| Project/Area Number |
01470039
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
分析・地球化学
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| Research Institution | Saga University |
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Principal Investigator |
ISAGAI Kiyoharu Department of Chemistry, Faculty Science and Engineering, Saga University ; Professor, 理工学部, 教授 (50039244)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIKAWA Sadakatu Department of Chemistry, Faculty Science and Engineering, Saga University ; Assi, 理工学部, 助教授 (40039293)
TABATA Masaaki Department of Chemistry, Faculty Science Engineering, Saga University ; Assistan, 理工学部, 助教授 (40039285)
KONDO Michio Department of Chemistry, Faculty Science and Engineering, Saga University ; Prof, 理工学部, 教授 (30039250)
SHIRAHAMA Keishiro Department of Chemistry, Faculty Science and Engineering, Saga University ; Prof, 理工学部, 教授 (50039252)
OKUBO Masao Department of Chemistry, Faculty Science and Engineering, Saga University ; Prof, 理工学部, 教授 (30039276)
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| Project Period (FY) |
1989 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1990: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | Ariake sea / Floating soil / Phosphate ion / Nitrogen compounds / Tidal flat |
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| Research Abstract |
Ariake sea is semiclosed in the northern sea. The difference of tidal level between full and ebb tides is about 6m and that is the highest level of all Japanese bays. The tidal flat appears mcuh larger in northern area sea. In the coastal reagion of the Ariake sea, the tidal rivers are highly turbid and the waters contain a large amount of floating soil. Phosphate ion and nitrogen compounds are important chemical spacies of all phosphorus compounds as concentrations of these relate deeply to eutrophication.
Red tide whichi is the cause of decreasing fishery have hardly been observed in the Ariake sea, although the northern region of the sea is semiclosed and large amounts of nutrients are supplied by rivers. In the Ariake sea, it is considered that chemical compounds of nutrients are adsorbed on the floating soiles and these remove to bottom muds. This mechanism was clarified by this investigation.
Concentration of major chemical components in sea water were affected by inflow of river water and were high at full tide and low at ebb tide. Phosphate ion is adsorbed on the mud under aerobic condition and is desorbed in interstitial water under an aerobic condition. Phosphate ion adsorbed on the mud as forms of Fe-P, Al-P and Ca-P. Under an aerobic condition, Both of Fe-p and Al-P decease, and Ca-P increase. A large amount of hydrogen sulfide and sulfides are contained in the bottom mud. Major chemical components in interstitial water of the bottom mud are higher than those in the sea water. Micro elements indicator also similar tendency. Order of these are Ni, Cu, << Fe < Mn < Sr. Relationship between concentration of phosphate ion and turbidity indicates highly positive correlation. Relationship between concentration of phosphate ion and a amount of total sulfide indicates positive correlation.
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