EFECTO DE LA PRESENCIA DE LIGANTES ORGÁNICOS Y DEL pH EN LA ADSORCIÓN DE Cd Y Pb EN BENTONITA
The adsorption interaction between a bentonite (2:1, Namontmorillonitic clay) suspension and the metals Cd and Pb was studied by the static method at two pHvalues, 5.5 and 6.5. Ionic strength was controlled using a buffer solution of CH 3 COONH 4 NaNO 3 0.01M. Adsorption isotherms were plotted for b...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2011 |
| País: | México |
| Institución: | UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO |
| Repositorio: | Revista Internacional de Contaminación Ambiental |
| Idioma: | español |
| OAI Identifier: | oai:ojs.pkp.sfu.ca:article/25294 |
| Acceso en línea: | https://www.revistascca.unam.mx/rica/index.php/rica/article/view/25294 |
| Access Level: | acceso abierto |
| Palabra clave: | bentonite adsorption heavy metals speciation complexing bentonita adsorción metales pesados especiación complejación |
| Sumario: | The adsorption interaction between a bentonite (2:1, Namontmorillonitic clay) suspension and the metals Cd and Pb was studied by the static method at two pHvalues, 5.5 and 6.5. Ionic strength was controlled using a buffer solution of CH 3 COONH 4 NaNO 3 0.01M. Adsorption isotherms were plotted for both metal ions with and without the presence of organic ligands: etilendiamintetracetic acid (EDTA), glycine (Gly), iminodiacetic acid (IDA) and citric acid (Cit), at concentrations of 0.001 M. Results were analyzed by the theoretical Langmuir, Freundlich and Henry adsorption equations. The simulation of these models of adsoption applied differently for each metal, with and without ligands, for both pHvalues, indicating different relative metal affinities of the bentonite for the metal. In general, ligands abated the adsorption of both metals at both pHvalues, relative to the nonligand metalbentonite system. Adsorption of metals on bentonite varied inversely with the stability constant of metal complexes, suggesting some competence between bentonite and ligands for the ion metal. This study permitted both, to establish the affinity of bentonite for Cd 2+ and Pb 2+ at two pHvalues, and to observe the effect of some metal organic species in solution. |
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