Heavy metal adsorption isotherms on tailor-made brittle micas in water treatment applications

The removal of heavy metals from water is a critical challenge because of their high toxicity, persistence, and bioaccumulation in biological systems. Adsorption is widely recognised as a cost-effective and efficient treatment method, and equilibrium isotherms are essential for evaluating the perfor...

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Detalles Bibliográficos
Autores: Osuna, Francisco J., Pavón, Esperanza, Alba, María D.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2026
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/420832
Acceso en línea:http://hdl.handle.net/10261/420832
Access Level:acceso abierto
Palabra clave:Adsorption isotherm
Heavy metals
Swelling brittle mica
Thiol
Water purification
Descripción
Sumario:The removal of heavy metals from water is a critical challenge because of their high toxicity, persistence, and bioaccumulation in biological systems. Adsorption is widely recognised as a cost-effective and efficient treatment method, and equilibrium isotherms are essential for evaluating the performance of adsorbents. Here, the equilibrium isotherms of Pb2+, Cd2+ and Hg2+ adsorbed onto synthetic brittle micas, specifically as-made (Na-M2) and thiol-functionalised (MEA-M2) one, have been systematically analysed. Na-M2 exhibited a remarkably high adsorption capacity, up to ten times higher than conventional adsorbents (1402, 1111 and 1717 mmol/kg for Pb2+, Cd2+ and Hg2+). Despite its lower overall capacity, MEA-M2 demonstrated superior Hg2+ uptake (955 mmol/kg) compared to other thiol-functionalised materials. However, the high layer charge of MEA-M2 limited the access to thiol groups. Finally, the adsorption mechanism and the adsorption energy depended on both the nature of the heavy metal and the grafting, providing information on the structure-performance relationships for water treatment applications.