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19 Reaping of Bio-Energy from Waste Using Microbial Fuel Cell Technology

easily metabolized biomass to complex wastewater using microbes as biocatalysts.

The application of platinum group metal-free catalysts as air breathing cathode of

the MFC helps to activate the sludge, in addition to acetate for the source of carbon

energy [22]. A maximum power density of 1.3 W/m² (54 W/m³) is obtained with

iron aminoantipyrine catalyst. It is the highly reported type of MFC which is capa-

ble of continuous operation in wastewater and shows constancy and enhancement

in longtime operation [23].

19.3.1.1

Bio Hydrogen

MFC can be easily modified to produce hydrogen instead of electricity. The

protons and the electrons produced by the metabolism of microbes in MFC are

thermodynamically unfavorable. It applies an external potential to amplify the

cathode potential in a MFC circuit and thus overcome the thermo dynamic barrier.

Protons and electrons produced by the anolyte reaction are combined at the cathode

chamber to form hydrogen [24]. The external potential for an MFC theoretically

requires 100 mV, much lower than the 1110 mV required for direct electrolysis of

water at neutral pH. This may be due to the fact that some energy comes from the

biomass oxidation process in the anodic chamber. In bio hydrogen production using

MFC, oxygen is no longer needed in the cathodic chamber. Thus, oxygen leak to the

anodic chamber is no longer an issue in the improved MFC. The main advantage is

hydrogen that can be accumulated and stored for the future usage. Therefore, MFC

provide a renewable hydrogen source which can contribute to the overall hydrogen

demand in a hydrogen economy [25].

19.3.2

Wastewater Treatment

An important application of MFC is treating domestic as well as industrial wastew-

ater. Urban wastewater has a massive amount of organic compounds that can

fuel MFC. During the wastewater treatment process, electric power generated

potentially bisects the electricity needed in a conventional treatment process. A

hybrid technique incorporating both electrophiles and anodophilies is especially

suitable for wastewater treatment because organics can be biodegraded by a variety

of organic substances [26]. MFC using certain microbes has a special ability to

remove sulfides in wastewater treatment. During wastewater treatment, MFC can

improve the growth of bio-electrochemically active microorganisms. Continuous

flow and single-compartment MFC and membrane-less MFC are favorable for

wastewater treatment due to scale-up concerns. Sanitary waste, food industrial

wastewater, swine wastewater, and corn Stover are great biomass sources for MFC

as they are rich in organic matters. Up to 80% of the chemical oxygen demand

(COD) can be removed in some cases and columbic efficiency as high as 80% has

been reported [27].

19.3.3

Biosensor

Another potential application of the MFC technology is to use it as a sensor for

pollutant analysis and in situ process monitoring and control, apart from the