The effects of reaction conditions on liquid-phase hydroxyl radical production in gas-liquid pulsed-electrical-discharge reactors

High-voltage gas-, liquid- and gas-liquid phase pulsed electrical discharges are an emerging technique in environmental pollutant degradation, which that are characterized by the production of hydroxyl radicals as the primary degradation species. The initiation and propagation of the electrical discharges depends on several physical, chemical, and electrical parameters. These parameters also influence the physical and chemical characteristics of the discharges, including the production of reactive species such as OH center dot, H-center dot and H2O2. This paper focuses on quantification of hydroxyl radicals using chemical probes (DMSO and NaTA) in three different reactor configurations: reference (purely liquid-phase discharge), hybrid-series (combined gas-liquid discharge), and hybrid-parallel (combined gas-liquid discharge) for a wide range of operating conditions. The operating conditions that are evaluated are: input power, initial conductivity of solution, temperature of solution, presence of radical scavengers and additives in solution.