A critical study on the removal of copper by an electrochemically assisted coagulation: equilibrium, kinetics, and thermodynamics

The present paper provides an electrocoagulation process for the removal of copper from water through electrochemically generated Zn2+ using zinc as the anode and galvanized iron as the cathode. The different operating parameters on the removal efficiency of copper were investigated, such as initial copper ion concentration, initial pH, current density, and temperature. The results showed that the optimum removal efficiency of 96.6% was achieved at a current density of 0.05Adm2, at pH of 7.0. The effect of co-existing anions such as arsenate, phosphate, boron, and fluoride were studied on the removal efficiency of copper. The results of pilot scale study show that the process was technologically feasible. The adsorption of copper, preferably fitting the Langmuir adsorption isotherm, suggests monolayer coverage of adsorbed molecules. First and second-order rate equations, Elovich, and intraparticle diffusion models were applied to study adsorption kinetics. The adsorption process follows second-order kinetics model with good correlation. Temperature studies showed that adsorption was endothermic and spontaneous in nature. (c) 2012 Curtin University of Technology and John Wiley & Sons, Ltd.