Abstract

ABSTRACTThis study focuses on the degradation of the sulfonamide antibiotics, sulfadiazine, sulfamethazine, sulfamethoxazole, and sulfathiazole, using ultraviolet irradiation in various conditions. Different pHs were investigated in combination with the addition of hydrogen peroxide and further oxygen removal. High-performance liquid chromatography electrospray ionization ion-trap mass spectrometry was used to identify and elucidate degradation products and to establish concentration–time curves. Previously unknown degradation products could be characterized. Reaction rate constants of all compounds and transformation products were determined. The parent sulfonamides decayed according to first-order kinetics, while the concentrations of the transformation products varied with time according to a subsequent reaction of an intermediate product. Quantum efficiencies were analyzed for mechanistic purposes. As example, sulfamethoxazole was added to effluents from a wastewater treatment plant and irradiated. Phototoxicity and environmental hazard were assessed through quantitative structure-activity relationship computations. In addition, the minimal inhibition concentrations were determined for Pseudomonas fluorescens and Bacillus subtilis. Conclusions for UV-C irradiation as a fourth purification wastewater treatment stage were derived.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.