IMPACT OF IN SITU CHEMICAL OXIDATION ON SOIL HYDRAULIC CONDUCTIVITY.... IMPACT OF IN SITU CHEMICAL OXIDATION ON SOIL ADSORPTION PROPERTIES.... RAW DATA FOR IMPACT OF ISCO ON SOIL HYDRAUL
Trang 1ELUCIDATION OF KEY INTERACTIONS BETWEEN IN SITU CHEMICAL
OXIDATION REAGENTS AND SOIL SYSTEMS
By John Michael Harden
A Dissertation Submitted to the Faculty of Mississippi State University
in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy
in Chemical Engineering
in the Dave C Swalm School of Chemical Engineering
Mississippi State, Mississippi
May 2006
Trang 23238927 2007
Harden, John Michael
UMI Microform Copyright
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ProQuest Information and Learning Company
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by ProQuest Information and Learning Company
Trang 3Copyright by John Michael Harden
2006
Trang 4Approved:
_ _
(Director of Dissertation and Advisor)
_
(Committee Member)
_ _
Professor and Director of Associate Dean of Research and
Chemical Engineering
(Committee Member)
Trang 5Title of Study: ELUCIDATION OF KEY INTERACTIONS BETWEEN IN SITU
CHEMICAL OXIDATION REAGENTS AND SOIL SYSTEMS Pages in Study: 486
Candidate for Degree of Doctor of Philosophy
Many soil and aquifer systems in the United States have been subjected to chemical contamination from past industrial and military activities While many
remediation technologies are currently being applied, in situ chemical oxidation
(ISCO) is one option that is often favored because of its potential for fast remediation times and high user control This technology involves the direct injection of chemical oxidizers (e.g hydrogen peroxide, ozone, or permanganate) into targeted contaminant zones within the subsurface, and it has been proven to be amenable to both BTEX compounds and other volatile organic compounds such as chlorinated solvents
This study had several key objectives Firstly, multiple soil samples, each containing an elevated level of a targeted chemical constituent, were successfully collected in order to provide a wide range of soil types in order to make important
Trang 6populations, soil hydraulic conductivity, soil natural organic matter constituents, and soil adsorptive properties were all shown to be impacted following the application of chemical oxidizers.
Trang 7ii would never have been possible without the support of my parents, Michael and Sharon; my sister, Rebecca; my grandparents, Nana, Papa, Mamoo, and Papa J; my great-grandmother, Moms; and three of my closest friends, Danny Chapman, Marilyn Lauderdale, and Jeremy Lokits, each of whom will forever be considered “family.” Everything that I have and will accomplish in life is because of their Christian love and support.
Trang 8iii Professor, Dean of Engineering, University of Louisiana at Lafayette; Dr Rafael Hernandez, Assistant Professor, Dave C Swalm School of Chemical Engineering, Mississippi State University; Dr Kirk Schulz, Dean of Engineering, James Worth Bagley College of Engineering, Mississippi State University; Dr Clifford George, Professor, Dave C Swalm School of Chemical Engineering, Mississippi State
University; Dr William Kingery, Professor, Department of Plant & Soil Sciences, Mississippi State University The author would like to extend additional thanks to
Dr W Todd French, Assistant Research Professor, Dave C Swalm School of
Chemical Engineering, for his scientific and professional guidance Additional thanks is due to employees of the Environmental Research and Development Center, most notably, Dr Beth Fleming, Denise MacMillan, and Scott Waisner The Author also greatly appreciates the laboratory assistance provided by numerous
undergraduate researchers who have supported this project Finally, the author would like to thank the Strategic Environmental Research and Development Program for their financial assistance in supporting this effort
Trang 9iv
ACKNOWLEDGMENTS iii
