WeatherImpact Earth


Algae could be key to reducing carbon emission in wastewater treatment process

Posted at 4:10 PM, Dec 09, 2021
and last updated 2021-12-09 19:42:37-05

MESA, AZ — In a small area of the Mesa Northwest Water Reclamation facility, a big idea is churning its way to success.

“As my wife says, I’m an algae farmer,” said Everrett Eustance.

It’s a fitting description for Eustance and Justin Flory. For the past six weeks, the ASU researchers have taken the carbon dioxide produced during the water treatment process and fed it to micro-algae stored in racetrack shaped pools.

“Both CO2 and methane are critical greenhouse gases, they are causing global warming which is causing many other crises around the world,” said Eustance.

Wastewater treatment produces biogas made up of both. As with most treatment plants, the methane is burned away but the CO2 makes its way into our atmosphere. This project proposes a better solution with no burning required. Instead of burning the biogas, it’s piped into pools through thin, hollow fibers.

“With this process, you’re basically able to capture all that carbon dioxide and put it to productive use, it’s going in to grow a crop,” said Flory.

The Microalgae in the pools consume or “eat” the CO2 and researchers can use the algae that’s grown to create biofuels, pharmaceuticals, and even food. As for the methane, most of it goes out the end of the fibers and is captured for later use. Because nearly all the carbon dioxide is removed, the exiting gas is a purer form of biomethane.

“We have been experimenting for years using the methane that comes from wastewater to power our garbage trucks and that is something that we can harvest from this process that is very useful,” said Mesa Mayor John Giles.

Mayor Giles got a look at the ASU project Thursday. One of the many strategies being spearheaded by the city at the moment.

“We adopted a climate action plan and we set some very aspirational goals for ourselves including being carbon neutral by 2050,” said Mayor Giles. “This partnership with ASU where they’re going to use carbon dioxide in agriculture, to create these algae that really has a lot really positive uses, it really is not an overstatement to say this could really change the world.”

How Mesa reduces the carbon footprint of its wastewater treatment will play a major role in reaching that goal as our population continues to grow. The partnership with ASU taking the steps to figure it out.

“My goal eventually is to see thousands of these pools together working in unison,” said Eustance.

“We want to turn a problem into a solution, now we’ve got food, fuels, fertilizers, all kinds of great stuff that are coming out of that waste,” said Flory.