著者

辰巳 健一 中埜渡 丈嘉 三浦 勝巳 成田 隆広 神 和夫 眞柄 泰基 橘 治国

出版者

Japan Society of Civil Engineers

雑誌

環境工学研究論文集 (ISSN:13415115)

巻号頁・発行日

vol.39, pp.257-266, 2002-11-14 (Released:2010-06-15)

参考文献数

14

---

The Toyohira River, the source for Sapporo's waterworks, receives inflow discharged from mines and hot springs. The concentration of potentially hazardous substances in such inflow is high for some flow regimes, which raises concerns related to water quality management. We conducted a water quality survey during and after rainfall (Aug. 21-24, 2001). Rainfall totaled 79 mm. This report reviews the movement of arsenic identified from its runoff characteristics based on continuous observation of water quality during the rainfall. Dissolved arsenic was found to showpoint-type discharge (distilled) whereby the concentration decreased according to the increase in discharge. Suspended arsenic was found to show a non-point-type (outflow) discharge, as was true for suspended solids. Arsenic stored in thesilt and clay of bottom sediment at normal times is tracted by the turbulent flow that occurs during rainfall, becomes suspended, and flows down in high concentration.

著者

辰巳 健一 中埜渡 丈嘉 成田 隆広 眞柄 泰基 橘 治国

出版者

Japan Society on Water Environment

雑誌

水環境学会誌 = Journal of Japan Society on Water Environment (ISSN:09168958)

巻号頁・発行日

vol.25, no.5, pp.289-296, 2002-05-10

被引用文献数

1 3

---

Mine wastewater and hot spring water flow into the Toyohira River, a source of water for Sapporo City. Since the concentrations of components contained in such water change with the flow regime of the river, water quality management is considered a difficult challenge. The authors focused on the dynamic state of arsenic compounds, and found that hot spring water contains these arsenic compounds in dissolved state at high concentrations and that the characteristics of pulled runoff change from point source pollution (dilution pollution) to non point source pollution (runoff load increase pollution) in the flow process of the river. This change seems to closely involve water storage in dams, and we gathered that arsenic as a component of hot spring water entering the Toyohira River accumulates in dam sediment by absorption in silt and clay and that the runoff and re-dissolution of silt and clay at times of high flow rate causes the runoff and return of arsenic to the river. It was revealed that sediment in dams is a potential source of arsenic pollution.