Arango Ruiz, Álvaro de JesúsGarcés Giraldo, Luís Fernando2012-04-302012-04-3020091794-4449http://hdl.handle.net/10567/223Introduction. Residual water from the dye, food, textile and pharmaceutical industries, indiscriminately dumped into water bodies, are responsible of many harmful effects for the environment, the flora and the fauna that live in those waters. Among those effects, some very important ones are the reduction of the dissolved oxygen, eutrophication, recalcitrant compounds, which are harmful for cells, the obstruction of the light that should come into the water and an aesthetic deterioration. Electro coagulation is a technology that has been being developed recently, and can be seen as an alternative for the treatment of residual waters from the industries mentioned above. It offers many advantages if compared to traditional technologies. Objective. To study the removal of the amaranth azo dye from aqueous solutions by the use of electro coagulation. Materials and methods. Synthetic residual waters were treated with electro coagulation, by using a factorial experimental model 3X2X3 which obeys to pH variations, stream density and time of treatment. The response variables measured were the percentages of chemical demand of oxygen and color. Results. The removals of chemical demand of oxygen were 98.3% and those of the color, 99.3% at a pH of 4. The stream density was 40.86 A/m2y in a 15 minutes treatment. Conclusion: The results allow establishing that, from a technical point of view, electro coagulation can be used in aqueous solutions with amaranth red dye, for removing the color.esElectroquímicaCorporación Universitaria LasallistaColorante azoico amarantoAguas residualesContaminación del aguaAguas residuales industrialesElectrocoagulaciónTratamiento de aguas residualesArticle