PHENOL

Note: Phenol may contain 2-, 3-, and 4-methylphenols as impurities. CASRN: 108-95-2; DOT: 1671 (solid); 2312 (molten); 2821 (solution); DOT label: Poison; molecular formula: C6H6O; FW: 94.11; RTECS: SJ3325000; Merck Index: 12, 7390 Physical state, color, and odor: White crystals, crystalline solid, or light pink liquid which slowly turns brown on exposure to air. Phenol has an acrid or sweet, tarry-like odor resembling wet newspaper or cardboard. Sharp burning taste. At 40 °C, the average odor threshold concentration and the lowest concentration at which an odor was detected were 31 and 9.5 µg/L, respectively. At 25 °C, the lowest concentration at which a taste was detected was <2 µg/L (Young et al., 1996). Leonardos et al. (1969) and Nagata and Takeuchi (1990) reported odor threshold concentrations of 47 ppmv and 5.6 ppbv, respectively. Melting point (°C): 40.50 (Huang et al., 2003) Boiling point (°C): 183 (Huntress and Mulliken, 1941) Density (g/cm3): -1.0571 at 41 °C (Kuus et al., 1998) Diffusivity in water (x 10-5 cm2/sec): At ceff = 130 µM: 0.543 at 4.0 °C, 0.998 25.0 °C, 1.788 at 50.0 °C; 1.018 (ceff = 250 µM) at 25.0 °C (Niesner and Heintz, 2000)

Dissociation constant, pKa: 9.85 at 25 °C (Sprengling and Lewis, 1953) 9.90 (Blackman et al., 1955) Flash point (°C): 80 (NIOSH, 1997) Lower explosive limit (%): 1.8 (NIOSH, 1997) Upper explosive limit (%): 8.6 (NIOSH, 1997)

8.762 (Andon et al., 1963) Heat of fusion (kcal/mol): 2.752 (Andon et al., 1963) 2.898 (Mastrangelo, 1957) Henry’s law constant (x 10-7 atm⋅m3/mol): 3.937 at 27.0 °C (air stripping, Abd-El-Bary et al., 1986) 3.45 (Parsons et al., 1971) 5.30 at 20 °C (Sheikheldin et al., 2001) 13 at 25 °C (gas stripping-UV spectrophotometry, Warner et al., 1987) 1.21 at 11 °C, 1.09 at 11.3 °C, 1.96 at 16.3 °C, 2.58 at 20.3 °C, 3.15 at 25 °C, 3.75 at 29 °C

(column stripping, Harrison et al., 2002) 12.3 at 75.9 °C, 21.7 at 88.7 °C, 32.8 at 98.5 °C (VLE circulation still-UV spectrophotometry,

Dohnal and Fenclová, 1995) <23.8 at 25 °C (thermodynamic method-GC/UV spectrophotometry, Altschuh et al., 1999) 1.09 at 5 °C (average derived from six field experiments, Lüttke and Levsen, 1997) Interfacial tension with water (dyn/cm at 20 °C): 0.8 (quoted, Freitas et al., 1997) Ionization potential (eV): 8.51 (Franklin et al., 1969) Bioconcentration factor, log BCF: 1.24 (Brachydanio rerio, Devillers et al., 1996) 1.28 (Daphnia magna, Dauble et al., 1986) 4.20 (fathead minnow, Call et al., 1980) 0.54 (algae, Hardy et al., 1985) 1.30 (golden ide), 2.30 (algae), 3.34 (activated sludge) (Freitag et al., 1985) Soil organic carbon/water partition coefficient, log Koc: 1.72 (Batcombe silt loam, Briggs, 1981) 3.46 (fine sediments), 3.49 (coarse sediments) (Isaacson and Frink, 1984) 1.21 (Brookstone clay loam soil, Campbell and Luthy, 1985) 1.74 (Apison soil), 2.85 (Fullerton soil), 0.845 (Dormont soil) (Southworth and Keller, 1986) 1.24 (Boyd, 1982) 1.57, 1.96 (silt loam, Scott et al., 1983) 1.4 (river sediment), 1.6 (coal wastewater sediment) (Kopinke et al., 1995) 2.70 (glaciofluvial, sandy aquifer, Nielsen et al., 1996) 1.310, 1.750, 1.281, 1.601, 1.544 (various European soils, Gawlik et al., 2000) 1.35 using mobile phase buffered to pH 3 (estimated from HPLC capacity factors, Hodson and

