Radionuclides in the Environment (eBook)

Influence of chemical speciation and plant uptake on radionuclide migration

Clemens Walther, Dharmendra K. Gupta (Herausgeber)

eBook Download: PDF

2015
273 Seiten
Springer International Publishing (Verlag)
978-3-319-22171-7 (ISBN)

Infos

This book provides extensive and comprehensive information to researchers and academicians who are interested in radionuclide contamination, its sources and environmental impact. It is also useful for graduate and undergraduate students specializing in radioactive-waste disposal and its impact on natural as well as manmade environments.

A number of sites are affected by large legacies of waste from the mining and processing of radioactive minerals. Over recent decades, several hundred radioactive isotopes (radioisotopes) of natural elements have been produced artificially, including 90Sr, 137Cs and 131I. Several other anthropogenic radioactive elements have also been produced in large quantities, for example technetium, neptunium, plutonium and americium, although plutonium does occur naturally in trace amounts in uranium ores. The deposition of radionuclides on vegetation and soil, as well as the uptake from polluted aquifers (root uptake or irrigation) are the initial point for their transfer into the terrestrial environment and into food chains. There are two principal deposition processes for the removal of pollutants from the atmosphere: dry deposition is the direct transfer through absorption of gases and particles by natural surfaces, such as vegetation, whereas showery or wet deposition is the transport of a substance from the atmosphere to the ground by snow, hail or rain. Once deposited on any vegetation, radionuclides are removed from plants by the airstre

am and rain, either through percolation or by cuticular scratch. The increase in biomass during plant growth does not cause a loss of activity, but it does lead to a decrease in activity concentration due to effective dilution. There is also systemic transport (translocation) of radionuclides within the plant subsequent to foliar uptake, leading the transfer of chemical components to other parts of the plant that have not been contaminated directly.

