1. Modelling of metal cation adsorption on outer oxide film surfaces Jarmo Lehikoinen ANTIOXI Advisory Board Meeting VTT Materials and Building, 6 February, 2007

2. VTT TECHNICAL RESEARCH CENTRE OF FINLAND 2 Introduction In the adsorption studies, we adopt the surface complexation approach to elucidate the effects that solution conditions (e.g. pH, metal loading) have on adsorption. This approach provides a thermodynamically consistent framework for modelling the distribution of solutes between aqueous solution and oxide surfaces and supplies a quantifiable basis for assessing the identity of those surface species that may act as precursors in further surface-controlled processes. Mechanistic surface complexation modelling has been found an invaluable tool to explain and predict the uptake of contaminants on (hydr)oxides in various conditions. WP2

3. VTT TECHNICAL RESEARCH CENTRE OF FINLAND 3 Modelling

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12. VTT TECHNICAL RESEARCH CENTRE OF FINLAND 12 Modelling software FITEQL v. 4.0 modified at VTT for high-temperature systems Modelling procedure Optimization of surface hydrolysis constants (K a1, K a2 ) from titration data (constrained by pH PZNPC ) Optimization of metal adsorption stability constant(s) (K Me ) from batch adsorption data Prediction of metal adsorption on oxide surface in various conditions