Cover

Title Page

Copyright

Contents

Preface

Acknowledgment

Chapter 1 Ion Exchange and Ion Exchangers: An Introduction

1.1 Historical Perspective

1.2 Water and Ion Exchange: An Eternal Kinship

1.3 Constituents of an Ion Exchanger

1.4 What is Ion Exchange and What is it Not?

1.5 Genesis of Ion Exchange Capacity

1.5.1 Inorganic

1.5.2 Organic/Polymeric Ion Exchanger

Agreement and Anomaly

1.5.3 Strong-Base Type I and Type II Anion Exchanger

1.6 Biosorbent, Liquid Ion Exchanger, and Solvent Impregnated Resin

1.6.1 Biosorbent

1.6.2 Liquid Ion Exchange

1.6.3 Solvent-Impregnated Resins

1.7 Amphoteric Inorganic Ion Exchangers

1.8 Ion Exchanger versus Activated Carbon: Commonalities and Contrasts

1.9 Ion Exchanger Morphologies

1.10 Widely Used Ion Exchange Processes

1.10.1 Softening

1.10.2 Deionization or Demineralization

Summary

References

Chapter 2 Ion Exchange Fundamentals

2.1 Physical Realities

2.2 Swelling/Shrinking: Ion Exchange Osmosis

2.3 Ion Exchange Equilibrium

2.3.1 Genesis of Non-Ideality

2.4 Other Equilibrium Constants and Equilibrium Parameters

2.4.1 Corrected Selectivity Coefficient

2.4.2 Selectivity Coefficient, KIXse

2.4.3 Separation Factor (aAB)

2.4.4 Separation Factor: Homovalent Ion Exchange

2.4.5 Separation Factor: Heterovalent Exchange

2.4.6 Physical Reality of Selectivity Reversal: Role of Le Châtelier’s Principle

2.4.7 Equilibrium Constant: Inconsistencies and Potential Pitfalls

2.5 Electrostatic Interaction: Genesis of Counterion Selectivity

2.5.1 Monovalent-Monovalent Coulombic Interaction

2.6 Ion Exchange Capacity: Isotherms

2.6.1 Batch Technique

2.6.2 Regenerable Mini-Column Method

2.6.3 Step-Feed Frontal Column Run

2.7 The Donnan Membrane Effect in Ion Exchanger

2.7.1 Coion Invasion or Electrolyte Penetration

2.7.2 Role of Cross-linking

2.7.3 Genesis of the Donnan Potential

2.8 Weak-Acid and Weak-Base Ion Exchange Resins

2.8.1 pKa Values of Weak Ion Exchange Resins

2.8.2 Weak-Acid and Weak-Base Functional Groups

Weak-Acid Ion Exchange Resin

Weak-Base Ion Exchange Resin

2.9 Regeneration

2.9.1 Selectivity Reversal in Heterovalent Ion Exchange

2.9.2 pH Swings

2.9.3 Ligand Exchange with Metal Oxides

2.9.4 Use of Co-Solvent

2.9.5 Dual-Temperature Regeneration

2.9.6 Carbon Dioxide Regeneration

2.9.7 Regeneration with Water

2.10 Resin Degradation and Trace Toxin Formation

2.10.1 Formation of Trace Nitrosodimethylamine (NDMA) from Resin Degradation

2.11 Ion Exclusion and Ion Retardation

2.11.1 Ion Exclusion

2.11.2 Ion Retardation

2.12 Zwitterion and Amino Acid Sorption

2.12.1 Interaction with a Cation Exchanger: Role of pH

2.13 Solution Osmotic Pressure and Ion Exchange

2.14 Ion Exchanger as a Catalyst

Summary

References

Chapter 3 Trace Ion Exchange

3.1 Genesis of Selectivity

3.2 Trace Isotherms

3.3 Multi-Component Equilibrium

3.4 Agreement with Henry's Law

3.5 Multiple Trace Species: Genesis of Elution Chromatography

3.5.1 Determining Separation Factor from Elution Chromatogram

3.6 Uphill Transport of Trace Ions: Donnan Membrane Effect

3.7 Trace Leakage

3.8 Trace Fouling by Natural Organic Matter

3.9 Ion Exchange Accompanied by Chemical Reaction

3.9.1 Precipitation

3.9.2 Complexation

3.9.3 Redox Reaction

3.10 Monovalent-Divalent Selectivity

3.10.1 Effect of Charge Separation: Mechanistic Explanation

3.10.2 Nitrate/Sulfate and Chloride/Sulfate Selectivity in Anion Exchange

3.10.3 Genesis of Nitrate-Selective Resin

3.10.4 Chromate Ion Selectivity

