碩士 / 國立成功大學 / 環境工程學系碩博士班 / 93 / Recently, the water quality of source water for public water supply in Taiwan is deteriorating. The huge inflow of nutrients make the reservoir water becomes eutrophic, which also leads to an increase in algae concentration in the water. A large number of algae in the source water will give a burden to the water treatment process. On the purpose of solving algae problem, prechlorination is a useful method. However, prechlorination may increase the formation of disinfection by-products (DBPs). Consequently, finding a safe and useful preoxidant to replace prechlorination is very important.
In this studying, ozone and potassium permanganate were tested as alternative preoxidant. Two pure-cultured algae species, namely Chodatella sp. (green algae) and Oscillatoria sp. (blue-green algae), were selected. The effect of oxidants on algae cells and it’s variation between algae species were studied. Further, the mechanism of preoxidants oxidation on algae was also proposed.
The results show that for green algae, both ozone and potassium permanganate preoxidantion could effectively increase algae removal, and the removal rate increased with increasing dosage. For blue-green algae, there existed a minimum dosage for potassium permanganate. Only when dosage exceeded this value, did it show the effect of improving algae removal. This probably is due to the self-agglomeration of the blue-green algae. Ozone, due to it’s strong oxidation power, is not suitable for the fragile blue-green algae. Furthermore, for both ozone and permanganate, excessive dosage may cause the rupture of algae cell. Therefore, there existed the highest allowable dosage in preoxidantion, and this value would vary with algae species and cell concentration.
As far as the mechanism of ozone and permanganate preoxidation is concerned, ozone probably is using it’s oxidation power to change the surface properties of the cells, and then promoting their setting. Which for permanganate, in addition to changing cell surface properties of the cells through oxidation, permanganate could produce MnO2, the reducing product of permanganate, to promote cell agglomeration.
Key word：algae、preoxidant、ozone、potassium permanganate
| Identifer | oai:union.ndltd.org:TW/093NCKU5515026 |
| Date | January 2005 |
| Creators | Song-Ling Chou, 周松霖 |
| Contributors | Hsuan-Hsien Yeh, 葉宣顯 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 108 |
Page generated in 0.0153 seconds