Phsicochemical Treatment of Hazardous Wastes - Chapter 2 potx

2 Environmental Hazardous Wastes 2.1 Introduction As a result of worldwide urbanization and industrialization, numerous toxic and hazardous organic compounds have found their way into surface and ground waters, both of which are the source of drinking water. The disposal of over 40,000 organic chemicals used by various industries in the United States has resulted in a broad range of hazardous waste problems. The amount of industrial wastewater containing these recalcitrant pollutants is increasing significantly. Many of these chemicals are resistant to degradation and pose a potential health threat to the human population. In addition, many hazardous waste materials are recalcitrant, normally nonbiodegrad- able, and even toxic to microorganisms; therefore, physicochemical treatment techniques are better alternatives than biological treatment. Since 1970, one of the most widespread industrial practices has been the halogenation of organics, which produces organic solvents, pesticides, chlo- rofluorocarbons (CFCs), and polychlorinated biphenyls (PCBs). The haloge- nation of hydrocarbons yields compounds of lower flammability, higher density, higher viscosity, and improved solvent properties compared to non- halogenated solvents. For example, 46.5% of chlorine gas used in the United States was for the production of chlorinated organic compounds. Classified as derivatives of aliphatic hydrocarbons, halogenated solvents have been used extensively in a number of industrial processes, and over 400,000 tons of halogenated solvents are used annually for metal cleaning. Due to their higher density, high water solubility, and low degradability, chlorinated solvents are extremely mobile in groundwater. Chlorinated solvents are commonly used in the manufacturing of pesti- cides. Carbon tetrachloride is a commercial product widely used in the United States for dry cleaning, metal degreasing, and fire extinguishers. It is also used for the production of CFCs and grain fumigation. Methylene chloride is commonly used in paint stripping, for which it is mixed with alcohols, acids, and amines. Methylene chloride is also used in the extraction of caffeine from coffee and other beverages. As a result, chlorinated organic TX69272_C02.fm Page 23 Tuesday, November 11, 2003 11:34 AM © 2004 by CRC Press LLC 24 Physicochemical Treatment of Hazardous Wastes pollutants can still be found at most contaminated sites because of high resistance to biodegradation under natural environmental conditions. The most common nonhalogenated solvents are a group of petroleum distillates, aliphatic and aromatic hydrocarbons, alcohols, ketones, esters, and ethers. Nonhalogenated solvents have a number of industrial uses, such as cold cleaning, which includes metal degreasing, parts cleaning, and paint stripping. They have also been used as carriers for paints, varnishes, and printing inks. Prior to the RCRA, waste solvents were disposed of in landfills, sewers, and soil pits. After the Resource Conservation and Recovery Act (RCRA), they had to be disposed of through solvent recycling, fuel blending, and incineration. Hydrocarbons such as benzene, toluene, xylenes, and a number of alkylbenzenes and low-molecular-weight ketones are important classes of nonhalogenated solvents. Ketones consist of R and R ¢ alkyl groups linked to a keto or carbonyl group. Other miscellaneous nonhalogenated solvents include glycols, such as ethylene glycol and propylene glycol; ethers, such as dimethyl ethers; and amines, such as isopropylamine. 