CONICET | Buscador de Institutos y Recursos Humanos

Wastewaters containing high amount of organic matter are a potential energy storage that actually represent almost 10-fold the energy that is invested in their treating. Urban wastewaters are classically processed under anaerobic conditions in order to transform organic matter into acetate and short-chain organic acids, and then are further converted into methane through an additional treatment to be used as energy source. This process could be modified by replacing such a methanogenic stage by an advanced microbial fuel cell (MFC) system able to produce electricity from acetate at high rate by means of electrogenic biofilms. Therefore, MFC constitute an attractive option to couple wastewater treatment and energy recovery. Among the microorganism suitable for these purposes, bacteria belonging to Geobacter genera are currently being intensively investigated regarding their direct electron transfer electrodes. The most common anode reaction in MFC involves acetate oxidation that is combined with suitable cathodic reaction (for example, the reduction of oxygen). The development of the concept of energy cogeneration and effluent bioremediation using a MFC requires the analysis of all the elements of the cell and the study of the influence of different working conditions. In this study, we will present the results obtained with different cells inoculated with a pure culture of G. sulfurreducens. The MFCs were run with synthetic wastewater containing 20mM acetate as feed stream, at different operational conditions (batch and continuous mode), with several anode materials (carbon particles, carbon felt, graphite plates), and cathodic counterparts (Pt/C on carbon cloth, KmnO4 with graphite electrode and air diffusion cathodes). The data obtained in this work will be useful for the design, construction and optimization of a system dealing with real wastewater at a pre-industrial scale.