Henry's law constant measurements for phenol, o-, m-, and p-cresol as a function of temperature

Valérie Feigenbrugel (1) , Stéphane Le Calvé (2, 1) , Philippe Mirabel (1, 2) , Florent Louis (3)

1 CGS - Centre de géochimie de la surface
2 ICPEES - Institut de chimie et procédés pour l'énergie, l'environnement et la santé
3 PC2A - Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522

In this work, a dynamic system based on the water/air equilibrium at the interface within the length of a microporous tube was used to experimentally determine the Henry's Law Constants (HLC) of phenol and cresols. The measurements were conducted over the range 278-298 K in both deionized water and 35 g L-1°/°° solution of NaCl. At 293 K and in pure water, HLC were found to be equal to (in units of M atm-1): phenol, HLC = (1005  270); ocresol, HLC = (690  95); m-cresol, HLC = (1324  172); p-cresol, HLC = (1742 ± 360). The obtained data were used to derive the following Arrhenius expressions: HLC = (4.1 ± 0.6)  10-9 exp((7684 ± 874)/T), HLC = (1.5 ± 0.1)  10-10 exp((8544 ± 512)/T), HLC = (5.5 ± 0.4)  10-11 exp((9028 ± 508)/T) and HLC = (3.3 ± 0.4)  10-11 exp((9258 ± 818)/T) for phenol, ocresol, m-cresol and p-cresol, respectively. All of the values for HLC in 35 g L-1 salt solution were 10 to 30% lower than their respective values in deionised water, depending on the compound and the temperature. These data were then used to estimate the fractions of phenol or of cresols in atmospheric aqueous phase. In order to evaluate the impact of a cloud on the atmospheric chemistry of phenol and cresols, we compare also their atmospheric lifetimes under clear sky (τgas), and cloudy conditions (τmultiphase). The calculated multiphase lifetimes (in units of days) are 2 significantly lower than those in gas phase at a cumulus temperature of 283 K (in parentheses): phenol, 0.26 (0.45); o-cresol, 0.17 (0.24); m-cresol, 0.13 (0.22); p-cresol, 0.11 (0.23).

Mots clés: BTEX; Analytical method; GC-PID; GC-MS; GC-FID; Thermo-desorption Highlights; Henry's Law Constant; temperature; salinity; phenol; cresols

Domaines: Chimie analytique; Chimie théorique et/ou physique; Océan, Atmosphère

Valérie Feigenbrugel, Stéphane Le Calvé, Philippe Mirabel, Florent Louis. Henry's law constant measurements for phenol, o-, m-, and p-cresol as a function of temperature. Atmospheric Environment, 2004, 38 (33), pp.5577-5588. ⟨10.1016/j.atmosenv.2004.06.025⟩. ⟨hal-02416674⟩