Simultaneous treatment of sludge and generation of electricity with a microbial fuel cell

The seriousness of the global energy crisis led to a proposal to reduce the high level of energy consumed during sewage sludge treatment. A microbial fuel cell (MFC) is the novel result, utilizing sludge as a resource and allowing the recovery of electrical energy from the chemical purification process. A two-chambered microbial fuel cell, with potassium ferricyanide as its electron acceptor, was used to test electrical generation and sludge degradation effects when excess sludge from a wastewater treatment plant was used as its substrate. Some factors that might influence electrical generation and sludge degradation rates were also studied. These included mixing a buffer solution with the inflow, different influent total chemical oxygen demand (TCOD) concentrations, and stirring within the anode chamber. Maximum voltage output reached 0.66 V, and after one periodic running, the TCOD removal efficiency was 36.4%. Mixing the buffer solution with inflow as well as stirring in the anode chamber could significantly increase power output and TCOD removal efficiency.