Physicochemical Aspects of Electrocoagulation

Electrocoagulation is an electrochemical technique which is being applied to the removal of a number of water pollutants: metals, organic contaminants, dyes and pigments, colloidal solids and particles, soluble inorganic pollutants, and others. Both the electrochemical reactions that take place at the electrode and the effect on the bulk solution are explained. The influence of the metal cation concentration (iron or aluminum) as well as the pH of the aqueous solution is shown. The advantages and disadvantages of electrocoagulation compared to traditional coagulation methods are reviewed. Some considerations about the mathematical modeling of the process and actual reactor design are described. Some techniques that are derived from electrocoagulation—electro-Fenton and peroxi-coagulatio—are explained. Finally, the efficiency of removal for a number of pollutants from wastewater is presented.