Synthesis of zeolite a from metakaolin and its application in the adsorption of cationic dyes

The present work reports the synthesis of zeolites from two metakaolins, one derived from the white kaolin and the other derived from the red kaolin, found in a deposit in the city of São Simão (Brazil). The metakaolins were prepared by calcination of the kaolins at 600 ◦C; zeolite A was obtained af...

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Detalles Bibliográficos
Autores: Pereira, Priscila Martins, Ferreira, Breno Freitas, Oliveira, Nathalia Paula, Gil Bravo, Antonio, Korili, Sophia A.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/38813
Acceso en línea:https://hdl.handle.net/2454/38813
Access Level:acceso abierto
Palabra clave:Kaolin
Metakaolin
Zeolite A
Cationic dye adsorption
Descripción
Sumario:The present work reports the synthesis of zeolites from two metakaolins, one derived from the white kaolin and the other derived from the red kaolin, found in a deposit in the city of São Simão (Brazil). The metakaolins were prepared by calcination of the kaolins at 600 ◦C; zeolite A was obtained after alkali treatment of the metakaolins with NaOH. The resulting solids were characterized by powder X-ray diffraction, thermal analysis, scanning electron microscopy, and nitrogen adsorption/desorption at −196 ◦C, which confirmed formation of zeolite A. The zeolites were applied as adsorbents to remove methylene blue, safranine, and malachite green from aqueous solutions. The zeolites displayed high adsorption capacity within short times (between one and five minutes); qt was 0.96 mg/g. The equilibrium study showed that the zeolites had higher adsorption capacity for malachite green (qe = 55.00 mg/g) than for the other two cationic dyes, and that the Langmuir isotherm was the model that best explained the adsorption mechanism.