Environmental restoration of metals-contaminated soils /

Front Cover 1
Preface 6
Editor 8
Contributors 10
Contents 12
Section I 14
1 16
1.1 Introduction 16
1.1.1 Remediation Techniques 17
1.1.2 In Situ Remediation by Adding Solid Phase 17
1.2 Example of Study to Assess the Effectiveness of Several Amendments 20
1.2.1 Methods 20
1.3 Results and Discussion 27
1.4 Conclusion 30
References 33
2 34
2.1 Introduction 34
2.2 Techniques of In Situ Stabilization 36
2.2.1 Lime 36
2.2.2 Zeolites 38
2.2.3 Apatite 41
2.2.4 Fe and Mn Oxides, Fe- and Mn-Bearing Amendments 44
2.2.5 Alkaline Composted Biosolids 51
2.2.6 Other Minerals and Industrial By-Products 52
2.2.7 In Situ Redox Manipulation 60
2.3 Summary and Conclusions 66
Acknowledgments 66
References 66
3 74
3.1 Introduction 74
3.1.1 History of Lead Use 74
3.1.2 Sources of Lead in Soils 75
3.1.3 Health Hazards of Lead 76
3.1.4 In Situ Treatments of Lead in Contaminated Sites 77
3.1.5 Choice of Phosphate Amendment Treatment: Mechanisms of Lead Immobilization by Apatites 77
3.2 Estimation of Lead Bioavailability Using Chemical Extractants 79
3.3 Effects of Apatite Amendments on Lead-Contaminated Soils 80
3.3.1 Lead Phosphates in Contaminated Soils 80
3.3.2 Phosphate Amendment to Induce the Formation of Lead Phosphate to Reduce Plant Uptake of Lead 82
3.3.4 Full-Scale Studies 86
3.4 Conclusions 86
References 87
4 90
4.1 Introduction 90
4.2 Experimental Approaches 91
4.3 Results and Discussion 92
4.4 Conclusions 102
References 103
5 106
5.1 Introduction 106
5.2 Materials and Methods 107
5.2.1 The Contaminated Sites 107
5.2.2 Analysis of Basic Soil Properties 108
5.2.3 Treatments in Pot Experiments 108
5.2.4 Bioavailability to Wheat 109
5.2.5 Sequential Fractionation of Heavy Metals in Soils 109
5.2.6 Statistical Analyses 109
5.3 Results and Discussion 109
5.3.1 Cd and Pb Concentration Extracted by Different Reagents in Untreated Soils 109
5.3.2 Changes on the Bioavailability of Cd and Pb after Chemical Treatments 110
5.3.3 Transformation of Chemical Forms of Cd and Pb in the Amended Soils 111
5.3.4 Effect of Chemical Treatments on the Concentration of Cd and Pb Uptake by Wheat 115
5.4 Conclusions 115
Acknowledgments 116
References 116
6 120
6.1 Introduction 120
6.2 Materials and Methods 122
6.2.1 Soils and Measurements 122
6.2.2 Soil pH Adjustment 122
6.2.3 Trace Metal Fractionation 122
6.2.4 Statistical Analysis 123
6.3 Results and Discussion 123
6.3.1 Soil Characteristics 123
6.3.2 DTPA-Extractable Metals 123
6.3.3 Metal Fractions 124
6.3.4 Lead Fractions 124
6.3.5 Nickel Fractions 125
6.3.6 Zinc Fractions 125
6.3.7 Copper Fractions 126
6.3.8 Manganese Fractions 126
6.3.9 Relationship between DTPA-Extractable and Metal Fractions 126
6.4 Conclusions 129
6.5 Summary 131
References 131
7 134
7.1 Introduction 135
7.1.1 The Problem of Metals Contamination 135
7.1.2 The Purpose and Scope of This Chapter 135
7.2 Extent and Nature of Contamination 136
7.3 Soil Characteristics and Heavy Metal Contaminants 137
7.3.1 Soil Characteristics 137
7.3.2 Properties and Behavior of Metals/Inorganics 137
7.3.3 Toxicity 138
7.3.4 Heavy Metal Interactions with Soil Particles 138
7.4 Soil Property Data Required for Investigation and Remediation 139
7.4.1 Physical Properties 139
7.4.2 Site and Soil Characterization 140
7.4.3 Implications for Treatment Methods 141
7.5 Physical Separation 142
7.5.1 Background 142
7.5.2 Fundamentals of Physical Separation 143
7.5.3 Size-Based Separation 143
7.5.4 Gravity-Based (Density) Separation 147
7.6 Integrated Process Trans 168
7.6.1 Volume Reduction Unit 169
7.6.2 Toronto Harbor Soil Recycle Treatment Train 170
7.6.3 Volume Reduction and Chemical Extraction System (VORCE) 172
