| Project/Area Number |
03660059
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
土壌・肥料
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| Research Institution | Iwate University |
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Principal Investigator |
INOUE Katsuhiro Faculty of Agriculture, Department of Agronomy and Forestry Professor, 農学部, 教授 (30035109)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1992: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1991: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Surface characteristics / Hydroxyaluminosilicate ions / Hydroxyaluminum ions / Adsorption / Surface charge characteristics / Montmorillonite / Vermiculite / Clay complexes / スメクタイト / リン酸固定 / カリウム固定 / ラングミュア式 / 吸着等温線 / ヒドロキシケイ酸アルミニウム / ヒドロキシアルミニウム / バ-ミキュライト / 比表面積 / 陽イオン交換容量(CEC) / 陰イオン交換容量(AEC) |
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| Research Abstract |
The electric charge and surface characteristics of vermiculite or montmorillonite complexes with hydroxy-Al (HA) of hydroxyaluminosilicate (HAS) ions were studied in the pH range of 4 to 8. At pH 4 to 6, the negative charge of vermiculite or montmorillonite was drastically reduced by interlayer formation with HA or HAS ions. At pH 7 to 8, the magnitude of negative charge of these complexes was close to that of montmorillonite or vermiculite, suggesting that HAS or HA ions were excluded from the interlayer spaces of these clays. A significant positive charge was developed on HAS-montmorillonite complexes formed at NaOH/Al molar ratios of 2.0 and 2.5. The fixation of HAS or HA ions on montmorillonite or vermiculite caused significant reduction in total and internal surface areas but a slight increase in external surface area.
Hydroxyaluminosilicate-clay complexes fixed a significant amount of phosphate on the interlayer and planar surfaces of these clays by ligand exchange. However, the complextion of HAS ions with vermiculite caused the significant reduction of K fixation.
These data suggest that HAS and HA ions fixed on expansible 2:1 layer silicates contribute as active Al components to humus accumulation and phosphate retention in acidic and nonallophanic Andisols and related soils. Our data also indicate that the fixation of HAS and HA ions on 2:1 layer silicates can influence the levels of solution Al species that cause some toxicological problems in terrestrial and aquatic environments.
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