Improving performance of microbial fuel cell by enhanced bacterial-anode interaction using sludge immobilized beads with activated carbon

Performance of a microbial fuel cell (MFC) is greatly influenced by capability of anode material in promoting attachment of electrogenic bacteria on its surface, which assists in higher electron transfer with minimal electrode resistance. In this investigation, feasibility of different anode materials made of stainless-steel (SS) mesh cage filled with sodium alginate beads matrix containing either bacterial inoculum (Ic) or activated carbon (AC) or combination of both (AC-Ic) was evaluated and performance was compared with MFCs operated with bare carbon felt and SS mesh as an anode material. Superior performance was exhibited by MFC having anode containing bead matrix with AC-Ic in SS mesh cage, which exhibited a maximum power density of 2.6 W/m³ and chemical oxygen demand (COD) removal efficiency of 91.6 ± 2.1 % due to enhanced bacterial-electrode interaction. Furthermore, the cost of bead-based electrodes was seventeen folds cheaper than carbon felt electrode, making it ideal for pilot-scale MFCs.