Statistically optimized integration of plasma jet-assisted advanced oxidation processes for textile industrial wastewater reuse

Industrialization, particularly in the textile industry, has led to a significant increase in the use of synthetic dyes, resulting in the discharge of toxic, dye-contaminated wastewater. These pollutants pose a threat to both aquatic ecosystems and human health due to their presence of heavy metals and chlorinated compounds. Proper treatment of such wastewater is crucial before it is discharged or reused. This study introduces an optimized sono-photo-Fenton process, enhanced with atmospheric pressure argon plasma jet exposure, for catalytic treatment of azo dyes in wastewater. The process efficiency was assessed based on key factors: Fe²⁺ dosage, H₂O₂ dosage, sonication time, and sonication temperature. A four-factor, three-level Box-Behnken design and response surface methodology (RSM) were used to optimize operational conditions, achieving a degradation efficiency of 94.90% with 250 mg/L of Fe²⁺, 30 mg/L of H₂O₂, 120 minutes of sonication, and 30°C. The reactive species in the plasma were confirmed via optical emission spectroscopy, and the electron temperature was measured with Boltzmann plots. These results support the integration of advanced oxidation technologies into wastewater treatment, promoting environmental cleanup and resource conservation.