| Volatilization | The measured Henry's Law constant for chlorobenzene is 3.11X10-3 atm-cu m/mole at 25 deg C(1). This Henry's Law constant indicates that chlorobenzene is expected to volatilize rapidly 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 3.4 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 4.3 days(SRC). Chlorobenzene's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Chlorobenzene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 12 mm Hg(3). Chlorobenzene applied to soil at a uniform concentration of 1 kg/ha at depths of 1 cm and 10 cm underwent 86.5 and 23.4% loss, respectively, in a day; volatilization half-lives of 0.3 and 12.6 days, respectively, were estimated from this data(4). Volatilization half-lives of 13, 21, and 4.6 days were estimated for chlorobenzene using data obtained from an experimental marine mesocosm under simulated winter, spring, and summer conditions, respectively(5). Chlorobenzene was removed within 8 days in sterile pond water incubated in bottles open to the atmosphere(6). Volatilization rates of chlorobenzene from the wastewater-dependent constructed Tres Rios Demonstration Wetlands near Phoenix, AZ ranged from 5.11X10-6 to 8.48X10-6 sec-1, corresponding to a half-life of approximately 9 hours(7). In a closed aerated laboratory system simulating arable soil exposed to 14-C radio-labeled chlorobenzene, analysis of trapped 14-CO2 and 14-C chlorobenzene gas indicated that volatilization was the main loss mechanism with mineralization having minor importance(8).
Literature: (1) Shiu WY, Mackay D; J Chem Eng Data 42: 27-30 (1997) (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, Vol 3 (1987) (4) Jury WA et al; J Environ Qual 13: 572-9 (1984) (5) Wakeham SG et al; Environ Sci Technol 17: 611-7 (1983) (6) Bouwer EJ; J Environ Eng 115: 741-55 (1989) (7) Keefe SH et al; Environ Sci Technol 38: 2209-26 (2004) (8) Brahushi F et al; Fresenius Environmental Bulletin 11(9a): 599-604 (2002) |
| Soil Adsorption | Koc values of 313.1 and 146.5 were measured on Captina silt loam (1.49% organic carbon) and McLaurin sandy loam, (0.66% organic carbon), respectively(1). Equilibrium sorption constant (Ks) values of 0.295 and 0.09 were determined in Eustis fine sand (13 g/kg clay, 32 g/kg silt, 955 g/kg sand, 3.9 g/kg organic carbon) and Tampa (6 g/kg clay, 23 g/kg silt, 971 g/kg sand, and 1.3 g/kg organic carbon) soils, respectively(2); corresponding Koc values are 76 and 69(SRC). Equilibrium sorption coefficients of 0.014 and 10.20 were measured on Borden (98% sand, 1% silt, 1% clay, 0.29% organic carbon) and Mt. Lemmon (60.3% sand, 24.0% silt, 15.7% clay, 12.6% organic carbon) soils, respectively(3); corresponding Koc values are 4.8 and 81(SRC). According to a classification scheme(4), these Koc values suggest that chlorobenzene is expected to have moderate to very high mobility in soil(SRC). The sorption isotherm for chlorobenzene onto muck soil (49.0% organic carbon) was linear(5). A Kd value of 166.34 was measured for chlorobenzene using dewatered activated sludge (18% solids) that had been dried and sieved; 3.28% of the chlorobenzene was desorbed during the desorption phase of the experiment(6). Partition coefficients of 0.35, 0.33, and 0.38 were measured for chlorobenzene on primary sludge, mixed liquor solids, and digested sludge, respectively(7). Sorption coefficients of 0.48 and 0.29 were measured on primary sludge and anaerobically digested sludge, respectively(8). Partition coefficients of 48 and 29 were measured in high organic carbon (14.5%) and low organic carbon (3.6%) Sherman Island sediments, respectively(9).
Literature: (1) Walton BT et al; J Environ Qual 21: 552-8 (1992) (2) Brusseau ML; Environ Toxicol Chem 12: 1835-46 (1993) (3) Hu Q et al; Environ Toxicol Chem 14: 1133-40 (1995) (4) Swann RL et al; Res Rev 85: 23 (1983) (5) Sheng G et al; Environ Sci Technol 30: 1553-7 (1996) (6) Selvakumar A, Hsieh HN; Int J Environ Stud 30: 313-9 (1987) (7) Dobbs RA et al; Int Conf Innovative Biol Treat Toxic Wastewaters; Scholze, RJ Jr, eds; pp 585-601 (1987) (8) Dobbs RA et al; Environ Sci Technol 23: 1092-7 (1989) (9) Knezovich JP, Harrison FL; Ecotoxicol Environ Safety 15: 226-41 (1988) |
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