Determination of the trichloroethylene diffusion coefficient in water

Trichloroethylene (TCE) is a halogenated aliphatic organic compound frequently detected as pollutant in soils and ground water. To study the fate of TCE in water and to devise effective remediation strategies, a series of advection‐diffusion (dispersion) models, where the diffusion coefficient of TCE (D TCE ) is an important parameter, have been developed. However, D TCE in water has never been experimentally determined and only theoretical values ( ≃ 1 × 10 − 5cm 2 s −1 at 25°C) are present in the literature. A new method based on the Taylor dispersion technique, which allows to measure D TCE in a broad range of temperature and, in principle, in any solvent is presented. At 25°C D TCE  =  8.16 ± 0.06 × 10 − 6cm 2 s −1 and the value increases almost linearly with the temperature, while, in the limit of the experimental error, is independent from [TCE] for dilute solutions. From the temperature dependence of D TCE , it was possible to calculate the specific TCE fitting constant in the well‐known Wilke and Chang theoretical relation and the activation energy of the diffusion process through the Arrhenius plot. © 2015 American Institute of Chemical Engineers AIChE J , 61: 3511–3515, 2015