ISU Professor Develops Way to Detect, Remove Precious Metals from Wastewater

Recently, Assistant Professor of Chemistry Dr. Courtney “Cori” Jenkins, ISU undergraduate student Cameron Call, and Ball State University Masters student M. Logan Eder published a paper in the American Chemical Society’s Applied Polymer Materials detailing how they were able to detect and bind heavy metals using elemental sulfur, a petroleum refining waste by-product. Dr. Jenkins and her students were able to form a sulfur-based, water-soluble polymer that binds to gold and silver. 

“Most filters remove all metal ions, so they filter out precious metals like gold and silver, but they also remove common metals like calcium and iron,” said Dr. Jenkins. “Because the filters are removing all metals, this causes filters to clog more quickly and leaves you with an unusable mixture of metals. Because this polymer binds selectively to silver and gold, it allows those precious metals to be removed from wastewater and used.”

Their research also found that the polymer will cause water to change color when lead and other metals are present. 

“Another benefit of these polymers is that they are water-soluble, allowing them to be used to detect a variety of metals in water,” Jenkins said. “By adding a small amount of polymer to a water sample, we can see an obvious color change if toxic metals are present. This offers an inexpensive way to check the water for toxic metal contaminants such as lead which we can detect at very low concentrations.”

The polymer is also the first charged polymer formed using inverse vulcanization. Inverse vulcanization combines sulfur - a byproduct of petroleum refinement - with other molecules to form polymers. The method is fast, scalable, and uses green chemistry principles to limit additional waste. 

“This project has been and continues to be an invaluable part of my education,” said Cameron Call. I've learned so much in the lab that I wouldn't have in my classes. For instance, what it's like to go through the publication process.  I'm very grateful for Dr. Jenkins’ mentorship and that she has been able to put up with me for as long as she has.”

The National Science Foundation funded the research. 

Read their paper, “Utilizing Reclaimed Petroleum Waste to Synthesize Water-Soluble Polysulfides for Selective Heavy Metal Binding and Detection”. The paper was an Editor’s Choice selection by the American Chemical Society and also featured in the January 24 edition of Chemical and Engineering News.  

For more information visit ISU’s Chemistry Department.