Dissolved Organic Matter: One of the Largest and Most Poorly Understood Reservoirs of Carbon on the Planet

Join the College of Engineering for a special lecture with Yu-Ping “Yo” Chin, Edward C. Davis Professor of Civil, Construction and Environmental Engineering, as he explores dissolved organic matter (DOM), one of the largest and least understood reservoirs of carbon on Earth. DOM plays a central role in the global carbon cycle and influences everything from water quality to climate change. In this talk, Chin will share what decades of research have revealed about how DOM shapes environmental processes and why its impact matters for ecosystems and human health.

Thursday, November 6, 2025 | 4-6 p.m.

In person: Mitchell Hall

Livestream: https://sites.udel.edu/udlive/ 

Reception to follow in Du Pont Hall Lobby

ABSTRACT

Dissolved organic matter (DOM) is one of the two largest pools of reduced carbon on the planet. While its precursors are biogenic in origin, it has been worked and reworked to create an amorphous group of difficult-to-elucidate organic compounds. DOM is an important component of the carbon cycle and plays critical roles in processes of both biogeochemical and environmental importance. These include acting as a catalyst capable of producing reactive oxygen species (ROS) and other radicals in the presence or absence of sunlight, chelating both deleterious and beneficial metals, serving as an important substrate to support microbial activity, and participating in redox reactions of environmental importance.

Our research has focused on elucidating DOM’s structural components and its role in mediating both biogeochemical and environmental reactions of global importance. Advances in chromatography, high-resolution mass spectrometry and electroanalytical methods have shed light on both its composition and reactivity. What we have learned over more than a half century of research on DOM is that it plays an outsized role in regulating the cycling of major and minor elements, attenuating contaminants and mediating redox processes. One of its less desirable qualities, however, is the role that it plays in the formation of deleterious disinfection byproducts (DBPs) during the treatment of potable water sources.

This talk focuses on the role that DOM plays as a “photosensitizer” in catalyzing the photofate of organic contaminants, as well as investigating whether DOM can “buffer” aquatic organisms from harmful pesticides through partitioning processes. We demonstrated that DOM is capable of enhancing the photodegradation of these substances in natural sunlight through the production of ROS, but this enhancement appears to be independent of its composition and varies over time and space. Further, we observed that DOM is incapable of protecting invertebrates from the pesticide chlorpyrifos at environmentally relevant levels. As a consequence, the loss of invertebrates resulted in an increase in organic matter production from primary production. This observed change could have implications in the cycling of carbon in streams impacted by pesticide runoff.

BIOGRAPHY

Yu-Ping “Yo” Chin is the Edward C. Davis Professor of Civil, Construction, and Environmental Engineering and a member of the Delaware Environmental Institute. Prior to coming to the University of Delaware, he was a professor in the School of Earth Sciences at The Ohio State University with a joint appointment in the Department of Civil and Environmental Engineering. He has also been a visiting scientist at the Swiss Institute of Aquatic Science and Technology (EAWAG) In Switzerland and a visiting professor of chemistry at the University of Otago in Dunedin, New Zealand.

He earned his A.B. degree in geological sciences from Columbia University, his M.S. and Ph.D. in environmental engineering from the University of Michigan. Afterwards, he conducted postdoctoral research at the Ralph M. Parsons Lab at MIT. His research focuses on the role of dissolved organic matter in mediating reactions of environmental importance globally. 

Chin is co-PI on the National Science Foundation-funded Critical Zone Network, and a PI on the Multi-omics to Understand Climate Change project, which is funded by the Department of Energy. He is a Fellow of the International Association of Geochemistry and served two terms on the National Academy of Sciences Engineering and Medicine (NASEM) Water Science and Technology Board. He has also been involved as a committee member and reviewer for a number of NASEM studies.