VICKSBURG, Miss. – A study on breaking down PFAS molecules conducted by two researchers from the U.S. Army Engineer Research and Development Center’s (ERDC) was recently published in a leading, peer-reviewed scientific journal.
A breakthrough study from ERDC’s Environmental Laboratory reveals how zero-valent iron can trigger early-stage reactions to break down PFAS, opening the door to more effective environmental remediation strategies for “forever chemicals.”
Dr. Glen Jenness and Dr. Manoj Shukla’s article, “Exploring the initial bond activations of PFAS on zero-valent iron” was published in “Physical Chemistry Chemical Physics,” a peer reviewed scientific journal that publishes high-quality, original research in physical chemistry, chemical physics, and biophysical chemistry.
To Jenness and Shukla, having their work published in the journal marked a significant moment in advancing PFAS research.
“This journal is highly regarded in the areas of physical chemistry, chemical physics, and biophysical chemistry, and is published by the Royal Society of Chemistry, so having our work published in it feels good,” said Jenness, a research chemist. “The feedback from reviewers and editors is very constructive with a quick and efficient turnaround time.”
Jenness and Shukla’s manuscript focuses on using state-of-the-art quantum chemical calculations and reaction modeling to demonstrate the initial reaction steps in PFAS degradation, providing a method to limit the presence of the environmental contaminant.
Analyzing zero valent iron has been critical for the researchers, as the iron acts as a donor to break down contaminants in soil and groundwater.
“Zero valent iron binds PFAS molecules favorably,” explained Shukla, a research physical scientist. “Once PFAS is bound to zero valent iron, the iron atoms can donate electrons to the carbon-fluorine bonds of PFAS, resulting in the carbon-fluorine bond weakening to the point that ambient temperatures can easily break it. This is all due to how the electrons in iron are distributed and how they overlap with the chemical bonds of PFAS.”
Implementing quantum chemical calculations and reaction modeling enabled the researchers to overcome the most complex steps of their research, thanks to the method’s use of quantum mechanics to predict molecular structures and reaction pathways.
“The method we employed is the density functional theory, which originated in the early days of quantum mechanics and is now one of the major methodologies for exploring chemical phenomena,” said Jenness. “Unlike other quantum chemical methods, the density functional theory relies only on the electron density, which greatly reduces the complexity of solving our underlying equations. Density functional theory allows us to model large systems, such as surfaces, and study chemically relevant phenomena like bond breaking and formation.”
The researchers were careful in their approach, leading them to study environmentally responsible solutions to ensure a cleaner, safer environment in the future.
“We want a cure for PFAS that will not cause problems for future generations,” said Shukla. “By taking a more ‘green chemistry’ approach, we can ensure that we do not accidentally release more chemically invasive materials and substances into our environment. Zero valent iron is found worldwide in natural deposits, and mainly flora and fauna use iron metabolically, which means that any iron leftover will get processed naturally and safely.”
The research inspires more extensive analysis, expanding opportunities to better understand and address PFAS degradation.
“PFAS molecules are tricky as they are chemically evasive, manmade, and do not exist naturally, so we cannot rely on nature-inspired solutions,” said Jenness. “They are nicknamed as ‘Forever chemicals’ because they do not degrade in the environment. Our research creates an open field and allows us to look at and reassess our prior body of knowledge with a more critical eye. Being able to have this kind of intellectual freedom in research is invigorating.”
Now that the researchers grasp this concept, they’re inspired to take on more complex PFAS experiments while integrating real-life effects.
“Now that we have a firm understanding of the fundamentals involved in using zero valent iron and PFAS degradation catalyst, the next steps would be to look at a more complicated model and incorporate more real-world effects,” said Shukla. “For example, catalysts like zero valent iron are typically mounted on some sort of chemical support, with materials like silicon dioxide and titanium dioxide being two examples. While it has long been thought that these supports do not affect the catalytic activity, newer research over the past decade has shown that this is not the case. We believe that they offer a way to tune the chemical process and have the potential to increase the efficacy of zero valent iron.”