Preface ....................................................... xix
Acknowledgments ............................................. xxiii
Authors ....................................................... xxv
SECTION I Degradation and Transformation Processes
Chapter 1 Abiotic Reactions .................................... 3
Introduction .................................................... 3
Photochemical Reactions in Aqueous and Terrestrial
Environments ............................................ 3
The Diversity of Photochemical Transformations .................. 4
The Role of Hydroxyl Radicals ........................... 4
Illustrative Examples of Photochemical Transformations
in Aqueous Solutions ................................ 5
Hydroxyl Radicals in the Destruction of Contaminants ............ 9
Fenton's Reagent ........................................ 9
Polyoxometalates (Heteropolyacids) ..................... 10
Photolytic Degradation on TiO2 ......................... 10
Other Photochemically Induced Reactions ........................ 11
The Role of Humic Matter: Singlet Dioxygen ..................... 12
Interactions between Photochemical and Other Reactions ......... 13
Reactions in the Troposphere ................................... 14
Survey of Reactions .................................... 15
Survey of Reactants .................................... 17
Aliphatic Hydrocarbons ............................. 17
Aromatic Hydrocarbons .............................. 17
Biogenic Terpenes .................................. 17
Reentry of Tropospheric Transformation Products ................ 18
Halogenated Alkanes and Alkenes ........................ 18
Arenes and Nitroarenes ................................. 20
Alkylated Arenes ....................................... 21
Sulfides and Disulfides ................................ 21
Chemically Mediated Transformations ............................ 22
Hydrolysis ............................................. 22
Reductive Displacement: Dehalogenation and
Desulfurization .................................... 25
Reductive Dehalogenation ....................................... 25
Zero-Valent Metals ..................................... 25
Chromous Chloride ...................................... 26
Porphyrins and Corrins ................................. 26
Thiol Reductants ............................................... 27
Reductive Desulfurization ...................................... 28
Reductions Other than Dehalogenation ................... 28
Nucleophilic Reactions ................................. 29
Oxidations ............................................. 30
Anodic Oxidation ................................... 30
Ozone .............................................. 30
Hydrogen Peroxide .................................. 32
Manganese Dioxide .................................. 32
Sulfate Radicals ................................... 32
Halogenation ........................................... 32
Thermal Reactions ...................................... 34
Gas Phase .......................................... 34
In Water ........................................... 36
Electrocatalytic Reactions ............................. 37
References ..................................................... 38
Chapter 2 Biotic Reactions .................................... 51
Part 1 Microbial Reactions .................................... 51
Introduction ........................................... 51
Definitions—Degradation and Transformation ............. 51
Biodegradation of Enantiomers .......................... 54
Sequential Microbial and Chemical Reactions ............ 55
The Spectrum of Organisms .............................. 57
Bacteria in Their Natural Habitats ................. 57
Marine and Oligotrophic Bacteria ................... 58
Lithotrophic Bacteria .............................. 60
Phototrophic Organisms ............................. 61
Aerobic and Facultatively Anaerobic Bacteria ....... 62
Bacterial Metabolism of C1 Compounds: Methanotrophs,
Methylotrophs, and Related Organisms ............... 69
Methane Monooxygenase and Related Systems .......... 69
Anaerobic Bacteria ..................................... 72
Clostridia ......................................... 73
Anaerobic Sulfate-Reducing Bacteria ................ 73
Other Anaerobic Bacteria ........................... 73
Organisms from Extreme Environments .................... 74
Psychrophiles ...................................... 74
Thermophiles ....................................... 75
Alkaliphiles ....................................... 75
Halophiles ......................................... 75
Eukaryotic Microorganisms: Fungi and Yeasts ............ 75
Metabolism by Fungi ................................ 75
Metabolism by Yeasts ............................... 77
References ............................................. 78
Part 2 Reactions Mediated by Higher Organisms ................. 91
Introduction ........................................... 91
Metabolism by Fish ..................................... 93
Metabolism by Other Organisms .......................... 95
Mussels ............................................ 95
Insects ................................................ 96
Invertebrates .......................................... 96
Isopods ............................................ 97
Oligochaetes ....................................... 97
Polychaetes ........................................ 97
