How to Specify Concentration in Flux Boundary Conditions and Injection Wells in MRST

[Calvin Scott]

Dear MRST developers and community,

I hope you are doing well. I am currently working on a problem involving reactive transport in porous media using MRST, and I would sincerely appreciate your guidance.

I have two related questions:

1. Flux boundary condition without wells
   In a reservoir model without wells, I would like to impose a constant flux boundary condition on one side of the domain. The injected fluid is water containing certain concentrations of H+ and CO32−​.
   Could you please advise how to properly define such a boundary condition in MRST, particularly for specifying component concentrations together with the flux?
2. Single injection well with specified rate
   For a case with a single injection well operating at a fixed injection rate, the injected fluid is again water with given concentrations of H+ and CO32−​.
   I would like to ask how to correctly define the injection composition in this case within the MRST framework.

Additionally, if there are any example scripts that demonstrate similar setups, I would be very grateful if you could point me to them.

Thank you very much for your time and help.