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

Wastewater

Carbon dioxide

External electrical circuit

Anode chamber

Membrane

Cathode chamber

e^–

e^–

Oxygen

Cathode

(H⁺ + e^– + oxygen) = Water

Bacteria

Anode

H⁺

Figure 19.1

Schematic representation of a MFC for bioelectricity production.

oxygen) because oxygen reduction process takes place and it acts as electron donor

[10]. In the anode compartment, the degraded organic matters produce protons

and electrons by metabolic activity of microorganisms. The generated electrons

are transferred from the anode to cathode through external electrical circuit.

Protons are passed via membrane to reach cathode and forms water. The MFC

is a dual-chambered bioreactor having anode and cathode compartments which

is separated by a proton switch membrane. The membrane (PEM) permits the

transport of protons from the anode region to the cathode region, by maintaining

pH and electro-neutrality. The MFC performance is affected by separators because

of its ohmic resistance. The fundamentals of MFC systems are governed in research

for scrutinizing the performance of new electrode ingredient. General dual part

mode is divided by membrane [11]. The dual-chamber design of MFC would be

difficult for nonstop treatment of commercial plants.

The active parts of MFC might be included in simple designs, and effective cost

materials will offer more perspective for harnessing the energy from wastewater [12].

Naveen Kumar et al. states that in a single chamber MFC design consist of anode

placed at the nethermost and cathode placed at the chief as shown in Figure 19.2 and

Table 19.2. This setup reveals that the performance and efficiency can vary according

to the type of MFC.

19.2

Microbial Fuel Cell Components and Process

19.2.1

Mechanism Behind MFC

Microbes oxidizing the substrate in the anode chamber produce electrons by

metabolic actions. Main electron transfer mechanism is by direct electron transfer

(DET) and mediated electron transfer (MET) [13]. Electrons are directly transferred