Busca avançada
Ano de início
Entree
(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Adsorption kinetic, thermodynamic and desorption studies of phosphate onto hydrous niobium oxide prepared by reverse microemulsion method

Texto completo
Autor(es):
Rodrigues, Liana Alvares [1] ; Caetano Pinto da Silva, Maria Lucia [1]
Número total de Autores: 2
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Escola Engn Lorena, BR-12600000 Lorena, SP - Brazil
Número total de Afiliações: 1
Tipo de documento: Artigo Científico
Fonte: ADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY; v. 16, n. 3, p. 173-181, AUG 2010.
Citações Web of Science: 18
Resumo

A type of Nb(2)O(5)center dot 3H(2)O was synthesized and its phosphate removal potential was investigated in this study. The kinetic study, adsorption isotherm, pH effect, thermodynamic study and desorption were examined in batch experiments. The kinetic process was described by a pseudo-second-order rate model very well. The phosphate adsorption tended to increase with a decrease of pH. The adsorption data fitted well to the Langmuir model with which the maximum P adsorption capacity was estimated to be 18.36 mg-Pg(-1). The peak appearing at 1050 cm(-1) in IR spectra after adsorption was attributed to the bending vibration of adsorbed phosphate. The positive values of both Delta H degrees and Delta S degrees suggest an endothermic reaction and increase in randomness at the solid-liquid interface during the adsorption. Delta G degrees values obtained were negative indicating a spontaneous adsorption process. A phosphate desorbability of approximately 68% was observed with water at pH 12, which indicated a relatively strong bonding between the adsorbed phosphate and the sorptive sites on the surface of the adsorbent. The immobilization of phosphate probably occurs by the mechanisms of ion exchange and physicochemical attraction. Due to its high adsorption capacity, this type of hydrous niobium oxide has the potential for application to control phosphorus pollution. (AU)

Processo FAPESP: 06/05421-0 - Síntese de nanopartículas de óxido de nióbio hidratado via microemulsão inversa
Beneficiário:Liana Alvares Rodrigues
Linha de fomento: Bolsas no Brasil - Mestrado