Advanced Oxidation and Reduction Processes in the Gas Phase Using Non-Thermal Plasmas

Abstract : In the past several years interest in gas-phase pollution control has increased, arising from a larger body of regulations and greater respect for the environment. Advanced oxidation technologies (AOTs), historically used to treat recalcitrant water pollutants via hydroxyl-radicals (OH), are now being applied to gas-phase pollutants using non-thermal plasmas (NTPs). These plasmas are useful for generating highly reactive species (e.g., free radicals) which readily decompose entrained pollutants in atmospheric-pressure gas streams. Such plasmas can generate both oxidative and reductive radicals - showing promise for treating a wide variety of pollutants, in some cases simultaneously decomposing multiple species. In this paper, we will discuss NTPs views as an AOT; that is, a technique for free-radical-initiated pollutant decomposition. Our primary discussion topics are example applications of the technology, representative plasma reactors, reactive species generation, basic decomposition chemistry, simple analytical removal-scaling models, and the results of laboratory experiments and field trials on representative compounds.