Levofloxacin (LFX) is a widely used antibiotic medication. Persistent traces of LFX in water and wastewater may induce bacterial resistance. Photon-driven advanced oxidation processes (AOPs) can assist in attaining complete abatement of LFX for environmental protection. This work benchmarks different solar AOPs based on hydroxyl radical (OH•) and sulphate radical (SO4•−) chemistry. Other oxidant precursors, as radical sources, were used to selectively control the generation of either hydroxyl radical (i.e., H2O2), sulphate radical (i.e., peroxydisulphate (PDS)), or a controlled mixture ratio of both OH•/SO4•− (i.e., peroxymonosulphate (PMS)). The influence of pH on degradation performance was evaluated using unbuffered and buffered solutions. Simulated irradiation/PMS process exhibited a strong pH-dependence attaining partial degradation of ca. 56% at pH 5 up to complete degradation at pH 7. Despite the similitudes on the abatement of target pollutant LFX in pristine solutions, only simulated irradiation/PDS treatment achieved effective abatement of LFX in wastewater samples given the higher selectivity of SO4•−. Toxicity tests were conducted with Escherichia coli (LMG2092) and Micrococcus flavus (DSM1790), demonstrating successful inhibition of the antibiotic character of polluted waters, which would contribute to preventing the development of resistant bacterial strains. Finally, a degradative pathway was suggested from the by-products and intermediates identified by LC–MS. Results demonstrate that the degradation of specific functional groups (i.e., piperazine ring) is associated with the loss of antibacterial character of the molecule.

Comparison of sunlight-AOPs for levofloxacin removal. Kinetics, transformation products, and toxicity assay on Escherichia coli and Micrococcus flavus / Foti, L.; Coviello, D.; Zuorro, A.; Lelario, F.; Bufo, S. A.; Scrano, L.; Sauvetre, A.; Chiron, S.; Brienza, M.. - In: ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL. - ISSN 0944-1344. - 29:38(2022), pp. 58201-58211. [10.1007/s11356-022-19768-w]

Comparison of sunlight-AOPs for levofloxacin removal. Kinetics, transformation products, and toxicity assay on Escherichia coli and Micrococcus flavus

Zuorro A.;
2022

Abstract

Levofloxacin (LFX) is a widely used antibiotic medication. Persistent traces of LFX in water and wastewater may induce bacterial resistance. Photon-driven advanced oxidation processes (AOPs) can assist in attaining complete abatement of LFX for environmental protection. This work benchmarks different solar AOPs based on hydroxyl radical (OH•) and sulphate radical (SO4•−) chemistry. Other oxidant precursors, as radical sources, were used to selectively control the generation of either hydroxyl radical (i.e., H2O2), sulphate radical (i.e., peroxydisulphate (PDS)), or a controlled mixture ratio of both OH•/SO4•− (i.e., peroxymonosulphate (PMS)). The influence of pH on degradation performance was evaluated using unbuffered and buffered solutions. Simulated irradiation/PMS process exhibited a strong pH-dependence attaining partial degradation of ca. 56% at pH 5 up to complete degradation at pH 7. Despite the similitudes on the abatement of target pollutant LFX in pristine solutions, only simulated irradiation/PDS treatment achieved effective abatement of LFX in wastewater samples given the higher selectivity of SO4•−. Toxicity tests were conducted with Escherichia coli (LMG2092) and Micrococcus flavus (DSM1790), demonstrating successful inhibition of the antibiotic character of polluted waters, which would contribute to preventing the development of resistant bacterial strains. Finally, a degradative pathway was suggested from the by-products and intermediates identified by LC–MS. Results demonstrate that the degradation of specific functional groups (i.e., piperazine ring) is associated with the loss of antibacterial character of the molecule.
2022
AOPs; emerging contaminants; levofloxacin; photodegradation; sulphate radicals; toxicity
01 Pubblicazione su rivista::01a Articolo in rivista
Comparison of sunlight-AOPs for levofloxacin removal. Kinetics, transformation products, and toxicity assay on Escherichia coli and Micrococcus flavus / Foti, L.; Coviello, D.; Zuorro, A.; Lelario, F.; Bufo, S. A.; Scrano, L.; Sauvetre, A.; Chiron, S.; Brienza, M.. - In: ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL. - ISSN 0944-1344. - 29:38(2022), pp. 58201-58211. [10.1007/s11356-022-19768-w]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1667593
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