Membrane processes permeate withdrawal

Reverse osmosis" is the popular name of a general process for the separation of substances in solution. The process consists in letting the solution flow under pressure through an appropriate porous membrane (called the "reverse osmosis membrane") and withdrawing the membrane permeated product generally at atmospheric pressure and surrounding temperature. 

The depletion by membrane permeation of C02 in blood introduces cause for concern. This affects the evaluation of PBot and also shifts the position of the 02 dissociation curve. The correction for this effect requires the continuous evaluation of the acid—base status of the blood sample. Using an initial reference point obtained from a separate pH measurement and Pco2> the variation in pH during the withdrawal process can be determined with incremental measurements of PBc02 ( ) ... 

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