ABSTRACT
NO2 CASRN: 100-01-6; DOT: 1661; DOT label: Poison; molecular formula: C6H6N2O2; FW: 138.13; RTECS: BY7000000; Merck Index: 12, 6681 Physical state, color, and odor: Bright yellow crystalline powder or flakes with a faint, ammonia-like, slightly pungent odor. Combustible. Melting point (°C): 146 (Dean, 1987) Boiling point (°C): 331.7 (Weast, 1986) 336 (Weiss, 1986) Density (g/cm3): 1.424 at 20 °C (Weast, 1986) Diffusivity in water (x 10-5 cm2/sec): 0.78 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: 0.99 at 25 °C (Dean, 1973) Flash point (°C): 165 (Aldrich, 1990) 200.5 (NIOSH, 1997) Entropy of fusion (cal/mol⋅K): 12.0 (Andrews et al., 1926) Heat of fusion (kcal/mol): 5.04 (Andrews et al., 1926) Henry’s law constant (x 10-9 atm⋅m3/mol): 1.15 at 25 °C (thermodynamic method-GC/UV spectrophotometry, Altschuh et al., 1999)
8.85 (NIOSH, 1997) Bioconcentration factor, log BCF: 0.64 (Brachydanio rerio, Kalsch et al., 1991) Soil organic carbon/water partition coefficient, log Koc: 1.88 (Batcombe silt loam, Briggs, 1981) Octanol/water partition coefficient, log Kow: 1.39 at 25 °C (shake flask-UV spectrophotometry, Fujita et al., 1964) 1.40 (Campbell and Luthy, 1985) 1.51 (Kramer and Henze, 1990) Solubility in organics: In g/kg at 25 °C: benzene (5.794), chloroform (9.290), and ethanol (60.48) (Collett and Johnston, 1926) Solubility in water: 0.8 g/L at 30 °C (Phatak and Gaikar, 1996) 0.568 and 1.157 g/kg at 25 and 40 °C, respectively (shake flask-titration, Collett and Johnston,
1926) 728 mg/kg at 30 °C (shake flask-interferometer, Gross and Saylor, 1931) 380, 390, 400 mg/L at 20 °C (Hashimoto et al., 1982) 417 mg/L at 25 °C (shake flask-UV spectrophotometry, Brisset, 1985) At 20 °C: 390 to 400 mg/L after filtering with glass fibers; 380 mg/L after membrane filtration
(modified shake flask method-fluorometry, Hashimoto et al., 1982) Vapor pressure (x 10-3 mmHg): 1.5 at 20 °C, 7 at 30 °C (quoted, Verschueren, 1983) Environmental fate: Biological. A Pseudomonas sp. strain P6, isolated from a Matapeake silt loam, was grown using a yeast extract. After 8 d, 4-nitroaniline degraded completely to carbon dioxide (Zeyer and Kearney, 1983). In activated sludge inoculum, following a 20-d adaptation period, no degradation was observed (Pitter, 1976). Chemical/Physical: Spacek et al. (1995) investigated the photodegradation of 4-nitroaniline using titanium dioxide-UV light and Fenton’s reagent (hydrogen peroxide:substance – 10:1; Fe2+ 2.5 x 10-4 mol/L). Both experiments were conducted at 25 °C. The decomposition rate of 4-nitroaniline was very high by the photo-Fenton reaction in comparison to titanium dioxide-UV light (λ = 365 nm). Decomposition products identified in both reactions were nitrobenzene, pbenzoquinone, hydroquinone, oxalic acid, and resorcinol. Oxalic acid, hydroquinone, and pbenzoquinone were identified as intermediate products using HPLC. At influent concentrations of 10, 1.0, 0.1, and 0.01 mg/L, the GAC adsorption capacities were 250, 140, 74, and 40 mg/g, respectively (Dobbs and Cohen, 1980). Exposure limits (mg/m3): NIOSH REL: TWA 3; IDLH 300; OSHA PEL: TWA 6; ACGIH TLV: TWA 3 (adopted). Toxicity: EC50 (15-min) for Photobacterium phosphoreum 14.8 mg/L (Yuan and Lang, 1997).
