A method to measure Henry’s law constants of low volatile compounds

• Main Authors: Chun-Cheng Chen, 陳俊成
• Other Authors: Jiunn-Fwu Lee
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/91328375549602993729

碩士 === 國立中央大學 === 環境工程研究所 === 93 === The lack of accurate Henry's law constants (H) is one of the major problems on determining fates of organic compounds in the environment. Methods of experimentally determine H can be roughly divided into kinetic and static thermodynamic measurement. It takes more than half month for the traditional static methods to experimentally determining the Henry’s law constants of low volatility organic compounds. Thus, a new approach in this study has been developed to measure the H of low volatility organic compounds（dimensionless < 10-4）. According to the traditional concepts, the volatilization rate constants of low H compounds in aqueous solution have a good correlation with their H values. Thus, the H values of low H compounds （dimensionless < 10-4） were considerably obtained from the kinetic method based on the loss rate of a substance from water. In our previous investigation, the surface depletion rate-limiting model (SDRL) for calculating volatilization rates of low H compounds under gas and liquid turbulence was developed. As a result, the H values of the low H compounds under the gas and liquid turbulence were estimated with the SDRL model. The obtained H values were compared with other approaches including traditional two film theory, vapor pressure /aqueous solubility, bond contribution method and group contribution method. As the H values obtained form the above-mentioned method was compared the literature values, SDRL model shows more accuracy than the other method. It can be concluded that the presented approach is a good way on determining the H values for the low H compounds.