Clarkson University
Department of Chemical and Biomolecular Engineering
Seminar
The impact of OH radicals on the degradation and defluorination of poly- and perfluoroalkyl substances (PFAS) in a plasma spinning disk reactor
Foluke Jennifer Ganzallo
Abstract
The Plasma Spinning Disk Reactor (PSDR) effectively decomposes both short- and long-chain poly- and perfluoroalkyl substances (PFAS), compounds known for resilience against conventional water treatment methods due to their strong carbon-fluorine bonds. The PSDR uses electrical discharge plasma, which generates oxidative and reductive species, to rapidly mineralize these substances. In the case of perfluorobutane sulfonate (PFBS), the PSDR degrades 99% and defluorinates 47% of the parent compound within three hours of treatment. However, despite this success, partial defluorination highlights the potential presence of stable liquid byproducts resistant to plasma degradation.
In this study, the role that oxidative species, particularly OH radicals, play in the mineralization of PFBS was investigated. For that purpose, ferrous ions were used to decompose the hydrogen peroxide generated by the plasma to produce additional OH radicals in the bulk liquid. Results revealed that while oxidative species alone do not degrade PFBS, they are critical in the mineralization process. In fact, achieving full mineralization of PFAS requires the generation of oxidative species within the liquid phase.
Wednesday, 02/28/2024 at 2:30 pm
CAMP 194
Foluke Ganzallo is a Ph.D. candidate at Clarkson University. She has an undergraduate degree in Chemical Engineering from Ladoke Akintola University of Technology and a master’s degree in petroleum engineering from the African University of Science and Technology in Nigeria. Since January 2021, she has been conducting research on plasma technologies for wastewater treatment at the Plasma Research Laboratory under the guidance of Prof. Selma Mededovic-Thagard.
Figure 1 – Image showing plasma spread over a rotating disc in the plasma spinning disc reactor