Williams, 1988) Octanol/water partition coefficient, log Kow: 1.31-1.43 (Kubáň, 1991) 1.39 (Riederer, 1990) 1.45 (Mirrlees et al., 1976; generator column-HPLC/GC, Wasik et al., 1981) 1.46 (shake flask-UV spectrophotometry, Fujita et al., 1964; shake flask, Briggs, 1981; Berthod et

al., 1988)

1.55 (RP-HPLC, Garst and Wilson, 1984) 1.57 (Kishino and Kobayashi, 1994) Solubility in organics: Soluble in carbon disulfide and chloroform; very soluble in ether; miscible with carbon

tetrachloride, hot benzene (U.S. EPA, 1985), and alcohol (Meites, 1963). At 25 °C: 0.3 mol/L in isooctane and 4.0 mol/L in cyclohexane (Anderson et al., 1979). Solubility in water: 84,120 mg/L (Reinbold et al., 1979) 0.90 M at 25 °C (Caturla et al., 1988) In g/kg: 78 at 10 °C, 79 at 20 °C, 84 at 30 °C (shake flask-nephelometry, Howe et al., 1987) 0.813 M at 25.0 °C (generator column-HPLC/GC, Wasik et al., 1981) At 20 °C: 1.6, 1.35, 1.39, and 1.33 M in doubly distilled water, Pacific seawater, artificial

seawater, and 35% NaCl, respectively (modified shake flask method-fluorometry, Hashimoto et al., 1984)

76.044, 84.045, and 93.098 g/L at 15.1, 25.0, and 35.0 °C, respectively (shake flaskconductimetry, Achard et al., 1996)

75.00 g/kg at 25.0 °C (shake flask-GC, Krajl and Sinčić, 1980) 0.88 M at 25 °C (Southworth and Keller, 1986) In mmol/kg solution: 850.9 at 19.3 °C, 861.9 at 20.6 °C, 881.6 at 22.9 °C, 888.3 at 23.1 °C, 899.7

at 25.0 °C, 907.5 at 25.9 °C, 917.0 at 27.0 °C, 934.4 at 29.0 °C, 938.8 at 29.5 °C, 944.9 at 30.2 °C, 966.0 at 32.6 °C, 978.4 at 34.0 °C, 983.7 at 34.6 °C, 989.0 at 35.2 °C, 1,032.8 at 40.1 °C, 1,064.5 at 42.2 °C, 1,102.1 at 44.0 °C, 1,106.4 at 44.2 °C, 1,155.9 at 44.5 °C, 1,215.9 at 49.2 °C, 1,240.9 at 50.3 °C, 1,270.9 at 51.6 °C, 1,292.0 at 52.5 °C, 1,318.0 at 53.6 °C, 1,378.5 at 56.1 °C, 1,420.7 at 57.8 °C, 1,428.2 at 58.1 °C, 1,430.7 at 58.2 °C, and 1,486.8 at 60.4 °C (light transmission technique, Jaoui et al., 2002)

