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A. A. S. Al-Gheethi et al.
6.1 Introduction
The over increasing in the population, industrial, and agriculture activities associate
with the need for more energy. The traditional resource of the energy such as fossil
fuels is contributing to the environmental pollution. Many of the adverse effects on
the environment have been reported in literature since several years ago as a result of
overutilization of fossil fuels. Therefore, repair of the damage in the environment is
conducted with the long-term solution (IPCC 2014). More attention has been given
by researchers to find alternative resources for the energy. Microalgae–microbial fuel
cells (MMFCs) is one of the best alternative sources for the energy because algae
are photocatalytic organisms with very low nutrient requirements; therefore, algae
has a dual role for treatment of wastewater contaminated with nutrients and produce
the bioenergy as biohydrogen, biodiesel, and bioethanol as well as biomass yield.
Figure 6.1 shows the medical and environmental applications of algae.
Algae are among several photosynthetic organisms which have the ability to convert the solar light into biochemical energy (Mohan et al. 2011; Jais et al. 2017).
Several types of wastewater have been investigated as potential substrates for inducing microalgae and bacterial growth in the MMFCs (Pandey et al. 2016; Pahazri et al.
2016; Al-Gheethi et al. 2019). MMFCs with bacteria and MMFCs with algae are quite
different. In MFCs with bacteria, the chemical energy available in the chemical bonds
of the organic compounds is converted to bioelectrical energy through catalytic reactions of the bacterial cells under anaerobic conditions. Meanwhile, in MMFCs with
algae, the bioelectricity is generated as a result of converting the solar light during
photocatalysis process. The MFCs consist of two chambers, namely, the anode and
cathode chambers. In many cases, bacterial cells are used as anode which release the
electron as a result of oxidation process while microalgae are used as cathode which
received the electron to be used in the reduction process.
The current chapter aimed to highlight the potential of algae in the MMFCs for
production of bioenergy and factors affecting the bioenergy production process.
6.2 Microbial Fuel Cells (MFCs)
Microalgae fuel cells (MFCs) are a device used to convert solar energy into electrical
energy as a function of metabolic and anabolic pathways of the algae cells (Lee and
Huang 2013). The MFCs are different from the direct methanol fuel cells and other
non-biotic fuel systems. The main differences include the complexity of the biotic
system with addition of organisms which are responsible for inducing the electrochemical reactions. Moreover, the biological system for the production of bioenergy
is more flexible since it can work within a range of temperature (15–45 °C). pH also
can contribute efficiently in the treatment of the wastewater (Santoro et al. 2017).
The process has received high attention from researchers over the years due to the
simplicity of the process, absence of toxic by-products, and low requirements for
A. A. S. Al-Gheethi et al.
6.1 Introduction
The over increasing in the population, industrial, and agriculture activities associate
with the need for more energy. The traditional resource of the energy such as fossil
fuels is contributing to the environmental pollution. Many of the adverse effects on
the environment have been reported in literature since several years ago as a result of
overutilization of fossil fuels. Therefore, repair of the damage in the environment is
conducted with the long-term solution (IPCC 2014). More attention has been given
by researchers to find alternative resources for the energy. Microalgae–microbial fuel
cells (MMFCs) is one of the best alternative sources for the energy because algae
are photocatalytic organisms with very low nutrient requirements; therefore, algae
has a dual role for treatment of wastewater contaminated with nutrients and produce
the bioenergy as biohydrogen, biodiesel, and bioethanol as well as biomass yield.
Figure 6.1 shows the medical and environmental applications of algae.
Algae are among several photosynthetic organisms which have the ability to convert the solar light into biochemical energy (Mohan et al. 2011; Jais et al. 2017).
Several types of wastewater have been investigated as potential substrates for inducing microalgae and bacterial growth in the MMFCs (Pandey et al. 2016; Pahazri et al.
2016; Al-Gheethi et al. 2019). MMFCs with bacteria and MMFCs with algae are quite
different. In MFCs with bacteria, the chemical energy available in the chemical bonds
of the organic compounds is converted to bioelectrical energy through catalytic reactions of the bacterial cells under anaerobic conditions. Meanwhile, in MMFCs with
algae, the bioelectricity is generated as a result of converting the solar light during
photocatalysis process. The MFCs consist of two chambers, namely, the anode and
cathode chambers. In many cases, bacterial cells are used as anode which release the
electron as a result of oxidation process while microalgae are used as cathode which
received the electron to be used in the reduction process.
The current chapter aimed to highlight the potential of algae in the MMFCs for
production of bioenergy and factors affecting the bioenergy production process.
6.2 Microbial Fuel Cells (MFCs)
Microalgae fuel cells (MFCs) are a device used to convert solar energy into electrical
energy as a function of metabolic and anabolic pathways of the algae cells (Lee and
Huang 2013). The MFCs are different from the direct methanol fuel cells and other
non-biotic fuel systems. The main differences include the complexity of the biotic
system with addition of organisms which are responsible for inducing the electrochemical reactions. Moreover, the biological system for the production of bioenergy
is more flexible since it can work within a range of temperature (15–45 °C). pH also
can contribute efficiently in the treatment of the wastewater (Santoro et al. 2017).
The process has received high attention from researchers over the years due to the
simplicity of the process, absence of toxic by-products, and low requirements for