Precise measurement of membrane constants of cellulose acetate membranes by direct osmosis tests

A method for the determination of membrane constants by direct osmosis tests was studied using cellulose acetate membranes. A countercurrent type osmosis cell was designed and made for this study, and a method for precise measurements of permeated water and solutes through the membrane was established. Based on the membrane constants derived from direct osmosis tests, membrane performances of cellulose acetate membranes under pressure of 40 atm were predicted. The predicted values were in good agreement with the observed values in reverse osmosis experiments and it was confirmed that membrane performances under pressure could be predicted by the direct osmosis with considerably good accuracy.