2.2 Classification of Hazardous Pollutants In general, hazardous wastes are classified as organics, heavy metals, and radioactive. Organic pollutants are further classified as halogenated/nonh- alogenated volatile organic compounds (VOCs) and halogenated/nonhalo- genated semivolatile organic compounds (SVOCs). These classifications help facilitate the selection of remediation technologies according to the treatabil- ity of each class in a specific contaminated media: • Halogenated volatile organic compounds (HVOCs) — Halogenated organic compounds contain molecules of chlorine, fluorine, bro- mine, and/or iodine. The nature of the halogen bond and the halo- gen itself can significantly affect the performance of a specific treatment technology. HVOCs are difficult to treat. • Halogenated semivolatile organic compounds (SVOCs) — Halogenated SVOCs may also contain molecules of chlorine, bromine, iodine, and/or fluorine. The degree of volatilization from halogenated SVOCs is much less than for HVOCs. The most common types of halogenated SVOCs include polychlorinated biphenyl (PCBs), pen- tachlorophenol (PCP), and hexachlorobenzene. • Nonhalogenated volatile organic compounds (nonhalogenated VOCs) — Nonhalogenated compounds do not have a halogen attached to them. Common types of nonhalogenated VOCs include acetone, styrene, and methanol. TX69272_C02.fm Page 24 Tuesday, November 11, 2003 11:34 AM © 2004 by CRC Press LLC Environmental Hazardous Wastes 25 • Nonhalogenated semivolatile organic compounds (nonhalogenated SVOCs) — Nonhalogenated SVOCs do not contain halogens. The degree of volatilization from nonhalogenated SVOCs is much less than for nonhalogenated VOCs. The most common types of nonhalogenated SVOCs include pyrene, fluorene, and dibenzofuran. Each class of the aforementioned organic pollutants may include hundreds of substituted compounds. For example, chlorinated benzenes may include one hexachlorobenzene, a pentachlorobenzene, three dichlorobenzenes, and three trichlorobenzenes. Table 2.1 lists 100 priority pollutants classified by the USEPA. Halogenated and nonhalogenated VOCs are found in many products such as gasoline, paints, paint thinners, and solvents that are used for dry cleaning and metal degreasing. Furthermore, halogenated and nonhalogenated SVOCs also have the same properties and behaviors as VOCs. These com- pounds are typically used in liquid form and readily evaporate. They may cause adverse effects on the environment and human health through con- taminated soil and/or groundwater. Table 2.2 lists the hydrophobic and electronic properties of substituents. The most common substituents include a wide variety of electron-withdraw- ing substituents, such as –F, –Cl, –Br, –I, –NO 2 , –SO 3 H, –CN, and –COOH, and electron-donating substituents, such as –CH 3 , –C 2 H 5 , –NH 2 , –OH, and –OCH 3 . These substituents may form thousands of halogenated/nonhalo- genated VOCs and SVOCs or non-VOCs. 2.3 Sources of Hazardous Waste According to Toxic Release Inventory (TRI) reports, a total of 2.58 billion pounds of releases occurred in 1997, with two industries reporting more than half of that total. The chemical manufacturing industry was responsible for 797.5 million pounds of the total releases, and the primary metal industry reported a use of 694.7 million pounds. These amounts represented 30.9% and 27.0% the TRI, as illustrated in Figure 2.1. The chemical manufacturing industry ranked as the number one source of hazardous waste, with 742.6 million pounds of on-site releases, 342.2 million pounds of air emissions, 106 million pounds of surface water dis- charges, and 215.8 million pounds of underground