Volatilization | The Henry's Law constant for acetic acid has been experimentally determined to be 1.43X10-7 atm-cu m/mole at 25 deg C(1). This Henry's Law constant indicates that acetic acid is expected to be essentially nonvolatile from water surfaces(2). Acetic acid's Henry's Law constant indicates that volatilization from moist soil surfaces is not expected to be an important fate process(SRC). Acetic acid is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 15.7 mm Hg at 25 deg C(3). Literature: (1) Johnson BJ et al; J Atmos Chem 24: 113-119 (1996) (2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990) (3) Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals: Data Compilation. Design Inst Phys Prop Data, Amer Inst Chem Eng. New York, NY: Hemisphere Pub Corp (1989) |
Soil Adsorption | A log Koc of 0.00 (Koc = 1), which was derived from experimental measurements, has been reported for acetic acid(1,2). According to a classification scheme(3), this Koc value suggests that acetic acid is expected to have very high mobility in soil. No detectable sorption was measured for acetic acid using the OECD Guideline 106 method employing an acidic forest soil, pH 2.8, an agricultural soil, pH 6.7, and a lake sediment, pH 7.1(4). Adsorption of acetic acid to 3 nearshore marine sediments collected from three different locations resulted in Kd values of 0.65 (Koc = 228), 0.085 (Koc = 6.5) and 0.046 (Koc = 27) using clastic mud (3.5% organic carbon, pH 7.0), muddy sand (1.3% organic carbon, pH 7.7), and carbonate sand (0.17% organic carbon, pH 8.1), respectively(5). The pKa of acetic acid is 4.76(6), indicating that this compound will exist partially in anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(7). Literature: (1) Schuurmann G et al; Environ Sci Technol 40: 7005-7011 (Supplemental material) (2006) (2) Meylan WM et al; Environ Sci Technol 26: 1560-7 (1992) (3) Swann RL et al; Res Rev 85: 17-28 (1983) (4) Von Oepen B et al; Chemosphere 22: 285-304 (1991) (5) Sansone JF et al; Geochimica et Cosmochimica Acta 51: 1889-1896 (1987) (6) Serjeant EP, Dempsey B; Ionisation Constants of Organic Acids in Aqueous Solution. IUPAC Chemical Data Series No. 23. New York, NY: Pergamon Press, p. 989 (1979) (7) Doucette WJ; pp. 141-188 in Handbook of Property Estimation Methods for Chemicals. Boethling RS, Mackay D, eds. Boca Raton, FL: Lewis Publ (2000) Literature: #In 24 hr aqueous adsorption studies using montmorillonite and kaolinite clay adsorbents, 2.4-30.4% of added acetic acid was observed to be in the adsorbed phase(1). In adsorption studies using the adsorbent hydroxyapatite (a mineral which occurs in the environment as a result of the diagenesis of skeletal apatite), only 5% of added acetic acid (in aqueous solution, pH 8.0) became adsorbed to the hydroxyapatite(2). Acetic acid has been noted to leach from biological disposal areas(3). Literature: (1) Hemphill L, Swanson WS; Proc of the 18th Industrial Waste Conf, Eng Bull Purdue Univ, Lafayette IN 18: 204-17 (1964) (2) Gordon AS, Millero FJ; Microb Ecol 11: 289-98 (1985) (3) Abrams EF et al; Identification of Organic Compounds in Effluents from Industrial Sources. USEPA-560/3-75-002 p. 3 (1975) |