LIST OF TABLES xi
LIST OF FIGURES xxv
CHAPTER I INTRODUCTION 1
Technology Overview 2
Chemical Oxidizer Transport 2
Chemical Oxidation Processes 3
Chemical Oxidizer Types 4
Pollutants Amenable to Treatment via ISCO 7
Combination of ISCO with Bioremediation 9
In Situ Chemical Oxidation Process Safety 10
II RESEARCH HYPOTHESIS 12
Research Objectives 13
Objective 1: Collection of Soil Specimens 13
Objective 2: Impact of Common Soil Constituents on Process Reagent Transport 14
Objective 3: Investigation of Potential Personnel Safety Threats During Process Application 14
Objective 4: Impact of Process Application on Soil Fabric Properties 15
III LITERATURE REVIEW 16
Introduction to In Situ Chemical Oxidation 16
ISCO Technology Overview 16
Chemical Oxidation 17
Trang 10v
In Situ Ozonation 27
Auto-Degradation of Ozone 28
Reaction of Ozone with Organics 29
Ozone Scavengers 30
Kinetics of Ozone Degradation in Soil and Groundwater 32
Peroxone 33
Introduction to Peroxone 33
Peroxone Reaction Mechanisms 33
Additional Hydroxyl Radical Scavengers 34
Soil Hydraulic Conductivity 35
Darcy’s Law 35
Measurement of Soil Hydraulic Conductivity 35
Typical Values for Soil Hydraulic Conductivity 36
Soil Adsorption 38
Adsorption Theory 38
Freundlich Isotherms 38
2,4-Dichlorophenol as an Adsorbent 39
Potential Impact of ISCO on Soil Adsorption 40
IV METHODS AND MATERIALS 47
Introduction 47
Soil Collection 47
Soil Collection 47
Groundwater Simulation 49
Oxidizer Generation 50
Solution Preparations 50
Ozone Generation 51
Analytical Methods 52
Soil and Equilibrated Water Characterization 52
Analysis of Hydrogen Peroxide 52
Analysis of Ozone 53
Analysis of pH 55
Trang 11vi
Total Hydrogen Peroxide Demand 66
Results and Discussion 67
Characterization 67
Analysis of Soil 67
Analysis of Equilibrated Water 68
Hydrogen Peroxide Reaction Kinetics 68
Equilibrated Water Phase 68
Soil Phase 71
Hydrogen Peroxide Total Demands 74
Equilibrated Water Phase 74
Soil Phase 76
Equilibrated Water/Soil H2O2 Demand Correlation 78
VI IMPACT OF SOIL CONSTITUENTS ON OZONE 102
Background 102
Objective 102
Methods and Materials 103
Kinetics of Ozone Degradation 103
Total Ozone Demand 104
Results and Discussion 106
Ozone Reaction Kinetics 106
Equilibrated Water Phase 106
Soil Phase 109
Ozone Total Demands 112
Equilibrated Water Phase 112
Soil Phase 115
Equilibrated Water/Soil O3 Demand Correlation 118
VII IMPACT OF SOIL CONSTITUENTS ON ACIDS AND BASES 141
Background 141
Objective 143
Trang 12vii
Total NaOH Demands 156
Summary 158
VIII IMPACT OF SOIL CONSTITUENTS ON SOIL TEMPERATURE AND O2 PRODUCTION 180
Background 180
Objective 181
Methods and Materials 182
Fenton’s Reaction Temperature Profiles 182
Oxygen Production from the Reaction of Hydrogen Peroxide 183
Results and Discussion 185
Temperature Response due to H2O2/Fenton’s Reaction 185
Oxygen Production from Hydrogen Peroxide 186
Oxygen Production Data Analysis 186
Oxygen Production Results 188
IX KINETIC MODELING OF HYDROGEN PEROXIDE FATE WITHIN SOILS 196
Background 196
Objective 197
Methods and Materials 197
Results and Discussion 198
Proposed Mechanism 198
Rate Law Development 201
Steady State Approximation 202
Application of the Proposed Kinetic Model 206
Final Results and Discussion of the Proposed Kinetic Model 206
Summary of the Proposed Kinetic Model 208
Trang 13viii
Spreading of Samples onto Agar Plates 221
Results and Discussion 222
Data Analysis 222
Impact of ISCO on Aerobic Populations 223
Temperature’s Impact on Soil Aerobic Populations 227
Summary 228
XI IMPACT OF IN SITU CHEMICAL OXIDATION ON SOIL HYDRAULIC CONDUCTIVITY 239
Background 239
Objective 240
Methods and Materials 240
Column Supplies for H2O2-based ISCO Treatments 240
Column Assembly for H2O2-based ISCO Treatments 241
Column Operating Conditions for H2O2-based ISCO Treatments 242
Column Equilibration for H2O2-based ISCO Treatments 243
Determination of Hydraulic Conductivity Changes due to H2O2-based ISCO 243
