| URN | etd-0712110-222944 | Statistics | This thesis had been viewed 780 times. Download 25 times. |
| Author | Hsiu-Ting Lu | ||
| Author's Email Address | No Public. | ||
| Department | hazards | ||
| Year | 2009 | Semester | 2 |
| Degree | Master | Type of Document | Master's Thesis |
| Language | zh-TW.Big5 Chinese | Page Count | 154 |
| Title | The Feasibility study of Measuring Dust Amount by Light Attenuation Method |
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| Abstract | The light attenuation method, a quick and easy method, was established to measure the pollution load of dust. This method was applied to the sweep and wash operation plan of street dust as well as determination the hot spots of fugitive pollution. In this study, a transparent film coated with silicone oil was used to collect dust and placed at the dust collecting stations of Taipei County Government Environmental Protection Agency. Dust amounts were simultaneously collected by both transparent films and dust buckets. After sampling, the transparent films were irradiated by incandescent light (full spectrum) and intensities of illumination were measured by light meter. The dust weight on the transparent film was determined by the calibration curve. In laboratory, silt (grain size < 75 £gm), through the spoiler, evenly deposited onto a transparent film, followed by measurement of illumination intensity and silt weight. The data were analyzed with result R2=0.9979 for the relationship between light attenuation and silt weight, this indicated that the silt weight is highly correlated with light attenuation. The calibration curve was created according to a linear relationship between the illumination intensity and silt weight. These showed that weight of silt and illumination intensity has a high degree of correlation. In this study, 30 valid samples were concurrently taken by using both transparent films and dust buckets at the 10 stations owned by Taipei County Government Environmental Protection Agency. The dust amounts on the transparent films were determined according to the corresponding calibration curves. The relationship associated between the dust amounts collected by transparent films and dust buckets was evaluated using Pearson correlation analysis. In accordance with Pearson's correlation coefficient r=0.8315 demonstrates the dust weights derived from light attenuation method highly related to the actual measured dust weight in the dust buckets. These findings confirm that dust weights determined by light attenuation method are highly feasible. In addition, 68 sampling points were set on major roads in Taipei County. Light attenuation method was utilized to determine the tidiness of road, as the adjustment basis of road sweep and wash plan for roads and pollution control of hot spots for construction site. In accordance with the three levels of dirty road classification by EPA, the light attenuation level of each sample was divided into three grades: A-grade ¡]clean, light attenuation <80 Lux¡^, B-grade ¡]average, 80< light attenuation <160 Lux¡^ and C-grade ¡]dirty, light attenuation> 160 Lux¡^. The results show that a total of 24 roads were classified as minor dirty roads, maintaining current cleaning and sweeping frequency was suggested; seven roads were classified as moderate dirty roads, increasing the frequency of cleaning and sweeping was suggested; the other three roads were classified as serious dirty roads, priority cleaning and sweeping was recommended. Light attenuation method was applied to estimate dust loading of indoor and construction site, the result shows that the dust loading of indoor was between 5~50 lux, the conditions of dust loading for different coroners within same room were slightly dissimilar. In addition, the dust pollution was more serious, light attenuation>100 lux, during foundation excavation phase at the construction site. At the main structure period, the degree of light attenuation was around 20 to 40 lux. Furthermore, the light attenuation during land grading phase was 50~60 lux. The order of seriousness of dust fall for each construction phase were ranked as foundation excavation>land grading>main structure. |
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| Files | indicate access worldwide | ||
| Date of Defense | 2010-06-24 | Date of Submission | 2010-07-12 |