[okamal]

Let's say we have a double cell (2 compartments) and a porous membrane between them and both compartments are under stirring.

In the first compartment (feed S) we put copper with C concentration and we put water in the second compartment (Receiving R).

When the diffusion occures and ends the system reaches the equilibrium and both sides have the same concentration.

If we take samples (known volumes) from the Stripping phase at several times (t) we can draw the profile C = f(t) and if we draw Ln(Ct/C0) = f(t) where Co is the initial concentration of copper in the feed phase S and Ct the one at different times we get a strait line that has a slope. What model should I use to get the diffusion coefficient of copper in m2/s in this case.

Thanks