Integrated approach for assessing and mitigating antibiotic contamination in natural waters using bioaccumulation and phytoremediation

The increase in global antibiotic consumption has intensified the presence of these substances in aquatic ecosystems. Related to this, phytoremediation studies have gained prominence due to their high efficiency in mitigating the contamination of emerging pollutants in aquatic ecosystems. In this context, the current study aimed to investigate the occurrence of antibiotics in the aquatic environment the efficiency of the macrophyte Salvinia auriculata in phytoremediation, and the bioaccumulation, depletion, and genotoxic effects in Astyanax bimaculatus exposed to enrofloxacin (EFX) and chloramphenicol (CAP). Environmental samples were collected from the Piracicaba River (SP) at different seasonal periods and analysed using LC–MS/MS. Antibiotics from the tetracycline, fluoroquinolone, and phenicol classes were mainly quantified, with higher concentrations in the dry season. Phytoremediation experiments with S. auriculata demonstrated removal rates greater than 95% for EFX, especially in treatments with higher biomass, while CAP showed lower removal rates (45%). In bioaccumulation and depletion tests, CAP showed greater persistence in fish tissues, while EFX was rapidly eliminated. The presence of S. auriculata modulated bioavailability, reducing the concentration in water, but, in some cases, increasing the absorption rate in fishes. In addition, genotoxic analyses revealed a CAP-induced increase in the frequency of micronuclei (MN) and nuclear abnormalities in erythrocytes (ANEs), an effect that was attenuated in the presence of the macrophyte. The results highlight the potential of S. auriculata as an effective phytoremediation tool, capable of reducing the antibiotic load in the environment and partially mitigating the genotoxic effects in aquatic organisms.