Abstract: | The reflection coefficient method for describing volume and solute fluxes through membranes is generalized to take into account the nonideality of the solutions bathing the membrane and/or multicomponent systems. The reflection coefficient of the impermeable species in these systems is less than unity by a coefficient γ. The reflection coefficient obtained solely from the volume flow equation, σv, will always be less than the reflection coefficient obtained from the solute flow equation, σ8v. These two coefficients are related by σ8v = σv + γ. |