title: Influence of pH, inorganic anions, and dissolved organic matter on the photolysis of antimicrobial triclocarban in aqueous systems under simulated sunlight irradiation.
abstract: The photolysis of the antimicrobial triclocarban (TCC) in aqueous systems under simulated sunlight irradiation was studied. The effects of several abiotic parameters, including solution pH, initial TCC concentration, presence of natural organic matter, and most common inorganic anions in surface waters, were investigated. The results show that the photolysis of TCC followed pseudo-first-order kinetics. The TCC photolysis rate constant increased with increasing solution pH and decreasing the initial TCC concentration. Compared with the TCC photolysis in pure water, the presence of aqueous bicarbonate, nitrate, humic acids, and its sodium salt decreased the TCC photolysis rate, but fulvic acid increased the TCC photolysis rate. The electron spin resonance and reactive oxygen species scavenging experiments indicated that TCC may undergo two different types of phototransformation reactions: direct photolysis and energy transfer to generate (1)O2. The main degradation products were tentatively identified by gas chromatography interfaced with mass spectrometry (GC-MS), and a possible degradation pathway was also proposed.
authors.affiliation: School of Environmental Science and Engineering, Qilu University of Technology, Jinan, 250353, China.
authors.forename: Shi-Ling
authors.initials: SL
authors.lastname: Ding
authors.forename: Xi-Kui
authors.initials: XK
authors.lastname: Wang
authors.forename: Wen-Qiang
authors.initials: WQ
authors.lastname: Jiang
authors.forename: Ru-Song
authors.initials: RS
authors.lastname: Zhao
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Shen
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Xia
authors.initials: X
authors.lastname: Wang
mesh_terms: D000838:Anions / Q000737:chemistry*; D000890:Anti-Infective Agents / Q000032:analysis; D000891:Anti-Infective Agents, Local / Q000737:chemistry; D002224:Carbanilides / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009566:Nitrates / Q000032:analysis; D010782:Photolysis; D013472:Sunlight; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000838:Anions; D000890:Anti-Infective Agents; D000891:Anti-Infective Agents, Local; D002224:Carbanilides; D006812:Humic Substances; D009566:Nitrates; D014874:Water Pollutants, Chemical; D014867:Water; C009540:triclocarban