Optimization of the electrocoagulation process for the removal of copper, lead and cadmium in natural waters and simulated wastewater

Chemical, electrochemical and flow variables were optimized to examine the effectiveness of the electrocoagulation process for the removal of copper, lead and cadmium. The electrochemical process, which uses electrodes of commercial laminate steel, was applied to simulated wastewater containing 12 mg dm−3 of copper, 4 mg dm−3 of lead and 4 mg dm−3 of cadmium. The optimum conditions for the process were identified as pH=7, flow rate=6.3 cm3 min−1 and a current density between 31 and 54 A m−2. When the electrode geometric area and time of electrolysis reached critical values, the copper removal reached a maximum value of 80%. A linear relationship was identified between the current density and the mass of generated sludge. In addition, a linear relationship was found between specific energy consumption and current density. The results of this investigation provide important data for the development of an industrial-scale electrolytic reactor.