Photodegradation mechanism on recalcitrant substrates in the TiO2 photocataritic degradation
| Project/Area Number |
17550145
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Environmental chemistry
|
|---|
| Research Institution | Meisei University |
|---|
Principal Investigator |
HIDAKA Hisao Meisei University, Faculty of Science, Department of Chemistry, Professor (70062312)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Project Status |
Completed (Fiscal Year 2007)
|
| Budget Amount *help |
¥3,850,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥150,000)
Fiscal Year 2007: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2006: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2005: ¥2,700,000 (Direct Cost: ¥2,700,000)
|
|---|
| Keywords | photodegradation / Advanced Ocidation Process / Persistent Organic Pollutants / Titanium dioxide / Cyanuric acid / fluorinated aromatics / オゾン酸化 / 農薬分解 / 光触媒 / 難分解性物質 / 水晶振動微量天秤 (QCM) / フッ素系有機化合物 / シアヌール酸 / 光導路分光 (OWGS) / DNAダメージ / 内分泌かく乱物質 / 水晶振動子 / フッ素界面活性剤 / 均一系光触媒 |
|---|
| Research Abstract |
Chemical substances which can not be degraded even by bacteria remediation are accumulated in rivers, lakes and other. They cause a seriously ecological damage in aquatic environment. The detoxification and purification procedure for persistent organic pollutants were focused in this study.
(1) Non-degradable triazine agrochemicals were photocatalytically decomposed with titanium dioxide, followed by the final production of cyanuric acid not to be mineralized to carbon dioxide. Cyanuric acid can not be degraded with titanium dioxide. The triazine ring in the atrazine agrochemicals can be easily to carbon dioxide and nitrate ion by the photoinduced degradation of cyanuric acid with zinc oxide. The triazine compounds can be photocatalytically degraded by using titanium dioxide together with ozone in a high yield.
(2) Concerning the photodecomposition of chloro/fluoro benzoic acid homologs the benzene ring-opening occurred easily in a short illumination time to evolve carbon dioxide via formic acid and acetic acid. The dechlorination for the ortho-position and para-position happened more easily than that for the meta-position. However, the defluorination for all homologs was difficult. The intermediate oxidative products bearing C-F group were identified by TOF-MS spectroscopy.
(3) Perfluoro surfactants such as PFCA and PFSA could not be mineralized to florinated ion with titanium dioxide, but the defluorination was possible with homogeneous catalyst of polytungstanate in a low yield.
The optimum experimental factors such as light intensity, wavelength, catalyst-loading and pH value, as well as the degradation mechanism were revealed in detail.
|
Report
(4 results)
Research Products
(125 results)
