Hold on to sewage

What is scarce? - Energy, power. What is abundant? - Waste. And if you can convert the abundant into the scarce, what joy!

Engineers at Oregon State University have made a significant advance toward producing electricity from sewage, by the use of new coatings on the anodes of microbial electrochemical cells that increased the electricity production about 20 times.

The findings, just published online in Biosensors and Bioelectronics, a professional journal, bring the researchers one step closer to technology that could clean biowaste at the same time it produces useful levels of electricity -- a promising new innovation in wastewater treatment and renewable energy.

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.

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. Sewage is the fuel for electricity production.

The treatment of wastewater could be changed from an energy-consuming technology into one that produces usable energy. 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.

Now this is what makes more sense than trying to discover new sources of energy, right?