28. Production of Bio-Energy Using Biological Fuel Cell: Application to Electro-Dialysis for Recovery of Heavy Metal Traces from Treated Wastewater

Biological Fuel Cell (BFC) is a device that converts chemical energy into electric energy by using a biological catalyst such as enzyme, microbe, bacteria, etc.…, and a fuel. Although enzymes and microorganisms are highly efficient biocatalysts. The microbial desalination cell (MDC) a newly developed technology, integrated the Microbial Fuel Cell (MFC) process and electro-dialysis (ED) for wastewater treatment, water desalination and production of renewable energy. The cell developed herein, was composed of two compartments: anode and cathode compartments separated by a cation exchange membrane. The biocatalyst was either on the electrode and suspended in solution. The anode was in general a carbon-based electrode, while the cathode was stainless steel plate. The connection between the two electrodes via an electrical resistance allowed the flow of electrons from the anode to the cathode through the external circuit. This flow was compensated by the flow of ions through the internal circuit. Though it was relatively weak, the produced bio-energy was always enough to feed low energy devices. We have demonstrated herein the potential energy for the treatment of a wastewater. We have proved the degradation of organic matter using the bio-film, by measuring the abatement of Chemical Oxygen Demand (COD). Besides, we have eliminated the residual heavy metal traces using by electro-dialysis. In effect, we used the bio-energy produced by the (BFC) to feed the three-compartment electro-dialysis cell (EDC). Compared to electro-dialysis, our results proved the possibility to recover metal traces at approximately the same rate of abatement, using this novel biological device.