Neutron activation analysis and natural radioactivity measurements of lignite and ashes from Megalopolis basin, Greece

Characterization of PM10 Sources and Ambient Air Concentration Levels at Megalopolis City (Southern Greece) Located in the Vicinity of Lignite-Fired Plants

“…Release of As bearing particles from coal combustion facilities has been well documented by many researchers (Wang et al, 1999;Okuda et al, 2008). It should also be mentioned that, lignite and fly ash samples collected from the Megalopolis power plant A, as well as bulk deposition samples collected from sites in the Megalopolis city were, among other elements, enriched in As (Papaefthymiou et al, 2007;Papaefthymiou, 2008). Although the measurement uncertainty of As with ED-XRF in the examined samples was relative high, its detection in all collected PM 10 samples is an indication of the impact of the lignite-fired power plants on the Megalopolis city atmosphere due to fly ash escaping from the stacks or to re-suspended surface soil/road dust containing deposited fly ash or lignite particles.…”

“…Arsenic, Mo, Sb, Se and U were also enriched in fly ash samples collected from the electrostatic filters of the power plant A (Papaefthymiou et al, 2007). It should be pointed out that, there are no other major industrial activities in the greater area.…”

“…The stack height of Units I and II is 120 m, while the heights of units III and IV are 180 and 206 m, respectively (Papaefthymiou et al, 2005). The lignite deposit of the Megalopolis basin is of very low gross calorific value (16.9 MJ/kg on a dry basis) (Siavalas et al, 2007) and of high water content and ash yield (60% and 17%, respectively) (Papaefthymiou et al, 2007), reflecting its poor quality. At full load, the units consume about 22-25 × 10 6 kg of pulverized lignite per day.…”

“…In this study, Fe was used as reference crustal element, meaning that its presence in the examined samples is considered as soil derived. The use of Fe as crustal element was also based on the fact that its EF values were close to one in lignite and fly ash samples collected from the Megalopolis power plants (EF: 1.1 for both lignite and fly ash samples) (Papaefthymiou et al, 2007) …”

Neutron activation analysis of thermal power plant ash and surrounding area soils

“…High ECs of Fe and Ni were found to be in BA than in FA. These high ECs are due mainly to (Papaefthymiou et al 2007;Asokan et al 2005;Sushil and BatraVidya 2006), where the ECs of As, Hg, Se, Mo, Fe, and Co in BA and FA were comparable, while much higher values were found for Cr, Ni, and Zn.…”