Complexation of dissolved ions by mineral surfaces is one of the primary controls on the aqueous concentrations of trace micronutrients, toxic heavy metals and radionuclides. In many reactive transport simulations and geochemical box models, these sorption processes are modeled using a simple distribution coefficient

\[\mathit{K}_{\mathit{d}}\ =\ \frac{\mathit{M}_{\mathit{solid}}}{\mathit{M}_{\mathit{solution}}}\]

where Msolid is the mass concentration of component i in the solid and Msolution is the mass concentration of i in the aqueous solution. However, this approach fails to give a correct description of reactive transport (Brady and Bethke 2000). Even in simple batch simulations (no transport), the...

You do not currently have access to this article.