Environmental Surfaces and Interfaces from the Nanoscale to the Global Scale

Patricia Maurice is Professor in the Department of Civil Engineering and Geological Sciences at the University of Notre Dame. She is on the editorial panel of Environmental Engineering Science, and sits on the Board of Directors for the Consortium of Universities for the Advancement of Hydrological Sciences.

• Preface xvConstants and Units xviiPeriodic Table of the Elements 1 Some Fundamental Chemical Thermodynamic and Kinetic Concepts 1Concentration Units 1Thermodyamic Versus Kinetic Approaches 2Introductory Thermodynamics 3Gibbs Energy 4Chemical Potential and Activity 4Equilibrium Constants 5Calculating the Equilibrium Constant from Gibbs Energy Changes 6Temperature Effects on Keq 8Calculating Activities 9Saturation Indices (SIs) 12Carbonate Equilibria in Open or Closed Systems 13Calcite Equilibria in a System Open to Atmospheric Carbon Dioxide 14Redox Reactions 17Metal Speciation Diagrams 19A Brief Introduction to Kinetics 20Overall Versus Elementary Reactions 20Molecularity and Reaction Order 21Transition State Theory and the Arrhenius Equation 24Michaelis-Menten Kinetics 25The Elovich Equation for Chemisorption Kinetics 26Simultaneous Versus Sequential Reaction Sequences 27Transport Versus Surface Control of Mineral Growth and Dissolution Rates 28Rate Laws for Surface-Controlled Mineral Growth and Dissolution 30Equilibration Time in Porous Media 31Questions for Further Thought 31Further Reading 342 The Hydrologic Cycle as Context for Environmental Surfaces and Interfaces 35The Structure and Fundamental Properties of Water 35The Chemical Composition of the Earth 37The Critical Zone 38The Hydrologic Cycle 38Oceans 39Atmosphere 40Underground water 43Soils and Soil Water 44Groundwater 45Surface Waters: Focus on Rivers 52Stream Load 52Gibbs Plots 54The Hyporheic Zone 56The OTIS Model and Solute Transport in Streams 56Particle Transport and Sedimentation 57Water Budgets and Chemical Fluxes in Terrestrial Ecosystems 59Questions for Further Thought 62Further Reading 663 Some Minerals of Special Interest to Environmental Surface Chemistry 67Gibbsite 67Quartz 68Kaolinite 69Smectite: Example Montmorillonite 71Fe(hydr)oxides 73Hematite 73Goethite 73Lepidocrocite 76Maghemite 77Ferrihydrite 77Magnetite 77Manganese Oxides 77Calcite 78Feldspars 79Zeolites 79Questions for Further Thought 81Further Reading 814 Some Key Techniques for Investigating Surfaces and Interfaces 82A Brief Overview of Some Commonly Used Techniques 82In-Depth Descriptions of Some Key Techniques 86Scanning Electron Microscopy (SEM) 86Transmission Electron Microscopy (TEM) 87Scanning Tunneling Microscopy (STM) 90Case Study: Imaging Parameters and High-Resolution Imaging of Hematite 91AFM and Interfacial Forces 92X-Ray Photoelectron Spectroscopy (XPS) 99BET Surface Area Measurements 100Some Synchrotron-Based Techniques 103Microscopies for Biofilm Imaging 108Questions for Further Thought 108Further Reading 1115 Surfaces and Interfaces 112What is a Surface? What is an Interface? 112The Challenges of Defining Surfaces and Interfaces 113Surfaces are Complex 114Relaxation and Reconstruction 114Surface Sites 115Surface Microtopography 116Surface Free Energy 117Water Near Surfaces 119Dynamic Surfaces 120Bacterial Substrates 120Fractal Properties of Surfaces and Environmental Particles 120Interdisciplinary Topic of Study 123Surface Free Energy and Surface Excess 124Surface Tension and Related Phenomena 126Surfactants and Micelles 126Contact Angle 127The Young-Laplace Equation 128Meniscus and Capillarity 128The Gibbs Equation 130Some Approaches to Surface and Interface Modeling 130Case Study: Bacteria–Mineral–Gas Interactions in the Vadose Zone 132Questions for Further