Is it possible to set concentration in cell 0 to be changing linearly?

[MichaelZ20]

Hello!
Is it possible to set concentration in cell 0 to be changing linearly following a known law?

[dlparkhurst]

No, I don't think there is an easy way.

You have to break up the TRANSPORT calculation into several calculations.  You would define SOLUTION 0 as a mixture, run TRANSPORT for a time, then repeat.  After the first definition, you don't have to repeat TRANSPORT options that don't change, so the definition of each transport calculation can be relatively simple. IPhreeqc is another possibility to allow a little more flexibility.