Photolysis of aqueous H2O2: quantum yield and applications for polychromatic UV actinometry in photoreactors
| Autor: | Sara Goldstein, Yishay Diamant, Dorit Aschengrau, Joseph Rabani |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Actinometer
Aqueous solution Photolysis Chemistry Hydroxyl Radical Ultraviolet Rays Radical Methanol Photodissociation Formaldehyde Quantum yield General Chemistry Hydrogen Peroxide Hydrogen-Ion Concentration Photochemistry law.invention chemistry.chemical_compound law Yield (chemistry) Environmental Chemistry |
| Zdroj: | Environmental sciencetechnology. 41(21) |
| ISSN: | 0013-936X |
| Popis: | Methanol is used to measure the yield of *OH radicals produced in the photolysis of H2O2 in aqueous solutions. The UV photolysis of H202 generates *OH radicals, which in the presence of methanol, oxygen, and phosphate buffer form formaldehyde, namely, phi(HCHO) = phi(*OH). The quantum yield of *OH has been redetermined in view of literature inconsistencies resulting in phi(*OH) = 1.11 +/- 0.07 in the excitation range of 205-280 nm. The constancy of phi(*OH) and the ease and sensitivity of the formaldehyde product analysis makes the H2O2/CH3OH system suitable for polychromatic UV actinometry. In addition, the relatively low cost of the main components and the possibility of destroying the methanol before disposal qualify the system for both monochromatic and polychromatic actinometry in a large volume of water. The H2O2/CH3OH system was applied in different commercial UV photoreactors. |
| Databáze: | OpenAIRE |
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