Characterization and Treatment Performance of an Atmospheric Pressure Plasma Jet-Operated Spinning Disc Reactor for the Treatment of Rhodamine B Dye

Abstract

A spinning disc reactor is a design widely adopted in chemical process industries because of its capability to produce thin fast-moving films, which enhance the diffusive and convective transport of solutes.However, this configuration has yet to be explored for plasma-based water treatment, where mass transport limitations in the bulk liquid often limit reactor degradation efficiency. This study presents a novel plasma spinning disc reactor (PSDR) for degrading rhodamine B dye and characterizes its performance. The impact of discharge power, gas flowrate, liquid flowrate, disc rotational speed, and bulk liquid concentration on dye degradation was investigated. The results indicate that mass transport limitations within the fluid were the primary limitation to efficient degradation. Higher degradation rates were achieved primarily through changes in the plasma area, fluid velocity across the disc, and increased bulk liquid concentration, resulting in enhanced contact between the solute and the plasma. Residence time, a function of plasma area and fluid velocity, was used to describe and predict degradation rates on the PSDR using a 1-D fluid element model, which indicated that lower residence times favored dye degradation, especially for systems limited by small plasma areas.