Removal of arsenate from aqueous solution by adsorption onto titanium dioxide nanoparticles.
J Environ Sci Health A Tox Hazard Subst Environ Eng
; 41(8): 1519-28, 2006.
Article
em En
| MEDLINE
| ID: mdl-16835108
ABSTRACT
Titanium dioxide (TiO2) was investigated for the removal of pentavalent arsenate from aqueous solution. Kinetic results revealed that arsenate adsorption was almost instantaneous. The extent of arsenate adsorption decreased with increasing pH owing to the decrease of positively charged binding sites on the TiO2 surface. Adsorption isotherms measured at pH 3 and 7 generally followed the Langmuir model. The maximum uptake capacity ranged from 8 mg g-1 at pH 3 to 2.7 mg g-1 at pH 7. Addition of phosphate resulted in a significant reduction in arsenate adsorption, indicating that phosphate-a molecular analogue of arsenate-competes with arsenate for the same surface binding sites. By contrast, bicarbonate had little effect on arsenate adsorption, whereas sulfate exhibited a moderate suppression effect. A considerable reduction in arsenate adsorption was also observed in the presence of relatively high concentrations of background electrolytes (>50 mmol L-1).
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Arseniatos
/
Titânio
/
Poluentes Químicos da Água
/
Purificação da Água
/
Nanoestruturas
Idioma:
En
Revista:
J Environ Sci Health A Tox Hazard Subst Environ Eng
Assunto da revista:
TOXICOLOGIA
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
França