Treatment of complexed copper(II) solutions with electrochemical membrane processes

An electrochemical membrane process was used to treat complexed Cu(II) solutions of citric acid, nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA). An equimolar solution of Cu(II) and complexing agent was focused. The iridium oxide (IrO₂/Ti) and Pt (Pt/Ti) coated on titanium were used as anode and cathode, respectively. The cation exchange membrane Neosepta CM-1 was adopted. Experiments were carried out at different current densities (18.5-139 A/m²), initial catholyte pH (1-9) and Cu(II) concentrations (0.01-0.08 M), and initial anolyte NaNO₃ concentrations (0.001-0.2 M). An economically feasible current efficiency and recovery percentages of metals and complexing agents could be achieved if the concentration of the complexed Cu(II) was sufficiently high.