Thought 133Further Reading 1356 The Charged Interface and Surface Complexation 136Some Evidence for Surface Charge 136Sources of Mineral Surface Charge 137Points of Zero Charge 139Case Study: The Surface Charge Properties of Kaolinitic Soils 140Sorption Terminology 141Cation Exchange Capacity 145Sorption Isotherms 148Adsorption Isotherm Equations 151The Langmuir Isotherm Equation 151The Freundlich Isotherm Equation 152The Frumkin Isotherm Equation 153The Double Layer, Gouy-Chapman Theory 153Beyond Gouy-Chapman: Surface Complexation Models 155Constant Capacitance Model (CCM) 161The Diffuse Double Layer (DDL) Model 161Triple Layer Model (TLM) 161Charge Distribution CD/MUSIC Model 162Model Verification and Validation 163Case Study: Incorporating the Work Associated with Removal of Water During Adsorption into the TLM 164DLVO Theory and Colloid Attachment in Porous Media 165Questions for Further Thought 168Further Reading 1727 Sorption: Inorganic Cations and Anions 173A Typical Sorption Experiment Design 174Metal Cation Sorption 176The Complexity of Cation Adsorption 179Inorganic Anion Adsorption 183Phosphate Adsorption 184Nitrate Adsorption 186Sulfate Adsorption 186Carbonate Sorption 186Importance of Redox State and Valence to Inorganic Ion Adsorption 187Chromium 187Neptunium 188Uranium 188Selenium 188Case Study: Arsenic Speciation and Mobility 189Questions for Further Thought 192Further Reading 1938 Sorption: Organic Compounds 194A Brief Introduction to Organic Chemistry 195Some Organic Compounds of Interest in Environmental Surface Chemistry 200Polymers 200Organic Surfactants, Including Fatty Acids 200Humic Substances 201Polycyclic Aromatic Hydrocarbons (PAHs) 202Substituted Nitrobenzenes (SNBs) 204Volatile Organic Compounds (VOCs) 205Sorption of Simple Organic Ligands, Surfactants, and Natural Organic Matter 205Adsorption of Simple Organic Ligands 205Adsorption of Anionic Surfactants, Fatty Acids 207Sorption of Cationic Surfactants 208Sorption of Phospholipid Surfactants: Biomedical Implications 209Adsorption of Humic And Fulvic Acids (NOM) 210Metal–Ligand Coadsorption: Ternary Surface Complexes 214Sorption of Some Organic Pollutants 215Vapor Pressure, Solubility, and Density 215The Octanol-Water Partition Constant, Kow 218Organic Fuel and Solvent Leaks: Volatilization, Solubility, Density, and Kow 219The Hammett Constant σ for Substituted Aromatic Acids Based on the Benzene Ring 220Case Study: Sorption of SNBs 221Molecular Dynamics (MD) Modeling of Atrazine Absorption 223The K d Approach to Hydrophobic Organic Compound Transport in Porous Media 224Activated Carbon and Sorption of VOCs 226Questions for Further Thought 227Further Reading 2309 Mineral Nucleation and Growth 231Saturation State and Mineral Nucleation: An Example of the Confluence of Thermodynamics and Kinetics 231Hydroxypyromorphite Nucleation 233Heterogeneous Nucleation and Epitaxial Growth 233From Nucleation to Growth 236Ostwald Ripening 236Transport and Surface Controlled Growth 236The Special Importance of Kink Sites 237BCF Theory 238Growth Mode and Driving Force 240Case Study: Calcite Birth and Spread versus Spiral Growth: BCF Theory 241Rates of Step Advancement 242Impurities and Growth at Steps 245Monte Carlo Simulations of Crystal Growth 246Biomineralization 247Carbonate Precipitation in the Marine Environment 249Questions for Further Thought 251Further Reading 25210 Mineral Weathering and Dissolution 253Chemical, Physical, and Biological Weathering 253Thermodynamics of Mineral Weathering 256Kinetics of Mineral Dissolution 260Etch Pit Formation 261Oxalate Promoted Dissolution of Hematite 263Comparison of Laboratory- and Field-Based Dissolution Rates 264Reactive Surface Area and Feldspar Dissolution 266Rainfall and Weathering: An Example