Real-time monitoring of sediment bulking through a multi-anode sediment microbial fuel cell as reliable biosensor

Abstract

Sediment bulking was closely related to the occurrence of black water agglomerate in anoxic aquatic sediments. Real-time monitoring of sediment bulking can be labor intensive and technically difficult, especially in dynamic environments where a record of variation in height over time is desired. In this study, a vertically distributed multi-anodes sediment microbial fuel cell (SMFC) as biosensor was developed for monitoring the changes in sediment height. According to the principle of sediment microbial fuel cell (SMFC), the voltage of SMFC would increase when the anode embedded into the sediment. The results showed that when the anode buried in the sediment, the biosensing system delivered voltage can increase to 40 mV, where the power density of SMFC exceeded 10 mW m−2 with overshoot of power density appeared. However, for the anodes above the water-sediment interface, the voltages and power densities kept at around 0. The redundancy analysis further indicated that the labile carbon pool-I of sediment was a key factor for sediment bulking, which led to drastic changes in sediment characteristics. The results from this study can provide a simple strategy for identifying sediment bulking in shallow lakes.