| Project/Area Number |
62550404
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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 |
都市工学・衛生工学
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| Research Institution | National Institute for Environmental Studies |
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Principal Investigator |
EBISE Senichi NIES, Water & Soil Environ., Div., Chief, 水質土壌環境部, 室長 (80026260)
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| Co-Investigator(Kenkyū-buntansha) |
INOUE Takanobu NIES, Water & Soil Environ., Div., Researcher, 水質土壌環境部, 研究員 (00184755)
FUKUSHIMA Takehiko NIES, Water & Soil Environ., Div., Senior Researcher, 水質土壌環境部, 主任研究員 (90124354)
OHTSUBO Kuninori NIES, Water & Soil Environ., Div., Senior Researcher, 水質土壌環境部, 主任研究員 (20093205)
AIZAKI Morihiro NIES, Water & Soil Environ., Div., Chief, 水質土壌環境部, 主任研究官 (20109911)
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| Project Period (FY) |
1987 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1989: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1988: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1987: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | Micropollutant / Pesticides / Synthetic detergent / River / Lake / Water pollution / Water contamination / Runoff characteristics |
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| Research Abstract |
The weekly observations to estimate the runoff loads of micropollutants and these changes during flowing down were conducted in R. Koise during 1987-1988 and in R. Hinuma during 1988-1989. The runoff characteristics of pesticides, nutrients and inorganic inons were discussed. The concentrations of herbicides, insecticides and fungicides discharged from paddy fields had two peaks in river waters after the rice-transplanting period and the aerically spraying period. The maximum concentrations of these herbicides and pesticides became about 10 mug/1 during the short period and intensive observation of river pollution. The loading of these her bicides and pesticides decreased during flowing down for nearly 5 km by decomposition and adsorption to river mud. The ratios of flowing down in R. Koise for a year were estimated 0.82 for CNP, 0.87 for Oxadiazon, 0.96 for Butachlor, 0.93 for Isoprothiolane, 0.88 for phthalide and 1.06 for MEP. The runoff loadings of these herbicides and pesticides were also estimated in R. Koise for a year by the weekly observation data and in R. Hinuma for a rice-transplanting period by the intensive observation data.
Runoff behaviors of linear alkylbenzensulfonates (LAS) due to synthetic surfactant in domestic wastewaters were studied in urban rivers and lakes. Rivers Oohori and Ootsu, which are inflow rivers to Lake Teganuma, had higher concentrations of LAS, that is about 2-3 mg/l, in river waters. D-LAS in total LAS was nearly 90 % under the low-flow state during dry days. The absorbed LAS became higher concentration and loading under the high-flow state during stormy days. It became clear that the decomposition rate of dissolved LAS by microorganism is higher in summer than in winter on the basis of the monthly observation.
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