فهرست نشریات علمی دسترسی آزاد ایران

The current research was done to investigate the removal of Alizarin in the heat-activated sulfate radical-based advanced oxidation process in the batch system. The removal efficiency was evaluated based on the change in operating parameters, including pH (3-10), process temperature (50-80 °C), oxidant/pollutant molar ratio (20/1-80/1), and initial pollutant concentration (25-150 mg/L). From the results, the Alizarin oxidation was almost pH independent, and the final removal rate was about 90% in all experiment pHs. The maximum decolorization efficiency of about 95% was achieved when the process temperature reached 80 °C, along with the activation energy of +134.7 kJ/mol, which indicated the endothermic oxidation process. Moreover, the Alizarin removal was 94% at an initial concentration of 25 mg/L and a maximum oxidant per pollutant molar ratio of 80, and it fell to 24% as the initial concentration rose to 150 mg/L. Density Functional Theory (DFT) calculation was employed to identify the degradation mechanism of Alizarin, which revealed that the molecule has a high electron-accepting ability with significant reactivity. The effect of different oxidants was investigated, and the results show that more COD removal was observed when persulfate was used as an oxidant compared to hydrogen peroxide.