Experimental values of xp and xout can be used to determine α′ and M. First, an experiment is done in a very well mixed cell under conditions where there is no concentration polarization. Solving Eq. (17-19) for the selectivity, we obtain
where under the conditions of the experiment M = 1 and all other terms on the right-hand side are known. This method is illustrated in Example 17-4.
Example 17-4. Determination of RO membrane properties
We test a new composite membrane. Both experiments were done with a retentate pressure of 15.0 atm and a permeate pressure of 1.0 atm. The ...