Guide

10
Main Module | Energy from Mud? Thank a Microbe! Background
TeacherBackground
Microbial fuel cells, also referred to as biological fuel cells, have been of interest to
scientists as a source of electricity since the early 1900s. As our demand for energy
continues to increase and our supply of energy resources continues to be stressed, we
are constantly looking for alternative energy sources.
Criteria for alternative energy technologies is becoming more focused on nding
clean, renewable sources that minimizes both the amount of energy needed to be
put in and the amount of excess greenhouse gasses released during the electricity
generating process.
Microbial fuel cells are an excellent candidate for including in a clean energy
portfolio. They require no external energy source (unlike hydrogen fuel cells which
require energy to generate the hydrogen), they do not produce any additional
greenhouse gasses, they rely on naturally occurring processes, can be used anywhere
in the world, and are self-sustaining.
Currently, the U.S. spends roughly 5% of
its energy budget on treating wastewater.
Instead of consuming energy, wastewater
treatment plants may actually be able
to generate electricity while treating the
wastewater, using microbial fuel cells.
In addition, because while metabolizing
organic material, the bacteria respire a
variety of materials including iron, uranium
and other toxic materials, MFCs can also be
used for bioremediation (removal of harmful
materials in the environment through natural biological processes). MFCs have
been used to remove many different environmental pollutants including toxic heavy
metals, petroleum and Uranium from contaminated soils and wastewater,
Using the MudWatt microbial fuel cell students are able to explore concepts in
biology, physics and chemistry in a truly integrated manner.
The resources provided here will help students explore a wide range of design and
experimental parameters that can inuence the MudWatt’s performance. Challenge
your students to manipulate different variables to see if you can optimize power
output or meet the engineering design challenge goals.
backGrouNd
Biological wastewater treatment