Towards Miniature Microbial Fuel Cells for Water Quality Monitoring

To ensure adequate sanitation of water supplies a rapid, cheap and simple method to test water systems is required. The microbial fuel cell (MFC) technology has potential for the effective testing of water sources in real time. A single chamber (68 μL) miniature MFC biosensor for detection of the biological oxygen demand (BOD) of water systems and to detect toxicants is presented. The device showed a response to a change in BOD within 19 minutes. The effect of operational conditions (pH, temperature, flow rate) on current generation was shown to have a maximum sensitivity of 0.944 μA cm-2 per unit change of the operational parameter. The power output of the device was enhanced by a factor of 28 by doubling the length of the anodic chamber and doping the cathode with a sustainable biochar based catalyst. The promise for detection of ‘emerging’ contaminants and toxicants in developing countries is discussed.