The electrical energy generation from biodegradable waste, has been gainingground due the growing demand of this resource and the environmental impactassociated. The latter creates a paradox, from one side we have the satisfaction of theenergy demand, in other hand we create a problem that in long term could be worst, forexample the contamination of the soil, air and water by the use of toxic products(petroleum, carbon, uranium, etc.) in order to satisfy the growing demand. In that way themicrobial fuel cells, try to solve both problems at the same time, generating electricalenergy by oxidation of waste water and treat it in the process, reducing the organicloading (8). However, this technology is far from be perfect, because of the low powergeneration, that is not near to satisfy the actual energy demand. This work is looking tomodel the anode of a MFC from thermodynamics of irreversible process theory thisbecause of the need to taking account the fluxes and forces behind the behavior showedby these devices that arise from the two thermodynamic laws, in order to theorize aboutthis phenomena and to define the most appropriate parameters that make possible anoptimal performance. The main goal of this work is to open a new methodology of designMFC to treat the water of streams in the metropolitan area of Medellin, emphasizing inthe improvement of the power level of the cell.