A TWO-STAGE MICROBIAL FUEL CELL SYSTEM TO CONVERT SOLID ORGANIC WASTE TO ELECTRICITY

Microbial fuel cell (MFC) research has focused mostly on producing electricity using soluble organic and inorganic substrates. This study focused on converting solid organic waste into electricity using a two-stage MFC process. In the first stage, a hydrolysis reactor produced soluble organic substrates from solid organic waste. The soluble substrates from the hydrolysis reactor were pumped to the second stage reactor: a continuous-flow, air-cathode MFC. Maximum power output (Pmax) of the MFC was 296 mW/m3 at a current density of 25.4 mA/m2 while being fed only leachate from the first stage reactor. Addition of phosphate buffer increased Pmax to 1,470 mW/m3 (89.4 mA/m2), although this result could not be duplicated with repeated polarization testing. The minimum internal resistance achieved was 77 Omega with leachate feed and 17 Omega with phosphate buffer. The low coulombic efficiency (