Column Supplies and Assembly for O3-based ISCO Treatments 245
Application of Ozone to Soil Column 245
Startup Procedure for O3-based ISCO Treatments 246
Determination of Hydraulic Conductivity Changes due to O3-based ISCO 247
Results and Discussion 248
Determination of Hydraulic Conductivity 248
Column Equilibration 251
Impact of H2O2 and Fenton’s Reagent on the Hydraulic Conductivity of Sand 252
Impact of H2O2 Addition and Fenton’s Reagent on the Hydraulic Conductivity of Soils 254
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Objective 286
Methods and Materials 286
Soil Treatment 286
Soil Washings 287
Soil Extractions 287
Ion Exchange 287
Results and Discussion 288
NMR Analytical Results 288
Summary 290
XIII IMPACT OF IN SITU CHEMICAL OXIDATION ON SOIL ADSORPTION PROPERTIES 297
Background 297
Objective 298
Methods and Materials 298
Soil Treatments 298
Test Adsorbate 300
Shake Vials 301
Separation of Solid/Liquid Phases 301
Results and Discussion 301
Determination of the Freundlich Adsorption Coefficient 301
Adsorption of 2,4-DCP onto the Ozonated Sand Control 303
Results of the Impact of ISCO on Soil Adsorption Properties 304
Summary of the Impact of ISCO on Soil Adsorption Properties 307
XIV FUTURE WORK 316
XV CONCLUSIONS 319
Impact of Common Soil Constituents on Process Reagent Transport 319 Investigation of Potential Personnel Safety on Threats During
Trang 15x
B RAW DATA FOR OZONE FATE 349
C RAW DATA FOR SOIL pH BUFFERING 380
D RAW DATA FOR OXYGEN PRODUCTION FROM H2O2 399
E RAW DATA FOR IMPACT OF ISCO ON SOIL AEROBES 425
F RAW DATA FOR IMPACT OF ISCO ON SOIL HYDRAULIC CONDUCTIVITY 439
G RAW DATA FOR IMPACT OF ISCO ON SOIL ADSORPTION 475
Trang 16xi
(Siegrest et al., 2001; Hernandez et al., 2002) 41
3.2 Summary of the Auto-decomposition Kinetics of Ozone in Water (Gurol and Singer, 1982) 43
3.3 Typical Ranges of Hydraulic Conductivity for Various Soil Types (LaGrega et al., 2001) 44
3.4 Factors Affecting Adsorption of Organics (LaGrega et al., 2001) 45
3.5 Chemical and Physical Properties of 2,4-Dichlorophenol (LaGrega et al., 2001) 46
4.1 Nutrient Addition for Biologically Stimulated Soil 57
4.2 Properties of Iron (II) Sulfate Heptahydrate and Hydrogen Peroxide 58
4.3 GC Operating Conditions for Gas Analysis 59
4.4 HPLC Operating Parameters for 2,4-DCP Analysis 60
5.1 Physical Characterization of Experimental Soils 80
5.2 Chemical Characterization of Experimental Soils 81
5.3 Characterization Data for Equilibrated Water Samples 82
5.4 R2 Values for H2O2 Degradation in Equilibrated Water Based on First-Order Reaction Kinetics 83
5.5 R2 Values for H2O2 Degradation in Soil Based on First-Order Reaction Kinetics 84
Trang 17xii 7.4 H3PO4 Soil Buffering Kinetic Constants Data and R2 Values for
9.2 Regression Analysis of H2O2 Rate Data Using
Langmuir-Hinshelwood Approach 210 10.1 Experimental Matrix for Impact of ISCO on Biomass Populations 230 10.2 Difco Plate Count Agar Composition 231
13.1 Numerical Results for Kd, 95% Confidence Interval, and R2 for
Impact of ISCO on Soil Adsorption Experiments 310
A.1 H2O2 Degradation in Ozonated Sand Equilibrated Water
(No Autoclave) 337 A.2 H2O2 Degradation in Ozonated Sand Equilibrated Water
(With Autoclave) 337
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A.7 H2O2 Degradation in High Fe Soil Equilibrated Water (No Autoclave) 339
A.8 H2O2 Degradation in High Fe Soil Equilibrated Water (With Autoclave) 340
A.9 H2O2 Degradation in High TOC Soil Equilibrated Water (No Autoclave) 340
A.10 H2O2 Degradation in High TOC Soil Equilibrated Water (With Autoclave) 341
A.11 H2O2 Degradation in Biologically Stimulated Soil Equilibrated Water (No Autoclave) 341
A.12 H2O2 Degradation in Biologically Stimulated Soil Equilibrated Water (With Autoclave) 342
A.13 H2O2 Degradation in Ozonated Sand (No Autoclave) 342
A.14 H2O2 Degradation in Ozonated Sand (With Autoclave) 342
