Electricity Generation from Sewage Wastewater in a Microbial Fuel Cell Pilot Power Plant Using Aluminium Cathodes

Asia A. Saad; Hiram Ndiritu; Meshack Hawi

Asia A. Saad Department of Mechanical Engineering, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya/ Technical University of Mombasa, Mombasa Kenya
Hiram Ndiritu Department of Mechanical Engineering, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
Meshack Hawi Department of Mechanical Engineering, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya

Keywords: Aluminium cathodes, Microbial fuel cell pilot power plant, Sea sponge membrane, Sewage wastewater, Single Chamber Microbial Fuel Cell (SCMFC),

Abstract

Aluminium metal is a low-cost material which can be used as an alternative cathode to carbon-based electrodes, for oxygen reduction in microbial fuel cells (MFCs). This study showed the effect of using aluminium rods as cathodes and carbon rods as anodes in single chamber microbial fuel cells (SCMFCs) connected in series and parallel connections to form a pilot power plant for electricity generation. Each single cell generated an output voltage ranging between 0.5 to 0.7 V. The cells were arranged into two modules to increase the voltage and current in the system. Each module constituted of twenty-four cells connected in series. Module one generated a maximum output voltage of 13.72 V while module two generated 14.21 V. The two modules were then Connected in parallel to form the pilot power plant and increase the current in the system. The maximum output voltage obtained was 14.36 V and the maximum current was 3.5 mA when an external resistor of 815 Ω was connected in the system. The total working volume of sewage wastewater used in the system was 38.4 liters. The maximum power density obtained was 1281 W/ m³. The system was able to light DC bulbs, ranging from 3W and 5W. The results showed that SCMFCs using carbon rods as anode and aluminium rods as cathode can be connected in series to increase voltage and in parallel to increase the current, hence produced a good power output in watts.