Monitoring of Mercury Content in the Main Environmental Components Caused by Lignite Combustion in Large Thermal Power Plants

摘要

The aim of experiment was to evaluate the local impact of mercury accumulations, discharge from coal power plants, by examining samples of ash, slag, soil, spontaneous vegetation and crop plants, using as analytical techniques the cold vapor atomic absorption spectroscopy. Mercury determined in samples of lignite (0.020 mg.Kg(-1)), is found in fly ash samples retained by filters (0.037 mg.Kg(-1)), bottom ash transported hydraulic in deposit (0.022 mg.Kg(-1)), adjacent soils landfill and the power plant (0.12 mg.Kg(-1) or 0.049 mg.Kg(-1)). The mercury content in vegetation presents differentiated values depending on the bioavailability of plant, area and the positioning of the emission source, reaching values between 0.014 at 0.005 mg.Kg(-1) in the wild flora and 0.022 mg.Kg(-1) to 0.004 mg.Kg(-1) for plants crop. Data obtained for plants, confirmed that most families tend to accumulate mercury plant in larger quantities in the roots (0.022 +/- 0.0016 mg.Kg(-1)) and moderate quantities in the foliar level by translocation or by direct vapor absorption.