| Project/Area Number |
19K12371
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 64010:Environmental load and risk assessment-related
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| Research Institution | Saga University |
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Principal Investigator |
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2021: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2020: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2019: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
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| Keywords | 季別運転 / 硝化抑制 / アンモニア態窒素 / ノリ養殖 / 下水処理場 / 有明海 / 泥干潟 / 水温 / 放流水 / 底泥 / 巻き上げ / 干拓水路 / 灌漑水 / 水・底質環境 / 陸域負荷 / 栄養塩 |
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| Outline of Research at the Start |
下水処理の季別運転は，ノリ生産性向上のための有効策として全国的にも注目されている．一方で，十分な科学的根拠のないまま実水域で実施されている．とかく，短期的な漁獲収量に目を奪われやすい状況から，本研究が実施する現地調査および解析によって，これらに基づく問題点の有無などを明らかにし，現状の科学的な根拠に基づく整理が必要である．
本研究では，現地調査を通じて，有明海湾奥部のノリ養殖水域に対し，陸域負荷制御の有効性と将来的な水質・底質管理あるいは流域管理に向けた下水道の果たすべき役割への提案を目指す．
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| Outline of Final Research Achievements |
Flexible operational effects of sewage treatment according to the needs of the region and the impact on the water environment were investigated. The effect of treated water as irrigation water in summer has a low contribution to the amount of the whole canal water, but the increased concentration of nitrogen and phosphorous showed the possibility of reducing the amount of fertilizer applied and using it in the on-site environment such as paddy soil. In winter, the treated water with high nutrient concentration was released to the seaweed farm, and it was confirmed that the treated water had reached the fishing ground at the concentration level required for growth. In addition, as a result of evaluating the amount of nutrients transported in the water area, it was estimated that the amount of nutrient inflow was about the same as the amount of nutrients taken out by seaweed production. However, in the water area where the discharge is small, the effect was small at about 1/10.
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| Academic Significance and Societal Importance of the Research Achievements |
有明海湾奥部水域には，日本を代表するノリ養殖の一大拠点が形成されている．昨期のノリ生産高も日本一となり，地域産業としての役割も大きい．一方で，ノリ養殖は自然状況に大きく左右されるため，その管理が非常に難しい．特に，ノリの生長を左右する水域の栄養塩管理は毎年の課題となっている．とかく，短期的な漁獲収量に目を奪われやすい状況のままにある実態から，本研究が実施する現地調査・解析およびこれらに基づく現状の問題点の有無など明らかにすることで，懸念の払しょくもしくは現状の早期改善等を科学的な根拠に基づき，とりまとめることに大きな意義がある．
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