Higher Plants .......................................... 97
Other Organisms ........................................ 99
References ............................................ 100
Chapter 3 Mechanistic Aspects ................................ 103
Part 1 Introduction of Oxygen ................................ 103
Monooxygenation ....................................... 103
Hydroxylation of Alkanes .......................... 103
Epoxidation of Alkenes ............................ 104
Cycloalkanone Monooxygenases ...................... 105
Monooxygenation of Aromatic Compounds ............. 106
Reactions of Aromatic Hydrocarbons ................ 107
Reactions of Hydroxybenzoates and Related
Compounds ..................................... 108
Monooxygenation of Phenols ........................ 110
Cytochrome P450 Systems ............................... 113
Prokaryotic Organisms ............................. 114
Eukaryotic Organisms .............................. 116
Dioxygenation ......................................... 118
Dioxygenases Involved in Dihydroxylation of
Arenes ........................................ 118
Ring-Fission Dioxygenases ......................... 123
Incorporation of Oxygen from Water: Oxidoreductases
and Hydratases .................................... 129
Oxidoreductases ................................... 129
Hydratases ........................................ 130
Oxidases, Peroxidases, and Haloperoxidases ............ 131
Oxidases .......................................... 131
Peroxidases ....................................... 133
Haloperoxidases ................................... 134
References ............................................ 135
Part 2 Electron Acceptors Other than Oxygen .................. 147
Introduction .......................................... 147
Oxyanions: Nitrate, Sulfate, Chlorate, Selenate, and
Arsenate .......................................... 148
Nitrate and Related Compounds ..................... 148
Sulfate and Related Compounds ..................... 150
Chlorate and Perchlorate .......................... 150
Selenate and Arsenate ............................. 151
Metal Cations and Oxyanions ........................... 152
V(V), Mn(IV), Fe(III), Tc(VII), and U(VI) ......... 152
Humic Acid and Anthraquinone-2,6-Disulfonate in
Redox Systems ..................................... 154
Dehalorespiration ..................................... 156
Alkane Sulfonates as Terminal Electron Acceptors ...... 156
Nitroalkanes as Electron Acceptor ..................... 156
References ............................................ 157
Part 3 Reductases and Related Enzymes ........................ 162
Reduction of Nitroarenes .............................. 162
Nitrate Ester Reductase ............................... 162
Enones (α, β-Unsaturated Ketones) and Related
Reductases ........................................ 163
Aerobic Conditions ................................ 163
Anaerobic Conditions .............................. 163
Azo Reductase ......................................... 163
Aldehyde Oxidoreductases .............................. 164
F420-Dependent (Desazatetrahydrofolate) Reductases ..... 164
Other Carbocyclic Aromatic Compounds .................. 164
Reduction of Carbocyclic Rings .................... 164
Dehydroxylation ................................... 165
Reduction of Azaarene Rings ....................... 165
Metal Cations and Oxyanions ........................... 165
References ............................................ 166
Part 4 Microbial Reactions to Chemical Stress ................ 168
Introduction .......................................... 168
Hydrocarbon Tolerance ............................. 168
Antibiotic Resistance ............................. 170
Resistance to Metals and Metalloids ................... 172
Reduction ......................................... 172
Methylation ....................................... 173
Efflux Systems .................................... 175
Chlorophenol Tolerance ............................ 176
Resistance to High Acidity ........................ 176
References ............................................ 177
Part 5 Enzymes Containing Manganese, Iron, Nickel, Copper,
Molybdenum, Tungsten, and Vanadium .................... 181
Manganese ............................................. 181
Iron .................................................. 181
Nickel ................................................ 182
Copper ................................................ 184
Molybdenum ............................................ 185
Molybdopterin Oxidoreductases ..................... 185
Tungsten .............................................. 187
Vanadium .............................................. 188
References ............................................ 188
Chapter 4 Determinants and Interactions ...................... 193
Single Substrates: Several Organisms .......................... 193
Cometabolism and Related Phenomena ............................ 195
Induction of Catabolic Enzymes ................................ 195
Pre-Exposure to an Analog Substrate ................... 195
Enzyme Induction by Growth on Structurally Unrelated
Compounds ......................................... 197
Role of Readily Degraded Substrates ........................... 198
Physical Parameters ........................................... 200
Temperature ........................................... 200
