Experimental Determination of the Photooxidation of Aqueous I– as a Source of Atmospheric I2
The chemistry of iodine plays an important role in the oxidizing capacity of the global marine atmosphere. In this study, we experimentally determine the photooxidation parameters of iodide ions in aqueous phase (I–(aq)) and estimate the subsequent emission of gaseous iodine molecules (I2(g)) into t...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/206206 |
| Acceso en línea: | http://hdl.handle.net/10261/206206 |
| Access Level: | acceso abierto |
| Palabra clave: | Iodine molecule Iodide ion Photooxidation Molar absorption coefficient Photooxidative quantum yield Halogen chemistry |
| Sumario: | The chemistry of iodine plays an important role in the oxidizing capacity of the global marine atmosphere. In this study, we experimentally determine the photooxidation parameters of iodide ions in aqueous phase (I–(aq)) and estimate the subsequent emission of gaseous iodine molecules (I2(g)) into the atmosphere. The values of the molar absorption coefficient (εiodide(λ)) and the photooxidative quantum yields (Φiodide(λ)) of I–(aq) in the range of 290–500 nm were determined. The influence of pH and dissolved oxygen (DO) on the values of Φiodide(λ) was also investigated. The emission of I2(g) into the atmosphere following the photooxidation of I–(aq) in deionized water solution (pH 5.6, DO 7.8 mg L–1) and artificial seawater solution (pH 8.0, DO 7.0 mg L–1) was estimated to be (2.2 × 10–8 × [I–(aq)]sea) and (1.8 × 10–8 × [I–(aq)]sea) mol L–1 s–1, respectively. Using a global chemistry-climate model, we estimated that the photooxidation of I–(aq) can increase the atmospheric iodine budget by up to ∼8% over some oceanic regions. |
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