Geochemical modeling is used in a variety of fields, including environmental protection and remediation,[1] the petroleum industry, and economic geology.
[2] Models can be constructed, for example, to understand the composition of natural waters; the mobility and breakdown of contaminants in flowing groundwater or surface water; the ion speciation of plant nutrients in soil and of regulated metals in stored solid wastes; the formation and dissolution of rocks and minerals in geologic formations in response to injection of industrial wastes, steam, or carbon dioxide; the dissolution of carbon dioxide in seawater and its effect on ocean acidification; and the generation of acidic waters and leaching of metals from mine wastes.
Their calculation, computed by hand, is now known as an equilibrium model, which predicts species distributions, mineral saturation states, and gas fugacities from measurements of bulk solution composition.
[6] Geochemists are now able to construct on their laptops complex reaction path or reactive transport models which previously would have required a supercomputer.
[8] Creating geochemical models of such systems begins by choosing the basis, the set of aqueous species, minerals, and gases which are used to write chemical reactions and express composition.
[2] In finding the equilibrium state, a geochemical modeler solves for the distribution of mass of all species, minerals, and gases which can be formed from the basis.
By configuring the manner in which mass and heat transfer are specified (i.e., open or closed systems), models can be used to represent a variety of geochemical processes.
[11] Differences in the thermodynamic data (i.e. equilibrium constants, parameters for temperature correction, activity equations and coefficients) can result in large uncertainties.