A researcher at Oregon State University (OSU) in the USA is currently discussing with several companies potential collaboration over the development of a microbial fuel cell, which the university claims can produce 10-50 times more electricity from wastewater by volume than most other approaches.
This would allow wastewater treatment and reuse plants not only to power themselves, but to sell excess electricity.
The new approach, from research funded by the US National Science Foundation, would produce significant amounts of electricity while effectively cleaning the wastewater. The findings have been published in Energy & Environmental Science journal, by the Royal Society of Chemistry.
“If this technology works on a commercial scale the way we believe it will, the treatment of wastewater could be a huge energy producer, not a huge energy cost,” said Hong Liu, an associate professor in the OSU Department of Biological & Ecological Engineering. “This could have an impact around the world, save a great deal of money, provide better water treatment and promote energy sustainability.”
OSU researchers reported on this technology several years ago, but at that time the systems in use produced far less electrical power. With new concepts – reduced anode-cathode spacing, evolved microbes and new separator materials – the technology can now produce more than 2kW/m³ of liquid reactor volume, far exceeding anything else done with microbial fuel cells.
The system also works better than creating electricity from wastewater by producing methane. It treats the wastewater more effectively, and has none of the environmental drawbacks of methane production, such as unwanted hydrogen sulfide or possible release of methane, a potent greenhouse gas.
The OSU system has now been proven at a substantial scale in the laboratory, Liu said, and the next step would be a pilot study. A good candidate, she said, might initially be a food processing plant, which is a contained system that produces a steady supply of certain types of wastewater that would provide significant amounts of electricity.
Continued research should also find even more optimal use of necessary microbes, reduced material costs and improved function of the technology at commercial scales, OSU scientists said.