关键词: 碘代X射线造影剂, 高效低毒降解技术, 活性氧物种, 碘代消毒副产物

Abstract: Iodinated X-ray contrast media (ICM) is a crucial class of medical pharmaceuticals widely used for the diagnostic imaging of vascular organs and soft tissues. However, the extensive global utilization of ICM has resulted in its frequent detection in aquatic environments. ICM exhibits strong polarity and biochemical stability, making it a great challenge to effectively remove via conventional sewage treatment technologies. Recent studies have demonstrated that the migration and transformation of ICM in natural aquatic environment has led to the emergence of iodinated organic pollutants. Moreover, ICM is the primary source of organic iodine in aquatic environments and an important precursor of iodinated disinfection by-products. Consequently, the presence of ICM in aquatic environments poses a severe threat to both the ecological environment and human health, attracting extensive attention from scholars worldwide. Based on this background and the current research hotspots of ICM, this review comprehensively summarizes the pollution status of ICM, as well as its environmental fates and transformation processes. It systematically introduces the currently reported degradation technologies of ICM and their corresponding degradation mechanisms, with a focus on the roles of various free radicals involved in these degradation technologies of the ICM degradation process. Specifically, this review conducts a systematic analysis of the degradation pathways of ICM by various reactive oxygen species and identify the differences in reaction sites and mechanisms among. Furthermore, to gain insight into the generation process of iodinated organic pollutants during the degradation process of ICM, the present study performs an in-depth analysis of the transformation pathways of iodine element released during this process and finally summarizes the key steps in the generation of iodinated organic pollutants, such as iodinated disinfection by-products. These discussions will help deepen the understanding of the degradation process of ICM and provide a theoretical basis and practical reference for the development of high-efficiency and low-toxicity degradation technologies for ICM degradation.

Key words: iodinated X-ray contrast media, high-efficiency and low-toxicity degradation technologies, reactive oxygen species, iodo-disinfection byproducts