Temperature dependence cation exchange


I included cation exchange in my simulation, in which I simulate injection of hot (90 degrees C) water into a relatively cold aquifer with the exact same composition.

The temperature increase slightly reduces the pH, but if I exclude proton exchange, I see cation exchange as a result of the temperature increase. However, the reference manual does not mention any temperature effect on cation exchange (either total capacity or selectivity coefficient. Does anyone know if there is a temperature dependence built into the TOUGHREACT code?

Thanks in advance!


1 reply

    • Rasmus_Jakobsen
    • 1 mth ago
    • Reported - view

    Dear Marielle, There is a temperature dependency on the calculation of the activities of the ions in the water,. In the manual it reads "Debye-Huckel parameters bNa+,Cl-, bNaCl, Aγ and Bγ were regressed as a function of temperature and the resulting functions and regression coefficients are currently built into TOUGHREACT" - so it seems you are right that it is in fact built into TOUGHREACT - and perhaps/probably that is the reason you are seeing a temperature effect ?

    Apart from that I am interested in implementing cation exchange in a Toughreact simulation, but haven't been able to find an example - but it seems you have figured out how to set it up ? If possible it would be great to see what an implementation of cation exchange looks like. KR Rasmus (raj@geus.dk)

Content aside

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