Combined oil demulsification and copper removal from copper plating plant effluents by electrocoagulation in a new cell design

•Simultaneous oil and Cu2+ removal by electrocoagulation was studied.•Helical tube anode placed between two vertical cylindrical screen cathodes was employed.•The effect of various controlling variables on the cell performance was considered.•The cell was assessed in terms of the electrical energy consumption in kW.h/kg removed.•Merits of the suggested cell such as the dual function of the anode was highlighted. In an attempt to reduce the capital and operating costs of electroplating plant effluent treatment, simultaneous oil and copper ion removal by electrocoagulation from copper plating plant effluents were studied in a new cell design, the cell anode was Al helical tube placed between two vertical cylindrical Al screen cathodes. Variable studied were current density, pH, temperatures, initial pollutant concentration, NaCl supporting electrolyte concentration, and the effect of gas sparging. Under optimum conditions, 85% of the oil was removed in one hour while the % Cu2+ removal was 98% in only 15 min. Electrical energy consumption for oil removal ranged from 4.3 × 10−3 to 5.2 kW.h/kg, while that of copper removal ranged from 5.4 × 10−3 to 7.5 kW.h/kg depending on the operating conditions. The merits of the suggested cell such as compactness and the use of the internal surface of helical coil anode as a built-in cooler to prevent the increase in solution temperature which adversely affects the efficiency of large scale electrocoagulation processes was highlighted.