Electrocoagulation for nickel, chromium, and iron removal from mine water using aluminum electrodes

High global demand for nickel metal has contributed significantly to the growth of the nickel mining industry in Indonesia. This growth has a positive multiplier effect on the economy, with the potential to affect aquatic life and humans owing to the high levels of chromium, nickel, and iron in mine water. Therefore, this study aims to develop an electrocoagulation (EC) reactor to remove nickel, chromium, and iron from mine water. This study used a continuous reactor and aluminum electrodes with variations in current density (3.378, 6.757, and 10.135 mA/cm²) and inflow (0.3, 0.5, and 1 L/min). The results showed that the operating scenario with a current strength of 6 A and an inflow of 0.3 L/min had a removal efficiency of 86.89 % nickel, 99.51 % chromium, and 80.61 % iron with a charge loading value of 11,194 F/ma³ and Reynolds number of 39. These results are expected to provide valuable information for the development of an effective EC technology, thereby demonstrating its potential for the removal of metals from nickel mine water.