Photodegradation of the fluoxetine emerging contaminant: degradation mechanisms and toxicological investigation using aquatic organisms

• Grant number: 23/08044-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2023
• End date: November 30, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Principal Investigator: Ernesto Chaves Pereira de Souza
• Grantee: Pietra Terruggi Rabello
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 13/07296-2 - CDMF - Center for the Development of Functional Materials, AP.CEPID

Abstract

In the last decades, the scientific community has concentrated great efforts on the development of new environmentally friendly technologies aiming at the removal of emerging pollutants in aquatic environments, among which the heterogeneous photocatalyst stands out. However, many gaps persist in revealing in detail the degradation mechanisms of these pollutants and the toxicological effect on aquatic organisms after the degradation processes. In this context, the present project aims to investigate the photocatalytic degradation of fluoxetine and the toxicological effects of the main pollutant and by-products in aquatic organisms. Erbium-modified silver phosphate nanoparticles obtained from the microwave hydrothermal method (MHM) or MHM assisted by ultraviolet-visible radiation (MHM_UV_Vis) will be applied as a photocatalyst. The synthetic method developed for the first time by our group 1 shows great potential to obtain photocatalysts with optimized properties, which may improve the efficiency of fluoxetine degradation. After the degradation stage, the treated samples will be monitored quality-quantitatively by high-performance liquid chromatography using the analytical methodology of wide knowledge of the group2,3. After optimization of two degradation processes and identification of two main by-products, toxicological studies using Nile Tilápia (Oreochromis niloticus) as aquatic organisms will be carried out. Applying different concentrations of fluoxetine solutions and by-products, in addition to samples obtained after photocatalytic treatment, the influence of two contaminants on cardiorespiratory processes, development of body mass, and energy metabolism will be investigated. The studies of characterization and application of photocatalysts for photodegradation of fluoxetine, which is no longer in the domain of the group, will be added to the toxicological study of fluoxetine and by-products in aquatic organisms, configuring an important advance for the development of the area. This new approach, in which it is investigated, not only the main pollutant and its degradation but also the by-products and toxicological effects will provide an important contribution to understanding the impact that these treatment processes exert on the environment. Based on the two results obtained, we hope that our contribution to the scientific community will allow future works to use this approach that is concerned with or before, during, and after photocatalytic treatment of emerging pollutants.