Some Issues by Algae on Water Supply in Tropical Country
Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants|
Civil and environmental engineering
|Research Institution||TOHOKU INSTITUTE OF TECHNOLOGY|
KONNO Hiroshi Faculty of Engineering, TOHOKU INSTITUTE OF TECHNOLOGY,professor, 工学部, 教授 (40133053)
ISHIBASI Yoshinobu Faculty of Engineering, TOHOKU INSTITUTE OF TECHNOLOGY,professor (Tohoku-gakuin, 工学部, 教授 (10111246)
|Project Period (FY)
1997 – 1998
Completed(Fiscal Year 1998)
|Budget Amount *help
¥1,400,000 (Direct Cost : ¥1,400,000)
Fiscal Year 1998 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1997 : ¥800,000 (Direct Cost : ¥800,000)
|Keywords||Algae / Coagulation-blocking / Filter clogging / Dual media filter / anthracite / 複層ろ過 / 異臭水 / 浄水障害|
Water Quality of Water Source
Raw water turbidity is always higher than 50 NTU and is over than 150 NTU in rainy season. Average turbidity of raw water is around 80 NTU.The pH values of raw water are 7.3 to 7.7. The conductivity of raw water in September is the lowest, 200 mu s/cm and is the highest, 350 mu s/cm in February. The average conductivity is 270 mu s/cm and the thick soluble matter is contained.
Algae in River
The predominant species of the kind of algae in Chao Phya river as water source for metropolitan area are Cyclotella sp., Melosira sp., Diatom, Oscillatoria sp., Euglena sp., Chiorella sp., Clotieriopsis sp., Clasteriom sp. and Scenedesmus sp.. The total cell number of algae is thousands on average per 100 ml on maximum number. The species over the 70 % of total algae is the kind of affecting the filter clogging. It, therefore, comes as no surprise that the filter clogging problem becomes actual issue at once.
Treatability of Algae
The removal rate for algae is around 60 %
on average and is sometimes lower than 40 % in spite of getting high removal rate, 98 % for turbidity. It will be estimated to occur the some issues in distribution and service pipelines.
Algae in Lakes
In Payao lake, which has 18 km^2 in area and 1.8 m in average depth, in Thailand, at least all problems caused by algae will be occurred in the future though the existence of algae which affect the problem does not the occurrence of obstruction on same time. Now Thai people have no usage to drink tap water directly. Odour, toxic substances, soluble aluminium and THM problem in tap water may be no relation for Thai people and waterworks. However, coagulation blocking and sand filter clogging is deeply related to water treatment process and system.
In the water source such as river and lake in Thailand, the kind of species closely related to some issues caused by algae are observed. It will be occurred serious problem on waterworks in Thailand. The examination of algae in Thailand should be continued for not only the maintenance of water quality of water source but also for better operation of water purification process and system. Less
Research Products (8results)