Chemistry of Environmental Systems

JEFFREY S. GAFFNEY, PHD, is Emeritus Chair and Professor of Chemistry at the University of Arkansas at Little Rock, Arkansas, USA. Before retiring after 10 years at UALR, he was a senior chemist at three of the U.S. Department of Energy (DOE) National Labs (Argonne, Brookhaven, and Los Alamos) for 31 years, and was the Lead Scientist for the DOE Atmospheric Science Program's Megacity Aerosol Experiment – Mexico City. He served as Chief Scientist and Mentor of the DOE Global Change Education Program. He is internationally known for his work in air and water chemistry and global change research. NANCY A. MARLEY, PHD, is a retired Chemist from Argonne National Laboratory and past Research Associate Professor, Graduate Institute of Technology at the University of Arkansas at Little Rock. She was a Head Mentor for the DOE Global Change Education Program and held positions as a Senior Chemist at the Florida State Department of Environmental Regulation and the Florida State Childhood Lead Poisoning Program.

About the Authors xiii

Preface xv

Acknowledgments xix

Supplementary Material xxi

1 Introduction to Environmental Chemistry 1

1.1 What is Environmental Chemistry? 1

1.2 Anthropogenic Pollution 2

1.3 A Planet at Risk 4

1.4 Energy, Water, and Population Connections 6

1.5 The Need to Understand Environmental Problems 10

1.6 Atmosphere–Hydrosphere–Geosphere–Biosphere Linkages 13

References 16

Study Problems 16

2 Atmospheric Composition and Basic Physics 19

2.1 Evolution of the Atmosphere 19

2.2 Structure and Composition of the Modern Atmosphere 22

2.3 Atmospheric Circulation 27

2.4 Energy Balance 34

2.4.1 Milankovitch Cycles 35

2.4.2 Planetary Albedo 38

2.4.3 Greenhouse Gases 40

2.4.4 Aerosols 43

2.5 Global Climate Models 44

References 47

Study Problems 48

3 The Fundamentals of Photochemistry 51

3.1 Light and Photochemistry 51

3.2 The Laws of Photochemistry 57

3.3 Thermochemical and Photochemical Processes 59

3.3.1 Activation Energy 60

3.3.2 Kinetics 62

3.4 Photochemical Deactivation Processes 69

References 72

Further Reading 72

Study Problems 72

4 Chemistry of the Stratosphere 75

4.1 Structure and Composition of the Stratosphere 75

4.2 The Ozone Layer 78

4.3 Ozone Formation in the Stratosphere 80

4.3.1 The Chapman Cycle 80

4.3.2 Term Symbols 81

4.3.3 The HOx and NOx Cycles 83

4.4 Ozone Depletion 85

4.4.1 Chlorofluorocarbons 85

4.4.2 The “Ozone Hole” 88

4.4.3 Altitude Dependence 90

4.4.4 Ozone-Depleting Substances 93

4.5 Summary 95

References 98

Further Reading 99

Study Problems 99

5 Chemistry of the Troposphere 103

5.1 Structure and Composition of the Troposphere 103

5.2 History of Smog 105

5.3 The Clean Air Act 110

5.3.1 Criteria Pollutants 110

5.3.2 Non-Criteria Pollutants 112

5.4 Formation of Ozone in the Troposphere 113

5.4.1 The Photostationary State 113

5.4.2 The Hydroxyl Radical 114

5.4.3 Hydroxyl Radical Abstraction Reactions 115

5.4.4 Hydroxyl Radical Addition Reactions 118

5.5 Nitrate Radical and Ozone 121

5.6 The Peroxyacyl Nitrates 122

5.7 Troposphere–Biosphere Interactions 124

References 127

Further Reading 128

Study Problems 128

6 Aerosols and Cloud Chemistry 133

6.1 Aerosol Size Distributions 133

6.2 Aerosol Sources and Sinks 136

6.2.1 Primary Aerosol Emissions 138

6.2.2 Secondary Aerosol Formation 140

6.2.3 Wet Deposition and Henry’s Law 143

6.2.4 Dry Deposition 145

6.3 Aerosol Lifetimes 148

6.4 Determination of Aerosol Sources 151

6.5 Aerosol Health Effects 156

6.6 Aerosol Visibility and Climate Effects 158

6.7 Aqueous Chemistry 164

References 165

Further Reading 166

Study Problems 166

7 Analytical Methods for Air Analysis 171

7.1 Sampling Methods 172

7.2 Gas Species Measurement Methods 175

7.2.1 The Oxidants: Ozone, Hydroxyl Radical, Peroxyacyl Nitrates, Peroxides, and Peracids 175

7.2.2 The Oxides: Nitric Oxide, Nitrogen Dioxide, Nitric Acid, Carbon Monoxide, Carbon Dioxide, Sulfur Dioxide, and Nitrous Oxide 186

