In situ chemical oxidation of ciprofloxacin by activated peroxymonosulfate using nanometric MnOOH: investigation of operational parameters and changes on the catalyst surface

• Ano de defesa: 2023
• Autor(a) principal: Núñez de la Rosa, Yeison Neder
• Orientador(a): Aquino, José Mario de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de São Carlos; Câmpus São Carlos
• Programa de Pós-Graduação: Programa de Pós-Graduação em Química - PPGQ
• Palavras-chave em Português: Processos oxidativos avançados; Catálise heterogênea; Contaminantes emergentes; Radical hidroxila; Redução de Mn(IV) induzida por PMS
• Palavras-chave em Inglês: Advanced oxidation process; Heterogeneous catalysis; Emerging contaminants; Hydroxyl radicals; PMS induced Mn(IV) reduction
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: https://repositorio.ufscar.br/handle/20.500.14289/18318

Nanometric MnOOH compound was synthesized by a green approach, characterized, and used to remove ciprofloxacin (CIP) antibiotic by in situ chemical oxidation using peroxymonosulfate (PMS). The effects of varying concentrations of MnOOH, PMS and pH, on morphological, structural, chemical, and electrochemical changes were studied during and after the experiments. The CIP molecule was completely oxidized and partially mineralized (~ 60%) after 6 h under acidic conditions. The mechanism of CIP degradation was induced by PMS activated oxidants (HO• and 1O2) and, to a lesser extent, directly on the surface of MnOOH. The latter process was evidenced by transmission electron microscopy showing the formation of an amorphous shell (MnOx) over MnOOH crystallites, as verified using X-ray photoelectron spectroscopy and the subsequent increase of the charge transfer resistance that hindered a further electron transfer to the PMS oxidant. Such behavior is recoverable when using a freshly prepared PMS solution.