J. Phys. IV France 107 (2003) 1431
Development of a diffusion type of Reactive Gaseous Mercury (RGM) source and evaluation of the RGM collecting efficiency by KCI-coated annular denudersY. Lu Julia1, X. Feng1, Y. Hao1, C. Banic2 and W.H. Schroeder2
1 Department of Chemistry, Biology and Chemical Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada
2 Meteorological Service of Canada, Environment Canada, Air Quality Processes Research Division, 4905 Dufferin St., Toronto, Ontario M3H 5T4, Canada
A diffusion type of RGM (HgCl 2) source was constructed and tested in our laboratory. The temperature of the diffusion cell, which is regulated using a circulating bath, was set from -5.00 to 11.80 C that are below the room temperature. The carrier gas is dry nitrogen and its flow rate is set to 500 ml min -1 using a mass flow controller. It is shown that it will at least take 48 h for the system to reach steady state condition. There is an exponential correlation between RGM emission rate from the source and the source température. In the temperature range from -5.00 to 11.80 C, the Hg emission rate from the source varies from 1.8 to 14.2 pg min -1. Thé primary Hg species from the source is identified to be HgCl 2. The RGM source has been used to evaluate the collect efficiency of KCl-coated annular denuders with and without an impactor. The results show that the impactor located upstream of the denuder can absorb up to one third of RGM in the air.
© EDP Sciences 2003