碩士 / 中華大學 / 土木工程學系碩士班 / 100 / The indoor air quality indicator from Green Building Nine Indicators has chosen carbon dioxide as the main indicator for poor indoor air circulation and bad ventilation between floors whatever those will seriously affect the health of the body and the comforts of living at home. Moreover, the carbon dioxide is also considered as one of the major gases that cause the greenhouse effect; in major cities which are densely populated with large buildings everywhere, the CO2 emission from buildings causes the formation of heat island effect, and further has an impact on the climate change and the environment. This study investigated the feasibility of using algae to Green Building. On the roof of a building, the indoor carbon dioxide was captured through the alkaline medium of blue-green algae and its associated inherent photosynthesis, using the special regulatory mechanism for alkali condition which is very different from the general microbial growth and metabolism.
The preliminary idea is to have the reduction of indoor CO2 tested in a laboratory environment, and in the future the air will be pumped into the roof photo-bioreactor for removing CO2 and re-discharged into the indoor circulation system to improve air quality. In the first phase of the study, our laboratory successfully obtained a new species which was screened out of the local algi found in Nei-Wan hot spring and named as Thermosynechococcus elongates WFW-1, which was characterized as mesophilic and basophilic. When they were cultured in 40 °C, the strain WFW-1 grew well with a biomass concentration up to 2.14 g/L, the pH could be maintained at about 11.5 to 11.6. In the second phase of this study, we used a photo-bioreactor device which was designed by the Green Energy &; Environment Research Laboratories, Industrial Technology and Research Institute (ITRI) for algal cultures and the further experiments. All the experiments were carried out in batch- or continuous-mode, and in the simulated environmental conditions of the green building with seasonal daily temperature drop and the intermittent illumination during day and night. In order to increase the CO2 capture efficiency, sodium carbonate (Na2CO3) was used as a buffer agent to maintain algae being cultured in alkaline pH condition. The results show that the indoor CO2 was completely removed with influent CO2 of approximately 350 ppm under batch mode with light condition, “on for 24 hr”, for the simulated green roof environment in 40 oC, and the zero CO2 effluent lasted for about 80 hr when 0.5-2 g/L of sodium carbonate was added into the culture medium. The algal strain WFW-1 also survived in the simulated green roof environment in 30 oC and 50 oC with different light time (12 hr or 24 hr). The algal culture in 30 oC、40 oC and 50 oC shows the best CO2 removal rates for influent 300-400 ppm of CO2 were about 85 - 86%、100% and 100%, respectively. For simulated green roof in 40 °C under continuous operation mode, algal strains could completely remove approximately 360-380 ppm of influent CO2 with daily addition of sodium carbonate of 0.5 g/d for 2 to 3 days. For the simulation of the summer temperature drop conditions under the batch-mode, the 340-440 ppm of indoor CO2 was removed with initial 2 g/L of sodium carbonate with the efficiency of 80 to 85 %. The research results show using algae in Green Building to improve indoor air quality was very promising because it was able to resist the impact of the violent temperature difference, and it can possibly play an important role of carbon reduction in high temperature situation.
| Identifer | oai:union.ndltd.org:TW/100CHPI5015032 |
| Date | January 2012 |
| Creators | Fu-Wei Wang, 王復暐 |
| Contributors | Sz-Chwun John Hwang, 黃思蓴 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 127 |
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