Inhalt

Preface 6
Contents 10
Sources Contributing to Radionuclides in the Environment: With Focus on Radioactive Particles 12
1 Release of Radioactivity in the Environment 13
2 Particle Characterisation Techniques 18
2.1 Identification and Isolation of Radioactive Particles 21
2.2 Nano- and Microfocusing Analytical Techniques 21
2.3 Identification of Isotope Ratios for Source Identification of Single Particles Using MS Techniques 24
3 Linking Sources and Particle Characteristics 26
3.1 Particles Originating from Testing of Nuclear Weapons 27
3.2 Particles Released During Nuclear Accidents 30
3.3 Particles Originating from Nuclear Reprocessing Activities 32
3.3.1 Particles Released from North American Sites 32
3.3.2 Particles Released from Russian Sites 33
3.3.3 Particles Released from European Reprocessing Plants 34
3.4 Particles Associated with Dumping of Waste 35
3.5 Nuclear Accidents Involving Satellites 36
3.6 Conventional Detonation of Nuclear Weapons 36
3.7 Depleted Uranium Ammunitions 38
3.8 Radioactive Particles of Naturally Occurring Radioactive Material Origin 39
4 Conclusion 39
References 41
Mobility and Bioavailability of Radionuclides in Soils 48
1 Introduction 49
1.1 Objective and Overview 49
1.2 Vertical Movement of Radionuclides in Undisturbed Soils 51
1.3 The Solid-Liquid Distribution Coefficient, Kd 51
1.4 Radionuclide Bioavailability in Soils 52
2 Factors Controlling the Behaviour of Radionuclides in Soil 53
2.1 Soil Organic Matter 54
2.2 Mineral Soil Components 54
2.3 Redox Potential (Eh) and the pH 55
2.4 Rainfall 55
2.5 Soil Structure and Texture 55
2.6 Climate Change and Soil Management 56
3 Behaviour of Key Specific Artificial Radionuclides in Soil 56
3.1 Caesium 56
3.2 Plutonium and Americium 58
3.3 Strontium 61
4 Natural Radionuclides 61
4.1 Uranium 62
4.2 Thorium 63
4.3 Radium 64
5 Conclusions 65
References 65
The Influence of Edaphic Factors on Spatial and Vertical Distribution of Radionuclides in Soil 71
1 Introduction 72
2 Sources of Radionuclides in Soil 72
3 Environmental Geochemistry of Selected Radionuclides 77
4 Edaphic Factors Influencing Radionuclide Distribution in Soil 79
5 Conclusions 84
References 85
Modelling Speciation and Distribution of Radionuclides in Agricultural Soils 91
1 Introduction 92
2 Important Soil Parameters and Processes 93
2.1 Chemical Parameters and Processes 93
2.2 Physical Parameters and Processes 94
2.3 Influence of Agricultural Use 95
3 Sorption Modelling Concepts 95
3.1 Empirical Models 95
3.2 Ion Exchange 96
3.3 Mineral Surface Complexation Models 96
3.4 Ion Binding of Organic Matter 97
3.5 Model Parametrisation 98
3.6 Assemblage Models 99
4 Constructing a CA Soil Model 99
4.1 Speciation Code and Representative Soil Components 100
4.2 Thermodynamical Data 101
4.3 Model Parameters 101
4.4 Calculating the Distribution Coefficient 103
5 Verifying and Validating the Model 103
5.1 Comparison of Simulations with Averages of Experimental Kd Values for Two Soil Types 104
5.2 Simulating Experimental Uranium Distributions in Batch Experiments with Several Specified Soils 105
5.3 Sources of Uncertainties 105
6 Conclusion 107
References 107
Radiotracers as a Tool to Elucidate Trace Element Behaviour in the Water-Sediment Interface 110
1 Introduction 111
2 Experimental Studies on Sediment-Water Exchanges of Radiotracers 112
3 Biological Effects 113
4 Water and Sediment Effects 115
5 Transfer Kinetics from Overlying Water to Sediments 118
6 Conclusions and Recommendations 118
References 120
Uptake and Retention of Simulated Fallout of Radiocaesium and Radiostrontium by Different Agriculture Crops 123
1 Introduction 124
2 Interception of Radionuclides by Agricultural Crops 125
3 Activity Concentration of Radionuclides in Crops 129
3.1 Distribution of Radionuclides Between Plant Parts 132
4 Foliar Uptake of Radionuclides 134
4.1 Radiocaesium Transfer, from Potato Tops to Tubers 135
5 Conclusions 137
References 137
Root Uptake/Foliar Uptake in a Natural Ecosystem 141
1 Introduction 142
2 Materials and Methods 143
2.1 Study Area 143
2.2 Sample Collection and Processing 143
2.3 Activity Determination 144
3 Results and Discussion 145
3.1 Activity Concentration Radionuclides as a Function of Soil Depth 145
3.2 Activity Concentration in Sylva Plant Species 148
3.3 Activity Concentration of Radionuclides in Physiologically Different Plants 150
4 Conclusions 153
References 153
Assessment of Radioactivity in Forest and Grassland Ecosystems 155
1 Introduction 156
2 Materials and Methods 157
2.1 Study Area 157
