Ultrasonic degradation of sulfadiazine in aqueous solutions

Autor(es)

Lastre-Acosta, Arlen Mabel ^[1] ; Cruz-Gonzalez, German ^[2] ; Nuevas-Paz, Lauro ^[3] ; Jauregui-Haza, Ulises Javier ^[2] ; Silva Costa Teixeira, Antonio Carlos ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Chem Engn, Sao Paulo - Brazil

^[2] Higher Inst Technol & Appl Sci InSTEC, Havana - Cuba

^[3] CNGM, Havana - Cuba

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. 22, n. 2, p. 918-925, JAN 2015.
• Citações Web of Science: 14

Resumo

Advanced oxidation methods, like ultrasound (US), are a promising technology for the degradation of emerging pollutants in water matrices, such as sulfonamide antibiotics. Nevertheless, few authors report the degradation of sulfonamides by high-frequency US (> 100 kHz), and limited information exist concerning the use of ultrasonic-driven processes in the case of sulfadiazine (SDZ). In this study, SDZ degradation was investigated with the aim to evaluate the influence of initial concentration, pH and US frequency, and power. Ultrasonic frequencies of 580, 862, and 1,142 kHz at different power values and SDZ initial concentrations of 25, 50, and 70 mg L-1 were used. The results show that SDZ degradation followed pseudo first-order reaction kinetics with k values and percent removals decreasing for increasing solute initial concentration. Higher SDZ percent removals and removal rates were observed for the lowest operating frequency (580 kHz), higher dissipated power, and in slightly acidic solution (pH 5.5). Addition of the radical scavenger n-butanol confirmed that hydroxyl radical-mediated reactions at the interface of the cavitation bubbles are the prevailing degradation mechanism, which is directly related to the pK(a)-dependent speciation of SDZ molecules. Finally, addition of H2O2 had a detrimental effect on SDZ degradation, whereas the addition of the Fenton reagent showed a positive effect, revealing to be a promising alternative for the removal of sulfadiazine. (AU)

• Processo FAPESP: 08/57708-7 - CEPEMA-USP
• Beneficiário: Claudio Augusto Oller do Nascimento
• Modalidade de apoio: Auxílio à Pesquisa - Temático