Hector Moreno1, David L. Cocke1, Jewel Andrew Gomes1, Paul Morkovsky2, Eric Peterson1, and J. R. Parga3. (1) Gill Chair of Chemistry and Chemical Engineering, Lamar University, 4400 M.L.K. Parkway, Beaumont, TX 77710, (2) Kaspar Electroplating Corporation, Shiner, TX 77984, (3) Department of Metallurgy and Materials Science, Instituto Tecnologico de Saltillo, V. Carranza 2400, C.P. 25280, Saltillo, Coahuila, Mexico
The current models of Electrocoagulation (EC) have not been able to explain all the phenomena and mechanisms associated with EC for water and wastewater treatment, among others the differences in Chemical Oxygen Demand (COD) removal efficiency in wastewater. In this paper we discuss the facts associated with COD removal using EC and develop a mechanism that explains them. To do so first, the EC technology is reviewed. Second, the concepts related to Oxygen Demand are discussed; next, case studies from a pilot plant runs relative to COD removal efficiency using EC are shown. Last, two set of experiments are presented and a mechanism for COD removal is formulated. This mechanism fits data and observations, follows Pourbaix diagrams principles and Solubility diagrams, and is congruent with the characterization of EC products. Finally the factors affecting COD removal are discussed.