Application of ozone to enhance the defluoridation property of activated alumina: a novel approach

Drinking water containing high fluoride concentrations may lead to serious health problems. Thus, aiming at water defluoridation through adsorption, several adsorbent materials have been studied worldwide. Due to its low cost and selectivity for fluoride ions, activated alumina (AA) is one of the mo...

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Autores:
de Paula, Nátalie
Maraschin, Manoel
Mello Souza, Darliana
Dotto, Guilherme Luiz
Luiz Jahn, Sérgio
Simoes dos Reis, Glaydson
Gonçalves, Janaína O.
Lima, Eder C.
Naushad, Mu.
Carissimi, Elvis
Tipo de recurso:
Article of investigation
Fecha de publicación:
2023
Institución:
Corporación Universidad de la Costa
Repositorio:
REDICUC - Repositorio CUC
Idioma:
eng
OAI Identifier:
oai:repositorio.cuc.edu.co:11323/13327
Acceso en línea:
https://hdl.handle.net/11323/13327
https://repositorio.cuc.edu.co/
Palabra clave:
Activated alumina
Ozone
Defluoridation
Adsorption
Response surface methodology
Rights
embargoedAccess
License
Atribución-NoComercial-SinDerivadas 4.0 Internacional (CC BY-NC-ND 4.0)
Description
Summary:Drinking water containing high fluoride concentrations may lead to serious health problems. Thus, aiming at water defluoridation through adsorption, several adsorbent materials have been studied worldwide. Due to its low cost and selectivity for fluoride ions, activated alumina (AA) is one of the most applied materials. At the same time, AA has low adsorption capacity, the pH of the aqueous solution must be less than 6.0 for fluoride adsorption, and it requires a long contact time to reach adsorption equilibrium. This study investigated the use of ozone to enhance the defluoridation property of AA. For this purpose, AA was treated under various ozonation conditions. Subsequently, the ozone-treated AA (OAA) samples were applied to adsorb fluoride from an aqueous solution. The influence of some ozonation parameters (AA concentration, pH, and contact time) was evaluated by carrying out adsorption experiments under fixed conditions. As a result, by full-factorial central composite rotational design (CCRD) and response surface methodology (RSM), it was found that the effect of initial pH during the ozonation is negligible on improving the defluoridation property of AA. At the same time, the decrease of AA concentration in the ozonation system significantly enhances the defluoridation property of AA. For example, the ozonation of 10 g L−1 of AA at a pH of 7.0 increased the fluoride removal efficiency of this material from 77.4% to 98.3%. Finally, the analysis of the ozonation time (0–120 min) showed that 90 min are sufficient to promote a significant rise in the fluoride removal efficiency of AA (from 78.3% to 97.4%). AA was characterized by FTIR, SEM, EDX NMR, and N2 physisorption methods to elucidate factors responsible for the increased fluoride removal efficiency when the material is ozonized.