| Project/Area Number | 11480129 |
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | NAGOYA UNIVERSITY |
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Principal Investigator |
OHTA Keiichi Institute for Hydrospheric-Atmospheric Scineces, NAGOYA UNIVERSITY Associate Professor, 大気水圏科学研究所, 助教授 (80022250)
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| Co-Investigator(Kenkyū-buntansha) |
HAMA Takeo Tsukuba University, Biological Schiences, Associate Professor, 生物科学系, 助教授 (30156385)
YOSHIOKA Takahito Institute for Hydrospheric-Atmospheric Scineces, NAGOYA UNIVERSITY Assistant Professor, 大気水圏科学研究所, 助手 (50202396)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed(Fiscal Year 2000)
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| Budget Amount *help |
¥12,900,000 (Direct Cost : ¥12,900,000)
Fiscal Year 2000 : ¥2,700,000 (Direct Cost : ¥2,700,000)
Fiscal Year 1999 : ¥10,200,000 (Direct Cost : ¥10,200,000)
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| Keywords | photochemistry in water / humic substances / organic pollutants / irradiation experiments / 光化学分解 / 河川水 / 溶存有機物 / リグニンフェノール |
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| Research Abstract |
In order to clarify the photochemical degradability of humic substances and organic pollutants in water, separation and characterization of humic substances and photochemical experiments were conducted.
(1) Separation of humic substances from river and lake waters
To separate humic substances from water, several procedures including XAD-resin adsorption, concentration in vacuo and molecular sieving, and ultra-filtration were examined. Among them, tangential-flow ultra-filtration gave the best result. Thus, 10 to 60 L of river and Lake Biwa water samples were ultra-filtered to obtain humic fraction.
(2) Characterization and quantification of humic substances
The humic fractions separated water samples have following physical and chemical properties. They emit fluorescence of 478 nm by absorbing 365 nm of UV.Their UV spectra show little pH-dependent change. Lignin phenol compositions of the humic fraction in water are indicative of the temporal vegetation type of the watershed. The humic fraction accounts for more than 90% of DOC in upstream water and about 50% in Lake Biwa water with decreasing its contribution in the downstream.
(3) Photochemical degradability of humic fraction and organic pollutants
The humic fraction separated from water was irradiated with and without standard compounds identified as an organic pollutant in water. Solar and artificial lights were used as a light source, and a quartz bottle as a reaction vessel. A time course of photochemical degradation was monitored by changes in
They accelerated photo-degradation of aromatic hydrocarbons. Urea was found for the first time to be degraded photochemically in water.
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