Concentrations of a water soluble, gas-phase mercury species in ambient air: Results from measurements and modeling
- Oak Ridge National Lab., TN (United States). Environmental Sciences Div.
- Earlham Coll., Richmond, IN (United States). Dept. of Chemistry
- Atmospheric and Environmental Research, San Ramon, CA (United States)
- Electric Power Research Inst., Palo Alto, CA (United States)
There are few reliable data on the speciation of Hg in ambient air, although this information is critical to understanding the fate of Hg once released from point sources. The water soluble species of Hg that are thought to exist in flue gases would be subject to far greater local removal rates than is elemental Hg vapor, but methods are lacing to quantify this species. The authors developed a method using refluxing mist chambers to measure the airborne concentrations of reactive gaseous mercury (RGM) in short-term samples under ambient conditions. The method exhibits an effective detection limit of 0.02 ng/m{sup 3} and a precision for ambient concentration levels of {+-}20--30%. Using a model that simulates atmospheric transport and fate of anthropogenic mercury emissions over the contiguous United States, the authors generated 24-hr RGM concentrations to compare to the measurement data. The average RGM concentrations measured with their mist chambers at sites in Tennessee (TN) and Indiana (IN) were 0.065 ng/m{sup 3} and 0.100 ng/m{sup 3}, respectively. These averages represent about 3% of total gaseous mercury (TGM), and RGM generally exceeds regional particulate Hg. The 24-hr model-simulated RGM concentration averages in the modeling grid cells representing TN and IN are 0.051 ng/m{sup 3} and 0.098 ng/m{sup 3} respectively, in good agreement with the data. The measured concentrations at the two sites exhibit weak positive correlations with temperature, solar radiation, O{sub 3}, SO{sub 2}, and TGM. These concentrations are high enough to suggest that RGM can play an important role in both wet and dry deposition on a regional scale.
- Research Organization:
- Oak Ridge National Lab., Environmental Sciences Div., TN (United States)
- Sponsoring Organization:
- Electric Power Research Inst., Palo Alto, CA (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 296860
- Report Number(s):
- ORNL/CP-99813; CONF-9709302-; ON: DE99000304; BR: 14B380302; TRN: AHC29903%%258
- Resource Relation:
- Conference: Electric Power Research Institute (EPRI) conference, Washington, DC (United States), 1 Sep 1997; Other Information: PBD: [1997]
- Country of Publication:
- United States
- Language:
- English
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