Abstract
Sulfidated zerovalent iron (S-ZVI) has been extensively used for the degradation of pollutants under anaerobic conditions. However, the investigation of the ability and mechanism of S-ZVI to regulate the catalytic oxidation of pollutants under aerobic conditions has been overlooked. In this study, we revealed the mechanism of enhanced ibuprofen (IBP) degradation by decomposition and activation by S-ZVI under aerobic conditions using CaO2 as a slow-release oxygenate. Specifically, the S-ZVI/CaO2 showed a 2.98-fold increase in rate compared to ZVI/CaO2 within the previous 15 min of reaction. Two reaction stages of enhanced IBP degradation by the S-ZVI/CaO2 system were observed. In the initial stage, the shell layer on the surface of S-ZVI activates dissolved oxygen in water to form H2O2 through a continuous one-electron process. This process effectively prevents the oxidation of ZVI while enhancing the electron selectivity of ZVI and facilitates the decomposition of CaO2, resulting in the production of more H2O2. Subsequently, sulfur on the surface of S-ZVI acts as an electron shuttle in the second stage, facilitating the activation of H2O2 and improving the electron utilization of ZVI. This finding clarifies the mechanism of pollutant degradation by S-ZVI under aerobic conditions and provides a strategy for enhancing pollutant degradation.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call