Parametric and Kinetic Studies for The Defluoridation of Synthetic Fluoride Water by Electrocoagulation using Iron and Copper Electrodes

The present work has been focused on the removal of fluoride from aqueous solutions through the electrocoagulation process. This work aimed to assess the efficiency of electrodes and electrocoagulation process in fluoride removal from aqueous solutions. Batch experiments were carried out using monopolar Iron and Copper electrodes as anode and cathode. Fluoride removal were influenced by operating variables such as current density, nature of electrodes, initial fluoride concentration and NaCl amount which have significant effects on removal efficiency. Indeed, the increase of current density from 0.18 to 27.8 mA/cm2, fluoride removal efficiency increased from 61 to 98% using Fe electrodes while 57 to 63% using Cu electrodes during the electrolysis time indicating the high capacity of Fe electrodes for fluoride removal. The addition of NaCl solution increased the fluoride removal efficiency from 65% to 70% using Fe electrodes. Kinetics modelling revealed that Fluoride was removed on the surface of Fe electrodes following a pseudo-second order kinetic while pseudo-first order kinetic using Cu electrodes. Maximum energy consumption was 70 kWh/m3 with water containing 0.5 g/L of NaCl while an energy of 45 kWh/m3 for water without NaCl. Consequently, electrocoagulation technology is a promising method for defluoridation of water using iron electrodes.