Deep insight into methyl blue decolorization using non-thermal pulsed plasma: experimental and modeling approaches

This study investigates the rapid decolorization of methyl blue (MB) dye in water using a novel atmospheric non-thermal pulsed plasma system with a multi-pin-to-plate electrode configuration. The system integrates optical emission spectroscopy, UV-visible absorption spectroscopy, and response surface methodology for experimental design. A global kinetic model simulating over 150 species and 3500 reactions was employed to elucidate degradation mechanisms. Under optimized conditions, 97% of MB (initial concentration: 5 ppm) was decolorized within 120 s of plasma treatment. Significant increases in reactive species concentrations (·OH, O₃) were observed, alongside changes in water chemistry (pH, ORP, EC). These findings demonstrate the efficiency and scalability of the proposed plasma system for water treatment, providing new mechanistic insights and a framework for optimizing plasma-based degradation of organic pollutants.