Prince A Preszler, Kleiber P, Grassian V H, Young M A
Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
Phys Chem Chem Phys. 2007 Jul 14;9(26):3432-9. doi: 10.1039/b703296j. Epub 2007 May 24.
The heterogeneous chemistry of sulfur dioxide with CaCO(3) (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 SO(2) with calcite produced gas phase CO(2) 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 HNO(3), but much higher relative humidities were needed to significantly enhance the reaction. Mixed experiments in which calcite aerosol was exposed to both HNO(3) and SO(2) 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.
在大气反应室的孤立颗粒条件下，利用红外吸收光谱法研究了二氧化硫与碳酸钙（方解石）气溶胶的多相化学反应与相对湿度（RH）的关系。除了颗粒状碳酸盐转化为亚硫酸盐外，二氧化硫与方解石的反应还产生了气相二氧化碳作为产物。发现反应程度随相对湿度升高而增加，这与与硝酸的类似反应情况相同，但需要更高的相对湿度才能显著增强反应。还进行了方解石气溶胶同时暴露于硝酸和二氧化硫的混合实验。在给定相对湿度下，两种反应气体同时存在时，总体反应程度似乎并未增加。讨论了碳酸盐气溶胶作为大气中二氧化硫汇的作用以及颗粒态氮和硫的相关性。
