ELECTROEXTRACTION OF Cd(II) IONS FROM DILUTED SOLUTIONS BY A HYBRID PROCESS COMBINING ELECTRODIALYSIS AND ION-EXCHANGE

Abstract

The aim of this work is to highlight the coupling efficiency of electrodialysis and ion-exchange processes for treating water containing heavy metal ions at low concentrations. This hybrid technique called electropermutation (EP) or also continuous electroregeneration. The effects of various physico-chemical parameters on the efficiency of the coupled process such as pH, flow rate of feed solution circulation, density of the applied current and initial concentration of Cd(II) in the solution have been studied. The results obtained show that the removal and transfer of Cd(II) ions decreases with the increase of the flow rate of feed solution and with pH increasing. Furthermore, the increase of the current density enhances the elimination and therefore the transfer of this ion until a density value of 10 mA.cm−2. The EP on resin remains effective until a 224.8 mg.L−1 of Cd(II) ions in the feed solution. Overall, under the optimal operating conditions determined, the hybrid technique of EP removes about 98% of Cd(II) from a dilute solution