injection. The chemicals accounting for the largest amounts of underground injection by chemical manufacturing facilities were nitrate (40.6 million pounds) and ammonia (29.0 million pounds) compounds. The primary metal industry ranked sec- ond, with on-site releases of 405.9 million pounds. The paper product sector ranked third, with on-site releases of 228.8 million pounds, consisting mostly of air emissions of 193.8 million pounds. TX69272_C02.fm Page 25 Tuesday, November 11, 2003 11:34 AM © 2004 by CRC Press LLC 26 Physicochemical Treatment of Hazardous Wastes TABLE 2.1 USEPA Priority Pollutants 1. Acenaphthlene Dichloropropane and dichloropropylene Phthalate Esters 2. Acrolein 32. 1,2-Dichloropropane 66. bis (2-Ethylhexyl) phthalate 3. Acrylonitriline 33. 1,2-Dichloropropylene (1,3-dichloropropene) 67. Butyl benzyl phthalate 4. Benzene 34. 2,4-Dimethylphenol 68. Di- n -butyl phthalate 5. Benzidine Dinitrotoluene 69. Di- n -octyl phthalate 6. Carbon tetrachloride 35. 2,4-Dinitrotoluene 70. Diethyl phthalate Chlorinated benzenes (other than dichlorobenzenes) 36. 2,6-Dinitrotoluene 71. Dimethyl phthalate 7. Chlorobenzene 37. 1,2-Diphenylhydrazine Polynuclear aromatic hydrocarbons 8. 1,2,4-Trichlorobenzene 38. Ethylbenzene 72. Benzo[ a ]anthracene 9. Hexachlorobenzene 39. Fluoranthene 73. Benzo[ a ]pyrene Chlorinated ethanes Haloethers (others than those listed elsewhere) 74. 3,4-Benzofluoranthene 10. 1,2-Dichloroethane 40. 4-Chlorophenyl phenyl ether 75.Benz[ k ]fluoranthane 11. 1,1,1-Trichloroethane 41. 4-Bromophenyl phenyl ether 76.Chrysene 12. Hexachloroethane 42. bis (2-Chloroisopropyl) ether 77. Acenaphthylene 13. 1,1-Dichloroethane 43. bis (2-Chloroethoxy) methane 78. Anthracene 14. 1,1,2-Trichloroethane Halomethanes (others than those listed elsewhere) 79. Benzo[ g , h , i ]perylene 15. 1,1,2,2-Tetrachloroethane 44. Methylene chloride 80. Fluorene 16. Chloroethane 45. Methyl chloride 81. Phenanthrene Chloroalkyl ethers 46. Methyl bromide 82. Dibenzo[ a , h ]anthracene 17. bis (Chloroethyl)ether 47. Bromoform 83. Indeno[1,2,3- c , d ]pyrene 18. bis (2-Chloroethyl) ether 48. Dichlorobromomethane 84. Pyrene 19. 2-Chloroethyl vinyl ether 49. Trichlorofluoromethane 85. Tetrachloroethylene Chlorinated naphthalene 50. Dichlorodifluoromethane 86. Toluene 20.2-Chloronaphthalene 51. Chlorodibromomethane 87. Trichloroethylene Chlorinated phenols 52. Hexachlorobutadiene 88. Vinyl chloride 21.2,4,6-Trichlorophenol 53.Hexachlor ocyclopentadiene Pesticides and metabolites 22. p -Chloro- m -cresol 54. Isophorone 89. Aldrin 23. Chloroform (trichloromethane) 55. Naphthalene 90. Dieldrin 24. 2-Chlorophenol 56. Nitrobenzene 91. Chlordane Dichlorobenzenes Nitrophenols 92. 4,4 ¢ -DDT TX69272_C02.fm Page 26 Tuesday, November 11, 2003 11:34 AM © 2004 by CRC Press LLC © 2004 by CRC Press LLC Environmental Hazardous Wastes 27 25. 1,2-Dichlorobenzene 57. 2-Nitrophenol 93. 4,4 ¢ -DDE 26. 1,3-Dichlorobenzene 58. 4-Nitrophenol 94. 4,4 ¢ -DDD 27. 1,4-Dichlorobenzene 59. 2,4-Dinitrophenol Endosulfan and Metabolites Dicholorobenzidine 60. 4,6-Dinitro- o -cresol 95. a -Endosulfan 28. 3,3-Dichlorobenzidine Nitrosamines 96. b -Endosulfan Dichloroethylenes 61. N -Nitrosodimethylamine 97. Endosulfan sulfate 29. 1,1-Dichloroethylene 62. N -Nitrosodiphenylamine Endosulfan and Metabolites 30. 1,2- trans -Dichloroethylene 63. N -Nitrosodi- n -propyl-amine 98. Endrin 31. 