碩士 / 國立交通大學 / 環境工程所 / 90 / Raw water quality is deteriorating because of the excessive development of industries. Industrial pollution has caused eutrophication in surface water. It is speculated that algae may affect the coagulation and sedimentation processes in water treatment. The purpose of this study was to separate the coagulation between the simple inorganic particle and algae. Kaolin was the inorganic particle and Chlorella vulgaris was the biological particle used in this study. Synthetic water was prepared by mixing these two particles in different ratio to simulate the natural water. The coagulants used were aluminum sulfate (Alum) and polyaluminum chlorides (PACl).
The result shows that kaolin consumes more coagulant than Chlorella, which also yields higher residual turbidity. For both particles, better coagulation results and less dosage were associated with the charge neutralization mechanism. The test in which equal turbidity of kaolin and algae was used showed that PACl was the most effective coagulant, followed by PFS, with Alum being the least. At the same time, the coagulation characteristic of the mixed water was between those of the pure kaolin and Chlorella, but Chlorella is predominant. Results also showed that kaolin removal increased with the ratio of algae rose, which suggested that the presence of algae promoted the kaolin removal. The floc size from kaolin coagulation was small, therefore the flocs settled slowly and denser. The flocs of algae were bigger, settled faster but much looser. As the ratio of algae increased, the size of the floc and the settling velocity increased but the density decreased.
| Identifer | oai:union.ndltd.org:TW/090NCTU0515010 |
| Date | January 2002 |
| Creators | Shih An-chi, 施安琪 |
| Contributors | Huang Chih-pin, 黃志彬 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 115 |
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