Development of purification in closed natural water area by using of micro bubble technique

Research Project

Project/Area Number	06555153
Research Category	Grant-in-Aid for Developmental Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	水工水理学
Research Institution	Tokuyama College of Technology
Principal Investigator	SAGA Takanori Tokuyama College of Technology, Dep.of Civil and Architecutural Engineering, Assosiate professor, 土木建設工学科, 助教授 (60124096)
Co-Investigator(Kenkyū-buntansha)	MAEDA Kunio Chuden Technological Consultant Company. Dep.of Developmental technology, head, 技術開発部, 部長
Project Period (FY)	1994 – 1995
Project Status	Completed (Fiscal Year 1995)
Budget Amount *help	¥2,400,000 (Direct Cost: ¥2,400,000) Fiscal Year 1995: ¥800,000 (Direct Cost: ¥800,000) Fiscal Year 1994: ¥1,600,000 (Direct Cost: ¥1,600,000)
Keywords	closed water area / micro bubbles / aerater / water purification / turbidity / COD
Research Abstract	Water purification in closed natural water area is investigated by using micro-bubble techniques. New aerators which generate a lot of micro-bubble and form large-scale circulating flow in the normal cross-section of water area were developed. It was clear that mean diameter of micro-bubbles which these aerators generated was 10-30 mum. A spiral-type aerator could be used for the purification in the water area which depth was greater than about 1 m. Another dome-type aerater was investigated in shallow depth which was smaller than about 1 m. Some laboratory experiments of the waters in S lake at Nagano prefecture, M pond at Shimane prefecture, S pond at Hiroshima city, I pond at Iwakuni city, M lake at Ohmuta city, N pond at Tokuyama city and D small pond at Dazaifu city were performed. We got good results of the water purification in these experiments. Further, we got excelent results of the water purification experiment in fields which were N pond at Tokuyama city and D small pond at Dazaifu city. The values of turbidity and solid suspention decerased about 90% in about 600 hours. It was clear that the two types of aerator playd a very important roles of wastewater purification in closed natural water area.