2,4-Dichlorophenol 64. Pentachlorophenol 99. Endrin aldehyde 65. Phenol Heptachlor and metabolites 100. Heptachlor 101. Heptachlor epoxide 100. Heptachlor TX69272_C02.fm Page 27 Tuesday, November 11, 2003 11:34 AM © 2004 by CRC Press LLC © 2004 by CRC Press LLC 28 Physicochemical Treatment of Hazardous Wastes TABLE 2.2 Hydrophobic and Electronic Properties of Substituents Electron Withdrawing Log P s m s p FR Electron Donating Log P s m s p FR Br 2.34 0.4 0.2 0.44 –0.17 NH 2 0.04 –0.2 –0.7 0.02 –0.68 Cl 2.35 0.4 0.2 0.41 –0.15 OH 0.59 0.12 –0.4 0.29 –0.64 F 1.62 0.3 0.1 0.43 –0.34 OCH 3 1.34 0.12 –0.3 0.26 –0.51 I 2.60 0.4 0.2 0.40 –0.19 CH 3 1.94 –0.1 –0.2 –0.04 –0.13 NO 2 1.91 0.7 0.8 0.67 0.16 N(CH 3 ) 2 1.66 –0.15 –0.83 0.1 –0.92 COC 6 H 5 3.07 0.34 0.43 0.30 0.16 C 6 H 5 3.20 0.06 –0.01 0.08 –0.08 COOH 1.58 0.4 0.5 0.33 0.15 OC 6 H 5 3.5 0.25 –0.03 0.34 –0.35 CN 1.60 0.6 0.7 0.51 0.19 CH 2 OH 0.25 0.00 0.00 0.00 0.00 CH 2 Cl 1.66 0.11 0.12 0.10 0.03 C 2 H 5 2.50 –0.1 –0.2 –0.05 –0.10 CHO 1.35 0.4 0.4 0.31 0.13 NHC 2 H 5 1.56 –0.24 –0.61 –0.11 –0.51 COCH 3 1.35 0.4 0.5 0.32 0.20 NHCH 3 1.01 –0.30 –0.84 –0.11 –0.74 CF 3 2.36 0.43 0.54 0.38 0.19 OC 2 H 5 1.86 0.10 –0.24 0.22 –0.44 SCN — 0.4 0.5 0.36 0.19 C 3 H 7 2.13 –0.07 –0.13 –0.06 –0.08 CONH 2 –0.01 0.28 0.36 0.24 0.14 C(CH 3 ) 3 3.56 –0.10 –0.20 –0.07 –0.13 CO 2 CH 3 1.47 0.37 0.45 0.33 0.15 NHC 6 H 5 2.85 –0.12 –0.40 –0.02 –0.38 N(CH 3 ) 3 4.48 0.88 0.82 0.89 0 OC 3 H 7 2.53 0.10 –0.25 0.22 –0.45 H 1.48 0 0 0 0 H 1.48 0 0 0 0 Note: Log P is the partition coefficient; s m and s p are Hammett sigma constants at the meta and para positions, respectively; F and R are polar and resonance constants, respectively, proposed by Swain and Lupton (1968). TX69272_C02.fm Page 28 Tuesday, November 11, 2003 11:34 AM © 2004 by CRC Press LLC © 2004 by CRC Press LLC Environmental Hazardous Wastes 29 The five different pathways for the release of chemical waste products in the environment are: • Fugitive air refers to the release of chemicals into the air from on-site equipment leaks, evaporative losses from surface impoundments and spills, and building ventilation systems. • Stack air refers to the release of chemicals into the air through on- site stacks, vents, ducts, pipes, or any confined air stream. • Water refers to the release of chemicals into rivers, lakes, streams, oceans, and other bodies of surface water from all discharge points at the facility. This category includes the release from on-site waste- water treatment systems, open trenches, and stormwater runoff. • Underground refers to underground releases and is defined as the injection of fluids into on-site subsurface wells for the purpose of waste disposal. • Land refers to the release of chemicals onto the land. Land releases include landfills, land treatment, and surface impoundment. Prior to establishment of the RCRA in 1976, most disposals occurred through methods that were considered easiest for maintenance and indus- trial personnel. As a result, organic pollutants found their way into the environment through different pathways. For example, liquid wastes con- taining lubricating oils and other petroleum residues were commonly dis- carded onto soil and unpaved roads by soil spreading. Substances such as gasoline, heating oil, and jet fuels leak out of rusted and corroded under- ground storage tanks (USTs). Based on a 1991 survey covering 1.6 million active and closed tanks, gasoline and diesel tanks represented 62 and 20%, respectively, of the total USTs, respectively. The distribution of USTs has probably changed somewhat, as approximately 600,000 tanks have been sealed between 1991 to 1995. The substances stored in RCRA-regulated tanks are shown in Figure 2.2. Because gasoline and diesel fuels account for the majority of the USTs, these substances pose the greatest threat to ground- water due to leakage of the