New research shows that bacteria could harness energy from organic matter.
Our sewage contains a range of different organic compounds, mainly from our kitchens and bathrooms. These substances contain quite a bit of energy which until now has been washed out with the waste water. Researchers from Ghent University in Belgium have found a way to extract that energy using bacteria. Dr. Francis Meerburg, researcher for Ghent’s Center for Microbial Ecology and Technology says: “The levels of organic matter in sewage are too low to be directly recovered. We investigated how we can use bacteria to capture this material. Our approach is unique because we have developed a high-rate variation of the so-called contact-stabilization process.”
Professor Nico Boon explains: “We periodically starve the bacteria, in a kind of ‘fasting regimen’. Afterwards, wastewater is briefly brought into contact with the starved bacteria which are gluttonous and gobble up the organic matter without ingesting all of it. This enables us to harvest the undigested materials for the production of energy and high-quality products. We starve the rest of the bacteria, so that they can purify fresh sewage again. ”
The new contact-stabilization process is able to recover up to 55% of organic matter from the sewage, a big step from the 20-30% that previous methods could manage. According to the researchers, by extracting that much organic matter, the extractable energy could enable treatment of sewage without the need for electricity. “This is an important step in the direction of wastewater treatment that is energy neutral, or even produces energy,” said Professor Siegfried Vlaeminck.
It’s your new sanitation crew
The research is already showing interest in the waste industry. DC Water, which is responsible for water purification in the US Capital, is performing a trial of the contact-stabilization process for use in their full-scale water treatment facility. They’re evaluating whether the bacteria can help make water treatment more efficient.