title: Environmental behavior of sulfadiazine, sulfamethazine, and their metabolites.
abstract: Sulfonamides are one of the most frequently used antibiotics worldwide. Therefore, processes that determine their fate in the environment are of great interest. In the present work, biodegradation as biotic process and hydrolysis and photolysis as abiotic processes were investigated. In biodegradation experiments, it was found out that sulfonamides (sulfadiazine and sulfamethazine) and their N4-acetylated metabolites were not readily biodegradable. The results showed that decrease of concentrations were in the range from 4% for sulfadiazine to 22% for N4-acetylsulfamethazine. Hydrolytic experiments examined at pH values normally found in the environment also showed their resistance. However, photolysis proved to be significant process for decreasing concentrations of sulfonamides and their metabolites in three various aqueous matrices (Milli-Q water, river water, and synthetic wastewater). In addition, influence of ubiquitous water constituents (Cl-, NO3-, SO42-, PO43-, and humic acids) was also investigated, showing their different impact on photolysis of investigated pharmaceuticals. The results showed that photolysis followed first-order kinetics in all cases. The obtained results are very important for assesing the environmental fate of sulfonamides and their metabolites in the aquatic environment.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000, Zagreb, Croatia. mperisa@fkit.hr.
authors.forename: Martina
authors.identifier: http://orcid.org/0000-0003-1646-7118
authors.initials: M
authors.lastname: Biošić
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000, Zagreb, Croatia.
authors.forename: Marija
authors.initials: M
authors.lastname: Mitrevski
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000, Zagreb, Croatia.
authors.forename: Sandra
authors.initials: S
authors.lastname: Babić
mesh_terms: D000900:Anti-Bacterial Agents; D010782:Photolysis; D013411:Sulfadiazine; D013418:Sulfamethazine; D014874:Water Pollutants, Chemical
chemical_list: D000900:Anti-Bacterial Agents; D014874:Water Pollutants, Chemical; D013411:Sulfadiazine; D013418:Sulfamethazine
keywords: Biodegradation; Direct and indirect photolysis; Hydrolysis; Metabolites; Sulfonamides