Washington, July 22 (ANI): American engineers have made a significant advance toward generating electricity from sewage - by using new coatings on the anodes of microbial electrochemical cells that increased the electricity production about 20 times.
The findings, by researchers at Oregon State University, appear online in Biosensors and Bioelectronics, a professional journal.
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. 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," said Frank Chaplen, an associate professor of biological and ecological engineering.
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.
The technology already works on a laboratory basis, researchers claim, but advances are necessary to lower its cost, improve efficiency and electrical output, and identify the lowest cost materials that can be used.
"Recent advances in nanofabrication provide a unique opportunity to develop efficient electrode materials due to the remarkable structural, electrical and chemical properties of nanomaterials," the researchers wrote in their report. "This study demonstrated that nano-decoration can greatly enhance the performance of microbial anodes." (ANI)