Cement industry accounts for about 11% of the global anthropogenic mercury (Hg) emissions. It is the second largest source of Hg emissions in Europe after coal combustion. Inputs from local emission sources as well as global, and regional transport further influence Hg concentrations in the ambient air. Knowledge on Hg emissions and speciation in the atmosphere is critical when validating model predictions on their transport, deposition, and fate at local, regional, and global levels. The present study examines the influence of Hg emissions from the Salonit Anhovo cement plant on Hg levels measured in Vodarna, located 1 km SW direction to plant in the prevailing wind direction. The role of raw mills on emitted Hg levels from the plant and wind dispersion on elevated Hg concentrations in Vodarna was further evaluated. Findings reveal that the plant raw mill operational status plays an important role in concentrations of Hg emitted from the plant. Emitted total gaseous mercury (TGM) was on average higher when raw mills were in direct-mode (both raw mills-off) and lower in combined- mode (raw mills-on). Average Hg concentrations in Vodarna were 3.14 ng/m3 for gaseous elemental mercury (GEM), 53.7 pg/m3 for gaseous oxidised mercury (GOM), and 41.9 pg/m3 for particulate bound mercury (PBM) for the whole measurement period. Atmospheric Hg speciation in Vodarna coupled with plant emissions and wind data has revealed that Hg emissions from the cement plant is the major source of all Hg species in Vodarna. Wind blowing from the northeastern quadrant (NE, ENE) is responsible for elevated Hg levels in Vodarna where GOM levels are highly linked to the cement plant emissions. Meanwhile, elevated levels of Hg species in the absence of northeastern winds indicate potential inputs from other unknown local sources as well as inputs from regional and global transport mechanism.
Authors: Sreekanth Vijayakumaran Nair, Jan Gačnik, Igor Živković, Jože Kotnik, Alkuin Maximilian Koenig, Tanja Ljubič Mlakar, Milena Horvat