Electrochemical recovery of copper complexed by DTPA and C12‐DTPA from aqueous solution using a membrane cell

Abstract

AbstractBACKGROUNDThe electrochemical recovery of copper from diethylenetriaminepentaacetic acid (DTPA) and C12–DTPA (a surface‐active derivative of DTPA) complex solutions was investigated in a membrane flow cell. Electrolysis time, solution flow rate, applied current density, and solution pH were evaluated.RESULTSThe chelating surfactant C12‐DTPA can promote the kinetics of copper electrodeposition more than DTPA depending on the experimental conditions. At a current density of 30 A m–2, a solution flow rate of 0.6 L min–1, and pH 10 after 180 min treatment, the copper recovery and current efficiency were 50% and 43.3%, respectively, in the Cu(II)‐DTPA system and about 65% and 53.6%, respectively, in the Cu(II)‐C12‐DTPA system. The differences in the amount of recovery could be explained in terms of differences in the diffusion of copper complexes with DTPA and C12‐DTPA to the cathode, as well as their solution behavior and pH‐dependent conditional stability constants (log10 K'CuDTPA3‐).CONCLUSIONElectrochemical methods could be effectively combined with foam flotation for the chelating surfactant C12‐DTPA, to recover copper and C12‐DTPA. This makes the overall treatment more sustainable, and can be helpful in complying with the increasingly stringent environmental regulations. © 2017 Society of Chemical Industry