Simultaneous recovery of EDTA and lead(II) from their chelated solutions using a cation exchange membrane

Factors affecting the efficiency of electrochemical recovery of EDTA and Pb(II) from their chelated solutions were systematically examined using a cation exchange membrane Neosepta CM-1. The catholyte contained an equimolar amount of Pb(II) and EDTA, and the anolyte contained 0.1 M NaNO₃. The iridium oxide coated on titanium (IrO₂/Ti) and stainless steel were used as anode and cathode, respectively. Experiments were carried out at different current densities (46.3–185 A/m²), initial catholyte pH values (1.47–6.02) and Pb(II) concentrations (0.005–0.03 M). An economically feasible current efficiency and recovery percentages of Pb(II) and EDTA could be achieved if the concentration of the chelated Pb(II) was sufficiently high.