Speciated Atmospheric Mercury: Gas/Particle Partitioning, Transformations, and Source CharacterizationEPA Grant Number: R829798
Title: Speciated Atmospheric Mercury: Gas/Particle Partitioning, Transformations, and Source Characterization
Investigators: Schauer, James J. , Armstrong, D. E. , Krabbenhoft, David P. , Hurley, James P. , Gross, Deborah S.
Institution: University of Wisconsin Madison , Carleton College , United States Geological Survey [USGS]
EPA Project Officer: Chung, Serena
Project Period: January 1, 2003 through December 31, 2005 (Extended to December 31, 2006)
Project Amount: $898,388
RFA: Mercury: Transport, Transportation, and Fate in the Atmosphere (2001) RFA Text | Recipients Lists
Research Category: Mercury , Air Quality and Air Toxics , Safer Chemicals , Air
The overall goal of the proposed project is to quantify key atmospheric transformations
that impact the fate of mercury in transport from sources to receptor sites.
In particular, the chemical and physical controls on gas/particle partitioning
and deposition of mercury (Hg) to the earth's surface will be determined.
The goal will be realized by achieving the following objectives:
- Quantify and speciate the chemical and physical forms of atmospheric Hg
at both near-source impacted regions and sensitive receptor sites. Chemical
speciation will include elemental, reactive, monmethyl and dimethyl Hg. Physical
speciation will include gaseous, particulate and bioavailable Hg. From this
data deposition rates and gas/particle partitioning behavior will be evaluated.
- Quantification of atmospheric conditions and aerosol properties that control
gas/particle partitioning of the chemical forms of mercury in the atmosphere.
- Identification and quantification of homogenous and heterogeneous atmospheric chemical reactions of mercury with emphasis on processes involving aerosols, fog water, and cloud water.
An integrated field and laboratory approach is employed that incorporates expertise in the chemical analysis of mercury, mercury speciation, atmospheric chemistry, and aerosols science. These areas of expertise are applied to the following efforts:
- Integration of state-of-the-art real-time, and advanced off-line, measurements
of gas and particle-phase mercury, aerosol chemical composition, and reactive
gas-phase pollutants at a core sampling site located at Devil's Lake, WI (NADP
- Detailed characterization of the gas/particle partitioning and the distribution
of mercury among its chemical forms at impacted sites near mercury sources.
- Laboratory experiments to identify and quantify atmospheric transformations that involve heterogeneous chemical reactions with aerosols fog water, and cloud water.
These efforts will result in a better understanding of chemical transformation of mercury in the atmosphere, impacts of natural and anthropogenic sources on local and far down-wind receptor sites, and detailed information on the physical and chemical behavior of mercury in the atmosphere needed for numerical models to predict speciated mercury deposition, impact of control strategies, and cycling of mercury in the ecosystem.