FLAVIO KIYOSHI TOMINAGA
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Artigo IPEN-doc 30419 BDD-persulfate-based anodic oxidation process for progestin degradation2024 - JESUS, JULIANA M.S. de; ARGOLO, ALLAN dos S.; TOMINAGA, FLAVIO K.; BILA, DANIELE M.; BORRELY, SUELI I.; TEIXEIRA, ANTONIO C.S.C.Considering the increasing presence of the hormones levonorgestrel (LNG) and gestodene (GES) in wastewater, the limited effectiveness of conventional treatment methods, and the demand for advanced complementary processes, our study aimed to optimize an anodic oxidation treatment with a focus on low specific energy consumption (SEC) and costs. An electrochemical system coupled to a boron-doped diamond anode (BDD) was continuously used to treat synthetic and real pharmaceutical wastewater from contraceptive production. The central design composite and response surface methodology were the tools employed for optimization. The lowest SEC was obtained as a response to the main process variables: current density, initial pH, and the concentration of the support electrolyte ([Na2S2O8]). The optimal condition ([Na2S2O8]0 = 0.07 mol L−1; [LNG]0,RPW = 1.02±0.05 mg L−1 and [GES]0,RPW = 1.05±0.05 mg L−1; j = 37.5 mA cm−2; pH = 6.75) was established considering an SEC ≤ 3.6 ± 0.8 kWh g−1 and progestins removal ≥70%, which was the experimental condition used to evaluate acute toxicity to Daphnia similis and the effect on estrogenic activity removal using the YES assay. Notably, our study evaluated, for the first time, a comparative investigation that highlights the substantial effect of support electrolytes over the eco-compatibility assessment of the anodic oxidation process investigated. The adaptability of the operation indicates the prospective suitability for the implementation of the process in wastewater treatment facilities in the pharmaceutical industry.Artigo IPEN-doc 25144 Degradation of diclofenac by electron beam irradiaton: Toxicitiy removal, by-products identification and effect of another pharmaceutical compound2018 - TOMINAGA, FLAVIO K.; BATISTA, ANA P. dos S.; TEIXEIRA, ANTONIO C.S.C.; BORRELY, SUELI I.Water contamination by the anti-inflammatory drug diclofenac (DCF) is a consequence of its incomplete removal in wastewater and sewage treatment plants, which is potentialized by interactions with other pharmaceutical contaminants. In this context, electron beam irradiation (EBI) has been considered a clean technology for degrading pharmaceutical compounds in water. Nevertheless, the identification of DCF by-products and their correlation with biological recalcitrance and acute toxicity are poorly understood. In this study, the V. fischeri test was used to characterize DCF toxicity in the absence and presence of fluoxetine (FLX), prior and after irradiation. The results showed complete DCF degradation at low dose (5 kGy). DCF concentration followed pseudo first-order decay with respect to the absorbed, with k0 = (1.33 ± 0.10) kGy−1 (DCF) and k0 = (0.90 ± 0.12) kGy−1 (DCF+FLX). In contrast, negligible TOC removal was observed even at 7.5 kGy, with the formation of recalcitrant, non-biodegradable by-products, as also suggested by the respirometry test. Despite that, the toxicity of the DCF solution diminished from (19.6 ± 1.6) TU to (6.2 ± 2.3) TU, and from (6.8 ± 0.9) TU to (3.1 ± 0.2) TU, in the absence and presence of FLX, respectively, after irradiation up to 5 kGy. Four of the eleven by-products identified by direct-injection MS were easily degraded by EBI, and one (C13H14ClNO5) was considered the least recalcitrant but the most toxic. Based on these results, a possible DCF degradation pathway is proposed, involving hydroxylation and oxidation of aromatic rings, dehalogenation and C−N bond cleavage.