Effective henry's law constants for free chlorine and free bromine

Abstract

Volatilization represents a non-reactive loss mechanism for aqueous halogen biocides. Equilibrium volatilities, as measured by effective Henry's law constants, or effective dimensionless partition coefficients ( m), for free chlorine and free bromine were estimated to be 0.0604 atm ( m = 4.55 × 10 −5) and 0.0293 atm ( m = 2.21 × 10 −5), respectively, at 20°C using a stripping column. A true Henry's constant of 0.0600 atm ( m = 4.52 × 10 −5) was estimated for HOCl by application of equilibrium data to the system. The effective Henry's constant for free chlorine ( H Cl) is comparable to a previously published value determined under similar conditions. Prior to this investigation, no published values for a free bromine effective Henry's constant ( H Br ) were available.