Counterflow Method for Measurement of Henrys Law Constants

Accurate knowledge of Henryʹs law constants of chemicals under environmental conditions can be important for design of treatment systems, and for understanding the fate of chemicals in the environment. A new counterflow method has been developed for measurement of Henryʹs law constants. The method makes use of a small-diameter packed column air stripper, and Henryʹs law constant determinations are based on the mass balance equations for counterflow air strippers. Preliminary experimental tests with the method show good agreement with literature values for the Henryʹs law constants of isopropanol and methyl tert-butyl ether. As described here, the method is best suited to the analysis of compounds with low to moderate volatility (KH values ranging from approximately 1*10^-4 to 5*10^-2, dimensionless).