Efficient Decomposition of Environmentally Persistent Perfluorooctanesulfonate and Related Fluorochemicals Using Zerovalent Iron in Subcritical Water
| Autor: | Ryuichi Arakawa, Sachi Taniyasu, Issey Osaka, Ari Yamamoto, Hisao Hori, Shuzo Kutsuna, Taizo Sano, Nobuyoshi Yamashita, Yumiko Nagaoka |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Fluorocarbons
Zerovalent iron Aqueous solution Chemistry Iron Inorganic chemistry Water General Chemistry Decomposition Iron powder Metal Adsorption Alkanesulfonic Acids Semiconductors Yield (chemistry) visual_art visual_art.visual_art_medium Environmental Chemistry Environmental Pollutants Oxidation-Reduction Chemical decomposition |
| Zdroj: | Environmental Science & Technology. 40:1049-1054 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/es0517419 |
| Popis: | Decomposition of perfluorooctanesulfonate (PFOS) and related chemicals in subcritical water was investigated. Although PFOS demonstrated little reactivity in pure subcritical water, addition of zerovalent metals to the reaction system enhanced the PFOS decomposition to form F-ions, with an increasing order of activity of no metal approximately equal Al < Cu < Zn << Fe. Use of iron led to the most efficient PFOS decomposition: When iron powder was added to an aqueous solution of PFOS (93-372 microM) and the mixture was heated at 350 degrees C for 6 h, PFOS concentration in the reaction solution fell below 2.2 microM (detection limit of HPLC with conductometric detection), with formation of F-ions with yields [i.e., (moles of F- formed)/(moles of fluorine content in initial PFOS) x 100] of 46.2-51.4% and without any formation of perfluorocarboxylic acids. A small amount of CHF3 was detected in the gas phase with a yield [i.e., (moles of CHF3)/(moles of carbon content in initial PFOS) x 100] of 0.7%, after the reaction of PFOS (372 microM) with iron at 350 degree C for 6 h. Spectroscopic measurements indicated that PFOS in water markedly adsorbed on the iron surface even at room temperature, and the adsorbed fluorinated species on the iron surface decomposed with rising temperature, with prominent release of F- ions to the solution phase above 250 degrees C. This method was also effective in decomposing other perfluoroalkylsulfonates bearing shorter chain (C2-C6) perfluoroalkyl groups and was successfully applied to the decomposition of PFOS contained in an antireflective coating agent used in semiconductor manufacturing. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|