Investigating degradation efficiency in plasma reactors through driving frequency optimization

Abstract Plasma-assisted degradation (PAD) methods have shown promise in water treatment applications, leveraging electrical energy to break down organic contaminants. Here we report our investigation of the driving frequency dependent nature of PAD using a falling-film plasma reactor for the degradation of brilliant blue dye in aqueous solutions. The degradation kinetics of the dye were analyzed and correlated with the energy efficiency, power consumption, and driving frequency of the reactor. Experimental trials revealed that tuning the driving frequency to align with the reactor’s natural resonance significantly enhanced degradation efficiency, achieving an electrical energy per order ( E EO ) of nearly 100 kW m −3 at an optimal frequency of 9 kHz. Results indicate a nonlinear relationship between power consumption and frequency, confirming harmonic resonance within the plasma reactor and underscoring the importance of optimizing electrical parameters for cost-effective treatment. An LCR circuit model was used to explain the differences in power consumption across the examined frequency range. This research highlights the potential of driving frequency tuning to optimize the generation of reactive chemical species in PAD methods for organic contaminant degradation. By highlighting how harmonic frequency tuning maximizes reactive species generation, this study provides a foundation for future improvements in PAD systems, offering a pathway to scalable, energy-efficient water treatment technologies.