A Comparison Between Aluminum and Iron Electrodes on Removal of Phosphate from Aqueous Solutions by Electrocoagulation Process

Abstract

This study presents a comparison between aluminum and iron plate electrodes on phosphate removal from aqueous solutions by electrocoagulation process. The effectiveness of main operational parameters such as initial pH, initial phosphate concentration and current density were examined. In addition, treated solution and sludge characteristics, energy consumption and electrode mass depletion were compared for both electrodes. All experiments were done in an electrocoagulation cell with effective volume of 2 liters. It was found that the aluminum electrode has higher removal efficiency compared to the iron electrode in the same operational conditions. Phosphate removal efficiencies of 100% and 84.7% were observed for aluminum and iron electrode in a special case with optimum initial pH, maximum current density and maximum initial phosphate concentration equal to 3, 250A/m2, 400mg/l PO4 3- , respectively. Furthermore, less treated solution turbidity, higher secondary pollution (remained Al) and less electrode mass depletion was observed for the aluminum electrode.