GEOC 78 |
| Chemical surface complexation models were developed to describe potentiometric titration and ion adsorption data on oxide minerals. These models provide molecular descriptions of adsorption using an equilibrium approach that defines surface species, chemical reactions, mass and charge balances and contain molecular features that can be given thermodynamic significance. Professor Garrison Sposito pioneered the use of surface complexation models to describe charging and ion adsorption reactions on soil surfaces. Applications of the models to phosphate, calcium, magnesium, boron, selenite, molybdenum, and arsenate adsorption by soils will be presented. A general regression model can predict model surface complexation constants from easily measured soil chemical properties such as: surface area, cation exchange capacity, organic carbon, inorganic carbon, aluminum oxide, and iron oxide content. This approach provides a completely independent model evaluation and is able to predict boron, molybdenum, selenite, and arsenate adsorption on numerous diverse soils having a wide range of chemical characteristics. |
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Physical Chemistry of Soil and Aquifer Systems: A Symposium in Honor of Garrison Sposito
1:30 PM-5:10 PM, Monday, 11 September 2006 Moscone Center -- Room 256, Oral
Division of Geochemistry |