Microbial Fuel Cell Experiment Report: Energy Generation Study

This report details a laboratory experiment investigating the use of Microbial Fuel Cells (MFCs) to generate electricity using three bacterial strains: E. coli, Enterobacter, and Citrobacter freundii. The experiment employed two different graphite electrodes (agar and felt) to measure voltage output over time. The report includes an introduction to MFC technology, the research aim, experimental results presented in tables and charts, a discussion of the findings in relation to existing scientific literature, and recommendations for future studies. The results indicate that electricity generation was achieved, with variations in performance observed across different organisms and electrode types. The study highlights the potential of MFCs as a renewable energy source and discusses areas for improvement and further research, including the use of more diverse bacterial strains and enhanced experimental setups. All the references used are peer-reviewed articles and the report adheres to the UWS Harvard Style.

Table of Contents
Introduction.................................................................................................................................................1
Research aim...........................................................................................................................................2
Research Results......................................................................................................................................2
Electrode graphite agar.......................................................................................................................2
Electrode graphite felt.........................................................................................................................3
Discussion................................................................................................................................................5
Recommendation to future studies.........................................................................................................6
List of reference...........................................................................................................................................7
Introduction
At the moment, the world at large is facing energy problems due to insufficient
production of energy which also sourced from non-renewable sources such as nuclear
energy, fossils fuels, coal and natural gas which its mining and production according
Bulut.U 2017 hampers the environment by excessive production of carbon (iv) oxide
which depletes the ozone layer also increase global warming, main cause of acidic rain
water, pose health hazard to human beings and also it residuals are usually non-
biodegradable. A hundred percent dependence of non-renewable sources would leave
the world in a serious energy crisis should such source become depleted. It is therefore
important that the world observe and appreciate the use of renewable sources of energy
that are environmentally and health friendly and it would save the world the risk of
running out of energy sources since it does not get depleted.
Panwar.N 2011 proposed renewable sources of energy including wind power, solar,
geothermal and the microbial fuel cells. Pant.D 2010 defined microbial fuel cell mostly
known as MFCs are devices convert energy from respiring oxidizing agents and
microbes from anodes using cell bacteria to catalyze the chemical reaction to generate
electric current, performing a redox reaction. According to Winfield.J 2014 the use of
microbes to generate electric energy began at the early twentieth century around the
year 1910 by a university professor named M.C Potter. Potter succeeded using the
E.coli organism to generate electric energy. His success motivated thousands of other
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scholars as the years eloped by who continued to lead massive developments in the
use of microbes to produce energy.
Numerous technological changes have been introduced since the invention of the
microbial fuel cell by MC. Potter. At the beginning of the 21st century scientist started
modifying the original experimental design configurations of the microbial fuels,
according to Karra.U 2013 this led to establishment of one chambered, two chambered,
tubular, h-type, and upflows Mfcs designs. The changing of the anodes and cathodes to
have a biological anode and abiotic cathodes joined by a porous proton layer with
experimental mediators of electrons and redox reaction temperature control resulted in
increasing the power outputs produced and easier way of controlling the experimental
residues such as toxicity and materials such as the oxygen.
The most used organisms in performing of the microbial fuel growth experiments
includes: E.coli, enterobacter and Citrobacter Freundii. Their scientific names are
Escherichia coli, Enterobacter and Citrobacter freundii respectively. Amazingly all the
organisms are placed under the same phylum Proteobacteria, family
Enterobacteriaceae and order Enterobacteriales. Their phylum mostly constitutes of
pathogens. It is believed that the organisms namely; E.coli, enterobacter and
Citrobacter Freundii can be helpful to the world by creating sources of sufficient
renewable energy and also help in treatment of waste water. This lab report is
interested in examining the abilities of the three organisms to generate electric energy
by using two different graphite electrodes. The Mfcs experiment is dived into four
experimental parts namely the anode part where the bacteria are held, the cathode part
which holds the reacting agents, the proton layer part which separates the anode and
the cathode and controls protons movements and the last part electric circuit part.
Research aim
The aim of the research is to demonstrate the use E.coli, enterobacter and Citrobacter
Freundii to produce electric energy.
Research Results
The experiment was conducted three times in two dimensions using the agar and felt
graphite electrodes. The results were recorded after one week a period of 168 hours.
The voltage is measured in mV units. The following results were obtained;
Electrode graphite agar
The following results were obtained on the organisms: Citrobacter Freundii,
enterobacter and E.coli having generated electric voltage of 109.7, 47.1, 85.5 on
experiment one, 105, 136, 21.1 on experiment two and 10, 61.5 and 72.4 on experiment
three respectively.
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The results are summarized in the table below
agar
organism pract
1
pract
2
pract
3
averag
e
sd
citrobactor freundii 109.7 105 10 74.9 56.2541
6
enterbacter 47.1 136 61.5 81.53 47.7158
6
e.coli 85.5 21.1 72.4 59.66 34.0359
1
Electrode graphite felt
The following results were obtained on the organisms: Citrobacter Freundii,
enterobacter and E.coli having generated electric voltage of 124.8, 133.7, 21.1 on
experiment one, 56.3, 139.3, 21.1 on experiment and 106.7, 75.7 and 300 on
experiment three respectively.
felt
sorganism pract
1
pract
2
pract
3
averag
e
SD
citrobactor freundii 124.8 56.3 106.7 95.93 35.4965
3
enterbacter 133.7 139.3 75.7 116.23
3
35.2143
9
e.coli 21.1 21.1 300 114.06
6
161.023
3

