Electrolytic recovery of dilute copper from a mixed industrial effluent of high strength COD.

In this study, the electrochemical treatment has been investigated in the real acidic effluent of copper-phthalocyanine dye manufacturing plant. Galvanostatic batch electrolyses have been carried out in an undivided cell using stainless steel as cathode, dimensionally stable anode (DSA) and graphite as anodes at different current densities and temperatures. The influence of these variables on current efficiency, cell voltage, energy consumption and deposit quality was reported. Under optimized conditions, the maximum copper recovery of 98% and COD removal efficiency of 87.3% with the energy consumption of about 11.23 kWh/kg of Cu and 6.08 kWh/kg of COD, respectively at 30 degrees C were achieved in the acidic raw effluent using 2D parallel-plate cathode. While in 3D stainless steel turning cathode reactor, 99.5% of copper can efficiently be recovered from dilute solution with an acceptable current efficiency of about 56.8% with minimum energy consumption of 2.37 kWh/kg of Cu. The experimental results suggested that the efficiency of copper removal is hindered by the presence of organic species in the mixed industrial effluent.