碩士 / 國立中山大學 / 海洋環境及工程學系研究所 / 105 / The nutrient salts and carbon dioxide (CO2) required for the growth of microalgae can be respectively obtained from waste water and flue gases emitted by wastewater plants and power plants. Therefore, a microalgae culture system can simultaneously attain multiple goals such as mciroalgae cultivation, water purification, and carbon storage. The produced microalgae can be used as fish feeds or processed and converted to economic by-products, including fertilizers, biodiesels, and health food. The growth of microalgae is affected by nitrogen and carbon sources as well as other environmental factors such as illumination.
Experiments were first conducted to investigate the effects of various environmental and operating factors on the biomass and oil accumulation of Nannochloropsis oculata (TF-11); these factors were nitrogen concentration, phosphorous concentration, salinity, pH, aeration ratio, high- and low-concentration nitrogen sources, light intensity, and carbon sources. According to the experimental results, the most influential growth factors, namely, salinity, nitrogen sources, and carbon sources, were selected to optimize the cultivation cost. Finally, experiments were conducted to examine whether N. oculata (TF-11) can be used to perform secondary treatment for fish farm and municipal wastewater to purify water and produce high-biomass algal solutions as animal feeds.
Applying various salinity levels (0.76–40 PSU) confirmed the euryhaline property of N. oculata (TF-11); in particular, the microalgae could grow under a salinity of merely 0.76 PSU. Regarding light intensity (300–6000 lux), the growth of N. oculata differed nonsignificantly between 3000 and 6000 lux.
The experiment on municipal wastewater showed that N. oculata completely removed 30.36 ± 0.54 mg L−1 total inorganic nitrogen in approximately 5 days, and the experiment on fish farm wastewater confirmed that the algae completely removed 2.95 ± 0.24 mg L−1 total inorganic nitrogen in approximately 3 days, attaining a removal rate of 76%.
The culture optimization experiment on the CO2 influx rate showed that the culture medium only required a CO2 influx of 4.4 mL min−1 L−1 to reduce the pH by 2.4; this influx rate was only 1/13 of the conventional method.
| Identifer | oai:union.ndltd.org:TW/105NSYS5282014 |
| Date | January 2017 |
| Creators | Ching-Yu Liu, 劉景育 |
| Contributors | Lei Yang, 楊磊 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 326 |
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