Generation of Electricity from Sewage

ABSTRACT

Instead of using energy to treat waste water; it is actually feasible for one to harness energy from wastes as well as treating it using a Microbial Fuel Cell (MFC). An MFC generates electricity from sewage with the help of bacteria. This research paper investigates the generation of electricity from sewage as well as sewage treatment in the same period. Four cells were used A, B, C and a control. The cells A, B and C all consisted of the anode and the cathode separated by a loamy-sandy soil of electrical conductivity, 160 􀀁S at 22.8°C. The cathode and anodes were made of carbon rods obtained from A size dry cell. The anode and cathode were separated by 25 mm, 50 mm and 75 mm for cells A, B and C respectively. The control cell had no electrical components but shared the other components as those for cell A, B and C. Sewage with COD of 2080 O2 mg/l was introduced into the cells. Voltage and COD measurements were made every 24 hours and 10 days respectively to investigate performance. Laboratory measurements and recordings were made for 60 days and maximum voltages of 0.426 V, 0.261 V and 0.267 V were recorded for A, B and C respectively. The COD removal efficiencies were over 90 %, for B and C; over 60 % for A and less than 40 % for the control even after 60 days. This asserted that MFCs generated electricity as well as being better waste treatment devices than natural or constructed waste treatment ponds. Results also showed that the further the anode - cathode separation, the lower the voltage that was developed owing to increase in cell internal resistance. This paper furthers the potential to generate green and clean energy by means of an MFC.

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