3. Mathematical solving and databases

From a mathematical point of view, hydrogeochemical software is a specialized computational tool that solves a (large) system of coupled, highly non-linear equations to calculate the equilibrium state (plus any kinetic controls) of an aqueous system interacting with its essentially inorganic environment. They read and manipulate extensive databases of thermodynamic data. The result is a final report characterizing the system under study, expressed in terms of hydro-geochemical parameters useful to the scientist and engineer. The most sophisticated software includes a user-friendly graphical interface for pre- and post-processing, optimizing the input of data and system specifics, followed by the interpretation of results (see figure 4 ). These programs are written...