A research team at the University of California, Davis has received a $3 million grant from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) to develop a new process for extracting rare earth elements from acidic wastewater produced by mines and industrial activities.
The project is led by Yi Wang, assistant professor in the Department of Biological and Agricultural Engineering at UC Davis. The team aims to engineer acid-tolerant microbes that can produce proteins capable of binding metals even in low pH environments. This approach could enable cost-effective recovery of rare earth elements onsite, reducing chemical use and waste compared to conventional extraction methods.
Rare earth elements are vital for manufacturing permanent magnets used in electric vehicles, wind turbines, and electronics. Current extraction techniques rely on intensive chemical processes that generate significant waste. The UC Davis initiative seeks to address these issues by using bio-based methods for selective capture directly at sites where acidic wastewater is generated.
“This technology aims to turn a liability into a resource,” said Wang. “By selectively capturing rare earths where acidic wastewater is generated — like acid mine drainage and tailings liquors — we can reduce chemical use and waste while strengthening a resilient domestic supply chain for clean‑energy manufacturing.”
Artificial intelligence will be used in the project for protein design, structural analysis, and development of acid-compatible processes. According to Justin Siegel, co-principal investigator and professor in the Department of Chemistry, “Our AI‑guided protein design lets us tune the protein binding loops to remain fast and highly selective even at very low pH. That molecular precision — coupled with acid-tolerant microbes — enables a shorter, greener recovery train with fewer unit operations.”
The team plans not only to demonstrate selective recovery but also onsite concentration of critical rare earth elements from challenging wastewaters. The goal is to reduce chemicals and energy use while making use of domestic resources that are currently discarded.
A focus on commercialization is also part of the effort. Boon-Ling Yeo, co-principal investigator responsible for tech-to-market tasks at UC Davis stated: “Our job is to make sure this doesn’t stay just a great idea on paper. We’re evaluating costs, markets and potential partners so that recovering rare earths from wastewater is not only technically feasible, but also economically attractive for utilities, mining operators and manufacturers across the United States.”
Collaborators include Libin Ye from the University of South Florida as well as Ning Sun and Chang Dou from Lawrence Berkeley National Laboratory.
The Proposal Development Services team within UC Davis’s Office of Research assisted with preparing the successful ARPA-E funding proposal.
This project forms part of ARPA-E’s $25 million RECOVER program investment aimed at developing technologies that recover critical minerals from U.S. wastewaters as announced earlier this year by the Department of Energy (https://arpa-e.energy.gov/news-and-media/press-releases/energy-department-announces-25-million-extract-critical-minerals).
The RECOVER program seeks to reduce reliance on imported critical minerals by establishing secure domestic supply chains through innovative extraction technologies.
