| Project/Area Number |
12680522
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | Saga University |
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Principal Investigator |
MIYAJIMA Tohru Saga University, Department of Chemistry, Faculty of Science and Engineering, Professor, 理工学部, 教授 (40128103)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2001: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2000: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | Fulvic acid / Humic acid / Silica / Heavy metals / Water Pollution / Adsorption / Complexation / Equilibria |
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| Research Abstract |
Fulvic acid(FA) and Humic acid(HA) have been extracted from standard soil samples. In addition, chemically bonded humic acid(CBHA) with silica was prepared. Both polyelectrolytic nature and heterogeneity nature of the FA, HA, and CBHA samples have been evaluated according to pH titration procedure. It has been clarified that 1) HA and CBHA samples mainly contain carboxylic acids with pKa > 4, whereas most of the carboxylic acids of FA show pKa<2, and 2) the time required for equilibration of HA and CBHA is much longer than FA, probably due to aggregation formation in aqueous solution. The hydrophobic nature of HA backbone is expected to be the main reason for the aggregation formation, which seems worth further study. Complexation equilibria of FA samples as well as CBHA samples have been analyzed based on Gibbs-Donnan model. Elution behavior of heavy metal ions on a cation-exchanger column has been monitored in the presence of FA and/or HA. The elution profile obtained by the column experiment reflects the migration profile of heavy metal ions in natural water/soil systems.
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