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Decomposition of hydrogen peroxide and organic compounds in the presence of iron and iron oxides

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dc.contributor.advisor Bettina M. Voelker. en_US Kwan, Wai P. (Wai Pang), 1974- en_US
dc.contributor.other Massachusetts Institute of Technology. Dept. of Civil and Environmental Engineering. en_US 2006-03-24T16:04:54Z 2006-03-24T16:04:54Z 2003 en_US 2003 en_US
dc.description Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003. en_US
dc.description Includes bibliographical references. en_US
dc.description.abstract Most advanced oxidation processes use the hydroxyl radical (OH) to treat pollutants found in wastewater and contaminated aquifers because OH reacts with numerous compounds at near diffusion-limited rates. OH can be made by reacting hydrogen peroxide (H202) with either Fe(II) (the Fenton reaction), Fe(1), or iron oxide. This dissertation investigated the factors that influence the decomposition rates of H202 and organic compounds, as well as the generation rate of -OH (VoH), in the presence of dissolved Fe(IH) and iron oxide. The Fe(III)-initiated chain reaction could be the dominant mechanism for the decomposition of H202 and organic compounds. The degradation rates of H14COOH, an OH probe, and H202 were measured in experiments at pH 4 containing either dissolved Fe(III) or ferrihydrite. Combined with the results from experiments using a radical chain terminator, we concluded that a solution chain reaction was important only in the Fe(III) system. In the ferrihydrite system the amount of dissolved Fe was insufficient to effectively propagate the chain reaction. In addition, a nonradical producing H202 loss pathway exists at the oxide surface. The oxidation rate of any dissolved organic compound can be predicted from VOH if the main sinks of -OH in the solution are known. Experiments using H14COOH and ferrihydrite, goethite, or hematite showed that VOH was proportional to the product of the concentrations of surface area and H202. Based on these results, a model was created for predicting the pseudo-first-order oxidation rate coefficients of dissolved organic compounds (korg) in systems containing iron oxide and H202. While our model successfully predicted korg in aquifer sand experiments, it yielded mixed results when compared to measurements from previously published studies. en_US
dc.description.abstract (cont.) Some factors that could have caused the disagreements between model predictions and measurements were examined to refine our model. Results from experiments containing goethite, H 4COOH, and 2-Chlorophenol showed that H 4COOH detected more OH, which is produced at the oxide surface, than did 2-Chlorophenol. This was attributed to electrostatic attraction between the formate anions and the positively charged oxide surface, and could explain why our model, based on H14COOH, overpredicted the korg values of many neutral compounds. en_US
dc.description.statementofresponsibility by Wai P. Kwan. en_US
dc.format.extent 182 p. en_US
dc.format.extent 6488698 bytes
dc.format.extent 6488505 bytes
dc.format.mimetype application/pdf
dc.format.mimetype application/pdf
dc.language.iso eng en_US
dc.publisher Massachusetts Institute of Technology en_US
dc.rights M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. en_US
dc.subject Civil and Environmental Engineering. en_US
dc.title Decomposition of hydrogen peroxide and organic compounds in the presence of iron and iron oxides en_US
dc.type Thesis en_US Ph.D. en_US
dc.contributor.department Massachusetts Institute of Technology. Dept. of Civil and Environmental Engineering. en_US
dc.identifier.oclc 52872721 en_US

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