Environmental Engineering Seminar Series: Professor William Arnold

Lecture / Panel
For NYU Community


The NYU Civil and Urban Engineering department is pleased to host our Environmental Engineering Seminar Series, featuring engaging research talks covering a spectrum of topics in the field, ranging from environmental chemistry and microbiology to water quality assessment and beyond. Join us as leading experts share their insights and advancements in environmental engineering, fostering a collaborative environment for knowledge exchange and exploration. 

This seminar is being co-hosted by the NYU Sustainable Engineering Initiative (SEI) and the NYWEA Student Chapter at NYU.

We are honored to welcome Distinguished Professor William Arnold from University of Minnesota to share his insights on the role of photolysis and oxidative treatment processes in determining the environmental fate of fluorinated compounds found in everyday products, in this research seminar titled 'Fluorine beyond PFAS: Tracking fluorine during photolysis of fluorinated pesticides and pharmaceuticals'.


Rachel Carson brought to light the dangers of persistent chlorinated chemicals in 1962, and we have spent decades dealing with these pollutants. Rather than learn from this lesson, we have incorporated another halogen, fluorine, into numerous industrial and consumer chemicals, including poly- and perfluorinated substances (PFAS). PFAS as a class of chemicals are under intense scrutiny by regulators and the public due to their persistence and toxicity. Fluorine incorporation into organic chemicals is, however, much more ubiquitous than is generally known by the public. There are many mass-produced chemicals, including pharmaceuticals, pesticides, and medical contrast agents, containing one or more fluorine atoms in a variety of chemical functional groups that are released into the environment and (waste)water treatment systems. Yet, we understand little about the fluorinated byproducts produced upon degradation of fluorinated pesticides and pharmaceuticals. Upon photolysis or oxidative treatment in aquatic systems, persistent fluorinated byproducts or fluoride from pesticides and pharmaceuticals are formed depending on the type and stability of the fluorine-containing functional group. Byproduct quantification was performed using 19F-NMR and high-resolution mass spectrometry. Some motifs are persistent, generating new PFAS, while others degrade to fluoride. Advanced oxidation often leads to a higher yield of fluoride as an end product, but also trifluoroacetic acid which is persistent. These results will assist in the future optimization of water treatment methods and development of pharmaceutical/pesticide structures to reduce persistent byproduct formation.

About the speaker

William Arnold is a Distinguished McKnight University Professor and the Joseph T. and Rose S. Ling Professor in the Department of Civil, Environmental, and Geo-Engineering at the University of Minnesota. For the 2023-2024 academic year, he is a Distinguished Teaching Professor at Princeton University. His research focuses on the fate of organic chemicals in natural and engineered aquatic systems. He received his S.B. in Chemical Engineering from MIT (1994), M.S. in Chemical Engineering from Yale (1995) and Ph.D. in Environmental Engineering from The Johns Hopkins University (1999). He then joined the U of MN faculty. He has won both the AEESP Frontiers in Research Award and Outstanding Publication Award, and was recently named the 2023 Distinguished Engineer of the Year by the Minnesota Federation of Engineering, Science, and Technology Societies.