Determination of the trichloroethylene diffusion coefficient in water

Abstract

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 (DTCE) is an important parameter, have been developed. However, DTCE in water has never been experimentally determined and only theoretical values ( cm2 s−1 at 25°C) are present in the literature. A new method based on the Taylor dispersion technique, which allows to measure DTCE in a broad range of temperature and, in principle, in any solvent is presented. At 25°C DTCE = cm2 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 DTCE, 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