ABSTRACT
NO2 CASRN: 121-14-2; DOT: 1600 (liquid); 2038 (solid); molecular formula: C7H6N2O4; FW: 182.14; RTECS: XT1575000 Physical state, color, and odor: Yellow to red needles or yellow liquid with a faint, characteristic odor Melting point (°C): 71.1 (Lenchitz and Velicky, 1970) 67-70 (Aldrich, 1990) Boiling point (°C): 300 with slight decomposition (quoted, Howard, 1989) Density (g/cm3): 1.521 at 15 °C (Sax, 1984) 1.379 at 20 °C (Weiss, 1986) 1.3208 at 71 °C (quoted, Keith and Walters, 1992) Diffusivity in water (x 10-5 cm2/sec): 0.76 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: 13.53 (Perrin, 1972) Flash point (°C): 206.7 (Weiss, 1986) Entropy of fusion (cal/mol⋅K): 14.01 (Tsonopoulos and Prausnitz, 1971) Henry’s law constant (x 10-8 atm⋅m3/mol): 5.39 at 25 °C (thermodynamic method-GC/UV spectrophotometry, Altschuh et al., 1999) Soil organic carbon/water partition coefficient, log Koc: 1.79 using method of Karickhoff et al. (1979) Octanol/water partition coefficient, log Kow: 1.98 (Mabey et al., 1982; Hansch and Leo, 1985) Solubility in organics: Soluble in acetone, ethanol, benzene, ether, and pyrimidine (Weast, 1986)
129 at 12.4 °C, 182 at 21.7 °C, 188 at 22.0 °C, 199 at 25.2 °C, 269 at 32.0 °C, 397 at 41.2 °C, 416
at 42.0 °C, 608 at 51.0 °C, 975 at 61.8 °C (Phelan and Barnett, 2001) 97 at 4 °C, 150 at 20 °C, 235 at 30 °C, 390 at 40 °C; in seawater (33.1 g of salt/kg of seawater): 78
at 4 °C, 127 at 20 °C, 197 at 30 °C, 321 at 40 °C (Prak and O’Sullivan, 2006) Vapor pressure (x 10-4 mmHg): 1.1 at 20 °C (quoted, Howard, 1989) 12.98 at 58.765 °C (Knuden effusion method, Lenchitz and Velicky, 1970) 450 at 72 °C (Rittfeldt, 2001) Environmental fate: Biological. When 2,4-dinitrotoluene was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum, significant biodegradation with gradual acclimation was followed by deadaptive process in subsequent subcultures. At a concentration of 5 mg/L, 77, 61, 50, and 27% losses were observed after 7, 14, 21, and 28-d incubation periods, respectively. At a concentration of 10 mg/L, only 50, 49, 44, and 23% were observed after 7, 14, 21, and 28-d incubation periods, respectively (Tabak et al., 1981). Razo-Flores et al. (1999) studied the fate of 2,4-dinitrotoluene (120 mg/L) in an upward-flow anaerobic sludge bed reactor containing a mixture of volatile fatty acids and/or glucose as electron donors. 2,4-Dinitrotoluene was transformed to 2,4-diaminotoluene (52% molar yield) in stoichiometric amounts until day 125. Thereafter, the amine underwent continued degradation. Approximately 98.5% of the volatile fatty acids in the reactor was converted to methane during the 202-d experiment. Haïdour and Ramos (1996) analyzed the degradation products of 2,4,6-trinitrotoluene, 2,4dinitrotoluene, and 2,6-dinitrotoluene by the bacterium Pseudomonas sp. clone A under aerobic conditions utilizing 2,4-dinitrotoluene as a source of nitrogen. Two metabolites tentatively identified were 2-amino-4-nitrotoluene and 4-amino-2-nitrotoluene. Also, three azoxytoluenes were identified: 4,4′-dinitro-2,2′-azoxytoluene, 2,2′-dinitro-4,4′-azoxytoluene, and 2,4′-dinitro2′,4-azoxytoluene. 2-Amino-4-nitrotoluene and 4-amino-2-nitrotoluene were also identified as products of 2,4-dinitrotoluene metabolism by Clostridium acetobutylicum via the hydroxylaminonitrotoluene intermediates, namely 4-hydroxylamino-2-nitrotoluene and 2-hydroxylamino4-nitrotoluene (Hughes et al., 1999). Photolytic. Low et al. (1991) reported that nitro-containing compounds (e.g., 2,4-dinitrophenol) degrade via UV light in the presence of titanium dioxide yielding ammonium, carbonate, and nitrate ions. By analogy, 2,4-dinitrotoluene should degrade forming identical ions. Chemical/Physical. Wet oxidation of 2,4-dinitrotoluene at 320 °C yielded formic and acetic acids (Randall and Knopp, 1980). 2,4-Dinitrotoluene will not hydrolyze because it does not contain a hydrolyzable function group (Kollig, 1993). At influent concentrations of 1.0, 0.1, 0.01, and 0.001 mg/L, the GAC adsorption capacities were 146, 71, 34, and 17 mg/g, respectively (Dobbs and Cohen, 1980). Toxicity: EC50 (15-min) for Photobacterium phosphoreum 4.17 mg/L (Yuan and Lang, 1997). IC50 (24-h) for river bacteria 35.5 mg/L (Yuan and Lang, 1997). Acute oral LD50 for mice 790 mg/kg, rats 268 mg/kg, guinea pigs 1.30 g/kg (quoted, RTECS, 1985). Chronic NOEC for Daphnia magna 60 µg/L (Kuhn et al., 1989). Drinking water standard: No MCLGs or MCLs have been proposed although 2,4-dichloro-
(U.S. EPA, 2000). Uses: Organic synthesis; intermediate for toluidine, dyes, explosives, and in manufacture of polyurethanes.
