title: Oxidation of sulfonamides, macrolides, and carbadox with free chlorine and monochloramine.
abstract: The oxidation of 10 antibiotics-carbadox, erythromycin-H(2)O, roxithromycin, sulfadimethoxine, sulfamerazine, sulfamethazine, sulfamethizole, sulfamethoxazole, sulfathiozole, and tylosin during chlorination and monochloramination in laboratory and surface waters was investigated to identify kinetics and treatment effectiveness. A kinetic model that incorporates pH-based speciation of both oxidant species and sulfonamide antibiotics was developed and validated. Specific rate constants for the individual ionic species were developed for the dominant reactant pairs. Liquid chromatography/mass spectrometry, preceded by solid phase extraction, was used to analyze antibiotics in kinetic experiments. With experimental conditions of 25 degrees C and reaction times of up to 2 h, an initial concentration of 1 mg/L of free chlorine removed an average of 88 percent of the antibiotics over a pH range of 6.1-9.1. Monochloramine was less effective at typical drinking water dosage concentrations of 3 mg/L, with average removals of 35, 10, and 0 percent at a pH of 6.1, 7.6, and 9.1, respectively.
authors.affiliation: Department of Civil, Architectural, and Environmental Engineering, Environmental Research Center for Emerging Contaminants, University of Missouri-Rolla, USA.
authors.forename: E
authors.initials: E
authors.lastname: Chamberlain
authors.forename: C
authors.initials: C
authors.lastname: Adams
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry; D002218:Carbadox / Q000737:chemistry*; D002700:Chloramines / Q000494:pharmacology*; D002713:Chlorine / Q000494:pharmacology*; D004355:Drug Stability; D018942:Macrolides / Q000737:chemistry*; D008954:Models, Biological; D008962:Models, Theoretical; D010084:Oxidation-Reduction; D010599:Pharmacokinetics; D013449:Sulfonamides / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D002700:Chloramines; D018942:Macrolides; D013449:Sulfonamides; D002713:Chlorine; C030816:chloramine; D002218:Carbadox