Bioelectricity generation and remediation of contaminated intertidal zone of Yamaguchi Bay, Japan

This study explores the use of sediment microbial fuel cells (SMFCs) to generate a safe, stable, and efficient supply of bioelectricity to sensors and simultaneously improve sediment quality. Supplying energy to geoenvironmental monitoring sensors remains a challenge as traditional batteries and solar cells are limited by the need to recharge and the erratic weather condition, respectively. Four different sediments from the Yamaguchi bay located in south part of the Honshu island, Japan were experimented on. The acid volatile sulfide (AVS) was the main source of contamination in the intertidal zone and was, hence, used as an indicator for possible bioremediation. Various factors have been studied for its effect on voltage generation. Voltage generation was dependent on the microbes in and grain size distribution of the sediment. It was found that voltage values showed almost twice when two anodes were used instead of a single anode. As the temperature reached optimum temperature of the enzymes of the Geobacteria, the increased activity lead to higher voltage. SMFC was effective in reducing the AVS value of the sediment. SMFCs in the field exhibited greater voltage generation compared to SMFCs of the same size in the laboratory. A positive correlation between voltage generation and AVS reduction was demonstrated. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study experimented with sediment microbial fuel cells (SMFCs) to generate bioelectricity for sensors. Factors such as microbes and grain size distribution were found to impact voltage generation, with the use of dual anodes showing nearly double the voltage. SMFCs in the field exhibited higher voltage generation compared to laboratory settings, and demonstrated a positive correlation between voltage generation and AVS reduction.