Mineral surface area in KINETIC and SURFACE

[janethalina]

Good morning

I have a doubt about mineral surface area.

For fitting quantity of dissolution of calcite from experimental column with Phreeqc, It is necessary to consider surface area as fitting parameter (A), but If I consider Surface complexation model (SURFACE) in the simulation, I also need surface area of the mineral. In this case It is possible to consider the same fitting parameter (A) in both case or It is possible, in KINETIC use fitting parameter (A) and in SURFACE use a constant surface area for example  BET surface area or other value.

Thank you

Sincerely

Janeth

[dlparkhurst]

You can use whatever parameters you want. In CD-MUSIC, the surface sites are related to different axes of the crystal, in which case the surface area for SURFACE might be different than for dissolution/precipitation.

Logistically, you can either specify a fixed surface area for SURFACE, or you can relate surface area to the amount of a KINETICS reaction or EQUILIBRIUM_PHASE minera. In either case, the surface area is specified to be proportional to the amount of the reactant.