An electrocoagulation column (ECC) for groundwater purification

A novel electrocoagulation column (ECC) has been evaluated for the treatment of brackish groundwater to reduce the concentrations of Cr(VI) and other ions to be within drinking water limits. The ECC was fabricated from Plexiglas and had a rod anode and helical cathode; both electrodes were made from iron. The effect of influent flow rate, applied current density, initial concentration, pH and air mixing were studied at a temperature of 25 °C. The results showed that Cr(VI) removal rate was inversely proportional to the inlet flow rate and directly proportional to applied current density, reaching 100% chromium removal for initial chromium concentration of 5 mg/L at inlet flow rate of 30 mL/min with lowest energy consumption of 0.75 kWh/m3 and dissolved iron of 0.185 mg/L with an electrical cost of 0.03 US $/m3 of treated groundwater. The EC column could also reduce other contaminants and metals ions such as Mg, Zn and Sr. Overall, the study affirmed that electrocoagulation is a reliable and environmentally compatible technique for the purification of groundwater.