If the partition coefficients in your model are defined as being independent of the concentration of the species (at a given temperature), the concentrations then vary linearly with mass in the Cell (assuming no solubility constraints). This relationship is referred to as a linear isotherm.
In many systems, however, species partition between media (e.g., water and sediment) according to a non-linear isotherm, in which the degree of partitioning varies with concentration. Non-linear isotherms can be readily represented in GoldSim by defining the partition coefficients as functions of the concentrations.
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