Abstract
In this study, waste self-heating bag was recycled as the raw material to fabricate supports (activated carbon and vermiculite) loading core–shell Fe0@Fe2O3 catalyst (CV-Fe0@Fe2O3). The successful construction of loading and Fe2O3 shell enhanced peroxydisulfate (PDS) activation performance for sulfapyridine (SPD) degradation by slowing the passivation and agglomeration of Fe0 nanoparticles, and endowed Fe0 with high stability (much fewer iron leaching). Besides, other typical refractory pollutants were efficiently degraded in the CV-Fe0@Fe2O3/PDS system, and the normalized pseudo-first-order kinetic rate constant (kN) of 1.581 L2 g−1 mmol−1 min−1 was achieved, which was higher than those of most reported iron-based catalysts. Furthermore, the CV-Fe0@Fe2O3/PDS system also exhibited a wide pH adaptability. The electron paramagnetic resonance (EPR) results and quenching experiments demonstrated that sulfate radicals (SO4⋅−) and hydroxyl radicals (⋅OH) were the dominated reactive oxygen species (ROS) responsible for the degradation, and the activation of dissolved oxygen produced the superoxide radicals (O2⋅−) and H2O2 contributing to the generation of more SO4⋅− and ⋅OH. Mechanism exploration declared that the Fe2O3 shell on the CV-Fe0@Fe2O3 mediated the electron transfer from Fe0 core to generate surface Fe2+ (≡Fe2+) and H2O2, and the former was the main active sites for the activation of PDS, H2O2, and dissolved oxygen to form SO4⋅−, ⋅OH, and O2⋅−, respectively. Finally, three degradation pathways of SPD were proposed according to the intermediates identification. In summary, this work may be valuable for water purification based on waste resource recycling.
Published Version
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