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 process for extracting rare earth elements from acidic wastewater produced by mines and industrial activities.
Led by Yi Wang, assistant professor in the Department of Biological and Agricultural Engineering, the project focuses on engineering acid-tolerant microbes that can produce metal-binding proteins. These proteins are designed to capture rare earth elements directly at low pH levels, potentially enabling cost-effective onsite recovery.
Rare earth elements are crucial for manufacturing high-efficiency permanent magnets used in electric vehicles, wind turbines, and advanced electronics. Traditional extraction methods rely heavily on chemicals and generate substantial waste. The UC Davis team aims to reduce chemical use and waste while supporting a domestic supply chain for clean-energy manufacturing.
“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.”
The research will utilize artificial intelligence to design proteins with molecular precision. 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 initiative also includes efforts to transition the technology from laboratory development to practical application. 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 on the project include Libin Ye from the University of South Florida as well as Ning Sun and Chang Dou from Lawrence Berkeley National Laboratory.
Support for proposal development was provided by Proposal Development Services within UC Davis’s Office of Research.
This work is part of ARPA-E’s RECOVER program—a $25 million federal initiative launched earlier this year by the Department of Energy aimed at developing technologies that recover critical minerals previously discarded in U.S. wastewaters (https://arpa-e.energy.gov/news-and-media/press-releases/energy-department-announces-25-million-extract-critical-minerals). The program seeks to reduce reliance on imported critical minerals by establishing secure domestic supply chains.
