Mixing of carbonate waters

T.M.L. Wigley; Niel Plummer

doi:10.1016/0016-7037(76)90041-7

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Mixing of carbonate waters

T.M.L. Wigley·Niel Plummer

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Abstract

When mineral solutions of different compositions are mixed, the molalities and activities of individual ions in the mixture are often non-linear functions of their end-member values. This non-linearity is particularly significant in determining mineral saturation levels. Mixtures of saturated solutions may be either undersaturated or supersaturated depending on the end-member compositions and the physical conditions in which end-members and their mixtures exist. In carbonate solutions important non-linear effects occur due to redistribution of carbonate species. In extreme cases this causes mixture pH to be below both the end-member pH values. A simple but precise computer program (WATMIX) has been developed for calculating mixture composition for closed and open system mixing of arbitrary end-members. A number of mixing examples are considered which allow one to isolate three important processes leading to non-linear behaviour: the algebraic effect, the δP CO 2 effect, and the ionic strength effect.

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T.M.L. Wigley, Niel Plummer. 1976. Mixing of carbonate waters. https://doi.org/10.1016/0016-7037(76)90041-7

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