Permeability of zinc ions across ion-exchange membrane of ion-exchange electrodialyzer

To evaluate the permeability of heavy-metal ions that exist as cation and anion species in seawater, we proposed a model equation that expresses the permeation rates of monovalent and divalent anions across an anion-exchange membrane using the permeation rates of Br− and SO42−. The permeability of zinc across a cation- and an anion-exchange membrane was evaluated using the cation- and anion-model equations. We analyzed the permeation rates of zinc species (image, image, image, image). We found that image and image decreased with an increase in the concentration of chloride ions in the feed solution, indicating that EZn(C) decreases with an increase in the concentration of chloride ions. Moreover, image and image increase with the concentration of chloride ions in the feed solution, indicating that EZn(A) increases with the concentration of chloride ions.