Oxidation of atrazine in aqueous media by solar- enhanced Fenton-like process involving persulfate and ferrous ion

摘要

The oxidation of s-triazines (using atrazine (ATZ) as a model compound) by a solar-enhanced Fenton-like process involving persulfate and ferrous ion was studied. A flow-through tubular photoreactor was employed for the experiments. The solar-enhanced oxidative system involving ferrous ion and persulfate (Solar/S2O82-/Fe2+) showed the highest ATZ degradation efficiency when compared with other treatments (unactivated S2O82-, Solar- sunlight only, /S2O82-/Fe-2, Solar/S2O82-). Complete degradation of ATZ and 20% reduction in total organic carbon (TOC) content were observed after 30 min of the treatment. The in situ generated center dot OH and SO4- radicals were shown to be involved in ATZ oxidation using the radical scavengers methanol and tert-butyl alcohol. Furthermore, iron compounds were shown to act not only as catalysts but also as photo-sensitizers, as the introduction of ferrous ion into the reaction mixture led to an increased absorbance of the solution and expansion of the absorption spectrum into the longer wavelength spectral region.