@ Anvar, What do you mean ...
Published by Dallas Weaver, Ph.D., P.E.
@ Anvar,
What do you mean by "Quasi" alkalinity? Alkalinity, as determined by titration, is a real measurement that should apply to SWRO. However, the Ca and Mg are near zero with higher removals than Li, Na, K. The alkalinity, CO2 partial pressure, and pH are all related so if you measure 2 you can calculate the third. For drinking water you need to add Ca and Mg back in.
The CO2 should go through the membrane and have the same partial pressure on both sides (maybe kinetic issues to this equilibrium)