Chao Keh-Ping, Ong Say Kee, Huang Mei-Chuan
Department of Occupational Safety & Health, China Medical University, 91 Hsueh-Shih Rd, Taichung 40402, Taiwan, ROC.
J Hazard Mater. 2008 Apr 15;152(3):1098-107. doi: 10.1016/j.jhazmat.2007.07.087. Epub 2007 Jul 31.
Volatilization of VOCs was investigated using a 55-gal laboratory-scale model in which air sparging experiments were conducted with a vertical air injection well. In addition, X-ray imaging of an air sparging sand box showed air flows were in the form of air bubbles or channels depending on the size of the porous media. Air-water mass transfer was quantified using the air-water mass transfer coefficient which was determined by fitting the experimental data to a two-zone model. The two-zone model is a one-dimensional lumped model that accounts for the effects of air flow type and diffusion of VOCs in the aqueous phase. The experimental air-water mass transfer coefficients, KGa, obtained from this study ranged from 10(-2) to 10(-3)1/min. From a correlation analysis, the air-water mass transfer coefficient was found to be directly proportional to the air flow rate and the mean particle size of soil but inversely proportional to Henry's constant. The correlation results implied that the air-water mass transfer coefficient was strongly affected by the size of porous media and the air flow rates.
使用一个55加仑的实验室规模模型对挥发性有机化合物（VOCs）的挥发情况进行了研究，在该模型中通过垂直空气注入井进行了空气注入实验。此外，对一个空气注入砂箱的X射线成像显示，根据多孔介质的大小，气流呈气泡或通道的形式。利用空气-水传质系数对空气-水传质进行了量化，该系数是通过将实验数据拟合到一个两区模型来确定的。两区模型是一个一维集总模型，考虑了气流类型和VOCs在水相中的扩散影响。本研究获得的实验空气-水传质系数KGa范围为10（-2）至10（-3）/分钟。通过相关性分析发现，空气-水传质系数与空气流速和土壤平均粒径成正比，但与亨利常数成反比。相关结果表明，空气-水传质系数受多孔介质大小和空气流速的强烈影响。
