Application of Electrocoagulation Process in Removal of Zinc and Copper From Aqueous Solutions by Aluminum Electrodes

In this study, the performance of electro-coagulation in combination with aluminum sacrificial anode, in removal of zinc and copper has been investigated. Several parameters, such as pollutant concentration, pH, electrical potential, COD, turbidity and contact time were studied to achieve a higher removal capacity. Variable concentrations (5-50-500 ppm) of zinc and copper solutions were prepared. In order to follow the progress of the treatment, samples of 25mL were taken at 15 min intervals up to 60 min and then filtered with 0.45 diameter to eliminate sludge formed during electrolysis. The varying pH of the initial solution was also studied to measure their effects on the zinc and copper removal efficiency. Results obtained with synthetic wastewater revealed that the most effective removal capacities of studied metals could be achieved at 40 V electrical potential. In addition, the increase of electrical potential, in the range of 20-40 V, enhanced the treatment rate without affecting the charge loading required to reduce metal ion concentrations under the admissible legal levels. The process was successfully applied to the treatment of an electroplating wastewater where an effective reduction of zinc and copper concentration under legal limits was obtained, just after 15-60 min. Moreover, it can be concluded that the electro-coagulation process has the potential to be utilized for the cost-effective removal of heavy metals from water and wastewater.