UV/TiO 2 /periodate system for the degradation of organic pollutants – kinetics, mechanisms and toxicity study Xi Zhang, Mohammadreza Kamali, Deirdre Cabooter, Raf Dewil KU Leuven, Belgium In this study, the removal of refractory organic pollutants by the UV/TiO 2 /periodate system and the effects of different process parameters are investigated. The UV/TiO 2 /periodate system proves good efficient for the degradation of various recalcitrant organic pollutants, including Rhodamine B (RhB), 17α-ethynylestradiol (EE2), diclofenac (DFC), sulfamethoxazole (SMX), ciprofloxacin (CIP) and carbamazepine (CBZ). The combined UV/ TiO 2 /periodate (IO 4 - ) system demonstrates an improved pollutant removal efficiency (93% in 30min) in comparison with UV/TiO 2 , UV/IO 4 - , UV/TiO 2 /IO 3 - and UV/TiO 2 /ClO 4 - processes. Scavenging experiments to identify the involved degradation mechanisms reveal the contribution of O 2 − > h + > IO 3 ∙ and IO 4 ∙ > O( 3 P) > ∙ OH in the UV/TiO 2 /periodate process. Ultra-high performance liquid chromatography in combination with high-resolution mass spectrometry (UHPLC-QTOF-MS) is employed to explore the degradation products. The performance of the system is shown to be independent of pH and flexible in dealing with a wide range of effluents. The system also shows a high efficiency towards the removal of pollutants from real wastewater samples (88% at 150min). Respirometric analyses show that the water treated with the UV/TiO 2 /periodate system is not toxic to microorganisms in activated sludge. In addition to the superior treatment efficiency, the UV/TiO 2 /periodate system exhibits a lower treatment cost compared to both UV/TiO 2 /IO 3 - and UV/TiO 2 /ClO 4 - systems, which can potentially promote its application for real wastewater treatment. References 1. Efficiency and mechanism of 2, 4-dichlorophenol degradation by the UV/IO4− process 2. X Zhang, X Yu, X Yu, M Kamali, L Appels, B Van der Bruggen, D Cabooter, ...Science of The Total Environment 782, 146781 3. Kinetics and mechanisms of the carbamazepine degradation in aqueous media using novel iodate-assisted photochemical and photocatalytic systemsX Zhang, M Kamali, X Yu, MEV Costa, L Appels, D Cabooter, R DewilScience of The Total Environment 825, 153871 4. Photo-assisted (waste) water treatment technologies—A scientometric-based critical reviewX Zhang, M Kamali, S Zhang, X Yu, L Appels, D Cabooter, R DewilDesalination 538, 115905
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