7.2.2.1 Nitric Oxide, Nitrogen Dioxide, and Nitric Acid 186

7.2.2.2 Nitric Acid, Carbon Monoxide, Carbon Dioxide, Sulfur Dioxide, and Nitrous Oxide 188

7.2.3 The Organics: Volatile Organic Hydrocarbons, Aldehydes, Ketones, and Halogenated Hydrocarbons 191

7.3 Aerosols 195

7.3.1 Sample Collection 195

7.3.2 Aerosol Composition 196

7.4 Aerosol Optical Properties 199

7.5 Method Selection 201

7.6 The Importance of Baseline Measurements 204

References 207

Further Reading 207

Study Problems 208

8 Chemistry of Surface and Ground Waters 213

8.1 The Unique Properties of Water 214

8.2 The Hydrological Cycle 216

8.3 Ocean Currents and Circulation 220

8.4 The Structure of Natural Aquatic Systems 224

8.4.1 The Oceans 224

8.4.2 Freshwater Systems 225

8.5 The Composition of Natural Aquatic Systems 228

8.5.1 Dissolved Oxygen 229

8.5.2 Nitrogen and Phosphorus 230

8.5.3 Sulfur 232

8.5.4 Carbon 233

8.6 Water Pollution 238

8.6.1 Point Sources 239

8.6.2 Nonpoint Sources 243

8.7 Contaminant Transformation 246

8.8 Contaminant Transport 252

References 257

Further Reading 258

Study Problems 258

9 Analytical Methods for Water Analysis 263

9.1 Sampling Methods 263

9.2 Dissolved Species 266

9.2.1 Electrochemical Methods 267

9.2.2 Spectroscopic Methods 272

9.2.3 Chromatographic Methods 286

9.2.4 Titration Methods 291

9.2.5 Radiochemical Methods 292

9.3 Particulates and Colloids 293

9.4 Contaminant Issues 297

References 299

Study Problems 300

10 Fossil and Biomass Fuels 305

10.1 Combustion Chemistry 305

10.2 Formation and Recovery of Fossil Fuels 308

10.2.1 The Formation of Fossil Fuels 309

10.2.2 Coal Mining 313

10.2.3 Oil and Gas Recovery 315

10.3 Fossil Fuel Use 319

10.4 Biomass Fuels 323

10.4.1 Biomass Fuel Production 324

10.4.2 Biomass Fuel Use 326

10.5 Impacts on Water Quality 330

10.5.1 Fossil Fuels 330

10.5.2 Biomass Fuels 335

10.6 Impacts on Air Quality 338

10.6.1 Fossil Fuels 338

10.6.2 Biomass Fuels 345

10.7 Gasoline Additives: Lessons Learned 347

References 349

Study Problems 350

11 Climate Change 355

11.1 Prehistoric Climates 358

11.2 Causes of Climate Change 360

11.2.1 Global Warming Potentials 362

11.2.2 Greenhouse Gas Sources and Sinks 363

11.2.3 Radiative Forcing 367

11.3 Climate Models 368

11.4 Predictions of Future Climate Change 370

11.5 Impacts from the Predicted Temperature Rise 373

11.6 Climate Effects on Air Quality and Health 377

11.7 Mitigation and Adaption Strategies 379

References 386

Study Problems 386

12 Nuclear Energy 391

12.1 Radioactivity 391

12.2 Radioactive Emissions and Decay Kinetics 394

12.3 Sources of Radioisotopes 399

12.4 Nuclear Fission 401

12.5 Nuclear Weapons Testing and Fallout 403

12.6 Nuclear Power 407

12.6.1 Harnessing Nuclear Energy 407

12.6.2 Uranium Production 410

12.6.3 Nuclear Plant Designs 412

12.6.4 Nuclear Waste 414

12.7 Radioisotopes in the Environment 417

12.8 Radiation Exposure 421

12.9 Applications of Radioisotopes 424

References 428

Study Problems 429

13 Future Energy Sources and Sustainability 433

13.1 The Need for Non-Fossil Energy Sources 434

13.2 Alternative Energy Sources 437

13.2.1 Wind Power 438

13.2.2 Hydropower 442

13.2.3 Geothermal Energy 444

13.2.4 Solar Power 445

13.2.5 Biomass 449

13.2.6 Hydrogen 450

13.3 Sustainability 452

13.4 Long-Term Planning 455

References 460

Study Problems 461

Appendix A Answers to Study Problems 465

Appendix B List of U.S. EPA Hazardous Air Pollutants – Air Toxics 503

Appendix C Henry’s Law Constants (Hx) for Selected Inorganic and Organic Compounds 509

Appendix D Organic Water Pollutants, their Chemical Structures, Sources, and Concentration Limits in U.S. Drinking Water 519

Appendix E Chemicals Used in the Hydraulic Fracturing of Oil Shales for Natural Gas Extraction 527

Glossary 529

Index 541