Ultraviolet-based advanced oxidation processes (UV-AOPs) are techniques that utilize the synergistic action of ultraviolet light and oxidants to generate highly oxidative active radicals (SO₄• − , •OH, etc.) to degrade organic pollutants. Currently, research on degrading various pollutants using UV-AOPs mainly focuses on degradation efficiency, toxic by-products, and mineralization rate. However, studies are limited on how the photochemical reactions of organic pollutants that absorb ultraviolet light themselves affect the advanced oxidation degradation process. As one of refractory pharmaceutical and personal care products (PPCPs), the ionic contrast agent sodium diatrizoate (DTZ) has excellent ultraviolet absorption, but there are no reports on how its optical behavior influences the photo-oxidative degradation process. In this study, spectroscopic techniques were employed to investigate the photodegradation pathways of DTZ under different wavelengths. It was found that under UVC irradiation, DTZ undergoes a deiodination pathway to form DTZ-I, which in turn affects the target of photoactivated generation of active radicals (SO₄• − ), leading to a DTZ advanced oxidation degradation pathway different from that under UVA irradiation. These results provide theoretical support and research insights for understanding the degradation processes of pollutants that can directly undergo photoreactions with ultraviolet light in UV based advanced oxidation processes.
Chen, H.B., Cheng, X.Y., Ye, X.F., He, H., Gao, Z.Q., Peng, Y., Hu, G.J., Yang, S.G., Li, S.Y. and Zhang, L.M. (2019) Research Progress on the Analytical Methods and Pollution Status of Iodinated X-Ray Contrast Media. Environmental Chemistry , 38, 1919-1929.
Yang, H.Y., Li, X.L., Wang, Z., Chen, L., Kong, Y. and Zheng, X. (2021) Research Progress on the Environment Concentration, Analytical Methods and Toxicity Evaluation of Iodinated X-Ray Contrast Medias. Environmental Chemistry , 40, 141-149.
Li, X., Hu, X.L. and Yin, D.Q. (2015) Review: Occurrence of Iodinated X-Ray Contrast Media and Their Removal Processes in the Aquatic Environment. Environmental Chemistry , 34, 555-564.
Sanderson, H., Dyer, S.D. and Price, B.B. (2006) Occurrence and Weight-of-Evidence Risk Assessment of Alkyl Sulfates, Alkyl Ethoxysulfates, and Linear Alkylbenzene Sulfonates (LAS) in River Water and Sediments. Science of the Total Environment , 368, 695-712. https://doi.org/10.1016/j.scitotenv.2006.04.030
Watkinson, A.J., Murby, E.J., Kolpin, D.W. and Costanzo, S.D. (2009) The Occurrence of Antibiotics in an Urban Watershed: From Wastewater to Drinking Water. Science of the Total Environment , 407, 2711-2723. https://doi.org/10.1016/j.scitotenv.2008.11.059
Ding, S.Y., Niu, J.F. and Bao, Y.P. (2013) Evidence of Superoxide Radical Contribution to Demineralization of Sulfamethoxazole by Visible-Light-Driven Bi 2 O 3 /Bi 2 O 2 Co 3 /Sr 6 Bi 2 O 9 Photocatalyst. Journal of Hazardous Materials , 262, 812-818. https://doi.org/10.1016/j.jhazmat.2013.09.048
Klavarioti, M., Mantzavinos, D. and Kassinos, D. (2009) Removal of Residual Pharmaceuticals from Aqueous Systems by Advanced Oxidation Processes. Environment International , 35, 402-417. https://doi.org/10.1016/j.envint.2008.07.009
Xu, W.H., Zhang, G. and Zou, S.C. (2007) Determination of Selected Antibiotics in the Victoria Harbour and the Pearl River, South China Using High-Performance Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry. Environmental Pollution , 145, 672-679. https://doi.org/10.1016/j.envpol.2006.05.038
Garcia-Galan, M.J., Diaz-Cruz, M.S. and Barcelo, D. (2011) Occurrence of Sulfonamide Residues along the Ebro River Basin: Removal in Wastewater Treatment Plants and Environmental Impact Assessment. Environmental Pollution , 37, 462-473. https://doi.org/10.1016/j.envint.2010.11.011
Dong, H.Y., Qiang Z.M. and Lian, J.F. (2018) Deiodination of Iopamidol by Zero Valent Iron (ZVI) Enhances Formation of Iodinated Disinfection By-Products during Chloramination. Water Research , 129, 319-326. https://doi.org/10.1016/j.watres.2017.11.032
Wei, H., Hao, M. and Li, J. (2021) The Oxidation Performance and Intermidates Toxicity of Sodium Diatrizoate in the Ultrasound Activated Peroxymonosulfate System. Acta Scientiae Circumstantiae , 41, 4538-4546.
