Could the clean energy revolution be powered by wastewater?
“As chemical engineers, we have to think of how to make [things] from waste,” said doctoral student Qudus Rafiu.
Rare earth elements, a group of chemical elements, and other critical minerals are generally costly and difficult to procure and dependent on complex supply chains. Yet some of these elements such as lithium are absolutely essential for technology from wind turbines to cell phones.
Northeastern University researchers are proposing a new source for some of these critical materials: wastewater. The finding is especially critical as the world transitions to clean energy, the researchers said.
“Clean energy technologies depend on critical materials, and this paper shows that we can offset some of the demands for these materials through wastewater,” said Qudus Rafiu, a doctoral student at Northeastern who conducted the research with Damilola Daramola, assistant professor of chemical engineering and chemistry and chemical biology.
The research was published online last week in Joule, a scientific journal focused on addressing the need for more sustainable energy
In November, the Department of the Interior’s U.S. Geological Survey (USGS) released its latest list of critical minerals: 60 minerals vital to the U.S. economy and national security that face potential risks from disrupted supply chains. The Department of Energy has a similar list that was last amended in May 2025.
The lists include the copper used in wiring and cables to the lithium used in batteries, as well as rare earth elements that are key components in many common electronic devices and in a variety of industrial uses, especially in areas of clean energy.
But these elements’ critical nature underscores the risks associated with obtaining these minerals.
Many critical materials are difficult, resource intensive and expensive to mine and refine. Rare earth elements are often found at low concentrations, which means additional efforts to mine the materials. Extraction can often can also pollute the environment as well.
Geopolitics also plays a role. The U.S. imported 80% of the rare earth elements it used in 2024, according to the USGS. China is the leading refiner of 19 of 20 important strategic minerals recently identified by the International Energy Agency, and U.S. and Chinese negotiations on everything from TikTok ownership to trade policy have touched on the importance of critical minerals.
Daramola, whose lab has previously focused on recovering nutrients from wastewater, and Rafiu wanted to find another source.
“As chemical engineers, we have to think of how to make [things] from waste,” Rafiu said. “If we can recover nutrients, there is a possibility that there are many other valuable materials available in these wastewater sources.”
The researchers examined ten “nontraditional water sources” which included the water that is left over after being used for hydraulic fracking for gas and oil extraction, coal-fired power plants, seawater desalination plants, and wastewater from abandoned mines.
They measured the type and abundance of critical materials that could be found in each wastewater source, the capabilities for removing the critical materials, and the technological challenges with extraction.
The researchers found that enough magnesium, lithium, uranium, titanium, fluorine and silicon could be recovered from wastewaters to meet at least one-tenth of each resource’s projected demand in the international clean energy sector. Copper, manganese, cobalt and nickel could be recovered if wastewater sources were processed, but recovering the materials would not sufficiently offset demand, the study found.
Daramola said that the paper gives a kind of roadmap for those looking to wastewater as an alternative source of critical materials, especially given their high demand.
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World production of rare earth elements, for example, was estimated at 64,500 tons in 1994. As our reliance on the materials for electronics and clean-energy technology has increased, that figure is estimated to have increased to 390,000 tons in 2025, according to the USGS 2026 Mineral Commodity Summaries.
Rafiu said the International Energy Agency predicts demand for critical materials to at least double and possibly quadruple between 2020 and 2040 as countries transition to clean energy technology.
“If you are thinking ‘which source is going to have the most value,’ our paper describes that,” Daramola said. “Then you might say, ‘Okay, well, I’m looking for this particular material, which wastewater should I go to?’ the paper provides that as well.”
Daramola said researchers plan to continue their investigation by looking at how enhanced technology may make recovery from wastewater more feasible. In the future, they may even look at waste in another state of matter.
“We have some information on the liquid side, and we have certain things we can go after there,” Daramola said. “But there’s also quite a significant amount of solid material that could be explored.”
