Study of Interfacial Mass-transport Process of Active Species by Laser-spectroscopic Measurements

痕量组分，特别是活性组分在气溶胶表面的非均相反应在大气化学的许多方面起着非常重要的作用，特别是在对流层酸雨的形成和平流层臭氧的消耗方面。液体吸收气体也是化学工程领域中的一个重要步骤，本文研究了大气中痕量气体组分在水表面的传输，以确定相应的吸收系数。第一次，在撞击流场中，使用激光光谱检测技术，在气相和水相之间的表面上方的气相中的痕量物种的分布的直接观察进行。通过对实验结果的分析以及与模拟结果的比较，证明了本文方法在SO_2吸收系数计算中的适用性。吸收系数强烈依赖于pH值，但几乎不受温度的影响。讨论了相关的水相反应。

Heterogeneous reactions of trace species, particularly active species, on aerosol surfaces play very important roles in many aspects of the atmospheric chemistry, particularly in the case of acid-rain formation in the troposphere, and in ozone depletion in the stratosphere. Gas absorption by liquids is also an essential step in the field of chemical engineering.In the present research, the transport of trace gaseous species from the bulk atmosphere across aqueous surfaces was studied in order to determin the relevant uptake coefficients. A direct observation of the distribution of the trace species in the gas phase above the surface between the gas and aqueous phase was conducted, for the first time, in an impinging flow field using a laser-spectroscopic detection technique. By analysing the experimental results and comparing them to simulation results, the applicability of the present method to obtaining the uptake coefficients was demonstrated in the case of SO_2. The uptake coefficient was strongly dependent on pH but was hardly affected by temperature. The relevant aqueous reactions were discussed.