Vapor pressure (x 10-2 mmHg): 20 at 20 °C, 100 at 40 °C (quoted, Verschueren, 1983) 35 at 25 °C (ACGIH, 1986) 6.4 at 8 °C, 34 at 25 °C (quoted, Leuenberger et al., 1985a) 62 at 25 °C (Riederer, 1990) Environmental fate: Biological. Under methanogenic conditions, inocula from a municipal sewage treatment plant digester degraded phenol to carbon dioxide and methane (Young and Rivera, 1985). Chloroperoxidase, a fungal enzyme isolated from Caldariomyces fumago, reacted with phenol forming 2-and 4-chlorophenol, the latter in a 25% yield (Wannstedt et al., 1990). In activated sludge, 41.4% mineralized to carbon dioxide after 5 d (Freitag et al., 1985). When phenol was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum, significant biodegradation with rapid adaptation was observed. At concentrations of 5 and 10 mg/L, 96 and 97% biodegradation, respectively, were observed after 7 d (Tabak et al., 1981). Phenol is rapidly degraded in aerobically incubated soil but is much slower under anaerobic conditions (Baker and Mayfield, 1980). Healy and Young (1979) studied the degradation of ferulic acid under strict anaerobic conditions using a serum-bottle variation of the Hungate technique. The medium was inoculated in a 10% (vol/vol) seed from a laboratory anaerobic digester fed primary sewage sludge. To ensure no oxygen was present, the methanogenic enrichment culture was flushed with oxygen-free gas for 20 min before incubating in the dark at 35 °C. After a 10-d acclimation period, the amount of

In a continuous stirred reactor maintained at 20 °C, phenol degraded at rates of 0.094 and 0.007/h at feed concentrations of 180 and 360 mg/L, respectively (Beltrame et al., 1984). In the presence of suspended natural populations from unpolluted aquatic systems, the second-order microbial transformation rate constant determined in the laboratory was reported to be 3.3 ± 1.2 x 10-10 L/organism⋅h (Steen, 1991). Bridié et al. (1979) reported BOD and COD values 1.68 and 2.33 g/g using filtered effluent from a biological sanitary waste treatment plant. These values were determined using a standard dilution method at 20 °C of 5 d. Similarly, Heukelekian and Rand (1955) reported a 5-d BOD value of 1.81 g/g which is 76.0% of the ThOD value of 2.38 g/g. In activated sludge inoculum, 98.5% COD removal was achieved. The average rate of biodegradation was 80.0 mg COD/g·h (Pitter, 1976). Soil. Loehr and Matthews (1992) studied the degradation of phenol in different soils under aerobic conditions. In a slightly basic sandy loam (3.25% organic matter) and in acidic clay soil (<1.0% organic matter), the resultant degradation half-lives were 4.1 and 23 d, respectively. Soil sorption distribution coefficients (Kd) were determined from centrifuge column tests using kaolinite as the absorbent (Celorie et al., 1989). Values for Kd ranged from 0.010 to 0.054 L/g. Surface Water. Vaishnav and Babeu (1987) reported a half-life of 11 d in river waters and 3 d in harbor waters. Groundwater. Nielsen et al. (1996) studied the degradation of phenol in a shallow, glaciofluvial, unconfined sandy aquifer in Jutland, Denmark. As part of the in situ microcosm study, a cylinder that was open at the bottom and screened at the top was installed through a cased borehole approximately 5 m below grade. Five liters of water was aerated with atmospheric air to ensure aerobic conditions were maintained. Groundwater was analyzed weekly for approximately 3 months to determine phenol concentrations with time. The experimentally determined first-order biodegradation rate constant and corresponding half-life were 0.5/d and 33.4 h, respectively. Vaishnav and Babeu (1987) reported a biodegradation rate constant of 0.035/d and a half-life of 20 d in groundwater. Photolytic. Absorbs UV light at a maximum wavelength of 269 nm (Dohnal and Fenclová, 1995). In an aqueous, oxygenated solution exposed to artificial light (λ = 234 nm), phenol was photolyzed to hydroquinone, catechol, 2,2 -, 2,4 - and 4,4 -dihydroxybiphenyl (Callahan et al., 1979). When an aqueous solution containing potassium nitrate (10 mM) and phenol (1 mM) was irradiated with UV light (λ = 290-350 nm) up to a conversion of 10%, the following products formed: hydroxyhydroquinone, hydroquinone, resorcinol, hydroxybenzoquinone, benzoquinone, catechol, nitrosophenol, 4-nitrocatechol, nitrohydroquinone, 2-and 4-nitrophenol. Catechnol and hydroquinone were the major and minor products, respectively (Niessen et al., 1988). Titanium dioxide suspended in an aqueous solution and irradiated with UV light (λ = 365 nm) converted phenol to carbon dioxide at a significant rate (Matthews, 1986). Irradiation of phenol with UV light (λ = 254 nm) in the presence of oxygen yielded substituted biphenyls, hydroquinone, and catechol (Joschek and Miller, 1966). A carbon dioxide yield of 32.5% was achieved when phenol adsorbed on silica gel was irradiated with light (λ >290 nm) for 17 h (Freitag et al., 1985). When an aqueous solution containing phenol was photooxidized by UV light at 50 °C, 10.96% degraded to carbon dioxide after 24 h (Knoevenagel and Himmelreich, 1976). The dye-sensitized photodegradation of phenol in aqueous solution was studied by Okamoto et al. (1982). They reported a first-order rate constant of 6.5 x 10-3/sec. Second-order rate constants of 2.66 x 10-8, 6.16 x 10-7, and 1.95 x 10-7 L/molecule⋅sec were determined at pH values 10.3, 9, and 8, respectively. Larson et al. (1992) studied the photosensitizing ability of 2′,3′,4′,5′-tetraacetylriboflavin to various organic compounds. An aqueous solution containing phenol was subjected to a mediumpressure mercury arc lamp (λ >290 nm). The investigators reported that 2′,3′,4′,5′-tetraacetylriboflavin was superior to another photosensitizer, namely riboflavin, in the degradation of

