2024 AIChE Annual Meeting
(589c) Advancing the Efficiency of Plasma-Based Water Treatment: Insights into Ion Effects on Contaminant Degradation
Plasma-based water treatment (PWT) has emerged as a promising technology for the degradation of organic and inorganic contaminants in various water sources. In PWT, an electrical discharge generates a wide range of reactive species by exciting and splitting water and background gas, enabling the in-situ formation of oxidative and reductive species without the need for chemical additives. This feature makes PWT an attractive and superior option for numerous water treatment applications. However, the performance of PWT reactors when applied to treat groundwater, wastewater, membrane concentrate, or ion exchange brine is influenced by the physicochemical properties of the solutions, with particular emphasis on solution electrical conductivity. Recent investigations into treatment of short- and long-chain poly- and perfluoroalkyl substances (PFAS) in ion exchange regenerant still bottom solutions and membrane concentrates, characterized by high solution electrical conductivities, have revealed that ion concentration plays a pivotal role in determining treatment effectiveness. This influence arises from its impact on the physical and chemical processes occurring at the plasma-liquid interface. This study explores the roles that inorganic ions play in bulk liquid and plasma chemistry by closely examining the transformation pathways of various alkali metal halide and ammonium halide salts. The insights gained from this research are extended to the treatment of industrial PFAS matrices in solutions characterized by high electrical conductivity.