Degradation of Reactive Yellow X-RG by O₃/Fenton system: response surface approach, reaction mechanism, and degradation pathway

O₃/Fenton for the treatment of effluent containing Reactive Yellow X-RG is investigated. The response surface methodology is applied to study the main and interactive effects of the parameters. With the initial dye concentration being controlled at 300 mg L⁻¹, the optimized conditions for wastewater treatment are 3.68, 29.19 and 18.49 mg min⁻¹ for initial pH, mole ratio of [H₂O₂]/[Fe²⁺] and ozone dosage, respectively. The regression quadratic model well describing the degradation efficiency of O₃/Fenton process is developed and validated by the analysis of variances, respectively. In addition, a possible pathway for Reactive Yellow X-RG degradation is proposed by detecting the temporal evolution of intermediates in the solution, with the use of some techniques including ultraviolet spectrophotometric method (UV-Vis), Fourier transform infrared spectroscopy (FT-IR) and gas chromatography–mass spectrometry (GC/MS). Meanwhile, every reaction step is given to explain the degradation mechanisms.