Oxidation of iodide and iodine on birnessite (δ-MnO2) in the pH range 4-8
The oxidation of iodide by synthetic birnessite (δ-MnO2) was studied in perchlorate mediain the pH range 4-8. Iodine (I2) was detected as an oxidation product that was subsequently further oxidized to iodate (IO3). The third order rate constants, second order on iodide and first order on manganese o...
| Main Authors: | , , , , |
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| Format: | Journal Article |
| Published: |
Elsevier Science Ltd
2009
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| Online Access: | http://hdl.handle.net/20.500.11937/22471 |
| _version_ | 1848750879180587008 |
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| author | Allard, Sebastien Von Gunten, Urs Salhi, E. Nicolau, R. Gallard, H. |
| author_facet | Allard, Sebastien Von Gunten, Urs Salhi, E. Nicolau, R. Gallard, H. |
| author_sort | Allard, Sebastien |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The oxidation of iodide by synthetic birnessite (δ-MnO2) was studied in perchlorate mediain the pH range 4-8. Iodine (I2) was detected as an oxidation product that was subsequently further oxidized to iodate (IO3). The third order rate constants, second order on iodide and first order on manganese oxide, determined by extraction of iodine in benzene decreased with increasing pH (6.3-7.5) from 1790 to 3.1 M2 s1. Both iodine and iodate were found to adsorb significantly on birnessite with an adsorption capacity of 12.7 mM/g for iodate at pH5.7. The rate of iodine oxidation by birnessite decreased with increasing ionic strength, which resulted in a lower rate of iodate formation. The production of iodine in iodide-containing waters in contact with manganese oxides may result in the formation of undesired iodinated organic compounds (taste and odor, toxicity) in natural and technical systems. The probability of the formation of such compounds is highest in the pH range 5-7.5. For pH <5 iodine is quickly oxidized to iodate, a non-toxic and stable sink for iodine. At pH >7.5, iodide is not oxidized to a significant extent. |
| first_indexed | 2025-11-14T07:43:50Z |
| format | Journal Article |
| id | curtin-20.500.11937-22471 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:43:50Z |
| publishDate | 2009 |
| publisher | Elsevier Science Ltd |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-224712017-09-13T15:57:05Z Oxidation of iodide and iodine on birnessite (δ-MnO2) in the pH range 4-8 Allard, Sebastien Von Gunten, Urs Salhi, E. Nicolau, R. Gallard, H. Birnessite Iodide Kinetics Iodate Oxidation Adsorption Iodine Manganese dioxide The oxidation of iodide by synthetic birnessite (δ-MnO2) was studied in perchlorate mediain the pH range 4-8. Iodine (I2) was detected as an oxidation product that was subsequently further oxidized to iodate (IO3). The third order rate constants, second order on iodide and first order on manganese oxide, determined by extraction of iodine in benzene decreased with increasing pH (6.3-7.5) from 1790 to 3.1 M2 s1. Both iodine and iodate were found to adsorb significantly on birnessite with an adsorption capacity of 12.7 mM/g for iodate at pH5.7. The rate of iodine oxidation by birnessite decreased with increasing ionic strength, which resulted in a lower rate of iodate formation. The production of iodine in iodide-containing waters in contact with manganese oxides may result in the formation of undesired iodinated organic compounds (taste and odor, toxicity) in natural and technical systems. The probability of the formation of such compounds is highest in the pH range 5-7.5. For pH <5 iodine is quickly oxidized to iodate, a non-toxic and stable sink for iodine. At pH >7.5, iodide is not oxidized to a significant extent. 2009 Journal Article http://hdl.handle.net/20.500.11937/22471 10.1016/j.watres.2009.05.018 Elsevier Science Ltd fulltext |
| spellingShingle | Birnessite Iodide Kinetics Iodate Oxidation Adsorption Iodine Manganese dioxide Allard, Sebastien Von Gunten, Urs Salhi, E. Nicolau, R. Gallard, H. Oxidation of iodide and iodine on birnessite (δ-MnO2) in the pH range 4-8 |
| title | Oxidation of iodide and iodine on birnessite (δ-MnO2) in the pH range 4-8 |
| title_full | Oxidation of iodide and iodine on birnessite (δ-MnO2) in the pH range 4-8 |
| title_fullStr | Oxidation of iodide and iodine on birnessite (δ-MnO2) in the pH range 4-8 |
| title_full_unstemmed | Oxidation of iodide and iodine on birnessite (δ-MnO2) in the pH range 4-8 |
| title_short | Oxidation of iodide and iodine on birnessite (δ-MnO2) in the pH range 4-8 |
| title_sort | oxidation of iodide and iodine on birnessite (δ-mno2) in the ph range 4-8 |
| topic | Birnessite Iodide Kinetics Iodate Oxidation Adsorption Iodine Manganese dioxide |
| url | http://hdl.handle.net/20.500.11937/22471 |