2.2 Sample Collection and Processing 157
2.3 Activity Determination 158
3 Results and Discussion 159
3.1 Dose Calculations 159
3.1.1 Absorbed and Observed Dose Rates 159
3.1.2 Annual Effective Dose Equivalents 161
3.2 Radiation Hazard Indices 162
3.3 Comparison of the Activity Concentrations with Those Found in Similar Studies 163
4 Conclusions 163
References 164
Terrestrial Environmental Dynamics of Radioactive Nuclides 166
1 Introduction 167
2 Deposition of Radioactive Nuclides in the Terrestrial Environment 167
3 Radioactive Nuclide Behavior Within Soil 169
4 Radioactive Nuclide Dynamics Within Forest Ecosystem 170
5 Rediffusion of Radioactive Nuclides 171
6 Conclusion 172
References 173
Biotransformation of Radionuclides: Trends and Challenges 176
1 Introduction 177
1.1 Uranium 178
1.2 Technetium 179
1.3 Plutonium 180
1.4 Neptunium 181
1.5 Strontium and Cesium 181
1.6 Iodine 183
2 Mechanisms of Bioimmobilization of Radionuclides 183
2.1 Biosorption 184
2.2 Bioaccumulation 185
2.3 Biomineralization/Bioprecipitation 185
2.4 Bioreduction 185
3 Prospects and Challenges 186
References 188
Methods for Decrease of Radionuclides Transfer from Soil to Agricultural Vegetation 192
1 Introduction 193
2 Characteristics of Radioactive Contamination of Soils 194
2.1 The Accident at Mayak PA, 1957 194
2.2 Chernobyl Disaster, 1986 195
2.3 Fukushima Dai-Ichi Nuclear Power Plant Accident, 2011 196
3 Methods for Decrease of Cesium and Strontium Radionuclides from Radioactively Contaminated Soil to Agricultural Vegetation 197
3.1 Removal or Plowing of Contaminated Soil Layer 198
3.2 Use of Mineral Fertilizers 199
3.3 Use of Organic Fertilizers 200
3.4 Liming 201
3.5 Phytoremediation 201
3.6 Addition of Sorbents 202
3.6.1 Materials and Methods 203
3.6.2 Results and Discussion 205
4 Conclusions 211
References 211
Bacterial Diversity in Clay and Actinide Interactions with Bacterial Isolates in Relation to Nuclear Waste Disposal 215
1 Introduction 216
2 Bacterial Diversity in Clay 217
3 Determination of Actinide Interactions with Mont Terri Opalinus Clay Isolates 220
3.1 U(VI) Interaction Studies with Paenibacillus sp. and Sporomusa sp. Cells 221
3.1.1 U(VI) Binding by Paenibacillus sp. and Sporomusa sp. cells as a Function of [U(VI)] and pH Including the Bacteria-Mediat... 221
3.1.2 U(VI) Speciation Explored by Potentiometric Titration (Lütke et al. 2013 Moll et al. 2013a)
3.1.3 U(VI) Speciation Explored by Time-Resolved Laser-Induced Fluorescence Spectroscopy (TRLFS) in the Paenibacillus sp. Syst... 225
3.2 Cm(III) Interaction Studies with Paenibacillus sp. and Sporomusa sp. Cells (Lütke 2013 Moll et al. 2013a, 2014)
4 Summary and Conclusions 229
References 231
Analysis of Radionuclides in Environmental Samples 236
1 Introduction 237
2 Principles of Sampling and Sample Pretreatment 239
3 Carriers and Tracers in Radiochemical Analysis 240
4 Methods of Nonselective Preconcentration of Radionuclides 241
5 Methods of Selective Preconcentration and Separation of Radionuclides in Radiochemical Analysis 245
5.1 Use of Selective Sorbents 245
5.1.1 Thin-Layer Inorganic Sorbents 245
5.1.2 Surface-Modified Sorbents 251
5.2 Use of Extraction Chromatographic Resins 253
6 Conclusions 254
References 255
Uncertainty Analysis and Risk Assessment 259
1 Risk Analysis 260
1.1 Definition of Risk 260
1.2 Relationships Between Risk and Uncertainty 261
1.3 Relationship Between Risk and Hazard 262
1.4 Risk Quantification and Presentation 263
1.4.1 Identification of Scenarios 263
1.4.2 Consequence Analysis 264
1.4.3 Assignment of Probabilities to the Scenarios 264
1.4.4 Risk Curves and Risk Matrices 264
1.4.5 Risk Quotients 267
2 Probability 269
3 Uncertainty Analysis 270
3.1 Sources of Uncertainty 270
3.2 Assigning Probability Distributions to Model Parameters 271
3.2.1 Distribution Fitting 271
3.2.2 Maximum Entropy 271
3.2.3 Bayesian Inference 272
3.2.4 Expert Elicitation 272
3.3 Propagation of Uncertainties 273
3.3.1 Monte Carlo Analysis 273
4 Sensitivity Analysis 274
5 Conclusions 276
References 276

Produkt-Details

• Erscheint lt. Verlag: 30.10.2015
• Zusatzinfo: X, 273 p.
• Verlagsort: Cham
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Biologie ► Ökologie / Naturschutz
• Themenwelt: Naturwissenschaften ► Chemie
• Themenwelt: Technik
• Schlagworte: Artificial radioisotopes • Bioaccumulation of radionuclides • ecotoxicology • Environmental radioactivity • radioactive waste • Radioecology • Radiotracer • terrestrial pollution
• ISBN-10: 3-319-22171-X / 331922171X
• ISBN-13: 978-3-319-22171-7 / 9783319221717