Platinum oxide-based peracetic acid activation for efficient degradation of typical antibiotic

Abstract

Peracetic acid (PAA)-based Advance Oxidation Process (AOP) is now used to treat pharmaceutically contaminated wastewater. Herein, PAA is heterogenically activated to degrade sulfamethoxazole (SMX) taking platinum oxide (PtO₂) as a catalyst for the first time. PtO₂/PAA system with good synergetic effect achieved 100 % SMX degradation in 75 min. Its corresponding kinetic rate constant (0.072 min⁻¹) was exceptionally higher than six other Transition Metal/PAA-based systems tested as well as than PtO₂ or PAA alone. The degradation improved by augmenting PAA and PtO₂ inputs. Radical scavenging and electron paramagnetic resonance pointed acetylperoxy (CH₃C(O)OO·) and acetoxyl (_CH3C(O)O·) as the main reactive radicals attributing SMX abatement. X-ray photoelectron spectroscopy and diffraction along with electrochemical tests (cyclic voltammetric curve, electrochemical impedance spectra, and I-t curve) recommended that the electron transfer of Pt²⁺/Pt⁴⁺ also facilitated PAA activation. Density Functional Theory (DFT) assisted in predicting the reaction sites on SMX molecules. Four degradation pathways are proposed with the help of DFT calculations and eight intermediate products identified by High-Performance Liquid Chromatography Mass-Spactrometry. Dissolved organic matter, anions and different waterbodies had tolerable degradation inhibition. Efficient reactivity and adequate stability attest PtO₂ as an ideal catalyst for oxidative degradations. The findings offer valuable insights into a novel, sustainable, and efficient approach to treat drug-contaminated wastewater.