Copper transfer modeling through a nanofiltration membrane in the case of ternary aqueous solution

Mixed solutions containing copper salts were separated using a nanofiltrati on membrane. For mixed electrolyte solutions with the same co-ion, the reje ction of copper was shown to depend strongly on the nature of the second co unter-ion. In the presence of H3O+ or at low concentration of Na+, copper i ons are completely rejected, while in the presence of Ca2+, their transfer is slightly improved. The extended Nernst Planck equation was applied to mo delize experimental results using specific calculated transfer parameters. The variations of the concentration and the electrostatic potential were co nsidered to be linear through the membrane. Moreover, the solute concentrat ion near the membrane was assumed to be equal to the feed solution concentr ation. Calculated copper rejections are in good agreement with experimental results.