[Comparison of power generation in microbial fuel cells of two different structures]

Low electricity productivity and high cost are two problems facing the development of microbial fuel cell (MFC). Comparative studies on electricity generation in MFCs of different designs while under the same conditions are important in enhancing the power output. Single-chamber MFC and dual-chamber MFC were constructed and acetate was used as the fuel. Power outputs in these MFC were compared side by side with a resistance of 1,000 Omega connected to each. Experimental results showed that the electricity was generated continuously and steadily in the MFCs. The average maximum output voltages obtained by the single-chamber and dual-chamber MFCs were 600 and 650 mV, respectively. The electric cycles were operated for 110 and 90 h for the single-chamber and dual-chamber MFCs, respectively. From the single-chamber and dual-chamber MFCs, the maximum area power densities were 113.8 and 382.4 mW/m2 respectively, and the maximum volumetric power densities were 1.3 and 2.2 mW/m3 respectively. The internal resistances of single-chamber and dual-chamber MFC were 188 and 348 Omega, respectively. Results indicated that the dual-chamber MFC had a better performance than the single-chamber MFC. The effective area of anode and the proton exchange membrane had a significant effect on the performance of MFCs.