resulted in a half-life of 76 h. In the presence of ribloflavin and 2′,3′,4′,5′-tetraacetylriboflavin, the half-lives were 11 and 8.7 min, respectively. The following half-lives were reported for phenol in estuarine water exposed to sunlight and microbes: 39 and 94 h during summer (24 °C) and winter (10 °C), respectively; in distilled water: 46 and 173 h during summer and winter, respectively; in poisoned estuarine water: 43 and 118 h during summer and winter, respectively (Hwang et al., 1986). Anticipated products from the reaction of phenol with ozone or OH radicals in the atmosphere are dihydroxybenzenes, nitrophenols, and ring cleavage products (Cupitt, 1980). Reported rate constants for the reaction of phenol and OH radicals in the atmosphere: 2.8 x 10-11 cm3/molecule⋅sec at room temperature (Atkinson, 1985) and with NO3 in the atmosphere: 2.1 x 10-12 cm3/molecule⋅sec at 296 K (Atkinson et al., 1984). Chemical/Physical. In an environmental chamber, nitrogen trioxide (10,000 ppb) reacted quickly with phenol (concentration 200 ppb to 1.4 ppm) to form phenoxy radicals and nitric acid (Carter et al., 1981). The phenoxy radicals may react with oxygen and nitrogen dioxide to form quinones and nitrohydroxy derivatives, respectively (Nielsen et al., 1983). Reported rate constants for the reaction of phenol and singlet oxygen in water at 292 K: 2.5 x 106/M⋅sec at pH 8, 1.9 x 107/M⋅sec at pH 9, 4.6 x 107/M⋅sec at pH 9.5, 9.0 x 107/M⋅sec at pH 10 and 1.8 x 108/M⋅sec at pH 11.5 (Scully and Hoigné, 1987). Groundwater contaminated with various phenols degraded in a methanogenic aquifer. Similar results were obtained in the laboratory utilizing an anaerobic digester. Methane and carbon dioxide were reported as degradation products (Godsy et al., 1983). Ozonization of phenol in water resulted in the formation of many oxidation products. The identified products in the order of degradation are catechol, hydroquinone, o-quinone, cis,cismuconic acid, maleic (or fumaric) and oxalic acids (Eisenhauer, 1968). In addition, glyoxylic, formic, and acetic acids also were reported as ozonization products prior to oxidation to carbon dioxide (Kuo et al., 1977). Ozonation of an aqueous solution of phenol subjected to UV light (120W low pressure mercury lamp) gave glyoxal, glyoxylic, oxalic, and formic acids as major products. Minor products included catechol, hydroquinone, muconic, fumaric, and maleic acids (Takahashi, 1990). Wet oxidation of phenol at 320 °C yielded formic and acetic acids (Randall and Knopp, 1980). Chlorination of water containing bromide ions converted phenol to 2,4,6-tribromophenol. Bromodichlorophenol, dibromochlorophenol, and tribromophenol have also been reported to form from the chlorination of natural water under simulated conditions (Watanabe et al., 1984). Wet oxidation of phenol at elevated pressure and temperature gave the following products: acetone, acetaldehyde, formic, acetic, maleic, oxalic, and succinic acids (Keen and Baillod, 1985). Chlorine dioxide reacted with phenol in an aqueous solution forming p-benzoquinone and hypochlorous acid (Wajon et al., 1982). Kanno et al. (1982) studied the aqueous reaction of phenol and other substituted aromatic hydrocarbons (aniline, toluidine, 1-naphthylamine, cresol, pyrocatechol, resorcinol, hydroquinone, and 1-naphthol) with hypochlorous acid in the presence of ammonium ion. They reported that the aromatic ring was not chlorinated as expected but was cleaved by chloramine forming cyanogen chloride (Kanno et al., 1982). The amount of cyanogen chloride formed increased at lower pHs. At pH 6, the greatest amount of cyanogen chloride was formed when the reaction mixture contained ammonium ion and hypochlorous acid at a ratio of 2:3 (Kanno et al., 1982). Spacek et al. (1995) investigated the photodegradation of phenol using titanium dioxide-UV light and Fenton’s reagent (hydrogen peroxide:substance - 10:1; Fe2+ 2.5 x 10-4 mol/L) at 25 °C. The decomposition rate of phenol 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 p-benzoquinone, hydroquinone, and oxalic acid. Augusti et al. (1998) conducted kinetic studies for the reaction of phenol (0.2 mM) and other monocyclic aromatics with Fenton’s reagent (8 mM

