Doctoral student’s research finds valuable rare earth elements in toxic waste

UNIVERSITY PARK, Pa. — Most people would view a lake full of radioactive, toxic waste as garbage — not Adam Smerigan. A doctoral candidate in Penn State’s Robert V. Waltemeyer Department of Chemical Engineering, Smerigan works with Professor Rui Shi in the Sustainable Design, Systems and Decision-Making (S2D2) Lab to focus on finding treasure in the trash — recovering rare earth minerals, such as neodymium, cerium and praseodymium, from toxic waste. Elements like these and more are used in everyday electronic devices like smartphones.

Through his research, Smerigan is developing an innovative, profitable and sustainable method of harvesting rare earth elements. He will graduate with his doctoral degree this summer.

Specifically, Smerigan’s research explores mineral recovery from a type of toxic waste known as phosphogypsum, which is created as a byproduct of processing phosphate to be used eventually in fertilizer, according to the United States Environmental Protection Agency.

“Phosphogypsum contains valuable rare earth elements that are used in things like your cell phone, electric vehicles and wind turbines,” Smerigan said.

Currently, phosphogypsum is stored in large lakes, which leak into the environment and can harm humans and wildlife, according to Smerigan.

“The idea is that we can clean up this toxic and radioactive waste by recovering the valuable rare elements,” he said. “The challenge is these rare earth elements are difficult to separate from one another, so we’re developing a new technology that uses peptides — building blocks of the proteins you eat — to separate different rare earth elements.”

Smerigan’s work with peptides involves manipulating their structure to improve their ability to identify and latch on to rare earth elements. His research determines how changes in peptide structure affect rare earth element separation performance, and then forecasts the profitability and environmental impacts of a system using this separation.

Smerigan said he hopes his contributions to this research lead to a more circular economy — an economic system that aims to minimize waste and maximize resource utility by reusing, regenerating and recycling materials or products — and a more cost-effective way of recovering rare earth elements. 

“It would be really great if we could use these other sources — wastes being produced that already contain rare earth elements — as opposed to extracting them from the earth natively, which further harms the environment,” Smerigan said. 

Shi is working with several Penn State campus resources to explore ways to scale up and commercialize the technology.

The road to researching relevant rare earth elements

Research wasn’t initially the path Smerigan thought he’d be taking. His passion for research began with a carbon dioxide capture project he was assigned as an undergraduate research assistant while studying chemical engineering at Michigan State University.  

“I came up with my own little absorption column for this project and started to think of my own ideas and express them to people around me, which ended up turning into a master’s degree,” Smerigan said.

As he completed his bachelor’s and master’s degrees, Smerigan wanted to continue advancing sustainable practices and reducing climate change.

“The fun part about research is that you’re never done learning,” he said. “There’s always more. There’s always some issue you’re trying to solve. There’s always a new frontier to explore.”

Smerigan noted that one of the primary reasons he chose Penn State for his doctoral degree was because of the University’s extensive research opportunities in his field of interest.

“I’m very focused on sustainability, and Penn State’s projects were new, exciting and sustainability focused,” he said.  

Growing at Penn State

While at Penn State, Smerigan was named runner up in the J. Jeffrey and Ann Marie Fox Graduate School’s annual Three Minute Thesis competition. For second place, he won $500.

Three Minute Thesis — an academic research presentation and communication competition created by the University of Queensland, Australia — was developed to give graduate and professional students an outlet to effectively explain their research to a general audience. Each competitor has exactly three minutes to present their research and may use only one slide as a visual aid.

Smerigan entered the competition to do just that — better his ability to convey his research clearly to an audience without a background in rare earth mineral recovery.

“Three Minute Thesis was a great opportunity for professional development,” he said. "You get the chance to kind of lock your audience into a room, talk to them and get some feedback on your communication skills.”

The importance of being able to communicate well is a lesson Smerigan didn’t anticipate he’d take away from his time at Penn State.

“A very important part of being a scientist or engineer is the ability to communicate your findings and gear them toward specific audiences to help them understand why your work is important,” he said. “It’s been really helpful in my job search, as well. I’m able to demonstrate how I’m improving soft skills, such as public speaking.”

During his time at Penn State, Smerigan said, he benefited from professional development workshops led by the Fox Graduate School. These workshops — designed to help students better their business, leadership and communication skills — helped prepare him for his career after Penn State.

Smerigan said skills he gained through the workshops helped him secure the job he began in July. He serves as a postdoctoral researcher at Lawrence Livermore National Laboratory in Livermore, California, researching energy systems on Lawrence Livermore’s Systems Analysis team.

At Lawrence Livermore, he will continue researching rare earth elements. 

Smerigan’s advice for new graduate students is to lean on their immediate support networks — fellow graduate students.

 “Building that community with your peers is really important,” he said. “These friendships can help you not only while you’re here, but once you all graduate, move on and try to find jobs, you may find that you know someone in that new location you’re moving to.”