Power from poo: Breakthrough could lead to sustainable electricity from sewage
Oh, the wonderful things that poo can do.
When it comes to talking about poo, it seems like most people's noses wrinkle up and they start looking for a quick exit from the conversation, which is a shame, because it's actually an incredibly useful material, whether you're talking about manure or human sewage. Sure, it needs to be handled correctly and dealt with intelligently, but feces and urine can provide a lot of benefits to us - mostly indirectly - by adding fertility to soils. And it's too bad that while we might know how to deal with it 'correctly' with our modern wastewater infrastructure, for the most part we don't handle it very intelligently.
Our wastewater systems combine stormwater, greywater, and even clean water (such as when we inadvertently let potable water run right down the drain without using it for some purpose) with the sewage from our toilets, when we could actually design and implement systems that would segregate the slightly tainted water (greywater and stormwater) from that which comes from toilets.
But that's a post for another day...
One innovation that could play a big part in wastewater reclamation (and its energy footprint) is using microbial fuel cells in the process, in order to at least partially power wastewater treatment facilities sustainably. And researchers at Virginia Tech have made a breakthrough in understanding how electrochemically-active bacteria create energy from the 'foods' they eat. This discovery may lead to more efficient wastewater-to-energy technologies, and could be an important stepping stone on the path to more sustainable infrastructure.
According to Virginia Tech News, Xueyang Feng and Jason He were able to trace the metabolic pathways of different strains of bacteria, and the researchers found that a "working relationship" between two different substrates was able to produce more energy either of them working separately
"While one substrate known as lactate was mainly metabolized by its host bacteria to support cell growth, another substrate known as formate was oxidized to release electrons for higher electricity generation."
Here's a basic explanation of the work being done to improve 'poo to power' systems:
"Tracing the bacteria gave us a major piece of the puzzle to start generating electricity in a sustainable way. This is a step toward the growing trend to make wastewater treatment centers self-sustaining in the energy they use." - Xueyang Feng, assistant professor of biological systems engineering
Thanks to work such as this, in the future, it may be possible to power the plants that treat our wastewater by using the wastewater itself as 'fuel' for an army of microorganisms that can produce electricity. More details about the research can be found published in the journal Nature.