tanks. FIGURE 2.1 TRI on-site releases. All Other 20% Transportation 4% Plastic 4% Multiple Code 5% Paper 9% Primary Metals 27% Chemicals 31% TX69272_C02.fm Page 29 Tuesday, November 11, 2003 11:34 AM © 2004 by CRC Press LLC 30 Physicochemical Treatment of Hazardous Wastes Before 1976, waste was usually poured into surface storage areas such as pits, ponds, and lagoons. The waste then disappeared by seeping through the soil in the pits. At sanitary landfills, which were designed to accept newspapers, cans, bottles, and other household waste, liquid hazardous wastes were often disposed of in drums and, in some cases, poured directly into the landfills, and the waste often migrated to surface and ground waters. Drum storage areas, where waste chemicals were stored in 55-gallon drums, were often located on loading docks, concrete pads, or at other temporary storage areas until the wastes could be disposed of. The drums that were stored in this manner eventually corroded and leaked, causing chemical releases that seeped into the underlying soil and groundwater. Uncontrolled incineration, in which hazardous waste such as chlorophenols and PCBs combusted, has sometimes resulted in incomplete combustion, formation of more toxic products in the ash, and emission of hazardous air pollutants. Typical sources of contamination from the contaminated sites of the Depart- ment of Defense (DOD) are shown in Figure 2.3. The most prevalent contam- inants in groundwater are VOCs and metals, which appear in 74 and 59% of the DOD groundwater sites, respectively. SVOCs and metals were more con- sistent across different media than were VOCs. SVOCs were found in 31 to 43% of the sites, and metals were found in 59 to 80% of the sites. Fuels were found at fewer than 22% of all sites, a figure that may reflect the reporting of BTEX (benzene, toluene, ethylbenzene, and xylene) constituents of fuels and petro- leum under VOCs. Figure 2.3 also shows the major contaminant groups by media and DOD component. The most frequently occurring group, metals, is found at 69% of all sites, followed by VOCs at 65% and SVOCs at 43%. VOCs and metals are found at most sites of all branches of the service, except at Army sites, where VOCs account for only 41% of the sites. FIGURE 2.2 Distribution of underground storage tanks. (From USEPA, National Survey of Underground Stor- age Tanks , U.S. Environmental Agency, Office of Underground Storage Tanks, Washington, D.C., Spring, 1991. Hazardous Material 2% Other 5% Empty 2% Heating 3% Kerosene 3% Diesel Fuel 20% Used Oil 3% Gasoline 62% TX69272_C02.fm Page 30 Tuesday, November 11, 2003 11:34 AM © 2004 by CRC Press LLC Environmental Hazardous Wastes 31 2.4 Contaminated Media of Hazardous Wastes Because hazardous wastes have different physicochemical properties (vapor pressure and solubility), contaminated media may contain incon- sistently distributed pollutants. The distribution depends on environmen- tal conditions and is a function of the properties of the chemical. In general, contaminated media are classified as: (1) soil, (2) air, (3) sludge and sedi- ments, and (4) groundwater, and each type may contain pollutants in different phases: • Gaseous phase — Contaminants are present as vapors in saturated zones. • Solid phase — Contaminants in liquid form are adsorbed in soil particles in both saturated and unsaturated zones. • Aqueous phase — Contaminants are dissolved into pore water accord- ing to their solubility in both saturated and unsaturated zones. • Immiscible phase — Contaminants are present as nonaqueous-phase liquids (NAPLs), primarily in unsaturated zones. Quantitative