2024 AIChE Annual Meeting
Polarity Effects on Organic Contaminant Chemical Degradation in a Continuous Gas-Liquid Flowing Reactor
Contaminants of emerging concern, such as per- and polyfluoroalkyl substances, pose threats to the environment and human health, and there is a need to effectively degrade these compounds. Plasma reactors can be used to enhance degradation through advanced oxidation and reduction pathways. This study uses a continuous gas-liquid flowing reactor, where the formed plasma propagates along the gas-liquid interface. This study provides insight into the effect of electrode polarity on chemical pathways for methylene blue (MB) decoloration and perfluorooctanoic acid (PFOA) defluorination while varying pulse frequency. For MB, both the co- and counter-current studies increased decolorationrates with increasing frequencies due to the increased discharge power. Decolorationwas not enhanced for methylene blue based on the polarity due to the oxidation occurring directly in the liquid phase. However, PFOA defluorination was enhanced 1.5 times for the counter current electric field. It is hypothesized that this is due to increases in the gas-phase electron density during counter-current flow because the PFOA is an interfacial species, but further studies on peak electron density are required.