Track: Environmental Engineering

Abstract

The biological nutrient removal waste water treatment process requires large amounts of electrical power mainly for pumping and aeration. This traditional waste treatment processes proves to be expensive mainly because of this huge electricity demand.  However, waste water contains 9.3 times more energy than is used to treat an equivalent volume, this is useful energy that is not being tapped into. Herein, an industrial scale Microbial Fuel Cell system is proposed to harness this energy in the form of direct electricity using the bacteria found in the waste water whilst simultaneously treating the waste water from the municipal waste water treatment plants with an assumed Biological Oxygen demand (BOD) and Chemical Oxygen Demand (COD) removal of 75%. Microbial fuel cells directly capture the electrons generated when electrochemically energetic bacteria breakdown organic substrates. Creating electrical energy from Microbial Fuel cells is basically as a result of microbes acting as catalyst in degrading the organic content and the existence of a potential gradient across the microbial cell membrane. This work evaluated the operational parameters of microbial Fuel Cell system and estimated the electricity generation potential of Firle waste water treatment plant (treating a volume of 90ML a day) as 900 kW. A cost analysis showed that Microbial Fuel Cells could be competitive as a sustainable and energy-efficient technology for municipal wastewater treatment.