A comparison of microbial fuel cell and microbial electrolysis cell biosensors for real-time environmental monitoring.

This study compares the biosensing performance of a microbial fuel cell (MFC) and a microbial electrolysis cell (MEC). Initial tests provided a qualitative comparison of MFC and MEC currents after the anode compartment liquid (anolyte) was spiked with acetate, or sulphates of NH, Na, Mg, Fe, or a fertilizer solution. Current measurements showed that the MFC sensor had a faster response time, higher sensitivity, and faster recovery time after the spike. Following the spike tests, the MFC and MEC were operated in a continuous flow mode at several influent concentrations of acetate, and sulphates of NH, Na, and Fe. The continuous flow tests confirmed the better performance of the MFC sensor, which was selected for further experiments. Two MFC sensors were used for real-time (on-line) COD measurements of brewery wastewater. Regression analysis showed a strong correlation between the MFC power output and COD concentrations in the anode compartment with a coefficient of determination (R) of 0.97. Overall, results of this study suggest that an MFC-based sensor can be successfully used as a simple and cost-efficient real-time monitoring tool.