Study on effect of particulate phosphorus of inflow origin on water quality in Lake
| Project/Area Number |
18K14262
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| Research Category |
Grant-in-Aid for Early-Career Scientists
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| Allocation Type | Multi-year Fund |
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| Review Section |
Basic Section 34030:Green sustainable chemistry and environmental chemistry-related
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| Research Institution | Shimane University |
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Principal Investigator |
EGAWA Michiko 島根大学, 学術研究院環境システム科学系, 助手 (20565882)
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| Project Period (FY) |
2018-04-01 – 2023-03-31
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| Project Status |
Completed (Fiscal Year 2022)
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| Budget Amount *help |
¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
Fiscal Year 2020: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
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| Keywords | 汽水湖宍道湖 / リンの溶出 / 湖底堆積物 / 懸濁態リン / 斐伊川 / 硫化水素 / リン起源 / Fe型リン / 増水時の流量 / 形態別無機態リン / 懸濁粒子 / 粒度 / シルト、粘土 / 無機態リン / 細砂，シルト / 表層堆積物 / 連続分画定量 / リンの循環 |
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| Outline of Final Research Achievements |
This study investigated the types of phosphorus and particularly the fluctuation of Fe bound phosphorus (Fe-P) in suspended particles and lake sediments entering Lake Shinji. Regarding the lake bottom, the percentage of Fe-P in the surface sediments at five sites was approximately 20% of the lake core, but it was only 10% at the other sites. This suggests that the clay and silt content (suspended particles) entering the lake from the Hii River are transported to the vicinity of the lake center (further away). Furthermore, laboratory investigations demonstrated that Fe-P contributes to phosphorus leaching from the lake bottom. The phosphorus morphology in suspended particles in the middle to lowest reaches of the Hii River and in the Aka River during floods revealed that Fe-P accounted for a large fraction of the particulate phosphorus at all sites.
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| Academic Significance and Societal Importance of the Research Achievements |
これまで有効な形態別無機態リンの分画定量法がなかったことから，その懸濁態リンの「流入→沈降堆積→還元反応」を介したリン酸イオンの湖水への回帰メカニズムの詳細は未解明であったが，報告者らが開発した定量法を用い，宍道湖へのリンの流入負荷源として斐伊川から増水時に流入する懸濁態リンの実態を明らかにすることができた。とくに，Fe型リンの占める割合が他の型のリンより高く，また，流量が大きい時に懸濁態有機態リン（POP）濃度が高くなる傾向を示した。これらの知見は，湖底に堆積した後，湖底で生成されるH2Sと反応しリン酸を溶離する，一連の生物・化学的なプロセスを解明する上で基礎的な情報となる。
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Report
(6 results)
Research Products
(11 results)