from the Hawaiian Islands 269Case Study: Weathering in the Antarctic Dry Valleys 270Reactors for Dissolution Experiments 273The Use of Radiogenic Isotopes in Weathering Studies 276Questions for Further Thought 276Further Reading 27911 Plants as Environmental Surfaces 280Ecohydrology and Soil Moisture Balance 280Some Notes on Angiosperm Physiology 282The Nutrient Needs of Plants 282Effects of Plants on Mineral Dissolution and Weathering 284Modes of Plant Elemental Cycling 287Plants and Biomineralization: Phytoliths 287Plants and Formations in Limestone Caves 289Phytoremediation as an Example of Plant-Mineral-Contaminant Interactions 291Case Study: Phytoremediation of Atrazine 293Questions for Further Thought 294Further Reading 29512 Microorganisms As Environmental Surfaces 296How Microorganisms “make a Living” 298Metabolic Pathways 298Microbial Redox Reactions and Michaelis-Menten Kinetics 303Microbial Temperature Ranges and Extremophiles 305Microbial Growth Curves 306Bacterial Groups 307Bacterial Cell Walls 307Bacterial Adhesion and Biofilms 309Bacterial–Metal Interactions 312Bacterial-Promoted Mineral Dissolution 313Dissolution of Fe(III)(hydr)oxides by DIRB 313Dissimilatory Metal-Reducing Bacteria 315Microbial Effects on Carbonate Dissolution 315The Importance of Field-Based Studies 317Case Study: The In Situ Microcosm Approach 318Coupling In Situ Microcosms with Community Analysis 318Siderophores 320Microbial Biomineralization 322Carbonate Precipitation 322Fe(III)(hydr)oxide Precipitaton: BIOS 323Banded Iron Formations (BIF) 324(Alumino)silicate Precipitation 326Case Study: Bioremediation of U at the Oak Ridge National Laboratory Site 327Microbial Fuel Cells 329Questions for Further Thought 332Further Reading 33313 Environmental Nanoscience and Nanotechnology 335What is a Nanoparticle? 335Nanoparticle Occurrence and Distribution 337What Makes a Nanoparticle Different? 339Nanoparticle Surface Area, Stability, and Reactivity 340Nanoparticles Have a Different Electronic Structure 340How Electronic Structure Influences Nanoparticle Behavior 342Nanoparticle Disorder and Defect Structures 343Ferrihydrite Size, Structure, and Stability 343Effects of pH and Adsorbed Ions on Nanoparticle Stabilities 344Case Study: Fe(hydr)oxide Size and Stability 345Secondary Growth of Nanoparticles 346Self-Assembly and Templating 348Nanoparticle Transport in Porous Media 348The Emergence of Nanotechnology 350Potential Environmental Effects of Engineered Nanoparticles 351Questions for Further Thought 353Further Reading 35414 The Big Picture: Interface Processes and the Environment 356Reactive Transport Models for Metals and Radionuclides in Porous Media 356The K d Approach Encounters Difficulties for Metals and Radionuclides 356Comparison of the K d versus Surface Complexation Modeling Approaches 357Acid Rain Effects on Chemical Weathering 358What Makes Rainfall Acidic? 359Effects of Acid Rain 360Acid Rain and Chemical Weathering 360The Small Watershed Approach 362NETPATH and PHREEQC 362The Clean Air Act and Acid Rain Over Time 363Acid Mine Drainage 364The Environmental Problem 365Nanoparticles and AMD 365Hydrobiogeochemical and Photoreductive Processes 365Biofilms and AMD 367Potential Remediation Strategies 369Environmental Particles and Climate Change 369Climate Forcing and Feedbacks 370Volcanoes and Climate 373CO2 and Weathering 374Modeling the C Cycle Over Geologic Time 376Scaling Phenomena: Integrating Observations from the Atomic to the Watershed to the Global Scale 378The Concept of the Macroscope 378Embedded Sensor Network Systems 379Sensors for Surface and Interface Phenomena 380New Opportunities: New Challenges 380Questions for Further Thought 381Further Readings 383Glossary of Terms 385References 405Index 437