| Summary: | 碩士 === 長榮大學 === 職業安全與衛生學系碩士班 === 102 === Abstract
Workers in petrochemical factories are frequently exposed to volatile organic compounds (VOCs). Climatic factors, such as: wind direction, wind speed, wind, humidity, rainfall, etc., may affect the diffusion of VOCs from the neighborhood of the factories and increase the environmental variability of exposure to VOCs for the workers. Detailed analyses of the influence of climatic factors on the distribution of VOCs can provide useful information for evaluating health risk due to VOCs exposure for the workers. In this study five petrochemical factories (A, B, C, D and E) were chosen to measure the concentrations of VOCs in the work environments by deploying 17~20 area samples in both autumn-winter and spring-summer seasons. The area samples were taken by an active sampling method for 6 hours to make full period single sample measurements. This method used a sampling pump and a manifold equipped with two stainless steel thermal desorption tubes filled with adsorbent Tenax TA and Carbopack X, respectively. The measured concentration of each area sample was input into S-PLUS statistical software according to the coordinates of the sampling area relative to the layout of each plant to draw the contour maps of VOCs.
The results of the measured data showed that in winter the average wind direction of the factories was northeastern and the average wind speed was 3.44 m/s; in summer the average wind direction was southwestern and the average wind speed was 3.21 m/s. Under the consideration of the wind direction changes in different seasons, the comparison of the VOCs concentration contours indeed indicated that the concentration distributions of VOCs varied with seasons. For factory A, the high concentration spots of VOCs in both seasons were relevant to the fugitive emissions of other manufacturing processes of the nearby factories; for factories B and C, the concentration distributions were influenced by the micro- and regional meteorological conditions, i.e., process air disturbance and floc flows due to large constructions and mechanical movements. For factories D and E, the observed high concentrations of VOCs were associated with the increase of emission sources of organic solvents coming from rust removal, painting, maintenance work, etc. The contours of VOCs concentrations showed the concentration was decreased in the area of downstream wind and influenced by the sources and meteorological conditions.
The conclusions of the study were that the area sampling measurements and the contour drawing of VOCs concentrations as well as the identification of emission sources and the recording of micro-meteorological conditions could provide useful information to assess the effects of meteorological and environmental factors on the VOCs concentration distributions of the petrochemical factories.
Keywords: petrochemical factory, volatile organic compounds (VOCs), area sampling, contour maps, micro-meteorological conditions.
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