0.0180/min. Phenol will not hydrolyze in water because it does not contain a hydrolyzable function group (Kollig, 1993). Reacts with sodium and potassium hydroxide forming sodium and potassium phenolate, respectively (Morrison and Boyd, 1971). At an influent concentration of 1,000 mg/L, treatment with GAC resulted in an effluent concentration of 194 mg/L. The adsorbability of the carbon used was 161 mg/g carbon (Guisti et al., 1974). Similarly, at influent concentrations of 10, 1.0, 0.1, and 0.01 mg/L, the GAC adsorption capacities were 74, 21, 6.0, and 1.7 mg/g, respectively (Dobbs and Cohen, 1980). Exposure limits: NIOSH REL: TWA 5 ppm (19 mg/m3), 15-min ceiling 15.6 ppm (60 mg/m3), IDLH 250 ppm; OSHA PEL: 5 ppm; ACGIH TLV: TWA 5 ppm (adopted). Symptoms of exposure: Ingestion of 5 to 10 mg may cause death. Toxic symptoms include nausea, vomiting, weakness, cyanosis, tremor, convulsions, kidney and liver damage. Eye, nose, and throat irritant. Burns skin on contact and may cause dermatitis (Patnaik, 1992). An irritation concentration of 182.40 mg/m3 in air was reported by Ruth (1986). Toxicity: EC50 (48-h) for Daphnia magna 6.60 mg/L (Keen and Baillod, 1985), Daphnia pulex 25.0 mg/L (Tisler and Zagorc-Koncan, 1997). EC50 (24-h) for Daphnia magna 9.1 mg/L (Keen and Baillod, 1985). LC50 (8-d) for fathead minnows 22 to 23 mg/L (Spehar et al., 1982). LC50 (96-h) for fathead minnows 28 to 29 mg/L (Spehar et al., 1982), mud crab (Panopeus herbstii) 1.06 mg/L (Key and Scott, 1986), Japanese medaka (Oryzias latipes) 38.3 mg/L (Holcombe et al., 1995). LC50 (48-h) for fathead minnows 8.3 mg/L (Spehar et al., 1982), zebra fish 60 mg/L (Slooff, 1979), Daphnia magna 12 mg/L (LeBlanc, 1980). LC50 (24-h) for Daphnia magna 29 mg/L (LeBlanc, 1980). LC50 (inhalation) for mice 177 mg/m3 (quoted, RTECS, 1985). Acute oral LD50 for mice 270 mg/kg, rats 317 mg/kg (quoted, RTECS, 1985). TLm values for brine shrimp after 24 and 48 h of exposure were 157 and 56 mg/L, respectively (Price et al., 1974). Source: Detected in distilled water-soluble fractions of 87 octane unleaded gasoline (1.53 mg/L), 94 octane unleaded gasoline (0.19 mg/L), Gasohol (0.33 mg/L), No. 2 fuel oil (0.09 mg/L), jet fuel A (0.09 mg/L), diesel fuel (0.07 mg/L), and military jet fuel JP-4 (0.22 mg/L) (Potter, 1996). Phenol was also detected in 80% of 65 gasoline (unleaded regular and premium) samples (62 from Switzerland, 3 from Boston, MA). At 25 °C, phenol concentrations ranged from 63 to 130,000 µg/L in gasoline and from 150 to 1,500 µg/L in water-soluble fractions. Average concentrations were 26 mg/L in gasoline and 6.1 mg/L in water-soluble fractions (Schmidt et al., 2002). Thomas and Delfino (1991) equilibrated contaminant-free groundwater collected from Gainesville, FL with individual fractions of three individual petroleum products at 24-25 °C for 24 h. The aqueous phase was analyzed for organic compounds via U.S. EPA approved test method 625. Average phenol concentrations reported in water-soluble fractions of unleaded gasoline, kerosene, and diesel fuel were 20, 8, and 19 µg/L, respectively. A high-temperature coal tar contained phenol at an average concentration of 0.61 wt % (McNeil, 1983). Phenol occurs naturally in many plants including blueberries (10 to 60 ppb), marjoram (1,4318,204 ppm), sweetflag, safflower buds (40 ppb), mud plantain, capillary wormwood, asparagus

