Microbial Fuel Cell –
Energy From Wastewater?
By James Donahue
Among the severe problems
created by world overpopulation are excessive body waste and a shortage of clean and environmentally friendly energy for heating
our homes and powering our machines.
Now an environmental
engineer at Penn State University
has dreamed up a possible way of using wastewater to generate a clean energy.
Bruce Logan says the
device, dubbed a “microbial fuel cell,” is still experimental and is perhaps no more than a concept that seems
The device involves two
electrodes separated by a proton exchange membrane similar to that used in a conventional hydrogen fuel cell. “It opens
the door to using existing hydrogen-gas-based stack technologies with bacteria in water,” Logan said.
He said wastewater flows
on one side of the cell and air flows on the other, continuously generating electricity while also removing organic matter
from the water.
The concept appears to
be a workable solution to some energy problems, although Logan
says he doesn’t see it solving all of the world’s needs.
Since the project began
about two years ago, the technology has grown from a device that produces from 0.1 to 350 watts of energy per square meter
of wastewater. “We’d like to get in the range of 500 to 1,000,” Logan
He said he doesn’t
see his microbial fuel cell used for running cars or heating homes, but he believes it will be a useful power source on farm
operations or at municipal waste treatment facilities where there is an abundance of organic material.
For example, Logan believes a wastewater treatment plant might power itself as it
treats water. He also thinks it might produce a net amount of energy.
David Bagley, a scientist
at University of Toronto,
says the energy potential in wastewater is estimated at about 10 times the cost of treating it. “If we could achieve
just one-twentieth of that power, we could break even,” he said.
Onward and upward.