A.15 H2O2 Degradation in Average Soil (No Autoclave) 343
A.16 H2O2 Degradation in Average Soil (With Autoclave) 343
A.17 H2O2 Degradation in High pH Soil (No Autoclave) 343
A.18 H2O2 Degradation in High pH Soil (With Autoclave) 344
A.19 H2O2 Degradation in High Fe Soil (No Autoclave) 344
A.20 H2O2 Degradation in High Fe Soil (With Autoclave) 344
Trang 19xiv
A.26 Soil Total H2O2 Demand Data 348
B.1 Fate of Ozone - Ozonated Sand Equilibrated Water (Run 1) 350
B.2 Fate of Ozone – Ozonated Sand Equilibrated Water (Run 2) 350
B.3 Fate of Ozone – Ozonated Sand Equilibrated Water (Run 3) 351
B.4 Fate of Ozone – Average Soil Equilibrated Water (Run 1) 351
B.5 Fate of Ozone – Average Soil Equilibrated Water (Run 2) 352
B.6 Fate of Ozone – Average Soil Equilibrated Water (Run 3) 353
B.7 Fate of Ozone – High pH Soil Equilibrated Water (Run 1) 354
B.8 Fate of Ozone – High pH Soil Equilibrated Water (Run 2) 355
B.9 Fate of Ozone – High pH Soil Equilibrated Water (Run 3) 356
B.10 Fate of Ozone – High Fe Soil Equilibrated Water (Run 1) 357
B.11 Fate of Ozone – High Fe Soil Equilibrated Water (Run 2) 358
B.12 Fate of Ozone – High Fe Soil Equilibrated Water (Run 3) 359
B.13 Fate of Ozone – High TOC Soil Equilibrated Water (Run 1) 360
B.14 Fate of Ozone – High TOC Soil Equilibrated Water (Run 2) 361
B.15 Fate of Ozone – High TOC Soil Equilibrated Water (Run 3) 361
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B.21 Fate of Ozone – Average Soil (Run 3) 367
B.22 Fate of Ozone – High pH Soil (Run 1) 368
B.23 Fate of Ozone – High pH Soil (Run 2) 369
B.24 Fate of Ozone – High pH Soil (Run 3) 370
B.25 Fate of Ozone – High Fe Soil (Run 1) 371
B.26 Fate of Ozone – High Fe Soil (Run 2) 372
B.27 Fate of Ozone – High Fe Soil (Run 3) 373
B.28 Fate of Ozone – High TOC Soil (Run 1) 374
B.29 Fate of Ozone – High TOC Soil (Run 2) 375
B.30 Fate of Ozone – High TOC Soil (Run 3) 376
B.31 Fate of Ozone – Biologically Stimulated Soil (Run 1) 377
B.32 Fate of Ozone – Biologically Stimulated Soil (Run 2) 378
B.33 Fate of Ozone – Biologically Stimulated Soil (Run 3) 379
C.1 Ozonated Sand (Run 1) H3PO4 Buffering Raw Data 381
C.2 Ozonated Sand (Run 2) H3PO4 Buffering Raw Data 381
C.3 Average Soil (Run 1) H3PO4 Buffering Raw Data 382
Trang 21xvi
C.9 High TOC Soil (Run 1) H3PO4 Buffering Raw Data 388
C.10 High TOC Soil (Run 2) H3PO4 Buffering Raw Data 389
C.11 Total H3PO4 Demand Raw Data 390
C.12 Ozonated Sand (Run 1) NaOH Buffering Raw Data 390
C.13 Ozonated Sand (Run 2) NaOH Buffering Raw Data 391
C.14 Average Soil (Run 1) NaOH Buffering Raw Data 391
C.15 Average Soil (Run 2) NaOH Buffering Raw Data 392
C.16 High pH Soil (Run 1) NaOH Buffering Raw Data 392
C.17 High pH Soil (Run 2) NaOH Buffering Raw Data 393
C.18 High Fe Soil (Run 1) NaOH Buffering Raw Data 394
C.19 High Fe Soil (Run 2) NaOH Buffering Raw Data 395
C.20 High TOC Soil (Run 1) NaOH Buffering Raw Data 496
C.21 High TOC Soil (Run 2) NaOH Buffering Raw Data 497
C.22 Total NaOH Demand Raw Data 498
D.1 Ozonated Sand, 10,000 mg/L H2O2 Application (Run 1) 400
D.2 Ozonated Sand, 10,000 mg/L H2O2 Application (Run 2) 400
Trang 22xvii D.8 High Iron Soil, 10,000 mg/L H2O2 Application (Run 2) 402 D.9 High TOC Soil, 10,000 mg/L H2O2 Application (Run 1) 402 D.10 High TOC Soil, 10,000 mg/L H2O2 Application (Run 2) 403 D.11 Biologically Stimulated Soil, 10,000 mg/L H2O2 Application (Run 1) 403 D.12 Biologically Stimulated Soil, 10,000 mg/L H2O2 Application (Run 2) 403 D.13 Ozonated Sand, 50,000 mg/L H2O2 Application (Run 1) 404 D.14 Ozonated Sand, 50,000 mg/L H2O2 Application (Run 2) 404 D.15 Average Soil, 50,000 mg/L H2O2 Application (Run 1) 404 D.16 Average Soil, 50,000 mg/L H2O2 Application (Run 2) 405 D.17 Average Soil, 50,000 mg/L H2O2 Application (Run 3) 405 D.18 High pH Soil, 50,000 mg/L H2O2 Application (Run 1) 405 D.19 High pH Soil, 50,000 mg/L H2O2 Application (Run 2) 406 D.20 High pH Soil, 50,000 mg/L H2O2 Application (Run 3) 406 D.21 High Iron Soil, 50,000 mg/L H2O2 Application (Run 1) 406 D.22 High Iron Soil, 50,000 mg/L H2O2 Application (Run 2) 407 D.23 High Iron Soil, 50,000 mg/L H2O2 Application (Run 3) 407
