Trace Elements in Soils

Trace Elements in Soils......Page 5
Contents......Page 7
Preface......Page 17
List of Contributors......Page 19
SECTION 1 BASIC PRINCIPLES, PROCESSES, SAMPLING AND ANALYTICAL ASPECTS......Page 23
1 Introduction......Page 25
References......Page 29
2.1 Introduction......Page 31
2.2 Distribution of Trace Elements in the Soil......Page 32
2.3 Chemical Species......Page 33
2.4.1 Sorption Mechanisms......Page 35
2.4.2 Sorption Isotherms......Page 38
2.5 Precipitation and Dissolution......Page 40
2.6.1 pH and Redox Potential......Page 41
2.6.2 Influence of Soil Constituents......Page 45
2.7 Transport......Page 47
2.8 Plant Uptake......Page 50
2.9 Concluding Remarks......Page 53
References......Page 54
3.1 Introduction......Page 61
3.2 Soil Sampling......Page 62
3.3 Errors Associated with Soil Sampling and Preparation......Page 63
3.4 Overview of the Current Situation......Page 68
3.5 Scale and Variability......Page 70
References......Page 71
4.1 Introduction......Page 75
4.2.1 Matrix Dissolution......Page 76
4.2.2 Instrumental Analysis Techniques......Page 77
4.2.3 Nondestructive Methods......Page 81
4.3.1 Single Extractions......Page 83
4.3.2 Sequential Extraction Procedures......Page 87
4.4 Species-Retaining and Species-Selective Leaching Techniques......Page 93
4.5 Equipment for Direct Speciation of Trace Elements in Soil......Page 95
References......Page 96
5.1 Introduction......Page 103
5.2 Soil Solution Sampling, Storage and Filtration......Page 104
5.3 Particle Size Fractionation......Page 105
5.5 Ion-Exchange Resins and Solid-Phase Extraction......Page 108
5.6 Derivatization Techniques to Create Volatile Species......Page 109
5.7 Chromatographic Separation of Trace Element Species......Page 110
5.8 Capillary Electrophoresis......Page 112
5.9 Diffusive Gradients in Thin Films......Page 113
5.10 Ion-Selective Electrodes......Page 115
5.11 Donnan Membrane Technique......Page 116
5.12 Voltammetric Techniques......Page 118
5.13 Microelectrodes and Microsensors......Page 120
5.14 Models for Predicting Metal Speciation in Soil Solution......Page 122
5.15 Conclusions......Page 124
References......Page 125
SECTION 2 LONG-TERM ISSUES, IMPACTS AND PREDICTIVE MODELLING......Page 133
6.1 Introduction......Page 135
6.2.1 Land Application and Trace Element Loading......Page 137
6.2.2 Trace Element Availability in Biosolids-Amended Soils – A Time Bomb?......Page 138
6.2.3 Plant Response to Trace Elements in Biosolids-Amended Soils – Is There a Plateau?......Page 140
6.3.1 Source Assessment......Page 142
6.3.2 End Measurement......Page 143
6.4.1 Rationale for Root Exudate-Based Trace Element Phytoavailability......Page 144
6.4.2 Case Studies......Page 147
6.5 Conclusions......Page 150
References......Page 151
7.1 Introduction......Page 157
7.2 Phosphatic Fertilizers......Page 158
7.4 Long-Term Accumulation of Fertilizer-Borne Trace Element Contaminants......Page 161
7.5 Trace Element Contaminant Transfer to Crops and Grazing Animals......Page 163
7.5.1 Arsenic......Page 164
7.5.2 Cadmium......Page 165
7.5.4 Lead......Page 167
7.6 Conclusions......Page 169
References......Page 170
8.1 Introduction......Page 177
8.2.1 Effects on Individuals, Risk Assessment and the Prediction of Population Effects......Page 178
8.2.2 Populations and Communities......Page 180
8.3.1 Uptake Routes and Speciation Models......Page 184
8.3.2 Toxicokinetics and Compartment Models......Page 185
8.3.3 Molecular Mechanisms of Detoxification and Effect......Page 188
8.4 Conclusions......Page 189
References......Page 190
9.1 Introduction......Page 197
9.2.1 The Role of Trace Elements as Essential Micronutrients......Page 198
9.2.2 Soil Trace Element Concentrations and Micronutrient Deficiencies......Page 199