Oxygen Concentration .................................. 201
Anaerobic Bacteria ................................ 202
Aerobic and Facultatively Anaerobic Organisms ..... 202
Redox Potential ....................................... 205
Association of Bacteria with Particulate Material: "Free"
and "Bound" Substrates ................................ 205
Biological Mechanisms for Association with Organic
Components of Soil and Sediment ................... 206
Aging ................................................. 208
Substrate Concentration, Transport into Cells, and Toxicity ... 210
Utilization of Low Substrate Concentrations ........... 211
Existence of Threshold Concentrations ................. 212
Strategies Used by Cells for Substrates with Low or
Negligible Water Solubility ....................... 213
Transport Mechanisms .................................. 214
Pre-Exposure: Pristine and Contaminated Environments .......... 215
Rates of Metabolic Reaction ................................... 218
Kinetic Aspects ....................................... 218
Metabolic Aspects: Nutrients .................................. 219
Regulation and Toxic Metabolites .............................. 220
Regulation ............................................ 220
Toxic or Inhibitory Metabolites ....................... 222
Catabolic Plasmids ............................................ 224
References .................................................... 227
SECTION II Experimental Procedures
Chapter 5 General Experimental Procedures .................... 245
Introduction .................................................. 245
Abiotic Reactions ..................................... 245
Microbial Reactions ................................... 246
Storage of Samples .................................... 247
Determination of Ready Biodegradability ............... 247
The Inoculum ...................................... 248
Concentration of the Substrate .................... 248
Endpoints ......................................... 248
Design of Experiments on Inherent Biodegradability .... 248
Metabolic Limitations ............................. 248
Application to Marine Systems ..................... 249
Isolation and Elective Enrichment ................. 249
General Procedures ................................ 250
Basal Media ....................................... 252
Mineral Media ..................................... 252
Trace Elements .................................... 253
Control of pH ..................................... 254
Vitamins .......................................... 254
Sterilization ..................................... 254
Metal Concentration in Metabolism ................. 254
Redox Potential of Media .......................... 256
Organic Substrates .................................... 256
Toxic Compounds ................................... 256
Volatile Compounds ................................ 257
Solid Media ........................................... 257
Growth at the Expense of Alternative Substrates ....... 258
Techniques for Anaerobic Bacteria ..................... 258
Design of Experiments on Biodegradation and
Biotransformation ................................. 259
Pure Cultures and Stable Consortia .................... 259
Cell Growth at the Expense of the Xenobiotic .......... 260
Stable Enrichment Cultures ............................ 260
Use of Dense Cell Suspensions ......................... 261
Use of Immobilized Cells .............................. 261
Application of Continuous Culture Procedures .......... 262
Simultaneous Presence of Two Substrates ............... 263
Use of Unenriched Cultures: Undefined Natural
Consortia ......................................... 264
Microcosm Experiments ................................. 264
Experiments in Models of Natural Aquatic Systems ...... 266
Evaluation of Degradation Using Metabolites ........... 267
Experimental Problems: Water Solubility, Volatility,
Sampling, and Association of the Substrate with
Microbial Cells ................................... 268
References .................................................... 269
Chapter 6 Elucidation of Metabolic Pathways .................. 277
Introduction .................................................. 277
Part 1 Application of Natural and Synthetic Isotopes ......... 277
Carbon (14C and 13C) ................................... 277
Sulfur (35S) and Chlorine (36Cl) ....................... 278
Hydrogen (2H) and Oxygen (18O) ......................... 278
Other Isotopes ........................................ 280
Isotope Effects and Stable Isotope Fractionation ...... 280
Experimental Procedures ........................... 282
References ............................................ 282
Part 2 Nondestructive Methods for Structure Determination .... 284
Application of NMR .................................... 284
Hydrogen 1H ....................................... 285
Carbon 13C ........................................ 285
Nitrogen 15N ...................................... 286
Oxygen 17O ........................................ 287
Fluorine 19F ...................................... 287
Phosphorus 31P .................................... 288
Silicon 29Si ...................................... 288
Application of EPR .................................... 288
Elucidation of the Unexpected Complexity of an
Apparently Straightforward Metabolic