distributions of organic pollutants in different phases largely depend on their physical properties: the solubility constants in water (K ow ) and soil (K oc ) and Henry’s constant. Figure 2.4 illustrates their distribution in these phases. FIGURE 2.3 Source of contamination at different DOD sites. (From DOD, Restoration Management Information System , Department of Defense, Washington, D.C., November, 1995.) Site Type Percent of sites TX69272_C02.fm Page 31 Tuesday, November 11, 2003 11:34 AM © 2004 by CRC Press LLC 32 Physicochemical Treatment of Hazardous Wastes 2.4.1 Groundwater Groundwater can be contaminated with water-soluble substances found in overlying soil. BTEX and fuel oxygenates, such as methyltertiary butyl ether (MTBE), can leak from USTs and contaminate groundwater (Suidan et al., 2002). These organic chemicals are known to be carcinogenic in nature and pose a great threat to human health, specifically to the 53% of the U.S. population who depend on groundwater as their drinking water resource. Concentrations of organic pollutants in groundwater largely depend upon their solubility in water. Water solubility is the maximal concentration of a compound that can be dissolved in water at a given temperature. The dis- solution of an organic compound into water mainly depends upon both the structure and size of an organic pollutant, and three factors are involved: Van der Waals forces, hydrogen bonding, and dipole–dipole interactions. Because water is a highly polar solvent, polar organic pollutants tend to have higher water solubility. In addition, substituents will also affect the solubility of a given class of organic compounds: • The presence of substituents such as hydroxyl (–OH) and amino (–NH 2 ) will increase the solubility of a compound due to hydrogen bonding. • Because halogens increase molecular volume, the more halogens a molecule contains, the lower the water solubility. • Due to the higher polar characteristics of nonsubstituted hydrocar- bons and less hydrogen bonding, organic acids, amines, alcohols, ethers, and ketones have higher solubilities than their corresponding hydrocarbons. • As the number of carbons increases in any given organic class, the solubility decreases due to high polarity. FIGURE 2.4 Schematic of contamination phases of NAPL in soil. TX69272_C02.fm Page 32 Tuesday, November 11, 2003 11:34 AM © 2004 by CRC Press LLC [...]... Malathion 2. 84 Parathion 3.43 Herbicides Atrazine 2. 68 2, 4-D 2. 94 2, 4,5-T 3.40 Trifluralin 5.31 © 20 04 by CRC Press LLC Range — — — — — — 1.95 2. 15 2. 21 2. 79 3.05–3.15 2. 77–3.13 — 3.15–3.18 — 5.90–5.91 — 5.60–5.91 — 3.01–4.70 — — — — 0 .26 –0 .29 — — 1.90–1.97 1 .25 –1.30 2. 53 2. 88 2. 18 2. 47 2. 29 2. 42 — 2. 31 2. 56 — 5.76–6.36 4.56–5.34 5.45–6.18 3.66–3.85 — 2. 15–3.93 — 1.57–4.88 — 5 .28 –5.01 continued TX6 927 2_C 02. fm... PCB 123 2 PCB 124 8 PCB 125 4 PCB 126 0 Chlorinated dioxins 2, 3,7,8-Tetrachlorodibenzop-dioxin Mean Water Solubility (mg/L) at 25 °C 33.0 697 27 3 1.0 14.0 at 20 ˚C 460 9750 4160 3 1.80 77,900 800 14,000 at 20 ˚C 130 at 20 ˚C Range — 522 –890 26 8 27 8 — — 29 5–503 4500–15,000 4000–4 320 — — 67,000–84,700 — — — 0. 42 1.45 0.036 0.011 0.0 027 — — 0.017–0.054 0.010–0.0 12 — 0.000 32 — Source: Watts, R.J., Hazardous Wastes: ... 57 24 .0 Range 58.4–66.5 — 0.56 2. 46 0. 020 –0. 022 2. 24–3.57 0.431–3.37 1740–1800 1 52 20 8 146–173 171 29 7 156 21 4 515– 627 0.045–0.073 0.0094–0.014 — 0.0018–0.006 1.69–1.98 30.0–34.4 0.994–1 .29 0.1 32 0.135 — — — — 757–1160 7100–9300 16,700–19,400 150–400 — 1100–1470 — 70–83 0.195–0 .20 0 0.00 12 0. 