7.6.4 Application of Physical Separations Systems 172
7.7 Summary 174
References 176
8 180
8.1 Introduction 180
8.2 Heavy Metals Transport under Electric Fields 181
8.8.1 Electrode Requirements 191
8.8.2 Electric Field Distribution 193
8.8.3 Remediation Time Requirements 194
8.8.4 Cost 195
References 197
Section II 200
9 202
9.1 Introduction 202
9.2 Background 203
9.2.1 Sources of Soil Contamination 203
9.2.2 Chelating Agents as Soil Tests for Heavy Metals 204
9.3 Materials and Methods 206
9.3.1 Field Observations 206
9.3.2 Sample Preparation and Analysis 206
9.4 Results and Discussion 207
9.4.1 Effect of Chelates on Metal Removal 207
9.4.2 Extractable Metals and Phytoavailability Relationships 207
9.5 Conclusions 210
9.6 Summary 210
References 210
10 212
10.1 Introduction 213
10.2 Source and Nature of Contamination 214
10.2.1 Parent Material 214
10.2.2 Fertilizers 215
10.2.3 Fly Ash 216
10.2.4 Sewage Sludge 217
10.2.5 Groundwater 218
10.3 Selenium Content of Seleniferous Soils 220
10.4 Restoration of Selenium-Toxic Soils 221
10.4.1 Bioremediation 221
10.4.2 Phytoremediation 224
10.5 Other Remedial Measures 228
10.5.1 Covering Selenium-Contaminated Sites with Selenium-Free Soil 228
10.5.2 Permanent Flooding 228
10.5.3 Chemical Immobilization 229
10.5.4 Presence of Competitive Ions in Soil Solution 230
10.5.5 Selecting Plants with Low Selenium Absorption Capacity 231
10.6 Conclusions 231
10.7 Future Research Needs 232
References 233
11 242
11.1 Introduction 243
11.2 Trace Metals in Soils and Crops 243
11.2.1 Trace Metals 243
11.2.2 Biogenic Trace Metals 246
11.3 Trace Metals and Environmental Problems 248
11.3.1 Aerosols 249
11.3.2 Industrial and Agricultural Chemicals 249
11.3.3 Mining Wastes 250
11.3.4 Sewage Sludges 250
11.4 Management of Trace Metals in Soils, Crops, and Environment 250
11.4.1 Soils 250
11.4.2 Environment 252
11.5 Conclusion 252
References 253
12 256
12.1 Introduction 256
12.1.1 Role of Chelators in Homogeneous Solution Processes vs. Column Elution 256
12.1.2 Requirements For Successful Use of Immobilized Chelators 257
12.2 Nature’s Metal Binding System: Proteins 258
12.2.1 Using Amino Acids as “Building Blocks” for Chelator Design 258
12.2.2 Metallothioneins 258
12.3 Model System: Poly-L-Cysteine 259
12.3.1 Characteristics of the Cysteine Homopolymer 259
12.3.2 Characterization of Homogeneous PLC 260
12.3.3 Immobilized Poly-L-Cysteine 260
12.3.8 Batch Studies and K 264
12.3.9 Flow Studies and Establishment of Keq 265
12.3.10 Redox Characteristics 267
12.4 Conclusions 269
Acknowledgment 270
References 271
13 274
13.1 Introduction 274
13.2 Materials and Methods 275
13.2.1 Soil Sample Collection and Characterization 275
13.2.2 Characterization of Natural Zeolites and Bentonite Used in the Experiment 275
13.2.3 Growth Chamber Pot Experiments with Chicory 276
13.2.4 Elemental Analysis of Soil and Plant Samples 277
13.2.5 Statistics 277
13.3 Results and Discussion 277
13.3.1 Phytoavailability of Heavy Metals in a Galvanic Mud-Contaminated Soil 277
13.3.2 Immobilization of Heavy Metals with Natural Zeolites and Bentonite 278
13.4 Conclusions 283
Acknowledgments 283
References 283
14 286
14.1 Introduction 286
14.2 Materials and Methods 288
14.2.1 Geographic and Climatic Conditions at the Experimental Site 288
14.2.2 Experimental Setup and Crop Chronology 288
14.2.3 Soil and Plant Analysis 290
14.3 Results 291
14.3.1 Heavy Metal Distribution and Migration in Soil 291
14.3.2 Plant Uptake of Heavy Metals 294
14.4 Discussion and Conclusion 299
14.4.1 Impact of the Waste and Sludge Applications on the Soil 299
14.4.2 Impact on Plants 301
Acknowledgment 302
References 302
INDEX 306