Volatilization | The Henry's Law constant for hentriacontane is estimated as 2040 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that hentriacontane is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 6.1 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 8.3 days(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The volatilization half-life from a model pond is greater than 2 years when adsorption is considered(3). Hentriacontane's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Hentriacontane is not expected to volatilize from dry soil surfaces(SRC) based upon an extrapolated vapor pressure of 1.40X10-11 mm Hg at 25 deg C(4). Literature: (1) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.1. Nov, 2012. Available from, as of Nov 21, 2016: http://www2.epa.gov/tsca-screening-tools (2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990) (3) US EPA; EXAMS II Computer Simulation (1987) (4) Zwolinski BJ, Wilhoit RC; Handbook of Vapor Pressures and Heats of Vaporization of Hydrocarbons and Related Compounds. API44-TRC101. College Station, TX: Thermodynamcs Research Center (1971) |
Soil Adsorption | Using a structure estimation method based on molecular connectivity indices(1), the Koc of hentriacontane can be estimated to be 4.3X10+8(SRC). According to a classification scheme(2), this estimated Koc value suggests that hentriacontane is expected to be immobile in soil. Literature: (1) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.1. Nov, 2012. Available from, as of Nov 10, 2016: http://www2.epa.gov/tsca-screening-tools (2) Swann RL et al; Res Rev 85: 17-28 (1983) |