Development of a dynamic mathematical model for biofilm based microbial fuel cells

Abstract

Studies cf Microbial Fuel Ceils (MI C) as Power production units is of increasing interest because it can convert a large diversity u organic compounds into electricity. In a MFC biolological,chemical and eicctro-chemical reaction- ‘ake place resulting in a change of concentration of substrate suspended microorganisms and growth of a biofilm leading to a production of an electrical urrent In tlus study a simplified mathematical modell is .developed that represents the behaviour of microbial fuel cells using set of derived equarions those describe the system and its activities. Moreover the model requires comparatively low simulation time and high power computers are not essential for simulation. The developed model considers that the suspended cells and the anode with an attached biofilm. This study evaluates the performance of a MFC, analyzing the variation of production of current with time variation of concrete of componants microorganisms, substrate, oxidized mediator andeduced mediator) m the bulk liquid with time and variation of concentration of mediators at the eieefa-ode surface with time in various reaction rates. Whence.maximum specific reaction rate is 2x10- 7mol mediator/ (mol mediator s) the production of mi-vimum current (0.038 mA) is achieved after 2 ays. On the other hand, comparatively low reaction rate constant, that is 5x10-8 mol mediator/ (mol mediator s) yield a maximum current of 0.026 mA by day 6. Based on modeling results, it can be concluded that higher the reaction rate the production of current by the fuel cell is high and at the same time reaching of maximum current production is rapid in the systems simulated with high reaction ra.e constants compared to that of the other.