TITLE:
Study on the Photodegradation Mechanism of Sodium Diatrizoate in UV-Based Advanced Oxidation Processes
AUTHORS:
Yuying Wang, Shuo Wang, Runnan Liu, Zhouna Li, Kunhui Liu
KEYWORDS:
Sodium Diatrizoate, UV-Based Advanced Oxidation Processes, Reactive Radicals, Degradation Pathway
JOURNAL NAME:
Journal of Environmental Protection,
Vol.16 No.3,
March
13,
2025
ABSTRACT: 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.