Biotic and abiotic dissipation of tetracyclines using simulated sunlight and in the dark

• Published in: The Science of the total environment Vol. 635; pp. 1520 - 1529
• Main Authors: Conde-Cid, M., Fernández-Calviño, D., Nóvoa-Muñoz, J.C., Arias-Estévez, M., Díaz-Raviña, M., Fernández-Sanjurjo, M.J., Núñez-Delgado, A., Álvarez-Rodríguez, E.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.09.2018
• Subjects: Abiotic dissipation; Antibiotics; Biotic dissipation; Simulated sunlight; Tetracyclines; Simulated sunlight; Antibiotics; Tetracyclines; Abiotic dissipation; Biotic dissipation
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2018.04.233

Veterinary antibiotics reaching soils and water bodies are considered emerging pollutants deserving special attention. In this work, dissipation of tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) is investigated. Dissipation experiments in filtered water, using simulated sunlight, resulted in the following degradation sequence: TC < OTC ≈ CTC, with half-life values of 229, 101 and 104 min, respectively; however, no dissipation took place in the dark. Dissipation of the three tetracyclines in culture medium and with simulated sunlight was much higher, giving the sequence TC ≈ OTC < CTC, with half-lives of 9, 10 and 7 min, respectively; in the dark, TC and OTC did not suffer dissipation, but it was around 28% for CTC at the end of the experiment (480 min). The variable explaining a higher dissipation in culture medium and with light was pH, as this parameter caused changes in the distribution of species of tetracyclines, affecting degradation. Adding bacterial suspensions extracted from soil and poultry manure increased dissipation, giving the sequence: TC ≈ OTC < CTC, which is attributed to the presence of humic acids, which adsorb these antibiotics. These results could facilitate understanding the fate of antibiotics reaching environmental compartments and causing public health hazards. [Display omitted] •Dissipation sequence in filtered water and with simulated light: TC < OTC ≈ CTC•Dissipation in culture medium and with simulated light was much higher.•No dissipation in the dark (in water), and just 20% for CTC (in culture medium)•Soil and poultry manure bacterial suspensions further increased dissipation.