Summary: | 碩士 === 國立臺灣大學 === 生物環境系統工程學研究所 === 104 === Taiwan has been facing a serious problem in reservoir siltation. Thus, removal and re-use of the deposited clay in reservoir is becoming more significant. Therefore, the main purpose of this study is to develop a method to produce plant growing substrate for green roof using the deposited clay in reservoir with a certain ratio of cement, neutralizer, water retention agent and organic fertilizer. Aside from this, in this study, green roof is modularized to make the construction of green roof simpler, so that the developed method is more likely to be accepted by people.
The deposited clay used in this study was collected from Zengwen Reservoir. After considering the properties of the deposited clay, different agents such as neutralizer, water retention agent, organic fertilizer and cement, were added with different ratios (mix formula) for trial mixing tests. Trial mixing tests were conducted in two stages, and 48 sets of test in total were completed. From the results of surficial soil strength and plant growth, it was found Formula No.7 was the best, and its formula was: deposited clay 1, neutralizer 0.08, water retention agent 0.05, organic fertilizer 0.6, and cement 0.08.
Samples were manufactured using Formula No.7 for demonstration and test. From the test results, it was found, the modules provided the beneficial effects for lowering the temperature and reducing the runoff. Besides, erosion tests were also conducted using the samples and the rainfall simulator in National Taiwan University. The erosion rates of the samples of Formula No.7 was as low as 8~17% of those without using any agent. The test results also showed the samples mixed using Formula No.7 could conserve the soil fertility and reduce the risk of environmental pollution. From the effect analysis, regarding the construction of green roof, the beneficial effect for the people was 169.3 NT dollars/years ; the beneficial effect for the government was 169.3 NT dollars/m2., and there was also about 3.3 NT dollars/m2 per year from the benefits of the carbon reduction, air cleaning and water retention.
It might be concluded that the development of green roof modules in this study has demonstrated certain benefits and it is expected feasible to be used for removal and re-use of the deposited clay in reservoir.
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