Rejection coefficient, definition

The salt content on the downstream side of the membrane is determined by the relative salt and water fluxes through the membrane. A combination of results from the solution-diffusion model outlined earlier with the definition of the rejection coefficient gives... 

The rejection coefficient when there is no concentration polarization (M = 1) is called the inherent rejection coefficient R°. By manipulating Eqs. fl7-21cl and (17-24a). we can find a relationship between retention R at one set of conditions and R at another set of conditions for well-mixed systems. Often the base case (Case A) condition is an e q)eriment with no concentration polarization (M ase a 1 f ase A = R°). Substitute Eq. fl7-21cl into the definition of R, Eq. ri7-24al. for both Cases A and B. Solve for 1 - R in both equations and then divide the Case B equation by the Case A equation. The ratio is... 

Rejection characteristics of ultrafiltration membrane were analysed and method to determine the transport coefficients is developed. Also the rejection characteristics of membrane with gel layer were analysed and it is found that the transport coefficients of gel layer have a definite relation with the gel layer resistance, and perhaps with gel layer thickness. 

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