Intensification of levofloxacin sono-degradation in a US/H2O2 system with Fe3O4 magnetic nanoparticles

Fe3O4 magnetic nanoparticles (MNPs) were synthesised, characterised, and used as a peroxidase mimetic to accelerate levofloxacin sono-degradation in an ultrasound (US)/H2O2 system. The Fe3O4 MNPs were in nanometre scale with an average diameter of approximately 12 to 18 nm. The introduction of Fe3O4 MNPs increased levofloxacin sono-degradation in the US/H2O2 system. Experimental parameters, such as Fe3O4 MNP dose, initial solution pH, and H2O2 concentration, were investigated by a one-factor-at-a-time approach. The results showed that Fe3O4 MNPs enhanced levofloxacin removal in the pH range from 4.0 to 9.0. Levofloxacin removal ratio increased with Fe3O4 MNP dose up to 1.0 g·L− 1 and with H2O2 concentration until reaching the maximum. Moreover, three main intermediate compounds were identified by HPLC with electrospray ionisation tandem mass spectrometry, and a possible degradation pathway was proposed. This study suggests that combination of H2O2, Fe3O4 MNPs and US is a good way to improve the degradation efficiency of antibiotics.

Graphical abstractThe Fe3O4 magnetic nanoparticles (MNPs, with an average diameter of approximately 12 to 18 nm) were synthesised, characterised, and used as a peroxidase mimetic to accelerate levofloxacin sono-degradation under an US/H2O2 system. The results showed that Fe3O4 MNPs enhanced levofloxacin removal over the range 4.0 ≤ pH ≤ 9.0, and levofloxacin removal ratio reached the maximum with Fe3O4 MNP dose up to 1.0 g·L− 1 and with H2O2 concentration. This study also identified the three main intermediate compounds for levofloxacin under US/H2O2/Fe3O4 MNP system by HPLC with electrospray ionisation tandem mass spectrometry (ESI–MS/MS), a possible degradation pathway was proposed as well.Figure optionsDownload full-size imageDownload as PowerPoint slide