de Catálisis y Procesos de Separación, Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain. arodri@quim.ucm.es
authors.forename: Araceli
authors.initials: A
authors.lastname: Rodríguez
authors.forename: Juan
authors.initials: J
authors.lastname: García
authors.forename: Gabriel
authors.initials: G
authors.lastname: Ovejero
authors.forename: María
authors.initials: M
authors.lastname: Mestanza
mesh_terms: D000327:Adsorption; D000838:Anions; D002412:Cations; D002606:Charcoal / Q000737:chemistry*; D004396:Coloring Agents / Q000302:isolation & purification*; D007700:Kinetics; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods
chemical_list: D000838:Anions; D002412:Cations; D004396:Coloring Agents; D012996:Solutions; D014874:Water Pollutants, Chemical; D002606:Charcoal