Abstract
Mercury is a notorious pollutant causing severe nerve diseases. This
metal has a semi-volatile nature under the STP condition, therefore, it
is emitted to atmosphere as gaseous elemental mercury (GEM) from variety
of sources, such as the ocean surface, volcanoes, and fossil fuel
combustion. Because of the long atmospheric life time, mercury is
transported for long distance and spreads globally, consequently
ubiquitous in the natural environment. The current global model for
mercury cycle assumes that oxidation is a predominant pathway for the
removal of GEM from the atmosphere. To the best of our knowledge,
however, none of heterogeneous uptake of GEM by atmospheric water, such
as cloud, fog, and rain droplets, has been evaluated to date. For more
accurate understanding of the mercury cycle, the evaluation of this
process is necessary. We conducted laboratory experiments to evaluate
GEM uptake by artificial atmospheric water. The experiments were carried
out using a 3 L glass cell. 500 mL of acidified water was transferred
into the cell, and approximately 50 to 10 ng m-3 of GEM gas mixture was
continuously flowed into and out of the open space above the solution in
the cell. After a definite time the solution was quantitatively analyzed
for mercury to investigate the uptake. At this presentation preliminary
results of the uptake experiments will be presented.