Trang 23xviii D.29 Biologically Stimulated Soil, 50,000 mg/L H2O2 Application (Run 3) 409 D.30 Ozonated Sand, 100,000 mg/L H2O2 Application (Run 1) 409 D.31 Ozonated Sand, 100,000 mg/L H2O2 Application (Run 2) 410 D.32 Ozonated Sand, 100,000 mg/L H2O2 Application (Run 3) 410 D.33 Average Soil, 100,000 mg/L H2O2 Application (Run 1) 410 D.34 Average Soil, 100,000 mg/L H2O2 Application (Run 2) 411 D.35 Average Soil, 100,000 mg/L H2O2 Application (Run 3) 411 D.36 High pH Soil, 100,000 mg/L H2O2 Application (Run 1) 412 D.37 High pH Soil, 100,000 mg/L H2O2 Application (Run 2) 412 D.38 High pH Soil, 100,000 mg/L H2O2 Application (Run 3) 412 D.39 High Iron Soil, 100,000 mg/L H2O2 Application (Run 1) 413 D.40 High Iron Soil, 100,000 mg/L H2O2 Application (Run 2) 413 D.41 High Iron Soil, 100,000 mg/L H2O2 Application (Run 3) 414 D.42 High TOC Soil, 100,000 mg/L H2O2 Application (Run 1) 414 D.43 High TOC Soil, 100,000 mg/L H2O2 Application (Run 2) 415 D.44 High TOC Soil, 100,000 mg/L H2O2 Application (Run 3) 415
Trang 24xix D.49 Ozonated Sand, Fenton’s Reagent (100,000 mg/L H2O2/5,000 mg/L
Trang 25xx D.63 Biologically Stimulated Soil, Fenton’s Reagent (100,000 mg/L
H2O2/5,000 mg/L Fe2+) Application (Run 1) 423
D.64 Biologically Stimulated Soil, Fenton’s Reagent (100,000 mg/L
H2O2/5,000 mg/L Fe2+) Application (Run 2) 423
D.65 Biologically Stimulated Soil, Fenton’s Reagent (100,000 mg/L
H2O2/5,000 mg/L Fe2+) Application (Run 3) 424
E.1 Constants for Impact of ISCO to Microbial Populations 426
E.2 Impact of ISCO on Average Soil, 1A 426
E.3 Impact of ISCO on Average Soil, 1B 426
E.4 Impact of ISCO on Average Soil, 1C 427
E.5 Impact of ISCO on Average Soil, 2A 428
E.6 Impact of ISCO on Average Soil, 2B 428
E.7 Impact of ISCO on Average Soil, 2C 429
E.8 Impact of ISCO on High pH Soil, 1A 429
E.9 Impact of ISCO on High pH Soil, 1B 430
E.10 Impact of ISCO on High pH Soil, 1C 430
E.11 Impact of ISCO on High pH Soil, 2A 431
E.12 Impact of ISCO on High pH Soil, 2B 431
Trang 26xxi E.18 Impact of ISCO on High Fe Soil, 2B 434 E.19 Impact of ISCO on High Fe Soil, 2C 435 E.20 Impact of ISCO on Biologically Stimulated Soil, 1A 435 E.21 Impact of ISCO on Biologically Stimulated Soil, 1B 436 E.22 Impact of ISCO on Biologically Stimulated Soil, 1C 436 E.23 Impact of ISCO on Biologically Stimulated Soil, 2A 437 E.24 Impact of ISCO on Biologically Stimulated Soil, 2B 437 E.25 Impact of ISCO on Biologically Stimulated Soil, 2C 438 F.1 Ozonated Sand, Data Set 1, DI-Water Treatment 440 F.2 Ozonated Sand, Data Set 1, 100,000 mg/L H2O2 Treatment 441 F.3 Ozonated Sand, Data Set 2, DI-Water Treatment 442 F.4 Ozonated Sand, Data Set 2, F.R (5,000 mg/L Fe2+ Addition) 443 F.5 Ozonated Sand, Data Set 2, F.R (100,000 mg/L H2O2 Addition) 444 F.6 Ozonated Sand, Data Set 3, Ozone Treatment 445 F.7 Ozonated Sand, Data Set 4, Peroxone Treatment 446 F.8 Average Soil, Data Set 1, DI-Water Treatment 447
Trang 27xxii F.14 Average Soil, Data Set 4, Peroxone Treatment 453 F.15 High pH Soil, Data Set 1, DI-Water Treatment 454 F.16 High pH Soil, Data Set 1, 100,000 mg/L H2O2 Treatment 455 F.17 High pH Soil, Data Set 2, DI-Water Treatment 456 F.18 High pH Soil, Data Set 2, F.R (5,000 mg/L Fe2+ Treatment) 457 F.19 High pH Soil, Data Set 2, F.R (100,000 mg/L H2O2 Treatment) 458 F.20 High pH Soil, Data Set 3, Ozone Treatment 459 F.21 High pH Soil, Data Set 4, Peroxone Treatment 460 F.22 High Iron Soil, Data Set 1, DI-Water Treatment 461 F.23 High Iron Soil, Data Set 1, 100,000 mg/L H2O2 Treatment 462 F.24 High Iron Soil, Data Set 2, DI-Water Treatment 463 F.25 High Iron Soil, Data Set 2, F.R (5,000 mg/L Fe2+ Treatment) 464 F.26 High Iron Soil, Data Set 2, F.R (100,000 mg/L H2O2 Treatment) 465 F.27 High Iron Soil, Data Set 3, Ozone Treatment 466 F.28 High Iron Soil, Data Set 4, Peroxone Treatment 467 F.29 High TOC Soil, Data Set 1, DI-Water Treatment 468
