Study of the interaction between europium (III) and Bacillus subtilis: fixation sites, biosorption modeling and reversibility.
J Colloid Interface Sci
; 262(2): 351-61, 2003 Jun 15.
Article
em En
| MEDLINE
| ID: mdl-16256615
ABSTRACT
In order to elucidate the underlying mechanisms involved in the biosorption of metal ions, potentiometric titrations, complexation studies, and time-resolved laser-induced fluorescence spectroscopy (TRLFS) measurements were used to characterize the interaction between Eu(III) and Bacillus subtilis. The reversibility of the interaction between Eu(III) and Bacillus subtilis was studied by a cation-exchange technique using the Chelex resin. For complexation studies in the presence of 0.15 mol/l of NaCl, the metal ion, the biomass, concentrations and the pH were varied. The adsorption data were quantified by a surface complexation model without electrostatic term. The data on the Eu(III)/B.subtilis system at pH 5 were satisfactorily described by one site at which Eu(III) was bound through one carboxylic function of the bacteria. With increasing pH, another site should be considered, involving a phosphate-bound environment. This was partially confirmed by time-resolved laser-induced fluorescence spectroscopy. In addition to this, it was evidenced that the site availability was dependent on the nature of the cation, i.e., a proton or Eu(III). Finally, it was shown that, at pH 5, the Eu(III)/Bacillus subtilis equilibrium was reversible.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bacillus subtilis
/
Európio
Idioma:
En
Ano de publicação:
2003
Tipo de documento:
Article