Chemical and toxicological evaluation along with unprecedented transformation products during photolysis and heterogeneous photocatalysis of chloramphenicol in different aqueous matrices

• Published in: Environmental science and pollution research international 2021-05, Vol.28 (19), p.23582-23594
• Main Authors: Marson, Eduardo O., Paniagua, Cleiseano E.S., Costa-Serge, Nayara M., Sousa, Raquel M.F., Silva, Gizele D., Becker, Raquel W., Sirtori, Carla, Starling, Maria Clara V. M., Carvalho, Solidônio R., Trovó, Alam G.
• Format: Article
• Language: English
• Subjects: Advanced Oxidation/Reduction Technologies: An Perspective from Iberoamerican Countries; Antibiotics; Antimicrobial resistance; Aquatic Pollution; Aromatic compounds; Atmospheric Protection/Air Quality Control/Air Pollution; Biodegradability; Biodegradation; Black light; Carcinogenicity; Carcinogens; Chloramphenicol; Chloroform; Chloromycetin; Degradation; Deionization; Earth and Environmental Science; Ecotoxicology; Effluents; Environment; Environmental Chemistry; Environmental Health; Environmental science; Evaluation; Genotoxicity; Irradiation; Mutagenicity; Organic matter; Oxidation; Photocatalysis; Photolysis; Preferential attack (corrosion); Propanol; Rate constants; Reaction kinetics; Reactive oxygen species; Sewage effluents; Sewage treatment plants; Toxicity; Toxicology; Waste Water Technology; Wastewater treatment; Wastewater treatment plants; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-020-09756-3

As the presence of antibiotics in environmental waters enhances antimicrobial resistance, photolysis and heterogeneous photocatalysis of chloramphenicol (CAP) were evaluated in deionized water (DW) and in sewage treatment plant (STP) effluent under black light and solar irradiation. Processes were compared in terms of CAP degradation, reaction kinetics, and electrical energy per order, as well as regarding theoretical toxicity, biodegradability, carcinogenicity, and mutagenicity of transformation products (TPs). Rate constants obtained under photolysis (0.008 min −1 ) and heterogeneous photocatalysis (0.18 min −1 ) only differed in DW. This is due to the generation of photo-active reactive oxygen species (HO · and HO 2 ·− /O 2 ·− ) under photolysis in STP effluent, as verified by experiments in the presence of 2-propanol and chloroform. Natural organic matter and HCO 3 − were the main responsible for reducing CAP degradation in STP effluent. Fifteen TPs were identified during both processes in DW, 13 of which are unprecedented. TPs were formed mainly via HO · preferential attack on the aromatic ring and on the α-carbon, and some of them were classified as persistent and toxic, genotoxic, or carcinogenic by Toxtree software. Results confirm that solar photocatalysis is less costly than to photocatalysis under black light for wastewater treatment.