Electrochemical degradation of the antibiotic ciprofloxacin in a flow reactor using distinct BDD anodes: Reaction kinetics, identification and toxicity of the degradation products

Autor(es)

Wachter, Naihara ^[1] ; Aquino, Jose Mario ^[1] ; Denadai, Marina ^[1] ; Barreiro, Juliana C. ^[2] ; Silva, Adilson Jose ^[3] ; Cass, Quezia B. ^[1] ; Bocchi, Nerilso ^[1] ; Rocha-Filho, Romeu C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Quim, CP 676, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Inst Quim Sao Carlos, Ave Joao Dagnone 1100, Ed Quim Ambiental, BR-13563120 Sao Carlos, SP - Brazil

^[3] Univ Fed Sao Carlos, Dept Engn Quim, CP 676, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Chemosphere; v. 234, p. 461-470, NOV 2019.
• Citações Web of Science: 0

Resumo

The performances of distinct BDD anodes (boron doping of 100, 500 and 2500 ppm, with sp(3)/sp(2) carbon ratios of 215, 325, and 284, respectively) in the electrochemical degradation of ciprofloxacin - CIP (0.5 L of 50 mg L-1 in 0.10 M Na2SO4, at 25 degrees C) were comparatively assessed using a recirculating flow system with a filter-press reactor. Performance was assessed by monitoring the CIP and total organic carbon (TOC) concentrations, oxidation intermediates, and antimicrobial activity against Escherichia coli as a function of electrolysis time. CIP removal was strongly affected by the solution pH (kept fixed), flow conditions, and current density; similar trends were obtained independently of the BDD anode used, but the BDD100 anode yielded the best results. Enhanced mass transport was achieved at a low flow rate by promoting the solution turbulence within the reactor. The fastest complete CIP removal (within 20 min) was attained at j = 30 mA cm(-2), pH = 10.0, and q(v)= 2.5 L min(-1) + bypass turbulence promotion. TOC removal was practically accomplished only after 10 h of electrolysis, with quite similar performances by the distinct BDD anodes. Five initial oxidation intermediates were identified (263 <= m/z <= 348), whereas only two terminal oxidation intermediates were detected (oxamic and formic acids). The antimicrobial activity of the electrolyzed CIP solution was almost completely removed within 10 h of electrolysis. The characteristics of the BDD anodes only had a marked effect on the CIP removal rate (best performance by the least-doped anode), contrasting with other data in the literature. (C) 2019 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 09/54040-8 - EMU: aquisição de um espectrômetro de massas de alta resolução Orbitrap para descoberta e elucidação estrutural compostos biologicamente ativos: aplicações em proteômica e biomarcadores, síntese, isolamento e caracterização de produtos naturais, estudos de sistemas redox em alimentos e síntese enzimática
• Beneficiário: Emanuel Carrilho
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários
• Processo FAPESP: 09/17138-0 - Métodos para análises de pequenas moléculas em fluidos biológicos: o uso de colunas de meios de acesso restrito para injeção direta de amostras
• Beneficiário: Quezia Bezerra Cass
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/13002-9 - Degradação eletroquímica de um fármaco: comparação entre anodos
• Beneficiário: Naihara Wachter
• Modalidade de apoio: Bolsas no Brasil - Mestrado