Field Experiments on Bioelectricity Production from Lake Sediment Using Microbial Fuel Cell Technology

Abstract

Since particular bacteria are able to oxidize organic matter under anaerobic conditions with concomitant electricity generation while an electrode is serving as an electron acceptor in a fuel cell environment, microbial fuel cells (MFCs) have recently received significant attention. Prototype sediment MFCs were placed in a shallow hypereutrophic lake and generated current for over six months. During the experimental period, a higher electrical current density with an average of 20.4 mA/m 2 was produced using electrodes with higher specific surface areas. Furthermore, parallel connection of sediment MFCs increased the current output. The results showed that current production was severely dependent on temperature and dissolved oxygen concentrations at the cathode. Other findings of this study include not only the direct coupling of current production with a decrease in the organic matter content of the sediment, as well as high positive redox potentials (> +120 mV vs. SHE) in the vicinity of the active anode as compared to sediments where electrodes were not embedded. This implies that the electrochemically active anode evidently acted as an alternative electron acceptor in the sediment, which likely decreased the activity of methanogens and improved the overall decrease in organic matter of sediment. Consequently, this study suggests that the sediment MFC could provide a means for the bioremediation of organic-rich sediment via anaerobic oxidation in conjunction with current production.

Effect of 3D Carbon Electrodes with Different Pores on Solid-Phase Microbial Fuel Cell

“…7−9 SMFCs are currently used mainly for two directions: (1) to repair soil/sediment contaminated by organic 10 and (2) to supply power to lowpower monitoring instruments or sensors. 11 Many factors that affect the electricity production of SMFCs, such as electrode material, 12 overlying water, 13 and substrate, 14 have been investigated in recent years. Among the factors, the low mass transfer rate in the anode area is the key limiting factor for SMFCs 15 and results in the higher internal resistance of SMFCs.…”

“…Many factors that affect the electricity production of SMFCs, such as electrode material, overlying water, and substrate, have been investigated in recent years. Among the factors, the low mass transfer rate in the anode area is the key limiting factor for SMFCs and results in the higher internal resistance of SMFCs .…”

Optimizing the electrode surface area of sediment microbial fuel cells

“…SMFC 646 generated an MP of 0.28 mW and a maximum power density of 4.3 mW m −2 (normalized to cathode surface area), which was comparable to several SMFCs that operated in lab or in practical fields. 15–18 The MP of the anode-limiting SMFCs increased from 0.04 to 0.25 mW when the anode increased from 166 to 486 cm 2 ( Fig. 2B ).…”

Responses of Aromatic-Degrading Microbial Communities to Elevated Nitrate in Sediments

“…Total organic carbon content (TOC) and dissolved organic carbon (DOC) were determined by a total organic carbon analyzer (Elementar Liquid TOC II, Germany). The loss on ignition (LOI) of the sediment was determined by gravimetrical methods as described previously . For gas chromatograph–mass spectrometer (GC–MS) analysis, 10 g of freeze-dried sediment was extracted with 200 mL of dichloromethane (DCM) for 48 h using a Soxhlet extractor.…”