Pathway ....................................... 289
Hydroxyl Radicals and Their Role in the Toxicity
of H2O2 to Bacteria ........................... 289
Elucidation of the Mechanism of Pyruvate Formate
Lyase ......................................... 289
The Function of Humic Acids in Reactions
Catalyzed by Geobacter metallireducens ........ 289
The Mechanism of Anaerobic Activation of
Toluene ....................................... 289
Dioxygenation with Elimination of Halide .......... 289
The Anaerobic Degradation of Benzoate ............. 290
Manganese-Containing Enzymes ...................... 290
Turnover of Naphthalene Dioxygenase ............... 290
Enzyme Structure ...................................... 290
References ............................................ 291
SECTION III Pathways and Mechanisms of
Degradation and Transformation
Chapter 7 Aliphatic Compounds ................................ 297
Part 1 Alkanes and Related Compounds ......................... 297
Alkanes ............................................... 297
Aerobic Conditions ................................ 297
Anaerobic Conditions .............................. 304
Alkenes ............................................... 305
Aerobic Conditions ................................ 305
Anaerobic Conditions .............................. 308
Alkynes ............................................... 308
Alkanols .............................................. 309
Aerobic Conditions ................................ 309
Anaerobic Conditions .............................. 310
Alkanones ............................................. 310
Alkylamines and Amino Acids ........................... 311
Aerobic Conditions ................................ 311
Anaerobic Conditions .............................. 316
Alkanoic Acids ........................................ 317
Aerobic Conditions ................................ 317
Anaerobic Conditions .............................. 318
Amides and Related Compounds .......................... 321
Amides ............................................ 321
Nitriles .............................................. 322
Isonitriles ........................................... 322
Sulfonylureas and Thiocarbamates ...................... 322
Carbon Monoxide ....................................... 323
Cyanide ............................................... 323
Thiocyanate ........................................... 324
References ............................................ 324
Part 2 Cycloalkanes .......................................... 336
Monoterpenes .......................................... 339
Steroids .............................................. 341
Hydroxylation ..................................... 341
Other Aerobic Transformations and Degradation ..... 341
Anaerobic Transformation .......................... 343
Diterpenoids .......................................... 344
Polycyclic Substrates ................................. 344
References ............................................ 346
Part 3 Alkanes, Cycloalkanes and Related Compounds with
Chlorine, Bromine, or Iodine Substituents ............. 349
Chlorinated, Brominated, and lodinated Alkanes,
Alkenes, and Alkanoates ........................... 349
Elimination Reactions ............................. 350
Corrinoid Pathways ................................ 355
Nucleophilic Substitution: Hydrolytic Reactions
of Halogenated Alkanes and Alkanoates ......... 358
Glutathione-Mediated and Other Reactions
Involving Nucleophilic Sulfur ................. 363
Monooxygenation ................................... 363
Reductive Reactions: Dehalogenation Including
Dehalorespiration ................................. 366
References ............................................ 370
Part 4 Fluorinated Aliphatic Compounds ....................... 378
Alkanes and Alkenes ................................... 378
Fluorohydrocarbons ................................ 378
Chlorofluorocarbons and
Hydrochlorofluorocarbons ...................... 379
Carboxylic Acids .................................. 380
Perfluoroalkyl Carboxylates and Sulfonates ........ 382
References ............................................ 382
Chapter 8 Carbocyclic Aromatic Compounds without Halogen
Substituents ....................................... 385
Part 1 Monocyclic Aromatic Hydrocarbons ...................... 385
Introduction .......................................... 385
Monocyclic Arenes ..................................... 385
Aerobic Conditions ................................ 385
Anaerobic Conditions .............................. 389
Synthetic Applications ............................ 392
References ............................................ 394
Part 2 Polycyclic Aromatic Hydrocarbons (PAHs) ............... 398
Introduction .......................................... 398
Aerobic Reactions Carried Out by Bacteria ......... 399
PAHs with Three or More Rings ..................... 402
Anaerobic Reactions Carried Out by Bacteria ....... 408
Fungal Transformations ............................ 409
White-Rot Fungi ................................... 413
References ............................................ 417
Part 3 Aromatic Carboxylates, Carboxaldehydes, and Related
Compounds ............................................. 424
Introduction .......................................... 424
Benzoates ............................................. 424
Aerobic Conditions ................................ 424
