resumo
In this work, the removal of Cd(2+) ions from aqueous solution using microporous titanosilicate ETS-10 was investigated in order to assess its potential as decontaminating agent in tertiary treatments. Accordingly, batch stirred tank experiments were carried out to study the ion exchange kinetics and equilibrium. Results show that pH affects considerably the ion exchange capability of ETS-10: at pH 4 it is 1.567 x 10(2) eq m(-3), at pH 6 it is 3.629 x 10(3), and no further increment was observed at pH 8. This is an extremely important observation since pH of industrial effluents and other wastewaters rounds 6. Both Langmuir and Langmuir-Freundlich isotherms were fitted to the experimental data measured. The second model performs slightly better as the calculated absolute average deviations show: AAD(L) = 2.94% and AAD(LF) = 2.40%. Concerning the kinetic behavior, the ion exchange was successfully represented by a Nernst-Planck based model (AAD = 11.9%). (C) 2009 Elsevier B.V. All rights reserved.
palavras-chave
HEAVY-METAL IONS; MAXWELL-STEFAN APPROACH; LENGTH-COLUMN METHOD; FIXED-BED COLUMN; MASS-TRANSFER; WASTE-WATER; DIFFUSION-COEFFICIENTS; MERCURY REMOVAL; KINETIC-MODELS; ZEOLITE-A
categoria
Engineering
autores
Camarinha, ED; Lito, PF; Antunes, BM; Otero, M; Lin, Z; Rocha, J; Pereira, E; Duarte, AC; Silva, CM
nossos autores
Carlos Manuel Silva
Professor associado
João Rocha
Prof. Catedrático
Patrícia Ferreira Lito
Bolseiro de pós-Doutoramento
Zhi Lin
Investigador Principalagradecimentos
Patricia F. Lito wishes to thank Ph. D. grant provided by Fundacao para a Ciencia e Tecnologia (Portugal) (SFRH/BD/25580/2005). Authors acknowledge FEDER for financial support.