RESUMO
The efficiency of advanced oxidation processes (AOPs) for disposing of non-steroidal anti-inflammatory drugs (NSAIDs) has been widely studied, but the environmental fates and effects of the NSAIDs and their degradation products (DPs) are poorly understood. In this study, the efficiency of ultraviolet light/Na2S2O8 (UV/PS) in degrading three NSAIDs-diclofenac, naproxen, and ibuprofen-and the toxicity of their DPs on Cyprinus carpio (C. carpio) was investigated. Results showed that the three NSAIDs can be completely removed (removal rate > 99.9%) by UV/PS, while the mineralization rate of the NSAIDs was only 28%. When C. carpio were exposed to 0.1 µM NSAIDs, 10 µM persulfate (PS), and 0.1 µM DPs of the NSAIDs for 96 h, respectively, the toxicity effects are as the NSAID DPs > PS > NSAIDs. Research results into the time-dependent effect of NSAID DPs on C. carpio demonstrated that obvious toxicity effects were observed in the first 48 hours, and the toxicity effects strengthened over time. NSAID DPs may have more severe toxicity effects than NSAIDs on C. carpio; therefore, the operating conditions of UV/PS must be optimized to eliminate the ecotoxicity of DPs.
Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Carpas , Poluentes Ambientais/toxicidade , Doenças dos Peixes/prevenção & controle , Purificação da Água/métodos , Animais , Anti-Inflamatórios não Esteroides/química , Diclofenaco/química , Diclofenaco/efeitos da radiação , Diclofenaco/toxicidade , Monitorização de Parâmetros Ecológicos , Poluentes Ambientais/química , Poluentes Ambientais/efeitos da radiação , Poluição Ambiental/prevenção & controle , Doenças dos Peixes/induzido quimicamente , Ibuprofeno/química , Ibuprofeno/efeitos da radiação , Ibuprofeno/toxicidade , Eliminação de Resíduos de Serviços de Saúde , Naproxeno/química , Naproxeno/efeitos da radiação , Naproxeno/toxicidade , Oxirredução , Fotólise/efeitos dos fármacos , Fotólise/efeitos da radiação , Compostos de Sódio/química , Sulfatos/química , Testes de Toxicidade Aguda , Raios Ultravioleta , Águas Residuárias/química , Águas Residuárias/toxicidadeRESUMO
The main objective of this study was to investigate the degradation mechanism, the reaction kinetics, and the evolution of toxicity of naproxen in waters under simulated solar radiation. These criteria were investigated by conducting quenching experiments with reactive oxygen species (ROS), oxygen concentration experiments, and toxicity evaluations with Vibrio fischeri bacteria. The results indicated that the degradation of naproxen proceeds via pseudo first-order kinetics in all cases and that photodegradation included degradation by direct photolysis and by self-sensitization via ROS; the contribution rates of self-sensitized photodegradation were 1.4%, 65.8%, and 31.7% via ·OH, (1)O2 and O2(â¢-), respectively. Furthermore, the oxygen concentration experiments indicated that dissolved oxygen inhibited the direct photodegradation of naproxen, and the higher the oxygen content, the more pronounced the inhibitory effect. The toxicity evaluation illustrated that some of the intermediate products formed were more toxic than naproxen.