Thermodynamic, kinetic, and extrathermodynamic considerations in the development of equilibrium models for aquatic systems

Thermodynamic and kinetic criteria are examined for the general application of equilibrium models to dynamic natural waters. The hypolimnion of a dimictic lake is used as a specific example. The majority of chemical reactions given consideration in equilibrium models are shown to be kinetically rapid in comparison to the chemical residence times in hypolimnetic waters. Extrathermodynamic relationships are explored as a method for extrapolating kinetic and thermodynamic constants from a limited set of experimental data.