Unraveling the time evolution and post mortem changes of nanometric MnOOH during in situ oxidation of ciprofloxacin by activated peroxymonosulfate

Autor(es)

Nunez-de la Rosa, Yeison ; Durango, Luis Guillermo Cuadrado ; Forim, Moacir Rossi ; Nascimento, Otaciro Rangel ; Hammer, Peter ; Aquino, Jose M.

• Tipo de documento: Artigo Científico
• Fonte: APPLIED CATALYSIS B-ENVIRONMENTAL; v. 327, p. 11-pg., 2023-02-17.

Resumo

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 center dot 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 (MnO2) 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. (AU)

• Processo FAPESP: 14/50918-7 - INCT 2014: para o Controle Biorracional de Insetos Pragas e Fitopatógenos
• Beneficiário: Maria Fátima das Graças Fernandes da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 19/07943-4 - Estudo comparativo de sistemas homogêneos e heterogêneos com partículas nano/micrométricas para a degradação de poluentes orgânicos via homólise in situ de oxidantes
• Beneficiário: José Mario de Aquino
• Modalidade de apoio: Auxílio à Pesquisa - Regular