Experimental closed-system ΔT acid-base titrations between 20 and 75℃ were used to constrain a temperature-dependent basic Stern model (BSM) of the surface properties of goethite. Modeling was performed using the new Gibbs-energy-minimization model GEMS. With the latter, S_(298)~0 and Cp_(298)~0 values could be fitted for the goethite surface acidity and background electrolyte outer-sphere complexes. Based on these BSM parameters, an adsorption model could be established for the pH-dependent selenate sorption continuum involving both an inner- and outer-sphere surface complex, where only the latter is affected by ionic strength and temperature.
展开▼
