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Reorienting Waste Remediation Towards Harnessing Bioenergy 255

Figure 6.4 Schematic representation of a single-chambered microbial electrolysis cell
for biohydrogen production.

from the anode under small applied voltages required to cross the endother-
mic barrier to form H 2 gas. Low energy consumption compared to the con-
ventional water electrolysis and more substrate degradation than the
dark-fermentation process are some of the potential benefits that make
MEC an alternate process.
The performance of MEC is influenced by several factors, such as reactor
configuration, electrode materials, membrane, and nature of substrate. Ini-
tially, double-chambered MECs were used with different types of mem-
branes for the production of H 2 (Cheng and Logan, 2007; Rozendal
et al., 2006). The performance of MEC was found to be most effective in
a single-chamber without using a membrane (Call and Logan, 2008; Hu
et al., 2008a,b; Lee and Rittmann, 2010a,b; Rozendal et al., 2006, 2007).
The removal of membrane economizes the construction, operation, and
maintenance of the MEC, but it also decreases the internal resistance of
the system. Various electrode materials have been used in lab-scale MECs,
including carbon felt (Parameswaran et al., 2009), stainless steel brushes (Call
et al., 2009), stainless steel and nickel alloys (Selembo et al., 2009), graphite
granules (Clauwaert and Verstraete, 2009), graphite fibers (Lee and
Rittmann, 2010b), and noncatalyzed graphite electrodes (Venkata Mohan
and Lenin Babu, 2011). The MEC has been operated with different