Abstract
The reverse permeation of Mn2+ across a cellulose membrane in CaCl2-MnCl2-H2O and NaCl-MnCl2-H2O systems was studied. The reverse permeation of an ion is described by equation (1) which consists of two terms, i.e., the electric potential gradient and concentration gradient terms. When the flux of an ion due to the electric potential gradient is large and opposite in direction to that due to the concentration gradient, reverse permeation can occur, i.e., concentration of the solute into the compartment with higher concentration. In both systems, Mn2+ (even at low concentrations) was concentrated in one compartment of the permeation cell by reverse permeation. The concentration of Mn2+ was more effective in the presence of Ca2+ than Na+. The experimental values were in good agreement with Guntelberg's approximations.
