A review on sediment microbial fuel cells as a new source of sustainable energy and heavy metal remediation: mechanisms and future prospective

Abstract

Summary Sediment microbial fuel cells (SMFCs) are different from microbial fuel cells because they are completely anoxic and lack a membrane. SMFCs are a novel technology for the simultaneous production of renewable energy and bioremediation of heavy metals. Recently, SMFCs have attracted the attention of many researchers because of their moderate functioning parameters and ability to use a range of biodegradable substrates like glucose, glutamic acid, river water, cysteine, acetate, and starch. The inocula used in SMFCs include river sediment, marine sediment, and wastewater. For power generation, many exoelectrogens in SMFCs have the ability to transfer electrons from electrodes by using natural electron shuttles. Exoelectrogens use four primary pathways to transfer electrons to the electrodes, including short‐range electron transfer through redox‐active proteins, soluble electron shuttling molecules, long‐range electron transport by conductive pili, and direct interspecies electron transfer. The most dominant mechanism is long‐range electron transfer via conductive pili because pili have metal‐like conductivity. The powering by microbes is an emerging technique for the remediation of heavy metals from sediments. The pathways for transferring electrons in electrotrophs operate in the opposite direction from those in exoelectrogens. To further upgrade SMFC technology, this review targets the prototype, operating factors, working mechanisms, applications, and future perspectives of SMFCs. Copyright © 2017 John Wiley & Sons, Ltd.

Electrochemistry and microbiology of microbial fuel cells treating marine sediments polluted with heavy metals

“…Oxidation and reduction phenomena may also be involved in lowering the voltage output due to the production of basic and acidic by-products at both terminals during later operational days. 16 …”

Energy harvesting from sediment microbial fuel cell to supply uninterruptible regulated power for small devices

“…Some researchers have paid their attention towards the technologies that are carbon free, renewable, and environment friendly. In turn, sediment microbial fuel cell (SMFC) has been proposed for electricity generation, which is a green energy technology and has the ability to convert chemical energy into electrical energy without any adverse effect on the environment …”

“…[4][5][6][7] SMFC generates electrical energy by using natural electron shuttles in the presence of the microbes in marine sediment, river sediment, and wastewater. 2,8 Several microbial reactions contribute to producing the electric current by SMFC. 9 A microbial electrolysis cell produces electricity as well as methane for 188 days with an efficiency of 51.30% during the yield test using water oxidation.…”

“…In turn, sediment microbial fuel cell (SMFC) has been proposed for electricity generation, which is a green energy technology and has the ability to convert chemical energy into electrical energy without any adverse effect on the environment. 2,3 In SMFC technology, an anode and a cathode are placed in the sediment and water, respectively. The current is generated by oxidizing on the anode present in sediment, and the oxygen reduction action occurs on the cathode in water.…”

Effects of unit distance and number on sediment microbial fuel cell stacks for practical power supply

“…Sediment microbial fuel cells (SMFCs) is a subgroup of microbial fuel cells (MFCs) that can convert the chemical energy stored in sediments to electricity via microbial extracellular electron transfer. Several pilot‐scale SMFCs have shown many advantages for remote power supply and sediment bioremediation . However, due to the slow chemical diffusion in sediments, SMFC power outputs are lower than MFCs with wastewater (WMFCs) and cannot meet the needs of practical electronic devices .…”