Study on wastewater treatment by wetland type microbial fuel cell and simultaneous electricity generation

A single-chamber wetland biocathode type microbial fuel cell (MFC) is constructed by means of reed in order to study the effects of cathode substrate materials and influent COD concentration on its power generation and wastewater treatment performance. The results indicate that species and particle size of the cathode substrate materials have a great effect in electricity generation performance of MFC. The maximum output voltage, the maximum power density and Kulun efficiency are 318 mV (external resistance of 1 000 Ω), 0.197 W/m³ and 2.1% respectively when the anode substrate materials are granular activated carbon (2-4 mm) and the cathode substrate materials are granular graphite (4-8 mm).Besides, species and particle size of the cathode substrate materials have little effect on wastewater treatment performance of MFC-CW. The removal rate of COD is about 80%.Furthermore, the influent COD concentration is a crucial operating parameter of MFC. The output power density and COD removal rate show a tendency of increasing at first and then decreasing with the growth of influent COD concentration, and the system will perform the best when influent COD concentration is in the range of 200-300 mg/L.