Stable operation of microbial fuel cells at low temperatures (5-10 ℃) with light exposure and its anodic microbial analysis

摘要

Performances of microbial fuel cells (MFCs) were studied at 5-10 and 25-30 ℃. Results showed stable operation of the MFCs at low temperatures with only slight reductions of voltage and power generation (11 versus 14 % for double-chamber MFC, while 14 versus 21 % for single-chamber MFC, 1,000 Ω) compared to those at mesophilic temperatures. MFCs operated at low temperatures showed lower COD removal rates accompanied by higher coulombic efficiencies (CEs). PCR-DGGE analysis revealed that psychrotrophic microbes (mainly Arcobacter, Pseudomonas, and Geobacter) dominated on anodes of the MFCs at low temperatures. Interestingly, light-induced red substances appeared on anode of the MFCs operated at low temperature and were proven to be the main anodic microbes {Arcobacter and Pseudomonas). Co-existence of the aforementioned microbes could assist stable low-temperature operation of the MFCs. Cyclic voltammetry analysis supported the results of the CE and DGGE. Stable performance of MFCs at low temperatures might be achieved by the control of anodic bacteria.