abstract
The present study reports the assembly and operation of a fixed bed using the microporous titanosilicate ETS-4 as sorbent. Sorption-desorption cycles were carried out on an ETS-4 fixed-bed, for the removal of Hg2+ from contaminated water. The sorption capacity of the ETS-4 in the column in two consecutive cycles remained constant (33.6 and 33.3 mg g(-1), respectively); however due to certain difficulties encountered during ETS-4 packaging and operation mode, breakthrough curves corresponding to these cycles showed dissimilar patterns. A concentration gradient of an EDTA-Na-2 solution (0.05-0.25 M) was efficient for bed regeneration, achieving an elution efficiency of 98%. The elution curve had an asymmetrical shape, the concentration peak was attained in less than 5 min, and the concentration factor was 920. Four kinetic models, namely Thomas, Bohart-Adams, Clark and Yoon-Nelson, were applied to predict the breakthrough curves and to estimate the characteristic parameters of the column, which are the basis for the process design at a real scale. The operation of an ETS-4 fixed-bed for the treatment of Hg2+. contaminated waters was shown to be feasible, despite some limitations mainly related with its loose packing. (C) 2011 Elsevier Inc. All rights reserved.
keywords
AQUEOUS-SOLUTIONS; ION-EXCHANGE; ACTIVATED CARBON; MERCURY REMOVAL; INORGANIC MERCURY; WASTE-WATER; ADSORPTION; COLUMN; SORPTION; EQUILIBRIUM
subject category
Chemistry; Science & Technology - Other Topics; Materials Science
authors
Lopes, CB; Pereira, E; Lin, Z; Pato, P; Otero, M; Silva, CM; Rocha, J; Duarte, AC
our authors
Carlos Manuel Silva
Associate Professor
Cláudia Batista Lopes
Assistant Researcher
João Rocha
Full Professor
Zhi Lin
Principal Researcheracknowledgements
We thank Fundacao para a Ciencia e a Tecnologia-FCT, FEDER and Fundo Social Europeu for financial support. This research was supported by FCT Post-Doctoral Grants funding C.B. Lopes (SFRH/BPD/45156/2008) and P. Pato (SFRH/BPD/35068/2007).