Trang 28xxiii F.35 High TOC Soil, Data Set 4, Peroxone Treatment 474 G.1 Ozonated Sand, No Treatment 476 G.2 Average Soil, No Treatment 476 G.3 Average Soil, DI Water Treatment 477 G.4 Average Soil, Fenton’s Reagent Treatment 477 G.5 Average Soil, Ozone Treatment 478 G.6 Average Soil, Peroxone Treatment 478 G.7 High pH Soil, No Treatment 479 G.8 High pH Soil, DI-Water Treatment 479 G.9 High pH Soil, Fenton’s Reagent Treatment 480 G.10 High pH Soil, Ozone Treatment 480 G.11 High pH Soil, Peroxone Treatment 481 G.12 High Iron Soil, No Treatment 481 G.13 High Iron Soil, DI-Water Treatment 482 G.14 High Iron Soil, Fenton’s Reagent Treatment 482 G.15 High Iron Soil, Ozone Treatment 483
Trang 29xxiv G.21 High TOC Soil, Peroxone Treatment 486
Trang 30xxv (Source: Adapted, ARS Technologies, 2005) 11 3.1 Chemical Structure of 2,4-Dichlorophenol (Subramani, 2002) 46 4.1 Schematic Drawing of Bioreactor Setup (Dieng, 2003) 61 4.2 Photograph of the Bioreactor Setup 62
5.1 H2O2 Reaction within Non-Autoclaved High TOC Equilibrated
Water (Run 1) 85
5.2 First-Order H2O2 Rate Constants within Equilibrated
Water, [H2O2]0 = 20 mg/L 86 5.3 Degradation of H2O2 within Non-Autoclaved 30% Soil Slurries 87 5.4 Degradation of H2O2 within Autoclaved 30% Soil Slurries 88 5.5 H2O2 Reaction within Autoclaved Average Soil (Run 2) 89
5.6 First-Order H2O2 Rate Constants within 30%
Soil Slurries, [H2O2]0 = 20 mg/L 90 5.7 First Order H2O2 Rate Constant vs Soil Iron and TOC Content 91 5.8 First Order H2O2 Rate Constant vs Initial Soil Microbial Populations 92 5.9 Autoclaved First Order H2O2 Rate Constant vs Soil Clay Content 93 5.10 Total H2O2 Demands for Equilibrated Water 94
Trang 31xxvi 5.15 H2O2 Fate vs Soil Bacterial Populations 99 5.16 Total H2O2 Demand Soil/Equilibrated Water Correlation (All Soils) 100
5.17 Total H2O2 Demand Soil/Equilibrated Water Correlation
(All Soils Except High TOC) 101 6.1 Groundwater Ozonation PFD 120 6.2 Soil Slurry Ozonation PFD 121
6.3 Sample Profile for Reactivity of Ozone with Equilibrated Water
(High pH Equilibrated Water – Run 3) 122 6.4 Equilibrated Water Ozone Utilization Rates 123
6.5 Sample Profile for Reactivity of Ozone with 30% Soil Slurries
(High pH Soil – Run 1) 124 6.6 Soil Ozone Utilization Rates 125 6.7 Soil Ozone Utilization Rates vs Soil TOC and Fe Content 126 6.8 Soil Ozone Utilization Rates vs Soil Microbial Populations 127 6.9 Soil Ozone Utilization Rates vs Soil pH 128 6.10 Soil Ozone Utilization Rates vs Soil Calcium Content for All Soils 129 6.11 Soil Ozone Utilization Rates vs Soil Calcium Content for All
Soils Excluding the High pH Soil 130
Trang 32xxvii 6.15 Total Ozone Demands for Soil, Exclusive of O3 Autodegradation
Losses 134 6.16 Soil Total Net Ozone Demand vs Soil Iron and TOC Content 135 6.17 Soil Total Net Ozone Demand vs Soil Microbial Populations 136 6.18 Soil Total Net Ozone Demand vs Soil pH 137 6.19 Soil Total Net Ozone Demand vs Soil Calcium Content 138
6.20 Soil Total Net Ozone Demand vs Soil Calcium Content for All
Soils Excluding the High pH Soil 139 6.21 Total O3 Demand Soil/Equilibrated Water Correlation (All Soils) 140
7.1 Acid/Base Neutralization Capacity of Experimental Soils, Note: A
negative acid addition indicates a positive addition of base 168
7.2 A typical second order kinetic plot for H3PO4 Buffering
(High Fe Soil, Run 2) 169 7.3 H3PO4 Buffering Kinetic Constants 170 7.4 H3PO4 Buffering Kinetic Constants vs Initial Soil pH 171 7.5 H3PO4 Total Demands 172 7.6 H3PO4 Total Demands vs Initial Soil pH 173 7.7 A typical second order kinetic plot for NaOH Buffering
(High pH Soil, Run 1) 174
Trang 33xxviii 8.1 Diagram of O2 Production Batch Reactor System (Taconi, 2004) 192 8.2 Maximum Observed Temperatures in Fenton’s Reaction Experiments 193
8.3 Ratio of Oxygen Produced to Hydrogen Peroxide Added for Multiple
