| 環境中動態 | TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 80(SRC), determined from a structure estimation method(2), indicates that cyclopentane is expected to have high mobility in soil(SRC). Volatilization of cyclopentane from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 0.19 atm-cu m/mole(SRC), based upon its vapor pressure, 317.8 mm Hg(3), and water solubility, 156 mg/L(4). Cyclopentane is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). Cyclopentane was not biodegraded by microorganisms isolated from soil(5), indicating that biodegradation is not an important environmental date process in soil(SRC).AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 80(SRC), determined from a structure estimation method(2), indicates that cyclopentane is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 0.19 atm-cu m/mole(SRC), derived from its vapor pressure, 317.8 mm Hg(4), and water solubility, 156 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 52 minutes and 3 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 44(SRC), from its log Kow of 3(7) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Cyclopentane was not biodegraded using an inocula from groundwater contaminated with gasoline(8), suggesting that biodegradation is not an important environmental fate process in water(SRC).ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), cyclopentane, which has a vapor pressure of 317.8 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase cyclopentane is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC)the half-life for this reaction in air is estimated to be 2.4 days(SRC), calculated from its rate constant of 4.97X10-12 cu cm/molecule-sec at 25 °C(3). Cyclopentane does not contain chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). |
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