Modeling the impact of chemical and physical processes of PFOA on their LRT in the global ocean

Per- and polyfluoroalkyl substances (PFAS), a class of anthropogenic organic pollutants, are of critical societal concern due to their persistence and toxic properties. One of the most widely known PFAS, perfluorooctanoic acid (PFOA), has been produced on an industrial scale since the 1950s. Due to its persistence and toxicity, PFOA has been gradually replaced by alternative PFAS in recent decades. However, between 200 and 300 tons of PFOA are still released into the environment annually, from both air and water sources. As an acid, PFOA dissociates to its ionic form in water, increasing its tendency to accumulate in the ocean. To explore PFOA's environmental behavior, we developed a mechanism to simulate its chemical and physical transformations in the ocean and implemented it in the fully resolved 3D global ocean model ICON-O. This Icosahedral Nonhydrostatic (ICON) model is a next-generation, multi-compartment Earth System Sodel that includes atmospheric transport. We assessed the influence of these processes on the long-range transport (LRT) of PFOA compared to passive tracer simulations. The model simulates PFOA’s photochemical degradation under UV light, partitioning into organic matter matrices, and re-emission from the surface layer via sea salt aerosols. These factors, combined with primary production, light exposure, salinity, and wind speed, shape PFOA's global distribution, enhancing our understanding of PFAS fate in the ocean.

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Primary Presenter: Elena Mikheeva, Hereon (elena.mikheeva@hereon.de)

Authors:

Elena Mikheeva, Hereon  (Elena.mikheeva@hereon.de)

Hiram Meza, Hereon  (Hiram.meza@hereon.de)

Kai Logemann, Hereon  (kai.logemann@hereon.de)

Johannes Bieser, Hereon  (Johannes.bieser@hereon.de)