Soil Treatments 194
8.4 Maximum Volume Percents of Oxygen Obtained during H2O2 Batch
Reactor Experiments 195 9.1 Diagram of Proposed Langmuir-Hinshelwood Model 211 9.2 Analysis of Diffusion Effects in H2O2 Degradation Modeling 212
9.3 Data Point Comparison of the H2O2 Degradation Experimental and
Model Results; Data Points 1, 2, 3, & 4 correspond to
[H2O2]0 = 20, 100, 1,000, and 10,000 mg/L H2O2 respectively 213
9.4 Deviation of the Langmuir-Hinshelwood Model from Observed
Experimental Results 214 10.1 Impact of ISCO on Aerobic Microbial Populations in Average Soil 232 10.2 Impact of ISCO on Aerobic Microbial Populations in High pH Soil 233 10.3 Impact of ISCO on Aerobic Microbial Populations in High Fe Soil 234
10.4 Impact of ISCO on Aerobic Microbial Populations in Biologically
Stimulated Soil 235 10.5 Net Decrease in Average Order of Magnitude for ISCO Treatments on
Average, High pH, High Fe, and Biologically Stimulated Soils 236
Trang 34xxix 11.2 Diagram of Column Manifold for H2O2 and Fenton’s Reagent
Applications 264
11.3 Diagram of Individual Column Assembly for O3 and Peroxone
Applications 265 11.4 PFD for O3-based ISCO of Soil Columns 266 11.5 Column Equilibration Results for Average Soil Runs with DI-Water 267
11.6 Impact of H2O2 and Fenton’s Reagent on the Hydraulic Conductivity
of Ozonated Sand (Control) 268
11.7 Impact of H2O2 and Fenton’s Reagent on the Hydraulic Conductivity
11.10 Impact of H2O2 and Fenton’s Reagent on the Hydraulic
Conductivity of High TOC Soil 272
11.11 Hydraulic Conductivity Reduction Factors for H2O2 and Fenton’s
Reagent Treatments on Multiple Soil Types 273 11.12 Hydraulic Conductivity Reduction Factors for H2O2 Treatment
Versus Soil Iron Content 274
Trang 35xxx 11.16 Impact of O3 and Peroxone on the Hydraulic Conductivity of
Ozonated Sand (Control) 278
11.17 Impact of O3 and Peroxone on the Hydraulic Conductivity of
11.20 Impact of O3 and Peroxone on the Hydraulic Conductivity of
High TOC Soil 282
11.21 Hydraulic Conductivity Reduction Factors for O3 and Peroxone
Treatments on Multiple Soil Types 283
11.22 Hydraulic Conductivity Reduction Factors for ISCO Treatments
on Multiple Soil Types 284 12.1 Photograph of Initial Average Soil NaOH Extract 292 12.2 Photograph of H2O2-Treated Average Soil NaOH Extract 293 12.3 Photograph of Peroxone-Treated Average Soil NaOH Extract 294
Trang 36xxxi 12.5 Figure 13.5: Impact of ISCO on Organics in High TOC Soil;
A =1H NMR TOC water control, B = 1H NMR TOC peroxone,
C = difference spectrum 1 = signals from aliphatic molecules,
*aliphatic signals from aliphatic acids/esters 2 = signals likely
from carbohydrate, such as cellulose, 3 = amide protons,
characteristic of proteins or peptides Assignments have been
confirmed by 2D NMR data not shown 296
13.1 A Typical Kd Isotherm for Impact of ISCO on Soil Adsorption
(High TOC Soil – No Treatment) 311 13.2 Impact of ISCO on the Adsorption Properties of Average Soil 312 13.3 Impact of ISCO on the Adsorption Properties of High pH Soil 313 13.4 Impact of ISCO on the Adsorption Properties of High Iron Soil 314 13.5 Impact of ISCO on the Adsorption Properties of High TOC Soil 315
Trang 371 chemical contamination from past industrial and military activities (Hong et al., 1996) A wealth of remediation options is often considered when determining the most efficient mechanism for site cleanup Remediation techniques fall into one of
two categories: ex situ and in situ Ex situ technologies are invasive procedures in
which soil is excavated from the contaminated site, treated in above-ground reactors,
and then returned to its natural environment (Acar and Zappi, 1995) While ex situ
treatments offer a high level of process control, they are often expensive due to the costs of excavation, surface equipment, and contaminated soil handling (Zappi et al.,
2000) In situ technologies are far less invasive, utilizing the subsurface as the
