Electrocoagulation (EC) technique was adopted for the treatment of iron containing drinking water using a reactor of 3 l capacity having 1 l liquid volume. Experimental investigation was carried out to observe the effect of different operating parameters such as pH, current density, inter-electrode distance and conductivity on the removal of iron from the iron-rich aqueous solution prepared with deionised water. Aluminium sheet was used as the electrode material and inter-electrode distance was varied from 0.005 m to 0.15 m. It was observed that 99% of iron was removed from the solution containing initial iron concentration of 5 mgl−1 at current density of 12.5 Am−2, solution conductivity of 0.4 Sm−1 and initial pH of 8 at the end of 25 min of EC. Solution pH was found to be an effective parameter for the efficient removal of iron. Conductivity of the iron-rich solution was improved with the addition of sodium chloride (NaCl), which increased the removal up to 99.4% for an initial iron concentration of 15 mgl−1. The optimum operating cost was evaluated as 0.285 US$ m−3 to remove 99% of iron from the solution with an initial iron concentration up to 10 mgl−1.
Keywords: electrocoagulation, iron removal, current density, aluminium electrodes, inter-electrode distance, drinking water, water treatment, sodium chloride