Determination of SO2 Deposition Velocity and Uptake Coefficient onto Yellow Sand Particles Collected in Lanzhou, China
In order to investigate heterogeneous reactions between yellow sand (China loess) particles and SO2, we have evaluated deposition of SO2 onto yellow sand collected in Lanzhou, by using a cylindrical flow reactor, developed in our laboratory. This reactor has a lot of advantages in determining experimental conditions (e.g. Flow rates, concentrations, temperatures, relative humidity (R. H.), and so on), and it accomplishes laminar flow so that we can evaluate SO2 deposition onto yellow sand by only SO2 molecules diffusion in the reactor. Results indicated that SO2 could easily react with yellow sand particles, especially under humid conditions. Deposition velocity was also calculated, the value increased under humid conditions, too. Therefore, it was shown that humidity has an important effect on SO2 deposition onto yellow sand. Our previous work referred to only influence of conditions (e.g. R.H. Or coexistence of other reactive gas) on SO2 deposition onto yellow sand. Therefore, a new analytical method was developed to determine SO2 uptake coefficient onto yellow sand. By using the method, which depends on the SO2 concentrations at the outlet of reactor, initial SO2 uptake coefficient for a geometric surface area was estimated in the order of 10-4. We also investigated SO2 uptake coefficients under humid condition, it increased with more humid surface. It was confirmed that under the presence of water vapor the properties of mineral dust surfaces changed significantly. Our works for determination of SO2 uptake coefficient can be used in atmospheric models to predict the dynamic behaviors between yellow sand and SO2.
yellow sand SO2 deposition velocity uptake coefficient
Yo TONEGAWA Yuji KAWASHIMA Yoichi HORITA Hidekazu ISHIHARA Kazuhiko SAKAMOTO
Department of Environmental Science and Engineering, Graduate School of Science and Engineering, Sai Department of Applied Chemistry, Graduate School of Science and Engineering, Saitama University, 255
国际会议
2007环境科学与技术国际会议(The 2007 International Symposium on Environmental Science and Technology)
北京
英文
2007-11-13（万方平台首次上网日期，不代表论文的发表时间）