**15. Application of MFC**

Although a centuries-old technique, initially recognized in the treatment of dairy wastewater, MFC is taking an interest in bioelectricity generation, bio-hydrogen, Nitrogen, and Phosphorus recovery and also used as a biosensor [33, 105–108]. Several issues such as expensive materials, complicated design, and low power output at higher internal resistance needed to be tackled before utilizing MFC for large scale applications.

#### **15.1 Treatment of wastewater**

During the early stage of MFC technology, it was considered that this technology could only be used for the treatment of the limited wastewater, but in the recent years, it has been seen that it could be used in the treatment of almost all kinds of industrial, agricultural and municipal wastewater. The most suitable temperature studied for electricity generation via MFC is about 30°C in a regulated climate. Glycerol wastewater, the main source of pollution in the biodiesel industries, has reported a maximum surface power density 600 mW/m2 [109]. The low cost and the operational stability is an important characteristic for an effective and efficient treatment technology. An earlier study has reported the simultaneous methane and bio-electricity production in the anaerobic digestion process for higher concentrated wastewater at a longer detention time [62]. MFC with certain microbes have the ability for removable of organic matter, sulfides, nitrides, phosphorous, salinity, etc. Do et al. [110] reported the maximum of 90% COD removal and 80% columbic efficiency.

#### **15.2 Bio-electricity**

MFC is a wonderful technology in transferring the chemical energy inside the wide varieties of the waste organic matter with the help of the microorganism into bio-electricity. The current MFC technology is capable of producing only low power outputs which are suitable for small telemetry and wireless sensor system with a small power requirement in the remote areas. However, [39] achieved a peak power density of 122 W/m3 with 81% COD removal using dairy wastewater as a substrate with 3D laminated composites as electrodes [39].

#### **15.3 Biohydrogen**

With a minor adjustment, MFCs could also be used to generate biohydrogen instead of bio-electricity that could be extracted and processed for later use. The anode potential is improved with an external voltage of 0.23 V for overcoming the thermodynamic barrier which is much lesser than the conventional fermentation process. The electron and hydrogen ion produced by the microbial activities at the anodic chamber combines at an oxygen devoid cathode chamber generating biohydrogen. MFC has a potential of about 8–9 mol H2/mol glucose in comparison to 4 mol H2/mol glucose produced from a conventional fermentation process [52]. In order to produce hydrogen gas in a standard MFC, the anodizing potential for an additional voltage must be increased roughly 0.23 V or more.

#### **15.4 Bio-sensor**

The MFC is also utilized as an electrochemical biosensor for pollutant analysis. The metabolic activities of the electrogenic microorganisms are highly affected by the sudden change in the concentration of the targeted analyte in the exposed aquatic environment and are reflected as a change of the output electric signal. MFC sensor is a self-sustained sensor unlike other types of the biosensor which require an external source of power. The biofilm-electrode is used as the sensing element in the MFC sensor [67].

#### **16. Conclusion**

Anaerobic treatment is most commonly used to treat dairy wastewaters, mainly hybrid anaerobic and UASB digesters. Upstream anaerobic sludge blanket reactors

**121**

India

**Author details**

Aman Dongre1

, Monika Sogani<sup>2</sup>

provided the original work is properly cited.

\*, Kumar Sonu<sup>2</sup>

1 Department of Biosciences, Manipal University Jaipur, Jaipur, Rajasthan, India

2 Department of Civil Engineering, Manipal University Jaipur, Jaipur, Rajasthan,

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: monika.sogani@jaipur.manipal.edu

, Zainab Syed1

and Gopesh Sharma1

*Treatment of Dairy Wastewaters: Evaluating Microbial Fuel Cell Tools and Mechanism*

are more commonly used and ideal for the wastewater treatment from the dairy sector since they can handle large amounts of influents within a short period. But, as dairy wastewater, these processes partially degrade wastewater that contains nutrients and fats. Further treatment for anaerobically treated wastewater from the dairy is therefore necessary. The proper selection of anode material it is made from is a key factor in attempts to obtain high-performance MFCs. Selecting the incorrect anode content would make this option obsolete. Since the kinetics of the microbes used in MFCs are far slower than that which can be accomplished with cathode content or cathode catalyst, the use of 3D anodes has so far been seen to be very advantageous and capable of raising power generation by many magnitudes. Developing countries like India who are the leading producers of milk and are among the top world dairy industries rely on the use of antibiotics for enhancing the production of milk in the cows but these antibiotics when finding their way into the water streams, these are very detrimental. Therefore, the adoption of circular practices for the management of the environment is increasing in order to promote the circular economy. From a future perspective, MFCs are the most promising and environmentally friendly approach to the management of environmental pollution. However, scaling up of this technology is an obstacle due to low power outputs but this could be overcome by integrating MFC with other wastewater treatment technologies and a centralized system will solve the problem. Also, various low-cost electrode materials such as ceramics and biological materials make this technology economically sound.

*DOI: http://dx.doi.org/10.5772/intechopen.93911*

#### *Treatment of Dairy Wastewaters: Evaluating Microbial Fuel Cell Tools and Mechanism DOI: http://dx.doi.org/10.5772/intechopen.93911*

are more commonly used and ideal for the wastewater treatment from the dairy sector since they can handle large amounts of influents within a short period. But, as dairy wastewater, these processes partially degrade wastewater that contains nutrients and fats. Further treatment for anaerobically treated wastewater from the dairy is therefore necessary. The proper selection of anode material it is made from is a key factor in attempts to obtain high-performance MFCs. Selecting the incorrect anode content would make this option obsolete. Since the kinetics of the microbes used in MFCs are far slower than that which can be accomplished with cathode content or cathode catalyst, the use of 3D anodes has so far been seen to be very advantageous and capable of raising power generation by many magnitudes. Developing countries like India who are the leading producers of milk and are among the top world dairy industries rely on the use of antibiotics for enhancing the production of milk in the cows but these antibiotics when finding their way into the water streams, these are very detrimental. Therefore, the adoption of circular practices for the management of the environment is increasing in order to promote the circular economy. From a future perspective, MFCs are the most promising and environmentally friendly approach to the management of environmental pollution. However, scaling up of this technology is an obstacle due to low power outputs but this could be overcome by integrating MFC with other wastewater treatment technologies and a centralized system will solve the problem. Also, various low-cost electrode materials such as ceramics and biological materials make this technology economically sound.
