A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development

Thesis (M.Sc.) - Asian Institute of Technology, 1980

The source sampling program was conducted at the Mae Moh Power Plant, a pulverized lignite fired steam power plant, to determine the stack gas emission characteristics and to develop the emission factors for sulfur dioxide and particulate. This power plant belongs to the Electricity Generating Authority of Thailand and is located at Lampang Province, North of Thailand. The long-term dispersion model was then developed to estimate the monthly average ground level concentrations of sulfur dioxide around the power plant by making use of the monthly stability wind rose. The model is a steady state, univariate Gaussian plume dispersion model with the treatments of complex terrain, mixing height, the chemical transformation, the wet-deposition, and the dry-deposition of sulfur dioxide, designed for a point source with multiple stacks. The model contains the concentration equation, the Pasquill-Gifford vertical dispersion coefficients and the Pasquill stability classes, as given by Turner. Plume rise is calculated according to Briggs. The chemical transformation, the wet-deposition and the dry-deposition mechanisms are assumed to be a first-order process. The effects of mixing height is included into the model by the method of multiple images. Finally, the test runs of the model were made to predict the monthly average ground level concentrations of sulfur dioxide around the Mae Moh Power Plant.