Hu, C.Y., Xu, L. and Lin, Y.L. (2024) A Comparative Study on the Degradation of Iohexol and Diatrizoate during UV/Persulfate Process: Kinetics, Degradation Pathways and Iodinated Disinfection By-Products. Environmental Science : Water Research & Technology , 10, 718-728. https://doi.org/10.1039/D3EW00696D
Velo-Gala, I., López-Peñalver, J.J. and Sánchez-Polo, M. (2012) Ionic X-Ray Contrast Media Degradation in Aqueous Solution Induced by Gamma Radiation. Chemical Engineering Journal , 195-196, 369-376. https://doi.org/10.1016/j.cej.2012.04.046
Hack, N., Reinwand, C. and Abbt-Braun, G. (2015) Biodegradation of Phenol, Salicylic Acid, Benzenesulfonic Acid, and Iomeprol by Pseudomonas Fluorescens in the Capillary Fringe. Journal of Contaminant Hydrology , 183, 40-54. https://doi.org/10.1016/j.jconhyd.2015.10.005
Zhang, W., Soutrel, I. and Amrane, A. (2022) Improvement of the Biodegradability of Diatrizoate by Electroreduction of Its Amido Groups. Separation and Purification Technology , 285, Article 120317. https://doi.org/10.1016/j.seppur.2021.120317
Liu, Y., Hu, J. and Xu, B. (2013) Isolation and Identification of an Iopromide-Degrading Strain and Its Application in an A 2 /O System. Bioresource Technology , 134, 36-42. https://doi.org/10.1016/j.biortech.2013.02.043
Xu, B.J., Gao, P. and Liu, Z.H. (2014) Influence of Cosubstrates on Iopromide Degradation by Pseudomonas sp. I-24. Water Air & Soil Pollution , 225, Article No. 1849. https://doi.org/10.1007/s11270-013-1849-x
Babbitt, C.W., Pacheco, A. and Lindner, A.S. (2009) Methanol Removal Efficiency and Bacterial Diversity of an Activated Carbon Biofilter. Bioresource Technology , 100, 6207-6216. https://doi.org/10.1016/j.biortech.2009.06.110
Lecouturier, D., Rochex, A. and Lebeault, J.M. (2008) The Mineralization of 5-Amino-2,4,6-Triiodoisophthalic Acid by a Two-Stage Fixed-Bed Reactor. Water Research , 42, 2491-2498. https://doi.org/10.1016/j.watres.2008.02.006
Kalsch, W. (1999) Biodegradation of the Iodinated X-Ray Contrast Media Diatrizoate and Iopromide. Science of the Total Environment , 225, 143-153. https://doi.org/10.1016/S0048-9697(98)00340-4
Hapeshi, E., Lambrianides, A. and Koutsoftas, P. (2013) Investigating the Fate of Iodinated X-Ray Contrast Media Iohexol and Diatrizoate during Microbial Degradation in an MBBR System Treating Urban Wastewater. Environmental Science and Pollution Research , 20, 3592-3606. https://doi.org/10.1007/s11356-013-1605-1
Allard, S., Criquet, J. and Prunier, A. (2016) Photodecomposition of Iodinated Contrast Media and Subsequent Formation of Toxic Iodinated Moieties during Final Disinfection with Chlorinated Oxidants. Water Research , 103, 453-461. https://doi.org/10.1016/j.watres.2016.07.050
Saeid, S., Tolvanen, P. and Kumar, N. (2018) Advanced Oxidation Process for the Removal of Ibuprofen from Aqueous Solution: A Non-Catalytic and Catalytic Ozonation Study in a Semi-Batch Reactor. Applied Catalysis B : Environmental , 230, 77-90. https://doi.org/10.1016/j.apcatb.2018.02.021
Xiang, W.M., Yang, S.G., Sun, D.Y., Ji, Q.Y., Zhou, W., Xu, C.M., He, H. and Li, S.Y. (2022) Research Progress of Advanced Oxidation Technology to Remove Iodine X-ray Contrast Media in Water. Environmental Chemistry , 41, 260-275.
Velo-Gala, I., López-Peñalver, J.J., Sánchez-Polo, M. and Rivera-Utrilla, J. (2014) Comparative Study of Oxidative Degradation of Sodium Diatrizoate in Aqueous Solution by H 2 O 2 /Fe 2+ , H 2 O 2 /Fe 3+ , Fe (VI) and UV, H 2 O 2 /UV, K 2 S 2 O 8 /UV. Chemical Engineering Journaly , 241, 504-512. https://doi.org/10.1016/j.cej.2013.10.036
Kazemifard, A.G., Moore, D.E. and Aghazadeh-Habashi, A. (2001) Identification and Quantitation of Sodium-Thyroxine and Its Degradation Products by LC Using Electrochemical and MS Detection. Journal of Pharmaceutical and Biomedical Analysis , 25, 697-711. https://doi.org/10.1016/S0731-7085(01)00370-3
Chen, B.Y., Lee, W. and Westerhoff, P.K. (2010) Solar Photolysis Kinetics of Disinfection Byproducts. Water Research , 44, 3401-3409. https://doi.org/10.1016/j.watres.2010.03.014
Sprehe, M., Geißen, S.U. and Vogelpohl, A. (2001) Photochemical Oxidation of Iodized X-Ray Contrast Media (XRC) in Hospital Wastewater. Water Science and Technology , 44, 317-323. https://doi.org/10.2166/wst.2001.0315
Gu, Y., Han, Q. and Dong, Z. (2022) Enhanced Degradation and Deiodination of Diatrizoate in a Sulfite Mediated Photolytic System: Performance, Products and Possible Pathways. Journal of Hazardous Materials Advances , 8, Article 100144. https://doi.org/10.1016/j.hazadv.2022.100144
Ye, T., Zhang, T.Y. and Tian, F.X. (2021) The Fate and Transformation of Iodine Species in UV Irradiation and UV-Based Advanced Oxidation Processes. Water Re search , 206, Article 11775. https://doi.org/10.1016/j.watres.2021.117755
Wei, Y.J., Liu, C.G. and Mo, L.P. (2005) Ultraviolet Absorption Spectra of Iodine, Iodide Ion and Triiodide Ion. Spectroscopy and Spectral Analysis , 25, 86-88.