Linking a Porous Media Flow to a Transport of Concentrated Species

Hello,

I have created a chamber that has sugar water running through a compartment and carbon cloth modeled by a free and porous media flow physics. I also want to create a transport of a concentrated species to model where the sugar is in the solution as it flows through this chamber. My questions are as follows:

Is it possible to link a transport of concentrated species physics to a porous media flow physics while using incomplete geometries? I don't care where the sugar end up in the carbon cloth, so I have deselected it for the geometries, and have been receiving negative feedback from the software.

How do you handle a physics when certain parts of the geometry have different characteristics? For example, the carbon cloth would have a different diffusion coefficient in comparison to the purely fluid filled chamber, however I cannot find where I can mathematically represent this.

Thanks in advance for any help.

-Payton G