US offers US$36m for process developers to recover ammonia and metals from wastewater

THE US is offering US$36m for researchers who can help recover ammonia and critical metals from wastewater as it looks to reduce its reliance on foreign supplies.

In 2023, the US consumed around 15m t of anhydrous ammonia, with more than 2m t imported. It is a crucial source of fertiliser and its production using the Haber-Bosch process is energy intensive, requiring high temperatures and pressures. Yet the use of this fertiliser is highly inefficient with more than 50% ending up in wastewater streams. On top of the production and processing emissions resulting from this wasteful practice, the nitrate discharged from treatment plants is a major environmental contaminant. It feeds algal blooms, which starve rivers and lakes of oxygen, killing wildlife.

As for metals, the government says the US is almost wholly reliant on foreign producers. This includes supplies of iridium, cobalt, magnesium and rare earth elements, 95% of which are mined and processed abroad. These are key components of green energy technologies and demand for them is expected to balloon as countries seek to decarbonise their economies.

The new funding programme – called Recover – has a target to replace 50% of domestic ammonia supplies and 100% of critical metals by recovering them from wastewater sources. This includes municipal plants, produced water from oil and gas operations, and mining drainage and tailing ponds.

The funding is for new materials and processes to make extraction energy efficient, selective and durable. ARPA-E, the agency managing the funding, says that project teams will need to reduce the number of recovery steps compared to conventional approaches, and tailor their technologies to work within existing or new wastewater facilities. The new processes must continuously recover ammonia and critical minerals without a drop in performance, and scale to large operations.

Evelyn Wang, ARPA-E director, said: “Recover technologies will transform waste streams into critical materials sources that commoditise the vast volumes of wastewater flowing through our systems and strengthen our energy security.”

The deadline for funding submissions is 31 December.