Simultaneous removal of Co, Cu, and Cr from water by electrocoagulation

Abstract

This study provides an electrocoagulation process for the removal of metals such as cobalt, copper, and chromium from water using magnesium as anode and galvanized iron as cathode. The various parameters like pH, current density, temperature, and inter electrode distance on the removal efficiency of metals were studied. The results showed that maximum removal efficiency was achieved for cobalt, copper, and chromium with magnesium as anode and galvanized iron as cathode at a current density of 0.025 A dm⁻² at pH 7.0. First- and second-order rate equations were applied to study adsorption kinetics. The adsorption process follows second-order kinetics model with good correlation. The Langmuir and Freundlich adsorption isotherm models were studied using the experimental data. The Langmuir adsorption isotherm favors monolayer coverage of adsorbed molecules for the adsorption of cobalt, copper, and chromium. Temperature studies showed that adsorption was endothermic and spontaneous in nature.

Keywords:

• electrocoagulation
• removal
• metals
• adsorption
• isotherms
• kinetics

Acknowledgments

The authors wish to express their gratitude to the Director, Central Electrochemical Research Institute, Karaikudi, for aid in publishing this article.