AuthorWard, Nancy Erica,1960-
Committee ChairBassett, Randy
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractAdsorption of hexavalent chromium on two commonly occurring clay minerals, illite (Fithian, IL) and kaolinite (Mesa Alta, NM), was investigated over the pH range 4.0-8.5. Batch experiments were conducted to determine the kinetics of chromium adsorption and the adsorption edge. Reactions were complete in ten hours. Chromium removal was 100% effective at low pH's and aluminum dissolution minimal. Adsorption results were modeled using MINTEQ and the Triple Layer Model. Experimental data indicated that chromium was bound at the aluminum site on kaolinite, and at both the aluminum and silica sites on illite. Iron coatings were not extensive enough to effect sorption. Discrepancies between simulated and experimental data were explained by high surface loading. Surface complexation constants determined for illite and kaolinite may be added to the thermodynamic databases of geochemical models for predicting concentrations of chromium in the aquatic environment.
Degree ProgramHydrology and Water Resources