Review of plasma-based water treatment technologies for the decomposition of persistent organic compounds
Nozomi Takeuchi, Koichi Yasuoka
Abstract
Abstract The establishment of economical and eco-friendly technologies for water treatment is a crucial issue for the realization of a sustainable society. Plasma-based treatments are promising methods for the decomposition of persistent organic compounds. This progress report summarizes recent improvements to plasma-based water treatment technologies by focusing on two types of contaminated solutions: solutions containing high concentrations of acetic acid and solutions containing surfactants, such as perfluorooctane sulfonic acid. Decomposition processes were analyzed based on chemical and physical characteristics, such as chemical reactions, the transportation of reactive species, and characteristics of target compounds. When treating solutions containing acetic acid, the optimization of bulk reactions involving ozone, which regenerates OH radicals from hydrogen peroxide, is a key factor for achieving high decomposition rates and energy efficiency. In contrast, the treatment of surfactants involves interfacial reactions at the plasma–liquid interface, where the accumulation of surfactants is a major concern.