Photodecomposition of iodinated contrast media and subsequent formation of toxic iodinated moieties during final disinfection with chlorinated oxidants

Autor: Justine Criquet, Annaïg Le Person, Janet Y. M. Tang, Cécilia Falantin, Sebastien Allard, Anaïs Prunier, Jean-Philippe Croué
Přispěvatelé: Curtin Water Quality Research Centre, Curtin University [Perth], Planning and Transport Research Centre (PATREC)-Planning and Transport Research Centre (PATREC), Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), National Research Centre for Environmental Toxicology (Entox), University of Queensland [Brisbane], Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL)
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Environmental Engineering
Halogenation
0208 environmental biotechnology
Iodide
chemistry.chemical_element
Contrast Media
Portable water purification
02 engineering and technology
010501 environmental sciences
Iodinated disinfection by-products (I-DBPs)
01 natural sciences
Water Purification
chemistry.chemical_compound
[CHIM.ANAL]Chemical Sciences/Analytical chemistry
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry
Chlorine
Photodegradation
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces
environment
Waste Management and Disposal
Chloramination
Iodate
0105 earth and related environmental sciences
Water Science and Technology
Civil and Structural Engineering
chemistry.chemical_classification
Natural organic matter
Chloramine
Toxicity
Chemistry
Ecological Modeling
Oxidants
Pollution
6. Clean water
020801 environmental engineering
Hypoiodous acid
UV
Disinfection
Iodinated X-ray contrast media
Environmental chemistry
Quantum yield
Water Pollutants
Chemical
Nuclear chemistry
Zdroj: Water Research
Water Research, 2016, 103, pp.453-461. ⟨10.1016/j.watres.2016.07.050⟩
Water Research, IWA Publishing, 2016, 103, pp.453-461. ⟨10.1016/j.watres.2016.07.050⟩
ISSN: 0043-1354
Popis: Large amount of iodinated contrast media (ICM) are found in natural waters (up to μg.L−1 levels) due to their worldwide use in medical imaging and their poor removal by conventional wastewater treatment. Synthetic water samples containing different ICM and natural organic matter (NOM) extracts were subjected to UV254 irradiation followed by the addition of chlorine (HOCl) or chloramine (NH2Cl) to simulate final disinfection. In this study, two new quantum yields were determined for diatrizoic acid (0.071 mol.Einstein−1) and iotalamic acid (0.038 mol.Einstein−1) while values for iopromide (IOP) (0.039 mol.Einstein−1), iopamidol (0.034 mol.Einstein−1) and iohexol (0.041 mol.Einstein−1) were consistent with published data. The photodegradation of IOP led to an increasing release of iodide with increasing UV doses. Iodide is oxidized to hypoiodous acid (HOI) either by HOCl or NH2Cl. In presence of NOM, the addition of oxidant increased the formation of iodinated disinfection by-products (I-DBPs). On one hand, when the concentration of HOCl was increased, the formation of I-DBPs decreased since HOI was converted to iodate. On the other hand, when NH2Cl was used the formation of I-DBPs was constant for all concentration since HOI reacted only with NOM to form I-DBPs. Increasing the NOM concentration has two effects, it decreased the photodegradation of IOP by screening effect but it increased the number of reactive sites available for reaction with HOI. For experiments carried out with HOCl, increasing the NOM concentration led to a lower formation of I-DBPs since less IOP are photodegraded and iodate are formed. For NH2Cl the lower photodegradation of IOP is compensated by the higher amount of NOM reactive sites, therefore, I-DBPs concentrations were constant for all NOM concentrations. 7 different NOM extracts were tested and almost no differences in IOP degradation and I-DBPs formation was observed. Similar behaviour was observed for the 5 ICM tested. Both oxidant poorly degraded the ICM and a higher formation of I-DBPs was observed for the chloramination experiments compared to the chlorination experiment. Results from toxicity testing showed that the photodegradation products of IOP are toxic and confirmed that the formation of I-DBPs leads to higher toxicity. Therefore, for the experiment with HOCl where iodate are formed the toxicity was lower than for the experiments with NH2Cl where a high formation of I-DBPs was observed.
Databáze: OpenAIRE
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