wort, European pennyroyal, tomatoes, white mulberries, tobacco leaves, benneseed, sesame seeds, tamarind, white sandlewood, patchouli leaves, rue, slash pine, bayberries, Scotch pine, and tarragon (Duke, 1992). A liquid swine manure sample collected from a waste storage basin contained phenol at a concentration of 22.0 mg/L (Zahn et al., 1997). Schauer et al. (2001) measured organic compound emission rates for volatile organic compounds, gas-phase semi-volatile organic compounds, and particle phase organic compounds from the residential (fireplace) combustion of pine, oak, and eucalyptus. The gas-phase emission rates of phenol were 525 mg/kg of pine burned, 300 mg/kg of oak burned, and 434 mg/kg of eucalyptus burned. Releases toxic and noxious fumes when heated at temperatures greater than its boiling point. Drinking water standard: No MCLGs or MCLs have been proposed, however, a DWEL of 20 mg/L was recommended (U.S. EPA, 2000). Uses: Antiseptic and disinfectant; pharmaceuticals; dyes; indicators; slimicide; phenolic resins; epoxy resins (bisphenol-A); nylon-6 (caprolactum); 2,4-D; solvent for refining lubricating oils; preparation of adipic acid, salicylic acid, phenolphthalein, pentachlorophenol, acetophenetidin, picric acid, anisole, phenoxyacetic acid, phenyl benzoate, 2-phenolsulfonic acid, 4-phenolsulfonic acid, 2-nitrophenol, 4-nitrophenol, 2,4,6-tribromophenol, 4-bromophenol, 4-tert-butylphenol, salicylaldehyde, and many other organic compounds; germicidal paints; laboratory reagent.