| Project/Area Number |
15310066
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Environmental technology/Environmental materials
|
|---|
| Research Institution | NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY |
|---|
Principal Investigator |
HORI Hisao National Institute of Advanced Industrial Science and Technology, Research Institute for Environmental Management Technology, Group Leader, 環境管理技術研究部門・未規制物質研究グループ・研究員グループ長 (50357951)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
EINAGA Hisahiro National Institute of Advanced Industrial Science and Technology, Research Institute for Environmental Management Technology, Researcher, 環境管理技術研究部門・励起化学研究グループ, 研究員 (90356593)
指宿 堯嗣 独立行政法人産業技術総合研究所, 環境管理研究部門, 部門長 (00356510)
|
|---|
| Project Period (FY) |
2003 – 2004
|
| Project Status |
Completed (Fiscal Year 2004)
|
| Budget Amount *help |
¥11,600,000 (Direct Cost: ¥11,600,000)
Fiscal Year 2004: ¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2003: ¥7,800,000 (Direct Cost: ¥7,800,000)
|
|---|
| Keywords | Persistent / Fluorine / Perfluorocarboxylic acid / Perfluorooctanoic acid / PFOA / Photocatalyst / Heteropolyacid / Persulfate / パーフルオロ酸 / 分解 / 界面活性剤 |
|---|
| Research Abstract |
The decomposition of environmentally persistent perfluorocarboxylic acids (PFCAs, typically perfluorooctanoic acid ; PFOA) in water by UV-visible light irradiation, by H_2O_2 with UV-visible light irradiation, by a tungstic heteropolyacid (polyoxometalate) photocatalyst, and by persulfate was examined. In the case of long-chain PFCAs such as PFOA, direct photolysis proceeded slowly to produce CO_2, F^- ions and short-chain PFCAs. Compared to the direct photolysis, H_2O_2 was less effective in PFCA decomposition. On the other hand, the heteropolyacid photocatalyst led to efficient PFCA decomposition and the production of F^- ions and CO_2. The photocatalyst also suppressed the accumulation of short-chain PFCAs in the reaction solution. PFOA in the concentrations of 1.35 mM was completely decomposed by the catalyst within 24 h of irradiation from a 200-W xenon-mercury lamp, with no accompanying catalyst degradation. Gas chromatography/mass spectrometry (GC/MS) measurements showed no trace of environmentally undesirable species such as CF_4, which has a very high global-warming potential. When persulfate was used as a photochemical oxidant, the PFCA decomposition proceeded more rapidly. PFOA at a concentration of 1.35 mM was completely decomposed by a photochemical system using 50 mM S_2O_8^<2-> and 4 h of irradiation and the initial PFOA decomposition rate was 11 times higher than with photolysis alone.
|
