Study on various factors improving cathodic reaction in a microbial fuel cell for phenol removal

Diminishment of fossil fuel reserves such as oil, gas and coal, and also increasing of environmental pollutions as a result of industrial development, has made humankind to find new source of energy and to provide more effective solutions for environmental issues. In recent years microbial fuel cells have been widely investigated as an eco-friendly source of renewable and clean energy. In the present work, performance of a microbial fuel cell regarding electricity generation from artificial wastewater using activated sludge was evaluated. Effect of graphite granules as electrode and potassium ferricyanide as electron acceptor in presence of oxygen were studied and it was found that presence of these acceptors increase power density from 1.8 mW/m3 to 70 mW/m3. Cell internal resistance also decreased from 3831.3 Ω to 253.76 Ω that revealed positive effect of these parameters on increasing reaction rate in cathode chamber. The maximum voltage and Coulombic efficiency were found to be 120 mV and 47%, respectively at 95% phenol removal. Moreover, effect of increasing air flow rate in cathode chamber was investigated which showed improvement in reduction reaction rate and therefore enhancement of generated power as well as reduction of internal resistance.

Keywords:

Microbial fuel cell , Wastewater treatment , Bioelectricity , Power density , Coulombic efficiency