9.2.3 Trace Element Deficiency as a Disturbance-Related Concept......Page 200
9.3.1 Detection and Diagnosis of Trace Element Deficiency......Page 201
9.3.2 Mapping of Trace Element Deficiencies......Page 203
9.4.1 General Relationships between Soil Factors and Micronutrient Deficiencies......Page 204
9.4.2 Boron......Page 205
9.4.3 Cobalt......Page 208
9.4.4 Copper......Page 209
9.4.6 Manganese......Page 210
9.4.7 Molybdenum......Page 211
9.4.8 Selenium......Page 212
9.4.9 Zinc......Page 213
9.5 Treatment of Soils Deficient in Trace Elements......Page 214
References......Page 216
10.1 Introduction......Page 221
10.2 The Structure of Chemical Speciation Models......Page 223
10.3 The Species/Component Matrix......Page 225
10.4 Aqueous Speciation Modelling......Page 226
10.4.1 Calculating the Concentration of Soluble Species of Toxic Elements......Page 227
10.5.1 Proton and Toxic Element Binding to Oxide Minerals......Page 229
10.5.2 Proton and Toxic Element Binding to Clay Minerals......Page 235
10.6 Modelling of Surface Complexation to Soil Organic Matter......Page 239
10.7 Discussion......Page 241
References......Page 244
SECTION 3 BIOAVAILABILITY, RISK ASSESSMENT AND REMEDIATION......Page 249
11.1 Introduction......Page 251
11.2 Speciation, Bioavailability and Bioaccumulation: Definitions and Concepts......Page 252
11.3.1 Single Chemical Extraction Procedures......Page 256
11.3.2 Sequential Extraction Procedures......Page 260
11.3.3 Soil Solution Concentration and Speciation......Page 262
11.3.4 Other Approaches......Page 266
11.3.5 Bioaccessibility......Page 271
11.3.6 Bioassays, Biosensors and Bioavailability......Page 273
11.4 Discussion and Conclusions......Page 275
References......Page 277
12.1 Introduction......Page 289
12.1.1 The ‘Classical’ Risk Assessment Model......Page 290
12.2.1 Approaches, Uncertainties, Issues for Discussion......Page 292
12.3.1 Approaches to Estimating Exposure from Trace Elements in Soils......Page 294
12.3.2 Environmental Measurements and Influence of Bioavailability......Page 298
12.4.1 High- to Low-Dose Extrapolation......Page 302
12.5 Risk Characterization......Page 306
12.6 Assessment of Mixtures and Disparate Risks......Page 309
References......Page 310
13.1 Introduction......Page 315
13.2.1 Environmental Protection Limit Values for Soils......Page 318
13.2.2 Human Health Protection Limit Values for Soils......Page 321
13.3 National and International Initiatives in Setting Limit Values......Page 323
13.4 Forward Look......Page 325
13.5 Conclusions......Page 326
References......Page 327
14.1 Introduction......Page 333
14.2 The Nature of Soil Contamination where Phytoextraction may be Applied......Page 337
14.3 Need for Metal-Tolerant Hyperaccumulators for Practical Phytoextraction......Page 338
14.4.1 Phytomining Soil Nickel......Page 339
14.4.2 Soil Cadmium Contamination Requiring Remediation to Protect Food Chains......Page 343
14.4.3 Phytoextraction or Phytovolatilization of Soil Selenium......Page 347
14.4.5 Phytoextraction of Soil Boron......Page 349
14.4.6 Phytovolatilization of Soil Mercury......Page 350
14.4.8 Induced Phytoextraction of Soil Lead......Page 351
14.4.9 Phytoextraction of Soil Arsenic......Page 353
14.4.10 Phytoextraction of Other Soil Elements......Page 355
14.5 Phytostabilization of Zinc-Lead, Copper, or Nickel Mine Waste or Smelter-Contaminated Soils......Page 356
14.7 Risks to Wildlife during Phytoextraction Operations......Page 358
14.8 Conclusions......Page 359
References......Page 361
15.1 Introduction......Page 375
15.2.1 Metal Oxides......Page 376
15.2.2 Natural and Synthetic Aluminosilicates......Page 380
15.2.3 Ashes......Page 383
15.2.4 Phosphates......Page 386
