Estimation of the volatilization of organic compounds from soil surfaces

• Published in: Chemosphere (Oxford) Vol. 58; no. 6; pp. 751 - 758
• Main Authors: Voutsas, Epaminondas, Vavva, Chrisanthi, Magoulas, Kostis, Tassios, Dimitrios
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.2005; Elsevier
• Subjects: Applied sciences; Atmospheric pollution; Biological and physicochemical properties of pollutants. Interaction in the soil; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Half-Life; Henry’s law constant; mathematical models; Models, Theoretical; Organic Chemicals - chemistry; partition coefficients; pesticide residues; Pesticides; Pesticides - chemistry; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; Pollution, environment geology; Reproducibility of Results; Soil; Soil and sediments pollution; Soil Pollutants; soil pollution; Solubility; surface layers; Vapor pressure; Volatilization; Soil; Half-life; Vapor pressure; Henry’s law constant; Volatilization; Pesticides; Pollutant behavior; Soil moisture; Henry constant; Troposphere; Environmental factor; Partition coefficient; Soil pollution; Depletion; Atmospheric boundary layer; Air pollution; Air ground interface; Henry's law constant; Computing method; Organic compounds; Half life
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2004.09.057

Several simple models for the estimation of the half-life ( t 1/2) for the depletion of an organic chemical from a soil surface to air were examined. For moist surfaces, two models are proposed: the first requires knowledge of the soil/organic carbon partition coefficient ( K oc) and the Henry’s law constant ( H) and the second the vapor pressure ( P s) of the chemical involved. Due to uncertainties in the experimental K oc values those ones predicted by the group-contribution model of Meylan et al. [Environ. Sci. Technol. 26 (1992) 1560]—and proposed by the U.S. Environmental Protection Agency (EPA)—should be used. If reliable experimental P s values are not available, the first model is proposed, where in cases when H values are not available, predicted ones by the Bond-Contribution method of Meylan and Howard [Environ. Toxicol. Chem. 10 (1991) 1283]—and also proposed by EPA—can be used. In general, the agreement of the predicted t 1/2 values with the measured ones is within a factor of 3–5. Similar expressions, but with somewhat poorer results, are presented for dry field soils. In all cases, the obtained results represent a substantial improvement over those obtained with the currently used Dow method: t 1 / 2 = 1.58 · 10 - 8 ( K oc · S P S ) , where S is the solubility of the compound in water.