Solute transport

I have been playing around with using OpenLB to model solute transport across a porous medium and was planning to use two lattices (one for the flow and the other to track the solute) as in the multicomponent example. Is there a way of including a concentration boundary condition, where the concentration (or flux) of a particular component at a boundary is fixed?

Also, the solute that I will be transporting reacts with the porous medium. This reaction is handled by a separate module that I have written. I will need to change the boundary conditions (as the solute reacts with the porous medium it deposits on the surface) but I do not want to lose the parallelizability of the system. Will changing the boundary conditions during the simulation affect the overall performance?