Abstract:
Textile effluents are generally treated by physico-chemical and biological processes, but these treatments do not always suffice to reach the required quality. For this reason, advanced oxidation processes are used to eliminate residual micropollutants. This study focuses on the degradation of the dye Safranine O (SO), used in various industries, by thermal activation of persulfate. An in-depth kinetic modeling allowed the exploration of reactive species involved and the determination of rate constants for radical and non-radical mechanisms.
Using the COPASI® software and a kinetic mechanism composed of 44 reactions, the model enabled precise fitting to experimental data. Simulations were conducted at 50 ± 1 °C, with 2 g/L persulfate, varying initial micropollutant concentrations (1, 10, and 100 mg), and a controlled pH of 3.5.
The results show that the higher the pollutant concentration, the slower its degradation. The radicals •OH and SO₄•⁻ are the main actors in this degradation. The model allows tracking the evolution of reactive oxygen species (ROS), the distribution of radicals, and estimating the rate constants related to the thermal activation of persulfate.
