Micrometeorological gradient approach for quantifying air/surface exchange of mercury vapor: Tests over contaminated soils
- Oak Ridge National Lab., TN (United States)
- National Oceanic and Atmospheric Administration, Oak Ridge, TN (United States)
The micrometerological modified Bowen ratio method was used for the first time to quantify fluxes of elemental mercury vapor (Hg[sup 0]) over contaminated soils during the spring and fall of 1993. We determined fluxes using relationships among the concentration gradients and fluxes of water vapor (measured with fast-response sensors and eddy correlation) and measured gradients in Hg[sup 0] (sampled with a multi-replicate, high-precision device). The contaminated soils consistently exhibited significant emission of Hg[sup 0] to the atmosphere. Fluxes associated with winds from the primary source area ranged from [approximately]10 to [approximately]200 ng m[sup [minus]2] h[sup [minus]1], up to several orders of magnitude above background. Fluxes increased exponentially with soil temperature, yielding a temperature coefficient similar to nitrogen oxide (exp[<(0.065 [+-] 0.011)> T[sub soil]], for T[sub soil] = 7-29[degrees]C). These results provided confidence in the method for Hg[sup 0] because the gradients and fluxes behaved predictably. Fluxes appear to be controlled by volatilization of existing contaminant elemental Hg plus reduction of Hg[sup 2+] to Hg[sup 0] in soil solution. We modeled the emission from an area of contaminated soils within approximately 20-50 m of our site using the flux/soil temperature relationship and annual temperature data. 55 refs., 8 figs., 1 tab.
- OSTI ID:
- 6594546
- Journal Information:
- Environmental Science and Technology; (United States), Vol. 29:1; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Air/surface exchange of mercury vapor in forests: Recent results of micrometeorological and chamber studies at Walker Branch watershed
Transpiration of gaseous elemental mercury through vegetation in a subtropical wetland in florida
Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
MERCURY
BIOLOGICAL ACCUMULATION
EMISSION
ENVIRONMENTAL TRANSPORT
CONCENTRATION RATIO
EXPERIMENTAL DATA
METEOROLOGY
SOILS
TESTING
VAPORS
DATA
ELEMENTS
FLUIDS
GASES
INFORMATION
MASS TRANSFER
METALS
NUMERICAL DATA
540220* - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)
400201 - Chemical & Physicochemical Properties