Activation of PAA by pyrite for the degradation of tetracycline with adjusted pH conditions: The overlooked role of sulfur species

Abstract

Recently, the water pollution caused by antibiotics has become an urgent problem to be solved. In this work, we developed a heterogeneous catalyst based on pyrite (i.e.FeS₂) via peracetic acid (PAA) activation and further explored the potential efficacy of tetracycline(TC) antibiotics degradation driven by different pH values. The preparation of pyrite under the action of sulfur species in the system solution can exists not only in a variety of forms, but also its general to produce more SO₄^•- trend. Mechanism analysis showed that the main active species including non-organic radical (R-O•) and •OH as the dominant reactive oxidized species (ROS) in pyrite(FeS₂)/PAA process. This results shown that the presence of different forms of sulfur species played a significant role in Fe(II) regeneration with a result of accelerated PAA activation. In addition, the generation of sulfur species with R-O^•was proposed as the primary reactive sites for PAA activation in the TC degradation of free radical primary and secondary change in heterogeneous catalyst/PAA reaction systems. DFT theoretical calculations indicate that the CH₃COO• prefers electron transfer with sulfur species, which also fully demonstrated the effect by the dual role of sulfur species in regulating the reactive oxidized species and Fe(II) regeneration. Finally, this study expanded the application in hydrophilized fiber via electrospinning technology, and FNC fiber film still could still maintain good catalytic activity of TC in the actual water by FNC/PAA system, verifing that FNC fiber film is suitable for the application of various pollutants and actual wastewater. This work could provide strong support for the use of natural minerals as heterogeneous catalysts for PAA activation and formed FNC fiber film in the practical wastewater treatment applications.