Choosing Model for Membrane Filtration

In our course separation processes, we talk about three different models that we call the Osmotic Pressure Model, the Resistance in Series Model and the Concentration Polarisation model. Students often ask us when to use what model. In our compendium we have an overview that gives an approximate range (ranging from micro filtration to reverse osmosis) for each model, but what this video tries to explain is that
* all three models are simplifications
* all three models can be combined if needed

[@nelsoniruonagbe3256]

what model would you advise I use for a flat sheet cellulose acetate membrane that is to adsorb dissolved CO2 in seawater?

[@PLE_LU]

Please do not make duplicate posts on the same channel

[@rubenrai6672]

Is there an example of how you solved iteratively in the end ?

[@PLE_LU]

No, but it's rather straightforward if you know some programming e.g. matlab, Fortran, Python or similar. Rearrange the euqation to form the residuals, e.g. write a function that use guesses of Cm and J and your values of ∆P etc to calculate residuals that should be zero, e.g.
dPi= function of Cm
… etc
res(1)=J-(dP-dPi)/mu/Rm
res(2)=J-k*log((Cm-Cb)/(Cb-Cp)
and use standard routines for searching for zeros
It's very similar to what's done (in matlab) in this video on evaporation (using different equations, but still, the principle is the same):
czcams.com/video/SYxQxwYpxhM/video.html
Doing the iteration by hand is a pain

[@user-bh7ps9jh9l]

I will use comsol to simulate nanofilters, what is your advice?