Algerian natural montmorillonites for arsenic(III) removal in aqueous solution

The adsorption of As(III) from aqueous solutions using naturally occurring and modified Algerian montmorillonites has been investigated as a function of contact time, pH, and temperature. Kinetic studies reveal that uptake of As(III) ions is rapid within the first 3 h, and it slows down thereafter....

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Detalhes bibliográficos
Autores: Zehhaf, A., Benyoucef, A., Quijada Tomás, Cesar, Taleb, S., Morallón, E.
Formato: artículo
Fecha de publicación:2015
País:España
Recursos:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglés
OAI Identifier:oai:riunet.upv.es:10251/53705
Acesso em linha:https://riunet.upv.es/handle/10251/53705
Access Level:acceso abierto
Palavra-chave:Adsorption
Clay
Ion exchange
Arsenic
Montmorillonite
QUIMICA FISICA
Descrição
Resumo:The adsorption of As(III) from aqueous solutions using naturally occurring and modified Algerian montmorillonites has been investigated as a function of contact time, pH, and temperature. Kinetic studies reveal that uptake of As(III) ions is rapid within the first 3 h, and it slows down thereafter. Equilibrium studies show that As(III) shows the highest affinity toward acidic montmorillonite even at very low concentration of arsenic. The kinetics of As(III) adsorption on all montmorillonites used is well described by a pseudo-second-order chemical reaction model, which indicates that the adsorption process of these species is likely to be chemisorption. Adsorption isotherms of As(III) fitted the Langmuir and Freundlich isotherm models well. The adsorption of As(III) is pH-dependent obtaining an optimal adsorption at pH 5. From the thermodynamic parameters, it is concluded that the process is exothermic, spontaneous, and favorable. The results suggest that M-1, M-2, and acidic-M-2 could be used as low-cost and effective filtering materials for removal of arsenic from water.