Study on the complexation mechanism of humic substance by nano-calorimetry
| Project/Area Number |
24760713
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Nuclear engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
KIRISHIMA Akira 東北大学, 多元物質科学研究所, 准教授 (00400424)
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Project Status |
Completed (Fiscal Year 2014)
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| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2014: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2013: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2012: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
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| Keywords | フミン物質 / 核種移行 / 錯生成 / カロリメトリー / エンタルピー / カロリメトリ / 電位差滴定 / エントロピー / 深部フミン酸 / 幌延フミン酸 |
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| Outline of Final Research Achievements |
Humic substances (HSs) are heterogeneous mixture of high-molecular-weight organic materials formed by humification of animals, plants and microbes. HSs plays an important role in the transportation of cations in environment, and are confirmed to be present even in the deep underground where radioactive wastes are planned to be disposed. The purpose of this study is accurate determination of delta_G, _H,_S in protonation and complexation of natural humic acid with Cu(II) by calorimetric titration. Furthermore, the reaction mechanism is discussed from the obtained thermodynamic quantities. It is revealed that the absolute value of complexation enthalpy is negative and decreases with pH increase. In addition, the complexation reaction of Elliot Soil humic acid is driven by enthalpy term, while the protonation reaction in this pH range is driven by entropy term. This difference is considered to be caused by the difference of the bonding mode between proton and Cu(II) to humic acid.
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Report
(4 results)
Research Products
(7 results)
