Heterogeneous photocatalytic degradation of ibuprofen in ultrapure water, municipal and pharmaceutical industry wastewaters using a TiO 2/UV -LED system

摘要

Graphical abstractDisplay OmittedHighlights?Degradation kinetics and mineralization rate of IBU wastewater using UV-(LEDs)/TiO2were studied.?The effect of the water matrix on the degradation of IBU was evaluated.?The formation of intermediates was followed by LC-MS-IT-TOF.?The toxicity of the treated IBU solutions was determined using the marine bacteriumVibrio fischeri.AbstractDegradation and mineralization of ibuprofen (IBU) were investigated using Ultraviolet (UV) Light Emitting Diodes (LEDs) in TiO2photocatalysis. Samples of ultrapure water (UP) and a secondary treated effluent of a municipal wastewater treatment plant (WWTP), both spiked with IBU, as well as a highly concentrated IBU (230?mg?L?1) pharmaceutical industry wastewater (PIWW), were tested in the TiO2/UV-LED system. Three operating parameters, namely, pH, catalyst load and number of LEDs were optimized. The process efficiency was evaluated in terms of IBU removal using high performance liquid chromatography (HPLC) and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Additionally, the mineralization was investigated by determining the dissolved organic carbon (DOC) content. The chemical structures of transformation products were proposed based on the data obtained using liquid chromatography with a high resolution mass spectrometer ion trap/time-of-flight (LC-MS-IT-TOF). A possible pathway of IBU degradation was accordingly suggested. Bioassays were performed using the marine bacteriumVibrio fischerito evaluate the potential acute toxicity of original and treated wastewaters. TiO2heterogeneous photocatalysis was efficient to remove IBU from UP and from PIWW, and less efficient in treating the wastewater from the municipal WWTP. The acute toxicity decreased by ca. 40% after treatment, regardless of the studied matrix.]]>