Persulfate activation by iron complex: A novel non-radical strategy for enhanced tetracycline degradation

Water pollution, particularly the widespread prevalence of antibiotic contaminants, has emerged as a pressing global environmental concern. As tetracycline (TC) exhibits both persistence and ecological toxicity, it has become a significant challenge in wastewater treatment. In response to this issue, a novel biocompatible catalytic system was developed, in which ellagic acid-iron complexes (Fe-EA) were employed to activate persulfate (PDS), enabling the effective degradation of TC. It was demonstrated through experimental results that Fe(IV) = O and 1 O 2 played pivotal roles in the degradation process. Density functional theory (DFT) calculations, which unveiled the chemical bonding characteristics between S = O, S-O, and Fe(III), elucidated the high reactivity and molecular-level mechanisms of this catalytic system. Through experimental validation, it was confirmed that the Fe-EA@PDS system exhibited excellent TC degradation performance, demonstrating high stability and adaptability under various environmental conditions. The degradation pathways of TC were analyzed using high- resolution mass spectrometry (LC-MS/MS), while the biological toxicity of TC and its degradation intermediates was assessed using the TEST model, indicating that this catalytic system significantly mitigated the toxicity of the degradation products. In conclusion, the Fe-EA@PDS system, which is characterized by its biocompatibility and high catalytic efficiency, demonstrates substantial potential for application in water treatment.