Insights into the Photochemical Transformation of Iodine in Aqueous Systems: Humic Acid Photosensitized Reduction of Iodate
| العنوان: | Insights into the Photochemical Transformation of Iodine in Aqueous Systems: Humic Acid Photosensitized Reduction of Iodate |
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| المؤلفون: | John M. C. Plane, S. M. MacDonald, R. W. Saunders, R. Kumar |
| المصدر: | Environmental Science & Technology. 46:11854-11861 |
| بيانات النشر: | American Chemical Society (ACS), 2012. |
| سنة النشر: | 2012 |
| مصطلحات موضوعية: | Ultraviolet Rays, Iodide, Diol, Inorganic chemistry, Catechols, Iodates, chemistry.chemical_element, Photochemistry, Iodine, complex mixtures, chemistry.chemical_compound, Ozone, Environmental Chemistry, Humic acid, Humic Substances, Iodate, chemistry.chemical_classification, Photolysis, Aqueous solution, Photodissociation, Hydrogen Peroxide, General Chemistry, Oxidants, chemistry, Seawater, Oxidation-Reduction |
| الوصف: | Marine aerosol is highly enriched in iodine, mostly in the form of iodate (IO(3)(-)) ions, compared to its relative abundance in seawater. This paper describes a laboratory study of the photochemical reduction of IO(3)(-) in the presence of humic acid. Spectroscopic analysis showed that ~20% of IO(3)(-) was converted to "free" iodide (I(-)) ions and this fraction remained constant as a function of time. Direct detection of an organically fixed fraction (i.e., ∼ 80%) was not possible, but a number of test reactions with surrogate organic compounds containing functional groups identified in humic acid structures indicate that efficient substitution of iodine occurs at aromatic 1,2 diol sites. These iodinated humic acids are stable with respect to photolysis at near-UV/visible wavelengths and are likely to account for a significant proportion of the soluble iodine-containing organic material occurring within aerosols. In the lower atmosphere, oxidation of I(-) to I(2) in marine aerosol occurs mostly through the uptake of O(3), with H(2)O(2) playing a very minor role. A model of iodine chemistry in the open ocean tropical boundary layer, which incorporates these experimental results, is able to account for the observed enrichment of iodine in marine aerosol. |
| تدمد: | 1520-5851 0013-936X |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::36ca0abb0e3a87e1956f39b625205f73 https://doi.org/10.1021/es3030935 |
| رقم الأكسشن: | edsair.doi.dedup.....36ca0abb0e3a87e1956f39b625205f73 |
| قاعدة البيانات: | OpenAIRE |
Find this issue from the American Chemical Society | تدمد: | 15205851 0013936X |
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