2.3 Microbial Fuel Cells
Microbial fuel cells (MFCs) have been focused due to its several advantages over
conventional treatment systems (Li et al. 2014; Gude 2016). It uses microbes that
catabolize organic biodegradable substrates to generate bioelectricity. The designs of
MFCs are similar to traditional fuel cells containing anode and cathode chambers
physically separated by a proton exchange membrane (Fig. 11.3). The anode chamber consists of microorganisms that play an essential role in generating electrons and
protons. Moreover, it provides all the required conditions for biomass degradation.
The external circuit allows the generated electrons to pass through, which are then
reduced to electron acceptors in the cathode. The proton exchange membrane passes
the protons generated in the anode chamber to the cathode chamber completing the
electrical circuit. The reduction reactions, generating electrons and protons and
electron acceptor conditions, develop a biopotential, which leads to the generation
of bioelectricity in MFCs (Rahimnejad et al. 2011).
MFCs have been used for the treatment of wastewater containing
nonbiodegradable metals. Some of the heavy metal-containing groups, with high
redox potentials, can serve as electron acceptors (Wang and Ren 2014), equipping
MFCs for both degradation and recovery of heavy metals (Mathuriya and Yakhmi
2014). Microorganisms also have the potential to facilitate bioremediation in areas
containing heavy metals. Both single-chamber and dual-chamber MFCs have used
microorganisms for the effective removal of metal from wastewater. Complete
reduction of chromium (VI) was achieved using Shewanella decolorationis S12,
Klebsiella pneumoniae L17, and mixed culture in a dual-chamber MFC (Liu et al.
Table 11.2 Nanobioremediation of environmental pollutants
Nanoparticles
Microorganisms used
Pollutant removed
References
Palladium/nanoscale
iron (Pd/nFe)
Sphingomonas wittichii
RW1 (DSM 6014)
Tetrachlorodibenzopdioxin (2,3,7,8TeCDD)
Bokare et al.
(2012)
nZVI (nano zerovalent
iron)-immobilized alginate beads
Bacillus subtilis,
Escherichia coli, and
Acinetobacter junii
Chromium (VI)
Ravikumar et al.
(2016)
Carbon nanotubes
Shewanella oneidensis
MR-1
Chromium (VI)
Yan et al.
(2013)
Iron(II, III) oxide
(Fe 3 O 4 ) nanoparticles
Sphingomonas
sp. XLDN2-5 cells
Carbazole
Li et al. (2013)
Carboxymethyl cellulose (CMC)-Pd/Fe
Sphingomonas sp.
Lindane
Singh
et al. (2013).
nZVI
Sphingomonas
sp. PH-07
Polybrominated
diphenyl ethers
(PBDEs)
Kim et al.
(2012)
Nanoscale zinc oxide
(n-ZnO)
Candida VITJzN04
Lindane
Salam and Das
(2015)
11 Modern Bioremediation Approaches for Clean and Green Environment
227
Microbial fuel cells (MFCs) have been focused due to its several advantages over
conventional treatment systems (Li et al. 2014; Gude 2016). It uses microbes that
catabolize organic biodegradable substrates to generate bioelectricity. The designs of
MFCs are similar to traditional fuel cells containing anode and cathode chambers
physically separated by a proton exchange membrane (Fig. 11.3). The anode chamber consists of microorganisms that play an essential role in generating electrons and
protons. Moreover, it provides all the required conditions for biomass degradation.
The external circuit allows the generated electrons to pass through, which are then
reduced to electron acceptors in the cathode. The proton exchange membrane passes
the protons generated in the anode chamber to the cathode chamber completing the
electrical circuit. The reduction reactions, generating electrons and protons and
electron acceptor conditions, develop a biopotential, which leads to the generation
of bioelectricity in MFCs (Rahimnejad et al. 2011).
MFCs have been used for the treatment of wastewater containing
nonbiodegradable metals. Some of the heavy metal-containing groups, with high
redox potentials, can serve as electron acceptors (Wang and Ren 2014), equipping
MFCs for both degradation and recovery of heavy metals (Mathuriya and Yakhmi
2014). Microorganisms also have the potential to facilitate bioremediation in areas
containing heavy metals. Both single-chamber and dual-chamber MFCs have used
microorganisms for the effective removal of metal from wastewater. Complete
reduction of chromium (VI) was achieved using Shewanella decolorationis S12,
Klebsiella pneumoniae L17, and mixed culture in a dual-chamber MFC (Liu et al.
Table 11.2 Nanobioremediation of environmental pollutants
Nanoparticles
Microorganisms used
Pollutant removed
References
Palladium/nanoscale
iron (Pd/nFe)
Sphingomonas wittichii
RW1 (DSM 6014)
Tetrachlorodibenzopdioxin (2,3,7,8TeCDD)
Bokare et al.
(2012)
nZVI (nano zerovalent
iron)-immobilized alginate beads
Bacillus subtilis,
Escherichia coli, and
Acinetobacter junii
Chromium (VI)
Ravikumar et al.
(2016)
Carbon nanotubes
Shewanella oneidensis
MR-1
Chromium (VI)
Yan et al.
(2013)
Iron(II, III) oxide
(Fe 3 O 4 ) nanoparticles
Sphingomonas
sp. XLDN2-5 cells
Carbazole
Li et al. (2013)
Carboxymethyl cellulose (CMC)-Pd/Fe
Sphingomonas sp.
Lindane
Singh
et al. (2013).
nZVI
Sphingomonas
sp. PH-07
Polybrominated
diphenyl ethers
(PBDEs)
Kim et al.
(2012)
Nanoscale zinc oxide
(n-ZnO)
Candida VITJzN04
Lindane
Salam and Das
(2015)
11 Modern Bioremediation Approaches for Clean and Green Environment
227