Two SURFACE in PHREEQCRM problem

[dksliusiyan]

Hi Mr. Parkhurst or anyone who may tried this:

Is it possible to create two SURFACE with two different surface complexation model with -edl option enabled in PHREEQCRM?

I have no problem running the simulations in the desktop version of Phreeqc, both surface complexation model (SCM) has their own SURFACE definition and the index, and the phreeqc will calculate both SCM results such as surface potential, debye length. The two SCM models are sharing the same solution concentrations, ionic strength, etc.

However, after I defined the two models in .pqi input script and trying to initialize PHREEQCRM, I realized that the 'InitialPhreeqc2Module' is only loading one index for each reaction type, it seems like I'm not able to run both SCM reactions at the same time within the same cell? Is there any way around to achieve this if PHREEQCRM does not have this feature?

Thank you so much in advance!

[dlparkhurst]

PHREEQC uses at most one SURFACE definition in a single reaction calculation, so, your PHREEQC calculations could not use two SURFACE definitions at the same time.

However, you can define multiple surfaces within a single SURFACE definition. Just put both definitions in the same SURFACE block.

[dksliusiyan]

Thank you for your prompt help Mr. Parkhurst!
I'll try to put all definitions in the same SURFACE block and see what happened.