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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

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

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Author(s):
Rodrigues, Liana Alvares [1] ; Caetano Pinto da Silva, Maria Lucia [1]
Total Authors: 2
Affiliation:
[1] Univ Sao Paulo, Escola Engn Lorena, BR-12600000 Lorena, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: ADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY; v. 16, n. 3, p. 173-181, AUG 2010.
Web of Science Citations: 18
Abstract

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)

FAPESP's process: 06/05421-0 - Synthesis of hydrous niobium oxide nanoparticles by reverse microemulsion
Grantee:Liana Alvares Rodrigues
Support Opportunities: Scholarships in Brazil - Master