Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 18, 2006
Publication Date: September 10, 2006
Citation: Goldberg, S.R. 2006. Application of surface complexation models to soil systems. American Chemical Society National Meeting, San Francisco, CA Sep 10-14, 2006. Paper No. GEOC 78 Technical Abstract: 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.