title: Adsorption rate of phenol from aqueous solution onto organobentonite: surface diffusion and kinetic models.
abstract: The concentration decay curves for the adsorption of phenol on organobentonite were obtained in an agitated tank batch adsorber. The experimental adsorption rate data were interpreted with diffusional models as well as first-order, second-order and Langmuir kinetic models. The surface diffusion model adjusted the data quite well, revealing that the overall rate of adsorption was controlled by surface diffusion. Furthermore, the surface diffusion coefficient increased raising the mass of phenol adsorbed at equilibrium and was independent of the particle diameter in the range 0.042-0.0126 cm. It was demonstrated that the overall rate of adsorption was essentially not affected by the external mass transfer. The second-order and the Langmuir kinetic models fitted the experimental data quite well; however, the kinetic constants of both models varied without any physical meaning while increasing the particle size and the mass of phenol adsorbed at equilibrium.
authors.affiliation: Centro de Investigacion y Estudios de Posgrado, Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, Av., Dr. M. Nava No. 6, San Luis Potosi SLP 78210, Mexico.
authors.forename: Raul
authors.initials: R
authors.lastname: Ocampo-Perez
authors.forename: Roberto
authors.initials: R
authors.lastname: Leyva-Ramos
authors.forename: Jovita
authors.initials: J
authors.lastname: Mendoza-Barron
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Guerrero-Coronado
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D004058:Diffusion; D007700:Kinetics; D008956:Models, Chemical; D010636:Phenols / Q000737:chemistry*; D012996:Solutions; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D010636:Phenols; D012996:Solutions; D014867:Water; D001546:Bentonite