Comparative investigation of X-ray contrast medium degradation by UV/chlorine and UV/H 2 O 2

• Published in: Chemosphere (Oxford) 2018-02, Vol.193, p.655
• Main Authors: Kong, Xiujuan, Jiang, Jin, Ma, Jun, Yang, Yi, Pang, Suyan
• Format: Article
• Language: English
• Subjects: Chlorides; Chlorine - chemistry; Contrast Media - chemistry; Halogenation; Hydrogen Peroxide - chemistry; Iopamidol; Oxidation-Reduction; Ultraviolet Rays; Waste Disposal, Fluid; Water Pollutants, Chemical - chemistry
• ISSN: 1879-1298

The degradation of iopamidol and diatrizoate sodium (DTZ) by UV/chlorine was carried out according to efficiency, mechanism, and oxidation products, and compared to that by UV/H O . The pseudo-first order rate (k') of iopamidol and DTZ was accelerated by UV/chlorine compared to that by UV and chlorine alone. k' of iopamidol and DTZ by UV/chlorine increased with increasing chlorine dosage. Both of iopamidol and DTZ could not be effectively removed by UV/H O compared to that by UV/chlorine. Secondary radicals (Cl and ClO) rather than primary radicals (HO and Cl) were demonstrated to be mainly responsible for the enhanced removal of iopamidol and DTZ by UV/chlorine. The oxidation products of iopamidol and DTZ resulting from UV/chlorine and UV/H O process were identified, and differences existed in the two systems. IO (the desired sink of I ) was the major inorganic product in the UV/chlorine process whereas I was the predominant inorganic product in the UV/H O process. The formation of chlorine-containing products during the degradation of iopamidol and DTZ by UV/chlorine was also observed. H-abstraction, additions, de-iodination were shared during the degradation of iopamidol by UV/chlorine and UV/H O . Neutral pH condition was preferred for the removal of iopamidol and DTZ by UV/chlorine. UV/chlorine could also be applied in real waters for the removal of iopamidol and DTZ.