Cleaning Up Antibiotics in Wastewater

By Kirsten Heuring

When she isn’t playing Dungeons and Dragons, Mellon College of Science junior Minerva Schafer is an absolute wizard at green chemistry.

“Minerva has exceptional chemical and problem-solving insight,” says Terrence Collins, the Teresa Heinz Professor in Green Chemistry and the Director of the Institute for Green Science. “She forms her own judgments on the chemistry she is studying. They are so solid that one wouldn’t want to shake her from her conclusions unless in possession of powerful contradicting data.”

Minerva became interested in safe and sustainable chemistry while growing up in Baton Rouge, Louisiana. Between her hometown and New Orleans is an area known as Cancer Alley, where more than 150 oil production facilities along the Mississippi River release chemicals into the air. Local populations have higher rates of cancer than national averages.

“I think my entire state of Louisiana is a very good example of why chemistry done without sustainability in mind can be massively harmful to humans and the environment,” Minerva says, who is pursuing her bachelor’s degree in chemistry.

In the spring of her first year of college, Minerva joined the Institute for Green Science on a project led by Ph.D. candidate Parameswar Pal — an in-depth analysis on how a specific type of catalyst, TAML, with the common oxidizing agent, hydrogen peroxide, could be better used to purify water. In the process, they discovered that the reaction rate fluctuates depending on the target they want to destroy and the acidity found in the contaminated water.

Using a Summer Undergraduate Research Fellowship, which provides CMU undergraduates with $3,500 to conduct full-time summer research, Minerva has moved on to her own research interests into fluoroquinolone contamination. A common antibiotic, fluoroquinolone is in use widely and appears in waterways globally.

“What goes into the body must come out, and in the case of many antibiotics, a fairly large percentage of what comes out is the antibiotic itself,” Minerva says. “That gives them a very direct route into wastewater streams, and that’s quite a substantial problem.”

When these antibiotics are left in wastewater streams, they are at concentrations high enough to inhibit bacteria but not kill them. These conditions make some sewers breeding grounds for antibiotic-resistant bacteria, which have the potential to jumpstart the next pandemic.

Minerva has found the same catalyst she has investigated in his previous research, TAML, provides a superior approach to significantly reduce fluoroquinolones in a water source.

“Our current generation catalyst was able to very nearly destroy antibiotics in about two hours of treatment using the bare minimum amount of peroxide,” Minerva says. “We’re looking at room for improvement that we know is possible with this catalyst. I’m very excited about how powerful we can make this technology.”

Minerva says the next steps for this research are to use the catalyst against real wastewater samples, so she can further enhance and refine the processes needed to remove antibiotic contaminants.

“Typically, producers and water purifiers want just to see the drug destroyed and declare victory,” Terrence says. “But there is much more to the environmental performance story for every drug, and Minerva is playing an important role in helping us to show how to get complete pictures.”

Outside of the lab and her classes, Minerva plays violin. She is a member of the CMU All University Orchestra, which provides a creative outlet. She also enjoys playing tabletop role-playing games with friends.

Minerva finds her true passion in safe and sustainable chemistry. She plans on pursuing a doctoral degree in the field.

“Another thing that excites me is the interdisciplinary potential that this research and sustainability chemistry really have,” Minerva says. “We as chemists can do a lot, but this scale of environmental contamination can’t be dealt with from just one field. We have to work very broadly to make sure we’re not doing things that will make our problems worse.”