碩士 / 東海大學 / 化學工程與材料工程學系 / 103 / In recent years, with the crisis of fossil energy supply and the requirement of environmental sustainable development, natural resources from fossil, such as petroleum, coal and natural gas, are currently scarce and are to be exhausted in the near future. Moreover, the extensive use of petroleum, coal and natural gas has caused a number of environmental concerns, i.e., the climate change resulting from the global warming effects. Therefore, the development of different renewable energy could not only meet the increasing energy demand, but also reduce the environmental impacts oriented from the over-consumption of conventional hydrocarbon oils.
In this sustainable cultivation system of aerobic yeast -Rhodotorula glutinis and photosynthetic microalgae -Chlorella vulgaris, a yeast and a microalgae were grown in two separate reactors connected by their gas transportation. The aerobic yeast provides CO2 for the growth of microalgae via photosynthesis process as both carrying out the production of lipids, and efficient CO2 fixation by Chlorella vulgaris.
The microalgae biomass productivity was 1.03 g /L when aerated with the exit gas from the yeast fermenter, as compared to a control culture aerated with gas mixture（air with 2 ％ CO2）the biomass productivity was 0.88 g /L. Moreover the aerobic yeast R. glutinis provides 8.49×10-3 kg CO2．Day-1 and C. vulgaris can utilize 6.42×10-3 kg CO2．Day-1. Microalgae can utilize CO2 of emission gas from the yeast fermenter efficiently up to 75.6 %. It was demonstrated that this sustainable cultivation system of the yeast Rhodotorula glutinis and the autotrophic growth of the microalgae Chlorella vulgaris was successful in the reduction of CO2 emission.
Additionally, green house gas emission. Heavy metals contamination has become a global issue of concern due to their higher toxicities. Especially, chromium (VI) is introduced in the environment mainly as a consequence of its industrial use and it has been causing serious environmental pollution due to its carcinogenicity.
In this study, the possible use of Chlorella vulgaris biomass as an alternative biosorbent for Cr (VI) removal was investigated. The extent of toxicity tolerance of batch and fed-batch of Cr (VI) with the tested C. vulgaris. The maximum toxicity tolerance of Cr (VI) was 20.0~30.0 mg/L. Then extended to design HRT (Hydraulic Retention Time) that continuous waste water of Cr (VI). The maximum reduction rate of Cr (VI) about 2.50 ~ 3.33 mg /L．day. Biosorption of Cr (VI) was studied using both alive and dead cell of C. vulgaris and in this study has shown the active biomass may be even more effective than inactive one in removal of heavy metals. Both showed comparable behavior suggesting that biosorption extremely probable can be reduction of Cr(Ⅵ) to Cr(Ⅲ).
Furthermore, the XANES technique was utilized in this work to discover the occurrence of biological reduction of hexavalent Cr in C. vulgaris cells. Since the x-ray absorption measurement reveals overall signals, the chromium presents a mixture of both trivalent and hexavalent states in C. vulgaris. Therefore, an evidence of biological induced chemical reduction of chromium in C. vulgaris is confirmed.
| Identifer | oai:union.ndltd.org:TW/103THU00063012 |
| Date | January 2015 |
| Creators | Chen,Pin-Wen, 陳品妏 |
| 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 | 80 |
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