碩士 / 東海大學 / 化學工程與材料工程學系 / 100 / Due to the depletion of energy and greenhouse effect recently, the applications of microalgae are getting important. Microalgae are organism with high growing rate, rich in fat contents and nutritional components. Also, it has great impact on water purifying. In this research, we investigate the following aspect by cultivating the microalgae: (1) Investigate the impact on the concentration of Scenedesmus obliquus and lutein content by changing the environment or the medium compositions. The result showed us that adding pressure would delay the growing of S. obliquus cells; the growing of algae could be significantly inhibited by continuous irradiating of ultraviolet UV-A; addition of phenol would inhibit the growth of algal cells; with different colors lighting experiment, culturing with white light earned the maximum concentration to S. obliquus to 2.45 g/L. As the study on the effect on lutein, illuminating ultraviolet UV-A in the last two days could increase the lutein content to 0.48%, while adding phenol and exerting pressure had less impact on lutein content. (2) Investigate the effect on the S. obliquus by cultivated by 20.0 L bio-photoreactor and continuous cultivation. The result showed that using the aeration of 0.1 vvm cultivation, the S. obliquus concentration could increase to 1.22 g/L. Apply with different aerations (vvm) do not show obvious effect on the growing of algal cells; with repeated- batch cultivation, at 0.1 vvm, under different dilution ratio for 21 days, the productivities obtain are about 0.134 g/L/day; with continuous cultivation, we study the effect of different hydraulic retention time (HRT), and in the HRT of 4.44 day, we obtain the maximum productivity, which is 0.134 g/L/day. (3) Investigate the optimal condition for extraction of lutein in S. obliquus with supercritical carbon dioxide. Applying of central composite design (CCD) to explore three factors: (a) pressure of 200 to 400 bar, (b) temperature of 40~80 ℃, (c) addition of co-solvent (ethanol) 20-50%. Results implied that, designed the experiment by response surface methodology (RSM), the largest extreme value of regression is obtained. While setting Co-solvent=50%, P=276.8 bar and T=70.1 ℃, we can obtain the lutein yield ratio up to 89.8%, compared with traditional extraction.
| Identifer | oai:union.ndltd.org:TW/100THU00063009 |
| Date | January 2012 |
| Creators | Chiang, Wei-Cheng, 江偉誠 |
| Contributors | Yen, Hong-Wei, 顏宏偉 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 91 |
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