A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment Jožef Stefan Institute, Department of Environmental Sciences, Jamova 39, 1000 Ljubljana, Slovenia
Received: 13 October 2009 – Published in Atmos. Chem. Phys. Discuss.: 25 November 2009 Abstract. Results obtained by a laboratory flux measurement system (LFMS) focused on
investigating the kinetics of the mercury emission flux (MEF) from
contaminated soils of the Idrija Hg-mine region, Slovenia are presented.
Representative soil samples with respect to total Hg concentrations
(4–417 μg g−1) and land cover (forest, meadow and alluvial soil)
alongside the River Idrijca were analysed to determine the variation in MEF
versus distance from the source, regulating three major environmental
parameters comprising soil temperature, soil moisture and solar radiation.
MEFs ranged from less than 2 to 530 ng m−2 h−1, with the highest
emissions from contaminated alluvial soils and soils near the mining
district in the town of Idrija. A significant decrease of MEF was then
observed with increasing distance from these sites. The results revealed a
strong positive effect of all three parameters investigated on momentum MEF.
The light-induced flux was shown to be independent of the soil temperature,
while the soil aqueous phase seems to be responsible for recharging the pool
of mercury in the soil available for both the light- and thermally-induced
flux. The overall flux response to simulated environmental conditions
depends greatly on the form of Hg in the soil. Higher activation energies
are required for the overall process to occur in soils where insoluble
cinnabar prevails compared to soils where more mobile Hg forms and forms
available for transformation processes are dominant.
Revised: 26 January 2010 – Accepted: 31 January 2010 – Published: 08 February 2010
Citation: Kocman, D. and Horvat, M.: A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment, Atmos. Chem. Phys., 10, 1417-1426, doi:10.5194/acp-10-1417-2010, 2010.