Environmental Impact of Heavy Metals Contained in Fly Ash Emitted from the Thai Lignite-fired Power Plant

In this work, the highly hazardous heavy metals (HM) are the focus of an assessment of the environmental impact of the Mae Moh Power Plant (Northem Thailand) fired with Thai lignites. The synergetic environmental impacts associated with the high sulfur content in the fuel (average value of 3.3% and maximum up to 7.0%) and the presence of a large number of heavy metals (As, Ba, Ce, Co, Cr, CS, Ni, U, Rb, SI, Th, etc) in the fly ash have been assumed in the model. Using data on the fly ash emission and HM content in the fly ash, the amount of heavy metals emitted from the lignite-fired boilers of the Mae Moh Power Plant was predicted. Calculation of the approximate rates of HM depositions was then conducted and the predicted values were compared with the corresponding element contents in regional soils. For various scenarios of power plant operation conditions and affected areq the environmental impact of heavy metals on that area was estimated. The results show the dangerous tendency of the HM accumulation in soil organic matter under certain conditions.