A study on characteristics of algae removal with chlorine, chlorinedioxide and coagulant addition was carried out from November, 1993 to June, 1994. The algae are identified as 48 taxa including Chlorophyceae 23 taxa, Bacillariophyceae 20 taxa, Cyanophyceae 3 taxa and Euglenophyceae 2 taxa. In these study areas the dominant species occured frequently were Cyclotella, Synedra, Melosira and Scenedesmus. The removal efficiency of algae with coagulant is higher than with oxidant (as chlorine or chlorinedioxide) and coagulant, but the oxidant had to be used for prevanting the algae regrowth in sedimentation process. To gain more than 70% removal efficiency of chlorophyll-a, demanded chlorine and chlorinedioxide are ten times NH₄^+-N plus (2-3㎎/ℓ) and 2-2.5㎎/ℓ respectively. |
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