2014 Fiscal Year Final Research Report
Important role of the storm runoff Fe(II) flux in the supply of the dissolved iron in coastal seawater
| Project/Area Number |
24651012
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | Kyushu University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
MATSUOKA Shiro 新潟大学, 理学部, 教授 (10219404)
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| Research Collaborator |
SATODA Makoto
AIMOTO Michihiro
KATO Toshiaki
TENNICHI Yoshika
SAREN Qiqige
KAI Satsuki
BANNO Yu
MATSUMOTO Megumi
UEHARA Wataru
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Keywords | 磯焼け / 河川水 / 溶存鉄 / スペシエーション分析 / オンサイト分析 / 固相分光法 / 洪水流出 / Fe(II)試料保存法 |
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| Outline of Final Research Achievements |
One of the causes of Isoyake, sea desert, around the Japan coast is attributed to the decline in the supply of the dissolved iron from river. Fe(III) complexes of humic substances in the river water should be coagulated when the river water is mixed with seawater. Our hypothesis is that Fe(II) is mainly supplied to the sea during storm runoff and forms dissolved Fe(III)-organic complexes in the presence of O2. To prove this hypothesis, on-site analysis method was established using solid-phase spectrophotometry to measure the low concentration of Fe(II). The sample collection method was also established by dissolving CO2 in sample solution to decrease pH and the dissolved O2 concentration and then by keeping pH at 2 within 1 hr after the sample collection. The bottom water of high Fe(II) concentration in the river was present in the local reduction environment under anoxic conditions. It was found that the Fe(II) flux at flood runoff was one hundred times more than that at base flow.
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| Free Research Field |
分析化学・地球化学
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