Notes

My research question was “Will adding Compost maker or Apple cider vinegar to
the mud increase the power output of the Fuel Cell?” Before I found that answer I
had to define a couple of terms first. Like what does benthic mud sample mean.
The bottom of lakes or Oceans were there is very little oxygen, this layer of soil is
usually found below the surface about a foot down. A fuel cell is a device that
converts the chemical energy from a fuel into electricity through a chemical
reaction with oxygen or another oxidizing agent. The most common fuel cell is a
Hydrogen fuel cell since hydrogen is the most abundant gas in the universe. A
Cathode is an electrode through which electric current flows out of a polarized
electrical device. An Anode is a positively charged electrode by which the
electrons leave a device. It is the opposite of a Cathode. Anaerobic means any
organism that requires very little oxygen for growth. Compost maker is food
designed to maximize anaerobic bacteria activity. Apple cider vinegar is apple
cider that has been fermented into an anaerobic product. Voltage output is the
amount of electrons flowing through the wire. A Microbial Fuel Cell (MFC)
converts chemical energy, available in a bio-convertible substrate, directly into
electricity. To achieve this, bacteria are used as a catalyst to convert substrate
into electrons. Bacteria are very small organisms which can convert a huge
variety of organic compounds into CO2, water and energy. The micro-organisms
use the produced energy to grow and to maintain their metabolism. However, by
using an MFC we can harvest a part of this microbial energy in the form of
electricity. A MFC consists of an anode, a cathode, and a proton exchange
membrane and an electrical circuit. The bacteria that live in the anode convert a
substrate such as glucose acetate into CO2. Under aerobic conditions, bacteria
use oxygen or nitrate as a final electron acceptor to produce water. However, in
the anode of a MFC, no oxygen is present and the bacteria need to switch from
their natural electron acceptor to an insoluble acceptor, such as the MFC anode.
Due to the ability of bacteria to transfer electrons to an insoluble electron
acceptor, we can use a MFC to collect the electrons originating from the
microbial metabolism. The electron transfer can occur either through a
membrane-associated component, a soluble electron shuttle or nano-wires. Why
does the cathode side need oxygen? The oxygen is what drives the chemical
reaction to produce electricity. Why is the voltage output erratic? Cause the
bacteria is never consistent. Who invented the microbial fuel cell? M.C. Potter
was the first to perform work on the subject in 1911. How do you measure the
voltage? You connect the volt meter with positive to the Cathode and negative to
the Anode. My results show that adding Compost maker to the Anode side has
greatly improved the power output of that fuel cell. Adding Apple cider vinegar
does nothing to increase the power output. This proves that it is possible to
increase the power of a microbial fuel cell by adding aerobic substances to the
mud. This project has been really fun to do over the course of about a month. It
really has showed me that there are more ways of producing power than just
burning fossil fuels and making the earth even more inhabitable.


Abstract
Man kind is always trying to look for a more effective way of
producing power because we can never seem to find a way that
is not only cost effective but is also eco friendly. This is where
the microbial fuel cell comes into use. It is a way of producing
energy from anaerobic bacteria. The purpose of my science fair
project was to find if adding Compost maker or Apple cider
vinegar to the mud samples would increase or decrease the
voltage output of the fuel cells. I built three fuel cells, one was
with no additives, the second was with Compost maker, and the
third was with Apple cider vinegar. These were two chamber
fuel cells with a PVC pipe glued between them. The connector
acted like my proton exchange membrane. Each chamber of the
fuel cell has a copper wire with a carbon fiber electrode
epoxied to it. I tested each fuel cell every day two times a day
for two weeks. All three fuel cells showed a steady state
voltage output of between 40 to 70 mV before additives. My
data shows that the Compost maker greatly increased the
voltage output to 249 mv, but the Apple cider vinegar did
nothing to change the voltage output. The fuel cell with the
Compost enhancer increased it’s voltage production by four
times over is steady state value. My experiment clearly shows
that there ways to increase the voltage produced by a Microbial
Fuel Cell.
conclusion