020 — 6.80–7.80 — — — continued TX6 927 2_C 02. fm Page 35 Tuesday, November 11, 20 03 11:34 AM Environmental Hazardous. .. Polychlorinated biphenyls Aroclor 1016 Aroclor 123 2 Aroclor 124 8 Aroclor 125 4 Aroclor 126 0 Chlorinated dioxins 2, 3,7,8-Tetrachlorodibenzo Mean Log Kow Range 4.41 3.81–5.01 2. 84 3.08 1.70 9.54 4. 52 1.47 3 .24 2. 71 2. 98 — 1.47 2. 00 9 .20 –9.87 4.00–5.04 1.46–1.48 1.69 2. 25 — 5.58 3.87 6.11 6.31 6.91 1.34 2. 03 — — — 3 .20 –4.54 — — — 5.77 5.38–6.15 Source: Watts, R.J., Hazardous Wastes: Sources, Pathways, Receptors,... Hazardous Wastes 43 TABLE 2. 6 (CONTINUED) Vapor Pressure and Henry’s Law Constants for Common Hazardous Chemicals Compound Diethyl phthalate Di-n-octyl phthalate Hexachlorocyclopentadiene p-Nitrophenol Phenol 1 ,2, 4-Trichlorobenzene 2, 4,6-Trichlorophenol Polychlorinated biphenyls Aroclor 1016 Aroclor 122 1 Aroclor 123 2 Aroclor 124 8 Aroclor 126 0 Chlorinated dioxins 2, 3,7,8-Tetrachlorodibenzop-dioxin (TCDD)... at 20 °C 0.05 at 70°C 1.4 ¥ 10–4 at 25 °C 0.081 at 25 °C 1 ¥ 10–4 0 .2 0 .29 at 25 °C 0.017 at 25 °C Henry’s Law Constant (atm-m3/mol) at 25 °C 8.46 ¥ 10–7 1.41 ¥ 10– 12 0.016 3 ¥ 10–5 at 20 °C 3.97 ¥ 10–7 2. 32 ¥ 10–3 9.07 ¥ 10–8 4 ¥ 10–4 6.7 ¥ 10–3 4.60 ¥ 10–3 4.9 ¥ 10–4 at 25 °C 4.1 ¥ 10–5 3.3 ¥ 10–4 3 .24 ¥ 10–4 8.64 ¥ 10–4 3.5 ¥ 10–3 7.1 ¥ 10–3 6.4 ¥ 10–10 5.40 ¥ 10 23 at 18 – 22 °C Source: Watts, R.J., Hazardous. .. CRC Press LLC TX6 927 2_C 02. fm Page 34 Tuesday, November 11, 20 03 11:34 AM 34 Physicochemical Treatment of Hazardous Wastes TABLE 2. 3 Water Solubilities of Common Hazardous Compounds Compound Mean Water Solubility (mg/L) at 25 °C Aliphatic hydrocarbons Cyclohexane Cyclohexene Isooctane n-Decane n-Heptane n-Octane Monocyclic aromatic hydrocarbons Benzene Ethylbenzene m-Xylene o-Xylene p-Xylene Toluene Polycyclic... 10–6 7 .26 ¥ 10 20 2. 1 ¥ 10–4 4.6 ¥ 10–4 2. 56 ¥ 10–4 1.87 ¥ 10–5 0.03 02 3 .2 ¥ 10–3 0.0067 2. 5 ¥ 10–3 2. 69 ¥ 10–3 0.0153 0.018 9.1 ¥ 10–3 1.4 ¥ 10–6 5 .20 ¥ 10–5 5.8 ¥ 10–5 4.3 ¥ 10–4 5.0 ¥ 10–7 1.7 ¥ 10–3 3 .25 ¥ 10–6 1.95 ¥ 10 2 at 20 °C 3.4 ¥ 10–6 1.1 ¥ 10–4 3.7 ¥ 10–3 8 .28 ¥ 10–6 6.3 ¥ 10–5 1.9 ¥ 10–3 3.60 ¥ 10–3 continued TX6 927 2_C 02. fm Page 43 Tuesday, November 11, 20 03 11:34 AM Environmental Hazardous. .. EPA-5 4 2- C-9 6-0 02, U.S Environmental Protection Agency, Of ce of Solid Waste and Emergency Response, Technology Innovation Of ce, Washington, D.C., January, 1997a USEPA, Clean Up the Nation’s Waste Sites: 1996, EPA 5 4 2- R-9 6-0 05, U.S Environmental Protection Agency, Of ce of Solid Waste and Emergency Response, Technology Innovation Of ce, Washington, D.C., April 1997b USEPA, Hazardous waste clean-up... Wastes 35 TABLE 2. 3 (CONTINUED) Water Solubilities of Common Hazardous Compounds Compound Herbicides Atrazine 2, 4-D 2, 4,5-T Trifluralin Fungicides Pentachlorophenol Industrial intermediates Chlorobenzene 2, 4-Dichlorophenol Dimethyl phthalate D-n-octyl phthalate Hexachlorocyclopentadiene Phenol 2, 4,6-Trichlorophenol Explosives Picric acid 24 ,6-Trinitrotoluene Polychlorinated biphenyls PCB 1016 PCB 123 2 . tetrachloride 2. 73 — Chloroform 1.94 1.90–1.97 Methylene chloride 1 .28 1 .25 –1.30 Perchloroethylene 2. 79 2. 53 2. 88 1,1,1-Trichloroethane 2. 33 2. 18 2. 47 Trichloroethylene 2. 33 2. 29 2. 42 Insecticides Aldrin. Nitrophenols 92. 4,4 ¢ -DDT TX6 927 2_C 02. fm Page 26 Tuesday, November 11, 20 03 11:34 AM © 20 04 by CRC Press LLC © 20 04 by CRC Press LLC Environmental Hazardous Wastes 27 25 . 1 , 2- Dichlorobenzene. (mg/L) at 25 °C Range Aliphatic hydrocarbons Cyclohexane 59.3 58.4–66.5 Cyclohexene 21 3 — Isooctane 1 .25 0.56 2. 46 n -Decane 0. 021 0. 020 –0. 022 n -Heptane 2. 91 2. 24–3.57 n -Octane 1.39