Revista de Engenharia Civil e Ambiental

The Electricity Generation in Microbial Fuel Cells Using Reaeration Mechanism for Cathodic Oxygen Reduction

Abstract

Chi-Yuan Lee and Yu-Hsuan Lin

Electricity generation in microbial fuel cell (MFC) using reaeration mechanism to facilitate cathodic oxygen reduction is sustainable and economical. This study examined the effects of operational parameters of electrical load (Rext), organic load and cathode area (Sa) on MFC performance under reaeration rate (K2) of 0.5-1.5 d-1in cathode chamber. Two MFCs, consisting of MFC-A (with Rext10 Ω) and MFC-B (Rext1000 Ω), were operated in parallel and continuously fed with influent chemical oxygen demand (CODin) 324–561 mg/L to anode chamber; and in each MFC the Sa covering 184, 553, 992 and 1290 cm2 was tested. Results indicated that in MFC-A the current production increased with aqueous COD in anode chamber, in which the relationship between current and aqueous COD can be modeled with Monod kinetics. The estimated kinetic constants of maximum current Imax is 3 mA, and half-saturation constant of current Ks is 310 mg/L. The lowest dissolved oxygen (DO) of 1.9 mg/L occurred at highest CODin of 561 mg/L. In MFC-B, constant current of 0.4 mA and DO at 3.2-3.7 mg/L were maintained for all CODin. The Sa had insignificant influence on electricity generation in both MFCs. This study demonstrated the importance of electrical load, organic load, and their interactions among them in designing reaeration-assisted MFC for organic waste treatment.