APPLICATION OF RELAXED EDDY ACCUMULATION TECHNIQUE TO QUANTIFY Hg~0 FLUXES OVER MODIFIED SOIL SURFACES

摘要

Fluxes of mercury from a waste repository and from an agricultural field amended with sewage sludge were measured. The measurements were performed by utilising a Relaxed Eddy Accumulation (REA) system synchronously coupled to automated mercury cold vapour atomic fluorescence analysers (CVAFA). The waste repository was severely contaminated and fluxes of between 0.16 μg m~(-2) h~(-1) and 29 μg m~(-2) h~(-1) could be measured. Fluxes at the slightly contaminated agricultural field measured between 8 ng m~(-2) h~(-1) and 1.9 μg m~(-2) h~(-1). The results showed that the REA-CVAFA system could be used for measurements above both severely-and slightly contaminated soils. The measurements at the chlor-alkali plant showed that temperature was the most important parameter controlling the release of mercury at this site. At the agricultural field, the measurements indicated that both solar radiation and temperature may have influenced the emissions. Most of the mercury added to the field was lost to the atmosphere during the summer season.