Reactive Yellow 160 Degradation by a Peroxymonocarbonate-Based Advanced Oxidation Process: Performance and Mechanistic Insights

Peroxymonocarbonate (PMC)-based advanced oxidation systems have recently emerged as promising methods for treating textile wastewater. In this study, Reactive Yellow 160 (RY160) was selected as a target dye to investigate optimal operating conditions and elucidate the contributions of individual reactive oxygen species (ROS) in the PMC oxidation process. Experiments were performed under the optimized conditions of 0.061 mM RY160 (50 mg/L), 20 mM NaHCO3, 50 mM H2O2, and 1.7 μM Co2⁺ at pH~9 (inherently buffered). Under these conditions, the RY160 degradation efficiency reached ~36% after 180 mins and increased to 99.7% with 30 min of UV irradiation. ROS quenching experiments indicated that hydroxyl radicals (•OH) and carbonate radicals (CO3•⁻) were the primary oxidants, contributing 42% and 47%, respectively, to the overall degradation, while singlet oxygen (¹O₂) accounted for ~6%. The steady-state concentrations of •OH and CO3•⁻ in the PMC system were determined to be 7.64 × 10⁻13 M and 2.50 × 10⁻16 M, respectively. These findings provide mechanistic insight into PMC-mediated dye degradation and support its potential application in advanced wastewater treatment.