Industrial potential of electro-oxidation and peroxymonosulfate coupling for efficient organic degradation in acidic dye wastewater

Dye manufacturing wastewater contains high sulfuric acid and organic contaminants. Organic contaminants complicate treatment and hinder sulfuric acid recovery, causing environmental issues and resource waste. This study combines electro-oxidation with peroxymonosulfate (EO-PMS) to treat highly acidic (∼10 %) wastewater from Dispersed Violet 93 dye. Degradation was monitored in real time using a modified continuous-flow UV-Vis spectrophotometer. EO-PMS efficiently removes organic compounds, allowing the treated acidic liquid to be reused in dye production. At 16 mA/cm² current density and 10 mM PMS, complete degradation of 300 mL wastewater occurred within 6 minutes, achieving 86 % mineralization. Degradation follows zero-order kinetics, with mass transfer efficiency being a key factor. Experimental variables influencing degradation efficiency were also investigated. Free radical scavenging and electron paramagnetic resonance experiments identified ·OH as the main active species (83.6 %), with minor contributions from SO 4 ·- (1.45 %) and others. Experimental data were used to fit the relationships between current intensity, PMS concentration, degradation time, and wastewater disposal costs to assess the economic feasibility of EO-PMS. This study presents an efficient, cost-effective degradation method with real-time monitoring, suitable for industrial-scale treatment and reuse of acidic dye wastewater. • Electro-oxidation coupled with peroxymonosulfate achieves effective degradation. • The degradation target is dye wastewater with complex components and 10 % H 2 SO 4. • The study investigates kinetics and the types and contributions of active species. • A circular real-time monitoring system simplifies degradation process monitoring. • Data fitting shows the system has high economic value for industrial applications.