| Project/Area Number |
07558205
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 試験 |
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| Research Field |
環境保全
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| Research Institution | Hokkaido University |
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Principal Investigator |
NAKAMURA Hiroshi Hokkaido Univ Graduate School of Environmental Earth Sci., Pro., 大学院・地球環境科学研究科, 教授 (00117194)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Shunitz Hokkaido Univ.Graduate School of Environmental Earth Sci., Assoc.Pro., 大学院・地球環境科学研究科, 助教授 (30142194)
HASEBE Kiyoshi Hokkaido Univ.Graduate School of Environmental Earth Sci., Pro., 大学院・地球環境科学研究科, 教授 (70000859)
福嶋 正巳 エネルギー総合工学研究所, 研究員
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1996: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | humic substance / humic acid / fulvic acid / hexavalent chromium / poly-aromatic hydrocarbon / tannic acid / pyrene / wood vinegar / 腐食物質 / 没食子酸 / 6価クロム / 還元無毒化 / 環境汚染物質 |
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| Research Abstract |
To evaluate the effects of humic substances on the diffusion and toxicity of environmental pollutants, the interaction between humic substances and some pollutants were investigated and the following new information was obtained. Furthermore, the possibility of humic substances as cleanup reagent for environment was confirmed.
1. The humic substances were extracted from peat soil sampled at some points in Hokkaido and purified to humic acied and fulvic acid. It was found that the chemical properties of these humic substances differed from one another.
2. The humic acid formed a complex with chromium (III), and the equilibrium condition of the complex formation was achieved after 30 hours. The equilibrium constants and rate of the complexing reaction were obtained.
3. The effects of humic substances on the redox reaction of chromium were investigated as well as some organic acids. The low molecular compounds such as tannic acid, gallic acid and wood vinegar reduced Cr (VI) to Cr (III) quickly, while the reduction rate of Cr (VI) with humic substances was slow significantly. On the other hand, Cr (III) was oxidized to Cr (VI) with manganese in the presence of oxygen. However, the presence of humic acid showed the suppression effects on the oxidation of Cr (III) to Cr (VI). Tannic acid, gaelic acid and wood vinegar did not show such effect. These results suggested that the complexing ability of humic acid with Cr (III) playd an important role to the suppression of the oxidation reaction.
4. Humic substances binded with poly-aromatic hydrocarbon (PAH) compounds and enhanced the solubility in water. The enhancement of the solubility of PAH in water was found in three phases system containing solid particle, water and humic substances. In this case, the solubility of PAH was controlled by the distribution to humic phase in water and humic phase on the surface of solid particle.
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