Mining Wastewater for Electricity

Solar-collecting panels / SCWA

At the Sonoma Valley County Sanitation District treatment plant, one-third of the power needs are met by a solar collecting system. It's great that our local wastewater treatment plant can take advantage of all that readily available sunshine to do its work, but what if sewage treatment could actually generate electricity?

That's a question researchers at Oregon State have been investigating -- and they're finding that the possibilities are quite promising. Here's what the Smithsonian Institution had to say recently about the studies on their blog:

Could Sewage Be Our Fuel of the Future?

"Previous methods relied upon anaerobic digestion, in which bacteria break down biodegradable elements in wastewater in the absence of oxygen and produce methane (natural gas) as a byproduct. This gas can then be collected and burned as fuel.

"The Oregon State team’s technology, in contrast, harnesses the biodegradable material in wastewater to feed aerobic bacteria, which digest the substances with the use of oxygen. When the microbes oxidize these components of sewage—and, in turn, clean the water—they produce a steady stream of electrons. As the electrons flow from the anode to the cathode within a fuel cell, they produce an electrical current, which can be directly used as a power source. Additionally, this process cleans the water more effectively than anaerobic digestion and doesn’t produce unwanted byproducts."...

Kind of takes the Reduce, Reuse, Recyle mantra to a whole new level, wouldn't you say?

Aeration ponds / SCWA

You can find out more about how our wastewater is treated these days from this nifty interactive diagram on the Sonoma County Water Agency website.

And read more of the background of the Oregon State work -- as well as other 'Surprising Science' news -- on the Smithsonian science blog.

Here's the article again...
Could Sewage Be Our Fuel of the Future?