Decision time? Check out our latest product comparisons

Nanotech coatings offer possibility of ‘brown’ electricity from sewage

By

July 22, 2010

Sewage plants like this could soon be soon be self-sufficient in terms of energy usage (Im...

Sewage plants like this could soon be soon be self-sufficient in terms of energy usage (Image: dweekly via Flickr)

Image Gallery (3 images)

While much of the focus on renewable electricity production focuses on green alternatives, a team of engineers at Oregon State University is looking at ways to improve electricity production from a “brown” source – namely sewage. The engineers found that using new coatings on the anodes of microbial electrochemical cells they were able to increase the electricity production from sewage about 20 times.

The researchers say that the findings are a promising new innovation in wastewater treatment and renewable energy as it brings them one step closer to technology that could clean biowaste at the same time it produces useful levels of electricity.

In this technology, bacteria from biowaste such as sewage are placed in an anode chamber, where they form a biofilm, consume nutrients and grow, in the process releasing electrons. In this context, the sewage is literally the fuel for electricity production.

Engineers found that by coating graphite anodes with a nanoparticle layer of gold, the production of electricity increased 20 times. Coatings with palladium produced an increase, but not nearly as much. And the researchers believe nanoparticle coatings of iron – which would be a lot cheaper than gold – could produce electricity increases similar to that of gold, for at least some types of bacteria.

“This is an important step toward our goal,” said Frank Chaplen, an associate professor of biological and ecological engineering. “We still need some improvements in design of the cathode chamber, and a better understanding of the interaction between different microbial species. But the new approach is clearly producing more electricity.”

In related technology, a similar approach may be able to produce hydrogen gas instead of electricity, with the potential to be used in hydrogen fuel cells that may power the automobiles of the future. In either case, the treatment of wastewater could be changed from an energy-consuming technology into one that produces usable energy.

The researchers say the development of this technology could significantly reduce the cost of wastewater treatment in the United States. It might also find applications in rural areas or developing nations, where the lack of an adequate power supply makes wastewater treatment impractical. It may be possible to create sewage treatment plants that are completely self-sufficient in terms of energy usage.

The technology already works on a laboratory basis, researchers say, but advances are necessary to lower its cost, improve efficiency and electrical output, and identify the lowest cost materials that can be used.

In their report, published online in the journal Biosensors and Bioelectronics. The researchers said, “Recent advances in nanofabrication provide a unique opportunity to develop efficient electrode materials due to the remarkable structural, electrical and chemical properties of nanomaterials. This study demonstrated that nano-decoration can greatly enhance the performance of microbial anodes.”

Is there any chance that in the future we’ll receive a payment for sitting on the toilet and providing the local electricity company with biofuel? In that unlikely event, people who are ‘full of it’ could be sitting on a potential energy goldmine.

About the Author
Darren Quick Darren's love of technology started in primary school with a Nintendo Game & Watch Donkey Kong (still functioning) and a Commodore VIC 20 computer (not still functioning). In high school he upgraded to a 286 PC, and he's been following Moore's law ever since. This love of technology continued through a number of university courses and crappy jobs until 2008, when his interests found a home at Gizmag.   All articles by Darren Quick
1 Comment

"The engineers found that using new coatings on the anodes of microbial electrochemical cells they were able to increase the electricity production from sewage about 20 times"

20 times grater than what?

20 times grater than 0.0001 kWh/(some volume of sewage) or per given population size is not so impressive.

How many times to we have to improve for this technology to be viable?

Dmitry
22nd July, 2010 @ 10:44 am PDT
Post a Comment

Login with your gizmag account:

Or Login with Facebook:


Related Articles
Looking for something? Search our 28,993 articles