Monitoring and Modeling of Ambient SO<,2> Concentration at a Lignite Mine
The ambient SO<,2> concentrations at an open-pit mining area and in surrounding communities were studied by passive air sampling method during the period from the winter season (November, 2005 to November, 2006). The duplicate samplers were collected once with a sampling period of 24 hours. It was found that the major source of ambient SO<,2> was that from the lignite spontaneous ignition. Higher SO <,2> concentration was found at sampling stations where the spontaneous burning occurs; compared to lower concentrations found in other areas. Also the SO<,2> concentrations monitored in the summer season (March 2006) were higher than those in other months, resulting from the large area of spontaneous ignition and the higher production of lignite. Nevertheless, the ambient SO<,2> concentrations at every sampling station were found lower than the average 24 hourly concentration given by the standard issued by the Department of Pollution Control of Thailand. Mathematical modeling of SO<,2> concentration was carried out using an off-the shelf modeling software, Disper 3.0, based on the dispersion method. Three SO<,2> sources used in the model were those at the lignite exposed area, lignite stock piles, and lignite spontaneous ignition sites. The SO<,2> emission rate form the spontaneous ignition was assumed using secondary data taken form the lignite burning rate in a power plant. The emission rate of 15.1 kg-SO_2~*(％ S)/ton-lignite was obtained for the SO_2 spontaneous-ignition (assuming the Na_2O content in the ash was 1.0 ％). The emission rates from lignite exposed area and the lignite stock pile were determined experimentally and found to be 10.42 and 7.63 ug/m~2-hr, respectively. The simulated SO_2 data was compared to the monitoring data and the mean absolute percentage error (MAPE) was calculated. The MAPE ranged between 19.79％-46.62％ when the amount of spontaneously-ignited lignite ranged between 3-7 ton/day. In the summer and the winter 2006, the MAPE will be 12.91％ and 46.62％ respectively, if the lignite spontaneous ignition was given at 7 and 4 ton/day.
Passive air sampling method Emission rates Dispersion Ambient SO<,2> Mathematical modeling of SO<,2>.
W. Koetsinchai W. Somboon S. Angkaew W. Chitsamphandhvej E. Chokasut
Department of Mathematic Department of Chemistry, Faculty of Science, King Mongkuts University of T Department of Chemistry, Faculty of Science, King Mongkuts University of Technology Thonburi, Thung
国际会议
北京
英文
303-311
2007-08-20（万方平台首次上网日期，不代表论文的发表时间）