Wg. Cobourn et al., LABORATORY MEASUREMENTS OF SULFUR-DIOXIDE DEPOSITION VELOCITY ON MARBLE AND DOLOMITE STONE SURFACES, Atmospheric environment. Part B, Urban atmosphere, 27(2), 1993, pp. 193-201
The deposition velocity of SO2 on marble and dolomite stone surfaces i
n a humid atmosphere was measured as a function of time in the laborat
ory using continuous monitoring techniques. The deposition velocity of
SO2 on marble varied between 0.02 and 0.23 cm s-1, and was generally
observed to decrease with time. The deposition velocity of SO2 on dolo
mite varied between 0.02 and 0.10 cm s-1, and gradually increased over
the first 2000 ppm-h of exposure. For both types of stones, the depos
ition velocity increased significantly when condensed moisture was obs
erved on the stone surface. Chemical analysis of the stone samples ind
icated that the SO2 deposited reacted with the stone materials to form
gypsum (CaSO4 . 2H2O) on the marble surfaces and gypsum and epsomite
(MgSO4 . 7H2O) on the dolomite surfaces.