Contribution to the Serbian coal ranking and fly ash characterization using Pb isotopic ratio

The Republic of Serbia generates the majority of its electricity at the thermal power plants (TE) Nikola Tesla, Kolubara, and Kostolac. Coal is extracted from the Kolubara basin, which produces approximately 70% of lignite (an average of 30 million tons per year), and the Kostolac basin, which produces 30% of lignite. Ash, fly ash, and slag are examples of coal combustion residues. Because of the high content of potentially hazardous elements such as As, Pb, Cd, and Cr, environmental pollution with ash and fly ash has been extensively researched. Stable isotopes of lead can be used to trace lead sources. It is possible to monitor the presence, transformation pathways, and environmental impact of Pb by determining its isotopic composition in coal and fly ash. For the first time, the isotopic composition of selected coal samples from the Kolubara and Kostolac mines, as well as fly ash from the Kolubara (A and B), Kostolac (A and B), and Nikola Tesla (TENT A3, A2, B2) thermal power plants, was investigated in this study. The obtained data for 206Pb/207Pb in coal serve as the foundation for ranking domestic coals, whereas the isotopic ratios 206Pb/207Pb and 208Pb/207Pb  in fly ash can be used to monitor and control lead pollution from investigated sources.