Effect of salt combination on separation of monovalent and divalent salts by electrodialysis

The separation of monovalent (Na+, K+) and divalent ions (Ca2+, Mg2+) from binary and ternary mixtures by electrodialysis was compared using various salt combinations (NaCl, NaNO3, KCl, KNO3, K2SO4, Na2SO4, CaCl2, Ca(NO3)2, MgCl2, Mg(NO3)2) at room temperature using a constant flow rate. The efficiencies of each run were evaluated as specific power consumption with the electrical energy consumed only in stack. At 5 V, percent removal of monovalent cations from salt solutions containing monovalent anions (chloride, nitrate) was performed with a higher efficiency than from the salt solutions containing divalent anions (sulfate). When the applied voltage increased to 10 V, the effect of anion charge on percent removal of cations disappeared.