The representation of results in the charts
0 20 40 60 80 100 120 140 160 180
0
20
40
60
80
100
120
140
160
citrobactor freundii
enterbacter
e.coli
Time (h)
Voltage (mV)
4

0 20 40 60 80 100 120 140 160 180
0
20
40
60
80
100
120
140
160
citrobactor freundii
enterbacter
e.coli
Time (h)
Voltage (mV)
Discussion
From the results, voltage production is above the baseline (reading at 0h), showing
electricity generation. Also the results from the experiment are inconsistent. This can
be seen on the amount of voltage produced by the organism Citrobactor freundii which
varied from 109.7mV from the first experiment to a voltage of 10mV on the last
experiment, such deviations led to enlarging the standard deviations. A comparison of
agar and felt graphite electrodes is obtained and how each organism reacted and
amount of energy produced.
The results found on the experiment matched other researches done by other scholars
such as Sharma.Y 2010 and Degrenne.N 2012 who found that the microbes could
produce energy.
Electrode agar
organism exp
1
exp
2
exp
3
mea
n
sd
citrobactor
freundii
10
9.7
105 10 74.9 56.2
5416
5

enterbacter 47.
1
136 61.5 81.5
3
47.7
1586
e.coli 85.
5
21.1 72.4 59.6
6
34.0
3591
On average the organism Enterobacter produced more energy than the rest of the
organisms but Citrobacter freundii had a bigger deviation which means that its values
were widely dispersed.
Electrode felt
organism exp
1
exp
2
ex
p 3
me
an
SD
citrobactor
freundii
124
.8
56.3 10
6.7
95.
93
35.4
9653
enterbacter 133
.7
139.
3
75.
7
116
.23
3
35.2
1439
e.coli 21.
1
21.1 30
0
114
.06
6
161.
023
On this experiment the organism Enterobacter had produced a bigger energy than the
rest of the other organisms but the organism Escherichia coli had a bigger standard
deviation of 161.023.
In conclusion using the graphite felt electrode produced a bigger energy than using
graphite agar electrode in all the three organisms. This means that felt is better than
ager in terms of energy production.
The achievement of the research aim to produce electric energy using the three
organisms shows that the world should be prepared to use green energy from microbes.
Recommendation to future studies
 More funds should be allocated to researches to be conducted in future. This is
to enable the research team to purchase technical apparatus that can assist in
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performing the experiment. According to McNay.I 2015 money affects quality of
research.
 A lot of bacteria and organisms of phylum Proteobacteria, family
Enterobacteriaceae and order Enterobacteriales such organisms should be
included in the study. There could be some organisms that can produce more
energy than the ones known.
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List of reference
Bulut, U., 2017. The impacts of non-renewable and renewable energy on CO 2
emissions in Turkey. Environmental Science and Pollution Research, 24(18), pp.15416-
15426.
Degrenne, N., Buret, F., Allard, B. and Bevilacqua, P., 2012. Electrical energy
generation from a large number of microbial fuel cells operating at maximum power
point electrical load. Journal of Power Sources, 205, pp.188-193.
Karra, U., Troop, E., Curtis, M., Scheible, K., Tenaglier, C., Patel, N. and Li, B., 2013.
Performance of plug flow microbial fuel cell (PF-MFC) and complete mixing microbial
fuel cell (CM-MFC) for wastewater treatment and power generation. International
Journal of Hydrogen Energy, 38(13), pp.5383-5388.
McNay, I., 2015. Debate: Does research quality assessment increase output and give
value for money?. Public Money & Management, 35(1), pp.67-68.
Pant, D., Van Bogaert, G., Diels, L. and Vanbroekhoven, K., 2010. A review of the
substrates used in microbial fuel cells (MFCs) for sustainable energy
production. Bioresource technology, 101(6), pp.1533-1543.
Panwar, N.L., Kaushik, S.C. and Kothari, S., 2011. Role of renewable energy sources in
environmental protection: A review. Renewable and Sustainable Energy
Reviews, 15(3), pp.1513-1524.
Sharma, Y. and Li, B., 2010. Optimizing energy harvest in wastewater treatment by
combining anaerobic hydrogen producing biofermentor (HPB) and microbial fuel cell
(MFC). International Journal of Hydrogen Energy, 35(8), pp.3789-3797.
Winfield, J., Chambers, L.D., Stinchcombe, A., Rossiter, J. and Ieropoulos, I., 2014. The
power of glove: Soft microbial fuel cell for low-power electronics. Journal of Power
Sources, 249, pp.327-332.
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