Temperature-dependence of soil/air partition coefficients for selected polycyclic aromatic hydrocarbons and organochlorine pesticides over a temperature range of -30 to +30 degrees C.
The soil/air partition coefficients (K(SA)) for two polycyclic aromatic carbons (PAHs) and six organochlorine pesticides (OCs) were determined by a solid-phase fugacity meter over a wide temperature range of -30 to +30 degrees C in a paddy field soil. Literature values for PAHs and OCs obtained by the same method were 1.9-5.1 times of present values at +20 degrees C. Experimentally determined K(SA) ranged over six orders of magnitude, with log K(SA) from 4.5 for alpha-hexachlorocyclohexane at +30 degrees C to 10.4 for trans-nonachlor at -20 degrees C. Separate linear regressions of log K(SA) and reciprocal absolute temperature were employed at temperatures above 0 degrees C and below 0 degrees C. The calculated enthalpies associated with the phase transfer from the soil to the air (DeltaH(SA)) over 0 to +30 degrees C range from 78 to 108 kJmol(-1), which are in a good agreement with the literature values.
He
Xin
X
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, China. nacyhe8735@yahoo.com.cn
Chen
Shuo
S
Quan
Xie
X
Zhao
Yazhi
Y
Zhao
Huimin
H
D000388:Air; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D007700:Kinetics; D010575:Pesticides / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D012987:Soil; D013696:Temperature; D013816:Thermodynamics
D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil