Interaction of peracetic acid with chromium(III): Understanding degradation of coexisting organic pollutants in water.
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
Peracetic acid (PAA, CH3C(O)OOH) has gained significant attention for its use in wastewater disinfection. Wastewater usually contains both metal ions and organic pollutants and understanding reactions after adding PAA to such contaminated water is needed. This paper presents results regarding the effect of interactions between chromium(III) (Cr(III)) and PAA on the degradation of selected pharmaceuticals, mainly trimethoprim (TMP). The degradation of pharmaceuticals by PAA, PAA-Cr(III), and H2O2-Cr(III) under different conditions was examined (pH = 6.0-10.0 and molar ratios of PAA to Cr(III)). The degradation rate of TMP by PAA-Cr(III) was greater than by PAA and H2O2-Cr(III) under alkaline conditions. Degradation studies using quenching agents and probing molecules, and spectroscopic measurements (UV-visible and electron paramagnetic resonance) suggest OH as the major radical species and Cr(IV)/Cr(V) as additional reactive species. The oxidized products of TMP by PAA-Cr(III) were identified and possible pathways proposed. Degradation of other pharmaceuticals having different molecular structures by PAA-Cr(III) and H2O2-Cr(III) systems were also investigated. Most of the pharmaceuticals degraded at faster rates by PAA-Cr(III) and H2O2-Cr(III) than by PAA alone, suggesting that co-present metal ions may play a significant role in PAA oxidation in water treatment.