Hydroxybenzoates and Related Compounds ................ 425
Mechanisms for Fission of Oxygenated Rings ........ 428
Alternative Pathways for the Degradation of
Benzoates and Related Compounds ............... 432
Aerobic Reduction of Arene Carboxylates ............... 433
Arenes with an Oxygenated C2 or C3 Side Chain ......... 433
Anaerobic Metabolism .............................. 435
Aldehydes ............................................. 439
References ............................................ 439
Part 4 Nonhalogenated Phenols and Anilines ................... 446
Phenols ............................................... 446
Aerobic Degradation ............................... 446
Anaerobic Degradation ............................. 449
Anilines .......................................... 452
References ............................................ 452
Chapter 9 Substituted Carbocyclic Aromatic Compounds ......... 455
Part 1 Halogenated Arenes and Carboxylates with Chlorine,
Bromine, or Iodine Substituents ....................... 455
Introduction .......................................... 455
Halogenated Arene Hydrocarbons ........................ 455
Aerobic Conditions ................................ 455
Monocyclic Chlorinated Arenes ......................... 456
Anaerobic Conditions .............................. 458
Polychlorinated Biphenyls ............................. 458
Aerobic Degradation ............................... 458
Degradation Is Initiated by Dioxygenation ......... 459
Ring Fission by 2,3-Dihydroxybiphenyl
Dioxygenase ................................... 461
Metabolites ....................................... 463
Fungal Dehalogenation ................................. 465
Reductive Dehalogenation .............................. 465
The Role of Temperature ........................... 466
Polyhalogenated Dioxins and Diphenyl Ethers ....... 468
Halogenated Benzoates ................................. 468
Dioxygenation ..................................... 469
Hydrolytic Reactions .............................. 472
Mechanisms for the Ring Fission of Substituted
Catechols ......................................... 472
Reductive Loss of Halogen ......................... 474
Halogenated Phenylacetates ............................ 475
Fungal Reactions .................................. 476
References ............................................ 476
Part 2 Halogenated (Chlorine, Bromine, and Iodine) Phenols
and Anilines .......................................... 482
Phenols ............................................... 482
Aerobic Conditions ................................ 482
Fungi and Yeasts .................................. 486
Anaerobic Conditions .............................. 487
Anilines .............................................. 489
Aerobic Conditions ................................ 489
Anaerobic Conditions .............................. 490
References ............................................ 491
Part 3 Fluorinated Hydrocarbons, Carboxylates, Phenols, and
Anilines .............................................. 494
Fluorinated Aromatic Hydrocarbons ..................... 494
Aerobic Conditions ................................ 494
Metabolism by Yeasts and Fungi .................... 495
Anaerobic Denitrifying Conditions ................. 495
Fluorobenzoates ....................................... 496
Aerobic Conditions ................................ 496
Difluorobenzoates ................................. 498
Degradation under Denitrifying Conditions ......... 499
Fluorinated Phenols ................................... 500
Aerobic Conditions ................................ 500
Anaerobic Conditions .............................. 501
Aromatic Trifluoromethyl Compounds .................... 502
References ............................................ 503
Part 4 Arene Sulfonates ...................................... 506
References ............................................ 508
Part 5 Aromatic Compounds with Nitro Substituents ............ 508
Nitroarenes ........................................... 508
Reduction of Nitro Groups .......................... 509
Reduction of the Ring .............................. 512
Dioxygenation ...................................... 512
Side-Chain Oxidation ............................... 513
Peroxidase Oxidation ............................... 513
Nitrobenzoates ........................................ 514
Nitrophenols .......................................... 514
References ............................................ 517
Part 6 Azoarenes ............................................. 520
References ............................................ 521
Chapter 10 Heterocyclic Aromatic Compounds ................... 523
Part 1 Azaarenes ............................................. 523
Five-Membered Monocyclic Aza, Oxa, and Thiaarenes ..... 523
Aerobic Conditions ................................ 523
Indole and Carbazole .................................. 524
Indole and 3-Alkylindoles ......................... 524
Carbazole ......................................... 527
Pyridine .............................................. 527
Aerobic Conditions ................................ 527
Anaerobic Conditions .............................. 534
Quinoline and Isoquinoline ............................ 536
Bacterial Metabolism .............................. 536
Hydroxylation ..................................... 537