15.2.5 Organic Amendments......Page 387
15.2.6 Liming Compounds......Page 389
15.2.7 Gypsum......Page 390
15.3 Method Acceptance......Page 391
15.4 Concluding Remarks......Page 392
References......Page 393
SECTION 4 CHARACTERISTICS AND BEHAVIOUR OF INDIVIDUAL ELEMENTS......Page 403
16.1 Introduction......Page 405
16.2.2 Antimony......Page 407
16.3 Sources of Soil Contamination......Page 408
16.4.1 Arsenic Speciation and Solubility......Page 409
16.4.2 Arsenic Retention in Soils......Page 410
16.4.3 Arsenic Desorption in Soils......Page 414
16.4.4 Antimony Speciation and Solubility......Page 415
16.4.5 Antimony Adsorption and Desorption in Soils......Page 416
16.5 Risks from Arsenic and Antimony in Soils......Page 418
References......Page 422
17.2 Geogenic Occurrence and Sources of Soil Contamination......Page 431
17.3 Chemical Behavior in Soils......Page 437
17.4 Plant Accumulation of Soil Cadmium and Zinc......Page 438
17.5 Risk Implications for Cadmium in Soil Amendments......Page 441
17.6 Plant Uptake of Cadmium and Zinc in Relation to Food-Chain Cadmium Risk......Page 444
17.7 Food-Chain Zinc Issues......Page 449
References......Page 451
18.1 Introduction......Page 463
18.2.1 Sources and Content of Copper in Soils......Page 465
18.2.2 Chemical Behaviour in Soils......Page 467
18.3.1 Sources and Content of Lead in Soils......Page 468
18.3.2 Chemical Behaviour in Soils......Page 470
18.4.1 Essentiality and Metabolism......Page 471
18.4.2 Exposure and Toxicology......Page 472
18.5 Concluding Remarks......Page 474
References......Page 475
19.1 Introduction......Page 483
19.2 Geogenic Occurrences......Page 485
19.3 Sources of Soil Contamination......Page 486
19.4.1 Chromium......Page 487
19.4.2 Nickel......Page 489
19.4.3 Cobalt......Page 490
19.5.1 Chromium......Page 492
19.5.2 Nickel......Page 494
19.6 Concluding Remarks......Page 496
References......Page 497
20.1 Introduction......Page 503
20.2.1 Manganese......Page 504
20.2.2 Selenium......Page 505
20.3.1 Solution and Solid Forms......Page 506
20.3.2 Ion-Exchange and Sorption–Desorption Reactions......Page 507
20.3.3 Precipitation–Dissolution and Oxidation–Reduction Reactions......Page 509
20.3.4 Availability of Manganese and Selenium in Soils......Page 511
20.4 Effects on Plant, Animal and Human Health......Page 512
References......Page 515
21.1 Introduction......Page 519
21.2.1 Tin......Page 522
21.2.2 Mercury......Page 523
21.3.1 Tin......Page 524
21.3.2 Mercury......Page 525
21.4.1 Tin......Page 527
21.5.1 Tin......Page 528
21.5.2 Mercury......Page 529
References......Page 531
22.1 Introduction......Page 537
22.2.1 Geochemical Occurrences and Soil Concentrations......Page 539
22.2.3 Chemical Behavior in Soils......Page 540
22.3.2 Sources of Soil Contamination......Page 545
22.3.3 Chemical Behavior in Soils......Page 546
22.4.1 Geochemical Occurrences and Soil Concentrations......Page 550
22.4.3 Chemical Behavior in Soils......Page 551
22.5.2 Sources of Contamination......Page 556
22.5.3 Chemical Behavior in Soils......Page 557
22.6.1 Molybdenum......Page 562
22.6.2 Silver......Page 563
22.6.4 Vanadium......Page 564
References......Page 565
23.1 Introduction......Page 573
23.2.1 Gold......Page 575
23.2.2 Uranium......Page 576
23.3.1 Gold......Page 577
23.3.2 Uranium......Page 578
23.4.1 Gold......Page 579
23.4.2 Uranium......Page 581
23.5.1 Gold......Page 582
23.5.2 Uranium......Page 583
References......Page 584
24.1 Introduction......Page 589
24.2.1 Geogenic Sources......Page 590
24.2.2 Anthropogenic Sources......Page 591
24.3 Emissions, Depositional Behavior, and Concentrations in Soils......Page 592
24.5 Bioavailability......Page 595
24.6 Conclusions......Page 596
References......Page 597
Index......Page 601