ENVR 135 |
| A significant fraction of iodine in water, soil and sediment is associated with organic matter. Iodine (as I2 or IOH) reacts rapidly with phenolic compounds by aromatic substitution. Recently we have demonstrated that iodate is reduced by natural organic matter (and synthetic analogs) through an I2 or IOH intermediate that may react with NOM by aromatic substitution. In this study we have demonstrated that a number of synthetic (nano-particle) manganese (III, IV) oxide preparations are capable of oxidizing iodide to iodine at pH as high as 7. This oxidation can result in incorporation of iodide into phenolic compounds that are present in the reaction mixture. We have characterized a number of synthetic nano-particle manganese oxides and examined the kinetics of iodide oxidation by these materials. We hypothesize that the oxidation of iodide by manganese oxides (MnO2 and MnOOH), which are widely distributed in nature, may contribute to the formation of organically bound iodide in soils and sediments. |
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General Papers
6:00 PM-8:00 PM, Wednesday, August 22, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Environmental Chemistry |