Dioxygenation ..................................... 537
Pyrimidine and Related Compounds Excluding Purines .... 540
Aerobic Conditions ................................ 540
Anaerobic Conditions .............................. 541
Purines ............................................... 542
Aerobic Degradation ............................... 542
Anaerobic Degradation ............................. 542
Ring-Fission Reactions ............................ 544
Triazines ............................................. 545
1,3,5-Triazines ................................... 545
1,2,4-Triazines ................................... 546
References ............................................ 546
Part 2 Oxaarenes ............................................. 553
Aerobic Conditions .................................... 553
Monocyclic Oxaarenes .............................. 553
Polycyclic Oxaarenes .............................. 553
References ............................................ 562
Part 3 Thiaarenes: Benzothiophenes, Dibenzothiophenes, and
Benzothiazole ......................................... 565
Benzothiazole ......................................... 567
References ............................................ 568
Chapter 11 Miscellaneous Compounds ........................... 569
Part 1 Carboxylate, Sulfate, Phosphate, and Nitrate Esters ... 569
Carboxylates .......................................... 569
Sulfates .............................................. 569
Phosphates ............................................ 570
Nitrates .............................................. 571
References ............................................ 572
Part 2 Ethers and Sulfides ................................... 573
Aliphatic and Benzylic Ethers ......................... 573
Aryl Ethers ........................................... 576
Diaryl Ethers ..................................... 576
Aryl-Alkyl Ethers ................................. 576
Sulfides, Disulfides, and Related Compounds ........... 578
References ............................................ 581
Part 3 Aliphatic Nitramines and Nitroalkanes ................. 585
Nitramines ............................................ 585
Nitroalkanes .......................................... 585
References ............................................ 586
Part 4 Aliphatic Phosphonates and Sulfonates ................. 588
Introduction .......................................... 588
Phosphonates .......................................... 588
Sulfonates ............................................ 589
Boronates ............................................. 591
References ............................................ 591
Part 5 Degradation of Organic Compounds of Metals and
Metalloids ............................................ 592
Tin ................................................... 593
Lead .................................................. 593
Mercury ............................................... 594
Arsenic ............................................... 594
References ............................................ 594
SECTION IV Bioremediation
Chapter 12 Bioremediation: Overview .......................... 599
Introduction .................................................. 599
Strategies ............................................ 599
Contaminants .......................................... 600
Sites ................................................. 602
Chemical Procedures ................................... 602
Phytoremediation .................................. 602
Primary Role of Plants ............................ 603
Secondary Role of Plants .......................... 605
Degradative Enzymes ............................... 606
The Role of Plant Exudates in Degradation ......... 607
Other Functions of Bacteria in the Rhizosphere .... 607
The Role of Mycorrhizal Fungi ..................... 609
Microbiological Aspects ....................................... 610
Regulation of Pathways ................................ 610
Alternative Electron Acceptors ........................ 611
Aging ................................................. 611
Biofilms .............................................. 611
Metabolites and Enzymes ............................... 611
Utilization of Nitrogen, Sulfur, and Phosphorus ....... 612
Substrate Concentration ............................... 612
Temperature ........................................... 613
References .................................................... 613
Chapter 13 Evaluation of Bioremediation ....................... 621
Introduction .................................................. 621
Analysis of Populations ....................................... 622
Analysis of Degradative Populations ................... 622
Application to the Degradation of Specific
Contaminants ...................................... 623
Hydrocarbons ...................................... 623
Trichloroethene ................................... 624
Phenol ............................................ 624
Chlorophenol ...................................... 625
Chlorobenzoate .................................... 625
Phenylurea Herbicides ............................. 625
Dehalogenation of Chloroalkanoates ................ 626
Dechlorination of PCBs ............................ 626
Application to Specific Groups of Organisms ........... 626
Nondirected Examination of Natural Populations ........ 627
Application of Stable Isotopes ................................ 627
