Development of continuous microbial fuel cell for renewable energy production from wastewater

There is around 9.5 kJ/L of energy contained in UK wastewater which is wasted through traditional aeration treatment. Microbial fuel cell (MFC) technology provides a new approach to carry the promise of both treating wastewater without aeration and producing renewable energy in the form of electricity and H2. This work has contributed to making this a reality. In this work, MFC designs were developed and constructed to test their energy performances. The power densities ranged from 13.3 mW/m2 to 30 mW/m2. The coulombic efficiency based on the contained substrates is in the range of 1 % to 7 0/0. The Chemical Oxygen Demand (COD) removal conversion per pass of MFCs arrived at 3.0 0/0. The H2 recovery rate was about 14 % with H2 yield of 11.6 mg/g COD. Comparative study suggested that continuous flow, no membrane and single chamber design can be used effectively in MFC for further application. The high temperature CO2 oxidation treatment of carbon anode materials resulted in an improvement of power by a factor of 2 when applied to MFC. Scanning Electron Microscopy (SEM) study and the textural property measurements based on Brunauer Emmett Teller (BET) theory suggested that treatments help bacteria to grow on the material surface resulting in power improvement. Graphite as cathode decreased the MFC power density by around 50 % compared to that of MFC with Pt contained cathode, but the cost is 1/1000 that of the Pt makes it a very attractive alternative. A typical industry case study for implementation of MFC were carried out that considerable energy cost savings and water disposal savings can offset the installation within 1-2 year. It shows that the MFC technology has a promising future for the sustainable development of the world with further research