Arango Ruiz, Álvaro de JesúsGarcés Giraldo, Luís FernandoMolina Gallo, SaraPiedrahita Arias, Jaime Sebastián2012-08-092012-08-092012-08-091909-0455http://hdl.handle.net/10567/589Introduction. Waste Waters from the Dairy industries are highly loaded with organic matter (DQO- Chemical Oxygen Demand in Spanish- and fat). These pollutants have a considerable impact on the environment, especially on water. Electrocoagulation is a process that has being developed recently and is an alternative for treating waste waters from the dairy industries, offering advantages in comparison to the traditional technologies. Objective. To calculate the costs of implementing and operating electrocoagulation in a dairy industry, and comparing them with those from chemical coagulation. Materials and methods. The waste water from a dairy industry was treated by using electrocoagulation, using a bach process in order to find better conditions to remove its DQO and fat pollutants. Later, the waters were treated continuously, according to the response variables measured (percentages of removal of DQO, oils and fat), with these results. The process was escalated and the costs of implementation and operation were compared to those from chemical coagulation. Results. The operative costs of electrocoagulation are 80,75% of the operative costs of chemical electrocoagulation, and the implementation costs of electrocoagulation are half the costs of chemical electrocoagulation. Conclusion. Electrocoagulation shows itself as an efficient treatment both technical and economically, for removing pollutants from waste water in dairy industries.esElectrocoagulaciónCorporación Universitaria LasallistaÁrea Metropolitana del Valle de AburráTratamiento de aguas residualesDemanda química de oxígeno (DQO)Industria lecheraAguas residualesAguas residuales industrialesAnálisis de costosArticle