Temperature dependence cation exchange

Hello,

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!

Marielle