Monod kinetics degradation of low concentration residual organics in membraneless microbial fuel cells

Microbial fuel cells (MFCs) are attracting considerable attention as innovative systems for energy production from renewable residual biomass and biomass-derived wastes dissolved in wastewaters. The current produced by a microbial fuel cell can also be used to quantify the rate of specific metabolic processes and the substrate concentration in real time. Aim of this work is the study of the correlation between the decay of current density in a microbial fuel cell and the concentration of the residual organic substrates when it reaches low concentration, in the rage of 0-500 mg/L COD. Tests were performed in continuous flow using an air breathing, membraneless MFC using sodium acetate as organic substrate. A direct concentration-dependent current output was achieved in the range of 0-100 mg/l, with a Monod kinetics as the best-fitting model. A step of current was also achieved at concentration higher than 120 mg/L.