Stable Isotope Probes ................................. 627
Application of Stable Isotope Enrichment .............. 628
Application of δ13C ............................... 629
References .................................................... 633
Chapter 14 Applications of Bioremediation ..................... 639
Introduction .................................................. 639
Part 1 Petroleum Hydrocarbons: Refinery Waste and Stranded
Oil ................................................... 639
Terrestrial Habitats .................................. 640
Alkanes ........................................... 640
Naphthenates ...................................... 641
Marine Habitats ....................................... 641
The Baffin Island Oil Spill Project ............... 641
Conclusion ............................................ 642
References ............................................ 642
Part 2 Coal Distillation Products ............................ 643
Introduction .......................................... 643
On-Site or Off-Site Treatment ......................... 644
The Physical State of the Contaminant ................. 646
Environmental Parameters .............................. 647
Determinants .......................................... 647
The Range of Substrates ........................... 647
The Range of Degradative Bacteria ................. 648
Bioavailability and the Use of Surfactants ........ 649
Supplementation with Fungi ............................ 650
Application of Higher Plants .......................... 652
Anoxic or Anaerobic Environments ...................... 652
Hydrocarbons ...................................... 652
Phenols ........................................... 652
Heteroarenes ...................................... 653
Abiotic Transformations ............................... 653
Conclusions ........................................... 654
References ............................................ 654
Part 3 Wood Preservation Sites: Chlorophenolic Compounds ..... 658
Aerobic Bacteria ...................................... 659
Degradation by Fungi .................................. 659
Anaerobic Dechlorination .............................. 660
Conclusion ............................................ 660
References ............................................ 660
Part 4 Chemical Waste ........................................ 661
Chlorinated Alicyclic Hydrocarbons .................... 662
Chlorinated and Brominated Aromatic Hydrocarbons ...... 662
Chlorobenzenes ........................................ 662
DDT ................................................... 663
Polychlorinated Biphenyls ............................. 663
Aerobic Conditions ................................ 664
Anaerobic Conditions .............................. 665
Polybrominated Biphenyls and Diphenyl Ethers .......... 666
Chlorinated Dibenzodioxins ............................ 666
Organofluoro Compounds ................................ 667
Conclusion ............................................ 668
References ............................................ 668
Part 5 Agrochemicals ......................................... 671
Phenoxyalkanoic Acids ................................. 672
Chlorinated Anilines .................................. 672
Triazines ............................................. 673
1,3,5-Triazines ................................... 673
1,2,4-Triazines ................................... 673
2,4-Dintro-6-sec-Butylphenol (Dinoseb) ............ 673
References ............................................ 674
Part 6 Military Waste ........................................ 675
Explosives ............................................ 675
Nitroarenes ........................................... 675
Nitrodiphenylamines ................................... 676
Nitrate Esters ........................................ 676
Nitramines ............................................ 676
Conclusions ........................................... 677
Chemical Warfare Agents ............................... 677
References ............................................ 677
Part 7 Groundwater Contamination ............................. 679
Benzene/Toluene/Ethylbenzene/Xylenes .................. 679
Aerobic Conditions ................................ 679
Anoxic or Anaerobic Conditions .................... 680
Halogenated Alkanes and Alkenes ....................... 682
Tetrachloromethane ................................ 682
Chloroethenes ..................................... 682
Aerobic Conditions ................................ 682
Application of Indigenous Bacteria ................ 683
Application of Exogenous Bacteria ................. 684
Anoxic and Anaerobic Conditions ................... 684
Application of Higher Plants ...................... 685
Conclusion ............................................ 686
Methyl tert-Butyl Ether ............................... 686
References ............................................ 687
Finale: A Hierarchical Strategy ............................... 690
I. Laboratory Experiments ........................... 690
II. Microcosm Experiments ............................ 691
III. Large-Scale Operations ........................... 691
Concluding Comments ........................................... 692
Index ......................................................... 693
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