RES³T - Rossendorf Expert System for Surface and Sorption Thermodynamics


A normalization procedure has been integrated into RES³T, allowing a comparison of the reaction constants for given combinations of SCM subtype and mineral. Following Kulik (2002) and setting the reference site density to 2.31 sites/nm² (Davis and Kent, 1990) the protolysis constants constants are normalized according the following equations, where Γexp is the experimentally determined surface site density:

pK normalize formel

According to Kulik (2006) surface complexation constants are normalized with this equation, where n is the stoichiometrical number of surface binding sites in the reaction equation of the surface complex formation:

logK normalize formel

Note, that this mormalization function does not concern multiple Site Types (e.g. strong and weak hydroxyl groups) on a surface so far!

The LogK conversion to zero ionic strength and the LogK normalisation to a SSD = 2.31 nm−1 are seperate and not cummulative.