碩士 / 國立成功大學 / 環境工程學系碩博士班 / 95 / Reservoirs are the main source of public water supply in Taiwan. However, many reservoirs are eutropic and resulted in the presence of algae and reluted problems, such as taste and odor,filter and clogging,and even toxins.Therefore the treatment of eutrophic reservoir water is a new challenge to the Taiwan’s water supply industry.Membrane process could remove algaes effieciently.However, fouling is the major constraintin membrane application, as it decreases water production and also shortens membrane lifespan. In this study, the effectof extracellular polymeric substances(EPS) of algae on membrane fouling is investigated.
First, three species of algae, namely green algae A (Chlorella vulgaris)、green algae B(Chodatella sp.) and blue-green algae (Microcystis sp.) were cultured under controlled condition.These three algae species have similar cell size and shape, but with different amount of EPS.Algal suspensions were prepared from harvested algal cells.Dead-end Stirred Cell with regenerated cellulose UF membrane (MWCO 10,000 Da) were need to conduct filtration with algal suspensions under constant pressure mode.Critical flux from each of three algal suspensions were determined.The effect of the thickness of bound EPS and the presence of soluble EPS on critical flux value were discussed. Further, the extent of membrane fouling was compared by observing the decreaseing rate of specific flux with transmembrane pressure higher than that under critical flux condition.Additionally, the relationship between membrane fouling and the amount protein and polysaccharides in bound EPS.The functional groups of algal cell surface and molecular weight distribution of bound EPS were also discussed.
The results show that algal suspension, containing cells with largest amount of EPS and higher proportion of polysaccharides, have lowest critical flux.The next is algae with medium amount of EPS which algae,with lowest amount of EPS and lower proportion of polysaccharides,have highest critical flux.However, the extent of membrane fouling,as shown by the decreasing rate of specific flux,is found to be independent of the thickness of bound EPS,the ratio of protein/polysaccharide,the functional groups of algae cell surface and also the molecular weight of EPS.
| Identifer | oai:union.ndltd.org:TW/095NCKU5515034 |
| Date | January 2007 |
| Creators | Yu-ting Chiou, 邱鈺婷 |
| Contributors | Hsuan-hsien, 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 | 102 |
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