Connect with us

Hi, what are you looking for?

There is a new and efficient version of a machine that both processes sewage and makes electricity doing it in town [...]

Green Economy

Energy Plus Clean Water from New Wastewater Treatment Tech Equals Awesome

There is a new and efficient version of a machine that both processes sewage and makes electricity doing it in town […]

electricity from sewage - new source of power?

One of the awesome things about living in the time we do is also one of the things that no one ever seems to mention – the sewer systems. The pipes and drains are below our feet, doing their thing every day, and a lot of us kind of seem to take it for granted. There’s quite a bit of energy that goes into processing and disposing of waste, though, which just makes the announcement at the 243rd National Meeting & Exposition of the American Chemical Society (ACS) that much greater: there is a new and efficient version of a machine that both processes sewage and makes electricity doing it, and that device could be commercially viable.

From Taking Energy to Making It

Current wastewater treatment tech has a lot of steps: separation, settling, filtration, biological digestion, and chemical treatment. There’s a lot of equipment, too, including settling tanks, macerators, membranes, and so on. At least one evaluation has estimated that wastewater treatment uses 2% of the United States’ overall energy consumption. It’s not the first waste-fueled machine in the United States, but it does seem to have the broadest potential application.

The machine in question, presented by Orianna Bretschger, Ph.D., is a new and improved version of a previous prototype. It’s a microbial fuel cell (MFC), and it has a 13% energy recovery capacity. That’s a pretty major improvement over the initial prototype, which had a 2% energy recovery capacity. Bretschger, when presenting the report, mentioned that this could have a significant impact on water treatment and availability, particularly in developing countries:

“We’ve improved its energy recovery capacity from about 2 percent to as much as 13 percent, which is a great step in the right direction. That actually puts us in a realm where we could produce a meaningful amount of electricity if this technology is implemented commercially. Eventually, we could have wastewater treatment for free. That could mean availability for cleaner water in the developing world, or in southern California and other water-short areas of the United States through the use of more wastewater recycling technologies.”

What’s A Microbial Fuel Cell?

An MFC is exactly what it says on the tin – it’s a biological fuel cell. Where traditional fuel cells convert fuel into electricity without igniting it (combining hydrogen and oxygen, as in the hydrogen fuel cell), an MFC uses organic matter as the fuel and microbes to break them down. As the microbes break down the organic matter, electrons (the movement of which constitutes electricity) are produced.

Bretschger’s revised MFC uses sewage from a bog standard sewage treatment plant. It’s made of a sealed container and an unsealed container, separated by a membrane. The microbes grow in a film on an electrode in the sealed chamber, sending electrons to the electrode and protons to the unsealed container. Oxygen in that container plus microbes on a second electrode plus the electrons from the sealed chamber combine to produce things that are not sewage and generate some electricity in the process (remember, electricity is electrons moving from point A to point B, which is pretty much what’s happening here).

The Final Results

New and improved: costs less, more power.

The new prototype is less expensive than the first one, since initial titanium components have been replaced with PVC and graphite (although, it’s still six or seven times the cost per gallon of conventional water treatment tech). The Bretschger’s team hopes to keep bringing the cost down. The team also hopes to further improve energy recovery efficiency – right now, it’s at 13%. Bretschger thinks that if they can get a big enough device going at maybe 20-25% (the same numbers as some current mass-produced solar cells), they could actually power a conventional sewage treatment plant.

The device also removes the vast majority of organic matter and potentially disease-causing microbes, Bretschger also pointed out. Although, it’s not quite at the point of creating drinkable water along with electricity:

“We remove about 97 percent of the organic matter. That sounds clean, but it is not quite clean enough to drink. In order to get to potable, you need 99.99 percent removal and more complete disinfection of the water.”

Life is a cycle, guys. I don’t think any one single clean energy technology is going to be the salvation wave breaking us free of fossil fuels; rather, I think a lot of types of tech working in tandem will eventually do the trick. This particular little machine uses a resource that is never, ever going to be used up, and I’d say that makes it a pretty viable area for further research. What do you think? Let us know in the comments, below.

Source: American Chemical Society via Science Daily
Image Credits: American Chemical Society, Wikimedia Commons

Sign up for daily news updates from CleanTechnica on email. Or follow us on Google News!

Have a tip for CleanTechnica, want to advertise, or want to suggest a guest for our CleanTech Talk podcast? Contact us here.

Former Tesla Battery Expert Leading Lyten Into New Lithium-Sulfur Battery Era — Podcast:

I don't like paywalls. You don't like paywalls. Who likes paywalls? Here at CleanTechnica, we implemented a limited paywall for a while, but it always felt wrong — and it was always tough to decide what we should put behind there. In theory, your most exclusive and best content goes behind a paywall. But then fewer people read it! We just don't like paywalls, and so we've decided to ditch ours. Unfortunately, the media business is still a tough, cut-throat business with tiny margins. It's a never-ending Olympic challenge to stay above water or even perhaps — gasp — grow. So ...
If you like what we do and want to support us, please chip in a bit monthly via PayPal or Patreon to help our team do what we do! Thank you!
Written By

spent 7 years living in Germany and Japan, studying both languages extensively, doing translation and education with companies like Bosch, Nissan, Fuji Heavy, and others. Charis has a Bachelor of Science degree in biology and currently lives in Chicago, Illinois. She also believes that Janeway was the best Star Trek Captain.


You May Also Like


Hyundai is reclaiming the Cybertruck look with a new hybrid fuel cell version of its iconic 1974 Pony Coupe Concept car.


Despite the attacks on ESG investing, Hyundai roars into Georgia with another new fossil-killing electric vehicle battery manufacturing plant.

Clean Power

The massive new SunZia wind energy transmission line is closing in on the finish line, ESG or not.


BMW is stepping up from vehicle-to-grid EV charging to kick vehicle-to-everything (V2X) into gear, with an assist from the California utility PG&E

Copyright © 2023 CleanTechnica. The content produced by this site is for entertainment purposes only. Opinions and comments published on this site may not be sanctioned by and do not necessarily represent the views of CleanTechnica, its owners, sponsors, affiliates, or subsidiaries.