| Abstract: | Photolysis of carboxylate anions adsorbed onto highly crystalline goethite (??-FeOOH) with 300-400-nm light produces Fe2+(aq) and ??OH from surface and solution redox reactions. The production of Fe2+(aq) and ??OH was studied in N2-purged and aerated aqueous suspensions, respectively, of goethite containing equimolar (10-3 M) concentrations of oxalate and benzoate (ob + g), succinate and benzoate (sb + g), benzoate alone (b + g), and goethite alone (g). The hydroxyl radical was measured by fluorescence analysis of salicylate formed in a reaction between benzoate and ??OH. Fe2+(aq) was determined colorimetrically. A proposed reaction mechanism includes the photoexcitation of Fe(III) surface complexes with OH-, HCO3-, and RCOO- ligands to form Fe2+(aq) and corresponding ligand radicals. Additional ??OH is made by the O2 oxidation of Fe2+(aq) (Haber-Weiss mechanism). Comparison of Fe2+(aq) and ??OH yields permitted an estimate of the relative importance of pathways leading to ??OH. |
| Genre: | Article |
| ProdID: | 70014301 |
| Citation Author: | Cunningham, K. M. |
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| Citation End Page: | 1097 |
| Citation Issue: | 9 |
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| Citation Language: | English |
| Citation Larger Work Title: | Environmental Science and Technology |
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| Citation Number Of Pages: | 8 |
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| Citation Search Results Text: | Mechanisms for aqueous photolysis of adsorbed benzoate, oxalate, and succinate on iron oxyhydroxide (goethite) surfaces; 1988; Article; Journal; Environmental Science and Technology; Cunningham, K. M. |
| Citation Start Page: | 1090 |
| Citation Volume: | 22 |
| Citation Year: | 1988 |
| Type: | citation/reference |
| Text: | Mechanisms for aqueous photolysis of adsorbed benzoate, oxalate, and succinate on iron oxyhydroxide (goethite) surfaces; 1988; Article; Journal; Environmental Science and Technology; Cunningham, K. M. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Fri, 1 Jan 1988 00:00 -0600 |
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