The photodegradation kinetics, transformation products and degradation pathways of CIP with different dissociation species (cations, zwitterions and anions) were investigated in photocatalytic system. Based on DFT calculation, Fukui index interpreted the active sites of different CIP species, and potential energy surface further elucidated the reaction transition state evolution for the radical attack (hydroxyl radical). Zwitterionic form of CIP exhibited the highest pseudo-first order rate constant (0.2217 ± 0.0179 min<sup>-1</sup>) during photocatalytic degradation. Combining the analysis of high performance liquid chromatography-mass spectrometry and DFT calculation, cationic and anionic CIP mainly experienced the cyclodealkylation of piperazine, while zwitterionic CIP mainly experienced the defluorination and epoxidation of piperazine. Toxicity evaluation showed that most of the transformation intermediates/products decomposed by defluorinated and hydroxylated CIP had low risk to aquatic organisms.

Photocatalytic transformation fate and toxicity of ciprofloxacin related to dissociation species

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.