Heterogeneous interactions of calcite aerosol with sulfur dioxide and sulfur dioxide–nitric acid mixtures.

Autor: A. Preszler Prince, P. Kleiber, V. H. Grassian, M. A. Young
Zdroj: Physical Chemistry Chemical Physics (PCCP); Jun2007, Vol. 9 Issue 26, p3432-3439, 8p
Abstrakt: The heterogeneous chemistry of sulfur dioxide with CaCO3 (calcite) aerosol as a function of relative humidity (RH) has been studied under isolated particle conditions in an atmospheric reaction chamber using infrared absorption spectroscopy. The reaction of SO2 with calcite produced gas phase CO2 as a product in addition to the conversion of the particulate carbonate to sulfite. The reaction extent was found to increase with elevated RH, as has been observed for the similar reaction with HNO3, but much higher relative humidities were needed to significantly enhance the reaction. Mixed experiments in which calcite aerosol was exposed to both HNO3 and SO2 were also performed. The overall reaction extent at a given relative humidity did not appear to be increased by having both reactant gases present. The role of carbonate aerosol as an atmospheric sink for sulfur dioxide and particulate nitrogen and sulfur correlations are discussed. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index