A systematic study on self-powered microbial fuel cell based BOD biosensors running under different temperatures

As a promising self-powered device for wastewater biochemical oxygen demand (BOD) monitoring, the actual applications of the microbial fuel cell (MFC)-based biosensor will be significantly affected by environment temperature changes. Herein, the effect of operating temperature on the performance of MFC-based biosensors for real-time wastewater BOD monitoring was thoroughly investigated. The linearity ranges between the output voltage and BOD values were obtained up to 50 mg L-1 (R-2 = 0.9855, at 15 +/- 1 degrees C), 70 mg L-1 (R-2 = 0.9917, at 25 +/- 1 degrees C) and 80 mg L-1 (R-2 = 0.9928, at 35 +/- 1 degrees C), respectively. Meanwhile, the shortest response time was 0.25 h (at 35 +/- 1 degrees C, 10 mg L-1) and the longest response time was 7.71 h (at 15 +/- 1 degrees C, 50 mg L-1). Furthermore, the MFC-based biosensors were capable of accurately measuring BOD concentrations in actual wastewaters with deviations of less than 4% (15-35 degrees C). PCR-DGGE analyses revealed that the compositions of the anodic microbial community at 15 +/- 1 degrees C were significantly different from those at 25 +/- 1 degrees C and 35 +/- 1 degrees C, but C. freundii, A. hydrophila and D. desulfuricans dominated at all three operational temperatures. Thus, it is suggested that the changes in operational temperature have an effect on the anodic microbial community compositions, which affects the response time and detection limit of MFC-based BOD biosensors.

Automated summary

This study comprehensively investigated the effect of temperature on the performance of MFC-based biosensors for real-time wastewater BOD monitoring. The results showed that temperature influenced the linear range, response time, and detection accuracy of the biosensors, as well as the composition of the anodic microbial community.