title: Transformation products and reaction pathways of carbamazepine during photocatalytic and sonophotocatalytic treatment.
abstract: This study examines the degradation of the antiepileptic carbamazepine (CBZ) by sonolysis, TiO2-based heterogeneous photocatalysis under UV-A and simulated solar irradiation, and by the combined use of UV-A and ultrasound irradiation (i.e. sonophotocatalysis) in demineralized water, ground water and effluent wastewater. The processes were compared with respect to substrate conversion rate and the extent of DOC reduction as a measure of mineralization. CBZ was degraded following a pseudo-first order kinetics. Sonophotocatalysis provided the highest rate of CBZ transformation over the time-course of the experiment while the degree of DOC removal in pure water was similar for all the studied treatments (around 40%), and always lower than CBZ conversion. This indicated that a considerable organic load remained in the treated solutions that could also be attributed to the presence of persistent oxidation products. UPLC-(+ESI)-QToF-MS was employed to determine major CBZ-related transformation products. Several recalcitrant hydroxy- and keto-derivatives of CBZ were tentatively identified. A Daphnia magna bioassay was used to evaluate the potential toxicity of the samples collected at different time points showing that the mixtures were highly toxic to D. magna.
authors: Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain.
authors: A
authors: A
authors: Jelic
authors: I
authors: I
authors: Michael
authors: A
authors: A
authors: Achilleos
authors: E
authors: E
authors: Hapeshi
authors: D
authors: D
authors: Lambropoulou
authors: S
authors: S
authors: Perez
authors: M
authors: M
authors: Petrovic
authors: D
authors: D
authors: Fatta-Kassinos
authors: D
authors: D
authors: Barcelo
mesh_terms: D000818:Animals; D000927:Anticonvulsants / Q000737:chemistry* / Q000633:toxicity; D002220:Carbamazepine / Q000737:chemistry* / Q000633:toxicity; D002384:Catalysis; D003621:Daphnia / Q000187:drug effects; D010782:Photolysis; D013010:Sonication; D013472:Sunlight; D014025:Titanium / Q000737:chemistry / Q000528:radiation effects*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000633:toxicity; D018508:Water Purification / Q000379:methods
chemical_list: D000927:Anticonvulsants; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D002220:Carbamazepine; D014025:Titanium
keywords: Carbamezapine; Mass spectrometry; Photocatalysis; Sonophotocatalysis; Toxicity; Transformation products