3.11 Entropy-Driven Selective Ion Exchange: The Case of Hydrophobic Ionizable Organic Compound (HIOC)

3.11.1 Focus of the Study and Related Implications

3.11.2 Nature of Solute-Sorbent and Solute-Solvent Interactions

Interaction during Desolvation of PCP-

Interaction during PCP- Sorption onto the Polymeric Exchanger

3.11.3 Experimental Observations: Stoichiometry, Affinity Sequence, and Cosolvent Effect

3.11.4 Energetics of the Sorption Process

3.11.5 Unifying Hydrophobic Interaction: From Gas-Liquid to Liquid-Solid System

3.11.6 Effect of Polymer Matrix and Solute Hydrophobicity

3.12 Linear Free Energy Relationship and Relative Selectivity

3.13 Simultaneous Removal of Target Metal Cations and Anions

3.14 Deviation from Henry's Law

3.14.1 Ions Forming Polynuclear Species

3.15 Tunable Sorption Behaviors of Amphoteric Metal Oxides

3.16 Ion Sieving

3.16 Example S3.1

3.16 Example S3.2

3.17 Trace Ion Removal

3.17.1 Uranium(VI)

3.17.2 Radium

3.17.3 Boron

3.17.4 Perchlorate (ClO4-)

3.17.5 Emerging Contaminants of Concern and Multi-Contaminant Systems

3.17.6 Arsenic and Phosphorus: As(V), P(V), and As(III)

3.17.7 Fluoride (F-)

Summary

References

Chapter 4 Ion Exchange Kinetics: Intraparticle Diffusion

4.1 Role of Selectivity

4.2 State of Water Molecules inside Ion Exchange Materials

4.3 Activation Energy Level in Ion Exchangers: Chemical Kinetics

4.3.1 Activation Energy Determination from Experimental Results

4.4 Physical Anatomy of an Ion Exchanger: Gel, Macroporous and Fibrous Morphology

4.4.1 Gel-Type Ion Exchanger Beads

4.4.2 Macroporous Ion Exchanger Beads

4.4.3 Ion Exchange Fibers

4.5 Column Interruption Test: Determinant of Diffusion Mechanism

4.6 Observations Related to Ion Exchange Kinetics

4.6.1 Effect of Concentration on Half-time (t1/2)

4.6.2 Major Differences in Ion Exchange Rate

4.6.3 Chemically Similar Counterions with Significant Differences in Intraparticle Diffusivity

4.6.4 Effect of Competing Ion Concentrations: Gel versus Macroporous

4.6.5 Intraparticle Diffusion during Regeneration

4.6.6 Shell Progressive Kinetics versus Slow Diffusing Species

4.7 Interdiffusion Coefficients for Intraparticle Diffusion

4.8 Trace Ion Exchange Kinetics

4.8.1 Chlorophenols as the Target Trace Ions

4.8.2 Intraparticle Diffusion inside a Macroporous Ion Exchanger

4.8.3 Effect of Sorption Affinity on Intraparticle Diffusion

4.8.4 Solute Concentration Effect

4.9 Rectangular Isotherms and Shell Progressive Kinetics

4.9.1 Anomalies in Arrival Sequence of Solutes

4.9.2 Quantitative Interpretation

4.10 Responses to Observations in Section 4.6

4.10.1 Effect of Concentration on Half-time (t1/2)

4.10.2 Slow Kinetics of Weak-Acid Resin

4.10.3 Chemically Similar Counterions: Drastic Difference in Intraparticle Diffusivity

4.10.4 Gel versus Macroporous

4.10.5 Intraparticle Diffusion during Regeneration

4.10.6 Shrinking Core or Shell Progressive Kinetics

4.11 Rate-Limiting Step: Dimensionless Numbers

4.11.1 Implications of Biot Number: Trace Ion Exchange

4.12 Intraparticle Diffusion: From Theory to Practice

4.12.1 Reducing Diffusion Path Length: Short-Bed Process and Shell-Core Resins

4.12.2 Development of Bifunctional Diphonix® Resin

4.12.3 Ion Exchanger as a Host for Enhanced Kinetics

Summary

References

Chapter 5 Solid- and Gas-Phase Ion Exchange

5.1 Solid-Phase Ion Exchange

5.1.1 Poorly Soluble Solids

5.1.2 Desalting by Ion Exchange Induced Precipitation

5.1.3 Separation of Competing Solid Phases

5.1.4 Recovery from Ion Exchange Sites of Soil

