Measuring PFAS in Watersheds
Public concern over PFAS is growing. Scientific understanding is growing as to how PFAS enters the environment, how it moves into water supplies, and, importantly, what strategies are effective in removing it from water supplies. Ohio is particularly susceptible to the effects of PFAS as these “forever chemicals” are more prevalent in watersheds with industrial sites, military fire training areas, and multiple wastewater treatment plants. Given the state’s manufacturing base, military installations, and large population density, we are working with Dr. Andy May to understand the atmospheric spread of PFAS.
See: Environ. Sci. Technol. 2020, 54, 12, 7175–7184
Check out a recent article on our work in C&E News or C&E News
Investigating Ultrasound as a Technology to Degrade PFAS
We are studying the effects of ultrasonic waves on the degradation of PFAS compounds in aqueous systems. Ultrasonic waves, when applied to water, result in cavitation bubbles shown in the picture beneath an ultrasonic probe. These microscopic bubbles grow and collapse with the ultrasound. Upon collapse, the bubbles generate extremely high temperatures (hotter than the sun!) and pressures (approximately 1000 atmospheres). As a result of these extreme conditions, the chemical bonds of water are broken generating reactive and highly oxidizing chemical species. In addition, contaminants in the water entering the cavitation bubbles undergo high temperature gas phase reactions.
The Weavers research group is exploiting these processes to selectively degrade PFAS that preferentially accumulate on air/water surfaces (i.e., on the bubbles). Recent work (J. Phys. Chem. A 2023, 127, 30, 6309-6319) indicates that smaller molecular weight PFAS degrade faster than larger molecular weight PFAS.