Kinetics of naphthalene adsorption on an activated carbon: Comparison between aqueous and organic media

The purpose of this work was to explore the kinetics of naphthalene adsorption on an activated carbon from aqueous and organic solutions. Kinetic curves were fitted to different theoretical models, and the results have been discussed in terms of the nature and properties of the solvents, the affinit...

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Detalhes bibliográficos
Autores: Cabal Álvarez, Belén, Ovín Ania, María Concepción, Parra Soto, José Bernardo, Pis Martínez, José Juan
Tipo de documento: artigo
Estado:Versión aceptada para publicación
Data de publicação:2009
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/99352
Acesso em linha:http://hdl.handle.net/10261/99352
Access Level:Acceso aberto
Palavra-chave:Organic solvents
Hydrophobicity
Polarity
Adsorption rate
Polycyclic aromatic hydrocarbons
Descrição
Resumo:The purpose of this work was to explore the kinetics of naphthalene adsorption on an activated carbon from aqueous and organic solutions. Kinetic curves were fitted to different theoretical models, and the results have been discussed in terms of the nature and properties of the solvents, the affinity of naphthalene to the solutions, and the accessibility to the porosity of the activated carbon. Data was fitted to the pseudo-second order kinetic model with good correlation coefficients for all the solution media. The faster adsorption rate was obtained for the most hydrophobic solvent (heptane). The overall adsorption rate of naphthalene seems to be controlled simultaneously by external (boundary layer) followed by intraparticle diffusion in the porosity of the activated carbon when water, ethanol and cyclohexane are used as solvents. In the case of heptane, only two stages were observed (pore diffusion and equilibrium) suggesting that the limiting stage is the intraparticle diffusion. The low value of the boundary thickness supports this observation.