| 환경 거동 | TERRESTRIAL FATE: Based on a classification scheme(1), measured Koc values of 13200, 13900, and 12500 for a lake sediment (foc=0.094), river sediment (foc=0.026), and aquifer material (foc=0.0084), respectively(2) indicate that 2,3,4,5-tetrachlorophenol is expected to be immobile in soil(SRC). A pKa of 6.35 indicates that 2,3,4,5-tetrachlorophenol exists mainly as the phenolate anion in neutral and alkaline environments(3). Volatilization of 2,3,4,5-tetrachlorophenol from moist soil surfaces is not expected to be important(SRC) given an estimated Henry's Law constant of 3.5X10-7 atm-cu m/mole(SRC), using a fragment constant estimation method(4). 2,3,4,5-Tetrachlorophenol is not expected to volatilize from dry soil surfaces based on an estimated vapor pressure of 1.6X10-4 mm Hg(SRC), determined from a fragment constant method(5). Based on limited data, biodegradation of 2,3,4,5-tetrachlorophenol may occur under both aerobic and anaerobic conditions. 31% and 0% biodegradation of 2,3,4,5-tetrachlorophenol was reported in an aerobic clay loam soil after 160 days and in an anaerobic clay loam soil after 80 days, respectively(6). However, another study using anaerobic estuarine sediment reported a half-life of 6.5 days with the formation of 3,4,5-trichlorophenol (27%) and 2,4,5-trichlorophenol (22%) as major intermediates(7). BCF values of 38 to 41 and 213 to 351 were measured in two species of earthworms, E. fetida andrei and L. rubellus, respectively(8).AQUATIC FATE: Based on a classification scheme(1), measured Koc values of 13200, 13900, and 12500 for a lake sediment (foc=0.094), river sediment (foc=0.026), and aquifer material (foc=0.0084), respectively(2) indicate that 2,3,4,5-tetrachlorophenol is expected to adsorb to suspended solids and sediment in water(SRC). In a field aqueous adsorption study, the ratio of 2,3,4,5-tetrachlorophenol concn in sediment to water was measured as 680 and in suspended matter to water was 240(3). 2,3,4,5-Tetrachlorophenol is not expected to volatilize from water surfaces(3,SRC) based on an estimated Henry's Law constant of 3.5X10-7 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(6), an estimated BCF of 930(5,SRC), from a log Kow value (7), suggests the potential for bioconcentration in aquatic organisms is high(SRC). Photolysis at water surfaces may be an important fate processa photochemical half-life of 0.88 hours was measured for 2,3,4,5-tetrachlorophenol in a 99% ethanol/1% sodium phosphate solution (pH=7) using filtered light at 295 to 500 nm to simulate sunlight(8). Based on limited data, biodegradation of 2,3,4,5-tetrachlorophenol may occur under both aerobic and anaerobic conditions. In a river die-away study, 2,3,4,5-tetrachlorophenol had a biodegradation rate constant of 1.4X10-7 M/hra lag phase of 17 days was reported(9). A study using anaerobic estuarine sediment reported a half-life of 6.5 days with the formation of 3,4,5-trichlorophenol(27%) and 2,4,5-trichlorophenol(22%) as major intermediates(10).ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2,3,4,5-tetrachlorophenol, which has an estimated vapor pressure of 1.6X10-4 mm Hg at 25 °C(2,SRC), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase 2,3,4,5-tetrachlorophenol 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 10 days(3,SRC). Particulate-phase 2,3,4,5-tetrachlorophenol may be physically removed from the air by wet and dry deposition(SRC). |
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