5.1.5 Composite or Cloth-like Ion Exchanger (CIX)

5.1.6 Heavy Metals (Me2+) with Solids Possessing High Buffer Capacity

5.1.7 Ligand-Induced Metal Recovery with a Chelating Exchanger

5.2 Coagulant Recovery from Water Treatment Sludge

5.2.1 Development of Donnan IX Membrane Process

5.2.2 Alum Recovery: Governing Donnan Equilibrium

5.2.3 Process Validation

5.3 Gas Phase Ion Exchange

5.3.1 Sorption of Acidic and Basic Gases

5.3.2 CO2 and SO2 Capture with Weak-Base Anion (WBA) Exchanger

5.3.3 Effect of Ion Exchanger Morphology

Gel versus Macroporous

Ion Exchange Fibers

5.3.4 Redox Active Gases: Hydrogen Sulfide and Oxygen

5.4 CO2 Gas as a Regenerant for IX Softening Processes: A Case Study

Summary

References

Chapter 6 Hybrid Ion Exchange Nanotechnology (HIX-Nanotech)

6.1 Magnetically Active Polymer Particles (MAPPs)

6.1.1 Characterization of MAPPs

6.1.2 Factors Affecting Acquired Magnetic Activity

6.1.3 Retention of Magnetic Activity and Sorption Behavior

6.2 Hybrid Nanosorbents for Selective Sorption of Ligands (e.g., HIX-NanoFe)

6.2.1 Synthesis of Hybrid Ion Exchange Nanomaterials

6.2.2 Characterization of Hybrid Nanosorbents

6.2.3 Parent Anion Exchanger versus Hybrid Anion Exchanger (HAIX-NanoFe(III)): A Comparison

6.2.4 Support of Hybrid Ion Exchangers: Cation versus Anion

Donnan Membrane Equilibrium and Coion Exclusion Effect

6.2.5 Efficiency of Regeneration and Field Application

6.2.6 Hybrid Ion Exchange Fibers: Simultaneous Perchlorate and Arsenic Removal

6.3 HAIX-NanoZr(IV): Simultaneous Defluoridation and Desalination

6.3.1 Field-Scale Validation

6.4 Promise of HIX-Nanotechnology

Summary

References

Chapter 7 Heavy Metal Chelation and Polymeric Ligand Exchange

7.1 Heavy Metals and Chelating Ion Exchangers

7.1.1 Heavy Metals: What are They?

7.1.2 Properties of Heavy Metals and Separation Strategies

7.1.3 Emergence of Chelating Exchangers

7.1.4 Lewis Acid-Base Interactions in Chelating Ion Exchangers

7.1.5 Regeneration, Kinetics and Metals Affinity

7.2 Polymeric Ligand Exchange

7.2.1 Conceptualization and Characterization of the Polymeric Ligand Exchanger (PLE)

7.2.2 Sorption of Polymeric Ligand Exchangers

7.2.3 Validation of Ligand Exchange Mechanism

Summary

References

Chapter 8 Synergy and Sustainability

8.1 Waste Acid Neutralization: An Introduction

8.1.1 Underlying Scientific Concept

Weak-Acid Cation Exchangers

Weak-Base Anion Exchangers

8.1.2 Mechanical Work through a Cyclic Engine

8.2 Improving Stability of Anaerobic Biological Reactors

8.2.1 Potential Use of Selective Ion Exchanger

8.2.2 Ion Exchange Fibers: Characterization and Performance

8.3 Sustainable Aluminum-Cycle Softening for Hardness Removal

8.3.1 Current Status and Challenges

8.3.2 Sodium-Free Approaches and Alternatives to Na-Cycle Softening

8.3.3 Underlying Scientific Approach of Al-cycle Cation Exchange

8.3.4 Comparison in Performance: Na-Cycle versus Al-Cycle

Softening with SAC-Na Resins

Softening with SAC-Al Resins

SAC-Al Regeneration and SEM-EDX Mapping

8.3.5 Regeneration Efficiency and Calcium Removal Capacity

8.3.6 Sustainability Issues and New Opportunities

8.4 Closure

Summary

References

Appendix A Commercial Ion Exchangers

Appendix B Different Units of Capacity, Concentration, Mass, and Volume

B.1 Capacity

B.2 Concentration (Expressed as CaCO3)

B.3 Mass

B.4 Volume

Appendix C Table of Solubility Product Constants at 25°C

Appendix D Acid and Base Dissociation Constants at 25°C

Index

EULA