reaction zone Therefore, there is no requirement to expend capital for excavation procedures or surface treatment system equipment (Nimmer et al., 2000; Chen et al.,
2001) In situ processes also allow the user to treat contaminated areas without
disturbing pre-existing buildings, and they also eliminate the need to handle
contaminated soil (Amarante, 2000) Finally, because of greatly reduced site worker
exposures, in situ technologies are generally considered to be safer than ex situ
processes (EPA, 2000; ITRC, 2005)
Trang 38large quantities of chemical oxidants into the subsurface to rapidly degrade organic
contaminants (Lowe et al., 2002) A simplistic diagram of a typical in situ chemical
oxidation application is shown in Figure 1.1 Once the targeted treatment zone is identified, the chosen chemical oxidizer is routed into the subsurface via above-
ground pumps A packer nozzle assembly is fixed at a desired location within the well, and this is used to create a seal within the well to prevent oxidizer solutions from simply rising to the surface The number of wells and their placement is
generally determined by characterization of both the site and the pollutant (Amarante 2000; ARS Technologies, 2005)
Chemical Oxidizer Transport
One of the primary limitations with in situ chemical oxidation involves the
efficient delivery of process reagents into the subsurface via the process diagram shown in Figure 1.1 In order for chemical oxidizers to react with subsurface
contaminants, the oxidizer must physically contact the contaminant in order for a reaction to take place (Amarante, 2000) Two primary concerns exist which must be overcome by practitioners applying an ISCO technology for contaminant remediation
Trang 39impact the rate at which oxidizers reach targeted contaminants (Amarante, 2000)
Chemical Oxidation Processes
Chemical oxidation may be broken up into two generic categories: primary oxidation and advanced oxidation (Zappi, 1995) In reactions via primary oxidation, the reaction with the specific contaminant relies more on the oxidation via the parent oxidizer (e.g ozone, hydrogen peroxide, permanganate) rather than via hydroxyl radicals Ozone, hydrogen peroxide and permanganate have all been historically used
in water and wastewater treatment and have recently been applied successfully in ISCO remediation projects (Zappi, 1995; Kuo et al., 1999; Amarante 2000) A
second type of oxidation is referred to as advanced oxidation These are processes that rely primarily on hydroxyl radicals (OH·) to oxidize particular contaminants within the subsurface Examples of advanced oxidation technologies include both Fenton’s Reaction and peroxone (Glaze et al., 1989; Hong et al., 1996; Amarante 2000)
Trang 40(Watts et al., 1999; Zappi et al., 2000) Fenton’s Reaction is considered an advanced oxidation process since the hydroxyl radicals are utilized as the principal reaction species (Kakarla et al., 2002) The reaction of hydrogen peroxide and ferrous iron results in the generation of these powerful hydroxyl radicals as reported by Watts et
al (1999):
Fenton’s Reaction is an extremely popular ISCO candidate because the chemicals are both abundant and relatively inexpensive Often times, naturally occurring iron minerals within the soil matrix can provide enough ferrous iron to efficiently react with injected hydrogen peroxide (Watts et al, 1999) Fenton’s Reaction also offers the potential for much quicker remediation times as opposed to bioremediation In the application of Fenton’s Reagent at a site in Warren County, NY, overall
concentrations of volatile and semi-volatile organic compounds were reduced by as much as 70%, with a required treatment time of less than three months (Violins et al.,
2003) These remediation times are much more favorable in comparison to other in
situ technologies such as bioremediation, which can often require treatment times of a