English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/40940
Share/Impact:
Statistics
logo share SHARE   Add this article to your Mendeley library MendeleyBASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Title

Modeling adsorption-desorption processes of Cd on montmorillonite

AuthorsUndabeytia López, Tomás ; Nir, Shlomo ; Rytwo, Giora; Morillo González, Esmeralda ; Maqueda Porras, Celia
KeywordsCadmium
Cation adsorption model
Hysteresis
Montmorillonite
Issue DateAug-1998
PublisherClay Minerals Society
CitationClays and Clay Minerals 46 (4): 423-428 (1998)
AbstractAdsorption-desorption of Cd to Ca montmorillonite (SAz-1) was studied at concentrations ranging from 44.5 to 266.8 IzM. An adsorption model was employed in the analysis of the data. The procedure consists of solving the electrostatic Gouy-Chapman equations and calculating adsorbed amounts of the cations as the sum of the cations residing in the double-layer region, and the cations chemically bound to the surface, in a closed system. The model also accounts explicitly for cation complexation in solution. The model yields good predictions for the adsorbed amounts of Cd, Ca and Mg, by employing binding coefficients from previous studies for the divalent cations and for Na, K and CdCI +. The model calculations also yield good predictions for the apparent hysteresis observed in the adsorbed amounts of Cd after each of 3 cycles of desorption. The apparent hysteresis is explained by the reduction in the total concentrations of Ca and Mg in desorption cycles, and the corresponding increase in the magnitude of the surface potential. Our estimates indicate that adsorption of Cd is mostly to planar, rather than edge sites of the clay mineral.
Description6 pages, 1 figure, 5 tables.
Publisher version (URL)http://www.clays.org/journal/archive/volume%2046/46-4-423.pdf
URIhttp://hdl.handle.net/10261/40940
ISSN0009-8604
Appears in Collections:(IRNAS) Artículos
Files in This Item:
File Description SizeFormat 
Modeling adsorption-desorption processes.pdf496,88 kBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.