Ff. Fenter et al., EXPERIMENTAL-EVIDENCE FOR THE EFFICIENT DRY DEPOSITION OF NITRIC-ACIDON CALCITE, Atmospheric environment, 29(22), 1995, pp. 3365-3372
The reaction between gas-phase nitric acid and calcite powder has been
studied in a low pressure flow reactor. It is found that nitric acid
is adsorbed onto the solid samples with very high efficiency, and that
the gas-phase products of the interaction are H2O and CO2. The uptake
coefficient for the process, defined as the probability that a collis
ion of a gas-phase species leads to irreversible uptake by the solid,
is determined to be (10 +/- 2) x 10(-2). A second series of experiment
s conducted on calcite pellets reveals that the rate of initial uptake
is independent of the sample ''porosity'', i.e. the fraction of inter
nal void. The implications of the finding are discussed in terms of th
e current understanding of the dry deposition of nitrogen oxides that,
may lead to the degradation of historical monuments and buildings.