Improved microbial fuel cell (credit: Oregon State University)
Engineers at Oregon State University have made a breakthrough in the performance of microbial fuel cells that can produce electricity directly from wastewater, opening the door to a future in which waste treatment plants not only will power themselves, but will sell excess electricity.
The new technology developed at OSU uses new concepts — reduced anode-cathode spacing, evolved microbes and new separator materials — and can produce more than two kilowatts per cubic meter of liquid reactor volume — 10 to 50 more times the electrical per unit volume than most other approaches using microbial fuel cells, and 100 times more electricity than some.
This technology cleans sewage by a very different approach than the aerobic bacteria used in the past. Bacteria oxidize the organic matter and, in the process, produce electrons that run from the anode to the cathode within the fuel cell, creating an electrical current.
Almost any type of organic waste material can be used to produce electricity — not only wastewater, but also grass straw, animal waste, and byproducts from such operations as the wine, beer or dairy industries.