ARPA-E to fund chemical capture from wastewater

Wastewater is full of valuable chemicals. They can be pollution problems when they end up in sewage sludge or mine-tailing ponds. But when isolated from wastewater, those same chemicals can feed domestic supply chains and displace climate-damaging feedstocks.

To that end, the US Department of Energy (DOE) today announced $36 million in funding for technologies to extract ammonia, critical metals, and other valuable chemicals from municipal, industrial, and mining wastewater streams. The program, from the DOE’s Advanced Research Projects Agency-Energy (ARPA-E), is called Realize Energy-rich Compound Opportunities Valorizing Extraction from Refuse Waters, or RECOVER.

RECOVER has goals of displacing 50% of conventional ammonia supplies in the US, according to program director Charles Werth, and reducing or eliminating the US’s reliance on imports of 25 critical metals. “The materials that we’re trying to recover from wastewater are very important to the energy landscape,” he says.

The US uses about 15 million metric tons (t) of ammonia per year, mostly as fertilizer, according to the US Geological Survey. It is made via the Haber-Bosch process, which emits 2 t of CO₂ per 1 t of NH₃ produced. “If we have the opportunity to recover that from waste streams, we can offset large amounts of energy use and CO₂,” Werth says.

“For the critical metals that we’re targeting, we import virtually all of those,” he says. “Finding new sources of those metals is very important to the United States.”

Werth says he wants to see proposals on novel adsorbants, membranes, biomolecules, and electrochemical cells that can selectively separate ammonia or specific metal cations in solution. He expects a mix of academic labs, start-ups, and US national laboratories to show interest.

RECOVER has a fast timeline. Concept papers are due by the end of December and full proposals at the end of January. Werth says ARPA-E hopes to execute award contracts by the end of September 2025. “We’re looking for ideas or concept papers from all different backgrounds: chemists, material scientists, engineers,” he says. “We’re hoping that teams of complementary skills come together and come up with the best possible ideas and approaches.”