title: Evaluating the biodegradability of sulfamethazine, sulfamethoxazole, sulfathiazole, and trimethoprim at different stages of sewage treatment.
abstract: The aerobic biodegradability of four antimicrobials (sulfamethazine, sulfamethoxazole, sulfathiazole, and trimethoprim) was investigated in sewage collected at four treatment stages (primary treatment, activated sludge treatment, aerobic nitrification process, and after disinfection of treated sewage) of a municipal sewage treatment plant. The biodegradability tests were conducted in aerated batch reactors by spiking the sewage with 20 microg/L of each of the test substance. Concentration profiles of the assayed compounds were monitored during a 54-d period using liquid chromatography/electrospray ionization/mass spectrometry. Substantial differences in the degradation curves were observed between trimethoprim and the three sulfonamides. The behavior of the latter was characterized by a general biodegradability in the primary and secondary treatment. The highest degradation rates were obtained in the sewage from the activated sludge treatment, where no adaptation phase was observed. On the other hand, the onset of biodegradation in the sewage from the primary treatment was preceded by a lag phase ranging from 10 to 15 d. In contrast, trimethoprim displayed high resistance to microbial degradation in the sewage from the primary treatment and the activated sludge treatment. However, primary degradation of this compound was completed within only 3 d in the sewage from the nitrification process.
authors.affiliation: The State University of New York at Buffalo, Chemistry Department, 611 Natural Sciences Complex, Buffalo, New York 14260-3000, USA.
authors.forename: Sandra
authors.initials: S
authors.lastname: Pérez
authors.forename: Peter
authors.initials: P
authors.lastname: Eichhorn
authors.forename: Diana S
authors.initials: DS
authors.lastname: Aga
mesh_terms: D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D002851:Chromatography, High Pressure Liquid; D012722:Sewage / Q000032:analysis* / Q000737:chemistry / Q000382:microbiology; D021241:Spectrometry, Mass, Electrospray Ionization; D013418:Sulfamethazine / Q000032:analysis / Q000378:metabolism; D013420:Sulfamethoxazole / Q000032:analysis / Q000378:metabolism; D013424:Sulfanilamides / Q000032:analysis / Q000378:metabolism*; D000077589:Sulfathiazole; D013432:Sulfathiazoles / Q000032:analysis / Q000378:metabolism; D014295:Trimethoprim / Q000032:analysis / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
chemical_list: D012722:Sewage; D013424:Sulfanilamides; D013432:Sulfathiazoles; D014874:Water Pollutants, Chemical; D013418:Sulfamethazine; D014295:Trimethoprim; D013420:Sulfamethoxazole; D000077589:Sulfathiazole