The importance of mechanistic studies in the development of cold plasma-based degradation of persistent organic pollutants in water

An overview is given of major recent advancements in cold plasma-based water treatment, with specific focus on the degradation mechanisms of organic pollutants. Mechanistic insight is indeed a powerful tool for process optimization considering the treatment duration, its products, and energy costs as it provides guidelines for the design of optimized reactors and the selection of best experimental conditions. The cases considered emphasize the importance of matching the plasma composition in terms of reactive species with the reactivity of the target pollutant(s), and of identifying and understanding the reciprocal effects of different pollutants as well as those of complex aqueous matrices. Harnessing the chemistry activated by the plasma to achieve the desired goal is the key to treatment success. A general strategy is outlined for designing the best plasma experimental set-up and for predicting possible byproducts.