Water is one of the most important things on earth. We all need it, we all use it. I mean, life wouldn't
exist on this planet without water. So we put a lot of energy into trying to figure out how to make sure
water is clean and available when we need it. What if we could use dirty water to clean itself and
make electricity? Then all the stuff we don't want could be used as fuel
to get what we do. Researchers at Penn State University are looking to see how little creatures
that can munch on waste could someday make a big difference by generating electricity.
BRUCE LOGAN: One of the main technologies that we study is what's called a microbial fuel cell. And this
is just simply a box that we put water into, and bacteria- they're not special bacteria, but they have
a special property- they can chew up organic matter and release electrons to electrodes.
LISA VAN PAY: Organic matter can be a whole lot of different things, including
well, you get the idea. The bacteria in the fuel cell like to munch on this stuff. And as a normal
part of their metabolism, they move electrons around. The tricky part is getting them to move electrons
where we want them. In this case, we force the bacteria to move electrons to these carbon bristles.
Eventually the electrons build up and push each other across a circuit, powering a fan or a light bulb, or
whatever you want.
BRUCE LOGAN: The end product is to break down the organic matter, and to produce harmless water.
LISA VAN PAY: So we're taking stuff we don't want anyway, and with the help of bacteria, turning it into
electricity to clean water. And all without any pollution or emissions.
LISA VAN PAY: I see you have a lot of wires strung across your lab benches here.
What do you do with those?
BRUCE LOGAN: Each pair of wires connects up to one of these reactors, wired into this multi-meter, which
collects data from all these reactors. (Lisa: So you can put different bacteria in each of
these and determine which one is giving you the most energy production?) Right, we put vinegar in this one,
banana peels in this one, or whatever you'd like in each reactor.
And we're looking for those super bacteria, ones that are capable of producing very high current densities.
LISA VAN PAY: So in the lab you're obviously studying something on a really small scale. How do you go about
learning enough about it to do something that we might be able to use in our houses?
BRUCE LOGAN: Well, we can study a lot of these systems at very small scales. It allows us to very
quickly determine what factors affect power generation. But we then have to understand what
factors change when you make them larger. So we go from these smaller reactors to slightly bigger
reactors, and then reactors maybe the size of this bottle, to bigger reactors like this.
LISA VAN PAY: So it takes a lot of time and a lot of different studies on a bunch of scales to really
understand how these things work. So the potential for bigger and better fuel cells in the future is
definitely there. And it's starting already. Bruce and his team have set up a couple of these reactors- this
time as big as refrigerators- to make electricity for treating the waste water of a winery in California.
LISA VAN PAY: And it's not just researchers and big laboratories. Just about anybody can make a microbial
fuel cell. There are lots of tutorials and instructions online, and people are building them
right now for science projects or school assignments, or just because they want to know how they work. This
kind of simple, inexpensive fuel cell can be built just about anywhere, including places that don't
usually have access to electricity.
BRUCE LOGAN: And we're hoping that this is the kind of device that would allow developing nations to have
access to clean water and to treat waste water. But at the same time producing electricity. And that could be
used for lighting, or it could be used to charge cell phones, or just about anything.
LISA VAN PAY: Water treatment uses a huge amount of the world's energy. If we could use microbial fuel
cells to power the process, we wouldn't have to rely on other sources for the energy. The National Science
Foundation funds people like Bruce so they can think of new ways to use what we know about the world to
help solve our problems. Because sometimes small things can lead to really big ideas.
I've always wanted to do this.