Advanced ozonation processes for water and wastewater treatment : active catalysts and combined technologies

Ozone has been actively and widely employed in water and wastewater treatment, but the utilization of ozone alone is insufficient for purifying and disinfecting water to the emission standard of real-world situations because of its selective oxidation behaviour. With the assistance of catalysts (especially heterogeneous catalysts) and coupling with other effective technologies such as the Fenton process, photocatalysis, electrocatalysis, ultrasound, microwave, and ceramic membranes, ozone can be effectively activated into more powerful reactive oxygen species (especially hydroxyl radicals). These combined technologies lead to an enhanced efficiency and complete mineralization capability that open up the method for more practical applications. Advanced Ozonation Processes for Water and Wastewater Treatment introduces the state-of-the-art catalysts used in catalytic ozonation and various combined processes with ozone. The reaction mechanisms, process kinetics, structure–property–activity relationships of catalysts, effects of operation parameters in these processes and the present state of practical applications and future trends are also discussed, making this a useful reference both for water treatment professionals and for those researching ozonation processes. Cover 1 Preface 6 Foreword 8 Contents 10 Chapter 1 Heterogeneous Catalytic Ozonation over Metal Oxides and Mechanism Discussion 18 1.1 Introduction 18 1.1.1 Typical Transition Metal Oxides as Ozonation Catalysts 19 1.1.2 Catalytic Ozonation over Other Single Metal Oxides 27 1.1.3 Mixed Metal Oxides for Catalytic Ozonation 35 1.1.4 Summary 41 References 41 Chapter 2 Heterogeneous Catalytic Ozonation over Supported Metal Oxides 46 2.1 Typical Supported Metal Oxides as Ozonation Catalysts 47 2.1.1 Metal Oxides/Al2O3 47 2.1.2 Metal Oxides/TiO2 48 2.1.3 Metal Oxides/Zeolites 49 2.1.4 Metal Oxides Supported on Other Porous Materials 51 2.2 Effects of Operation Parameters on Catalytic Ozonation Efficiency 52 2.2.1 Initial pH 52 2.2.2 Ozone Dosage 53 2.2.3 Catalyst Dosage 54 2.2.4 Initial Concentration of Contaminants 54 2.2.5 Reaction Temperature 55 2.2.6 Coexisting Ions in Water 55 2.3 Catalytic Reaction Mechanisms 56 2.3.1 The Circumstance of Radical and Non-radical Pathways 56 2.3.2 Identification of Catalytic Active Sites 59 2.3.3 Mechanism Analysis by Theoretical Calculation 61 2.4 Practical Applications 64 2.4.1 Application Case 65 2.4.2 Limitations in Practical Applications 65 2.5 Summary 68 Acknowledgements 68 References 69 Chapter 3 Catalytic Ozonation over Composite Metal Oxides 73 3.1 Introduction 73 3.2 Perovskite-type Catalysts 75 3.3 Spinel-like Oxide-type Catalysts 81 3.4 Other Natural Minerals 88 3.5 Concluding Remarks and Future Trend 94 3.5.1 Perovskite Oxides 95 3.5.2 Spinel Oxide 95 3.5.3 Natural Minerals 95 Acknowledgements 96 References 96 Chapter 4 Catalytic Ozonation over Activated Carbon-based Materials 102 4.1 Activated Carbon 102 4.1.1 Adsorption or Catalysis During Ozonation with AC? 102 4.1.2 Influence of Chemical Properties, Texture Characteristics and Impurities 106 4.1.3 Influence of Water Matrix 108 4.1.4 Deactivation and Regeneration of Activated Carbon 110 4.2 Activated Carbon-supported Metal Oxides 112 4.2.1 Single-metal Oxides 112 4.2.2 Bimetallic Oxides 115 4.3 Biochar-based Materials 118 4.3.1 Biochar 118 4.3.2 Biochar-supported Metal Oxides 121 4.4 Reaction Mechanisms 124 4.4.1 Brief Description of Several Viewpoints 124 4.4.2 Reactive Oxygen Species and Intermediates Formation 125 4.4.3 Hydroxyl Radical Mechanism 128 4.5 Practical Applications 133 Acknowledgements 134 References 134 Chapter 5 Catalytic Ozonation over Nanocarbon Materials 140 5.1 Introduction 140 5.2 Carbon Nanotube-based Metal-free Nanocarbons 141 5.3 Graphene-based Metal-free Nanocarbons 146 5.4 Other Types of Metal-free Nanocarbons 151 5.5 Active Sites on Metal-free Nanocarbons 158 5.5.1 Carbon Framework and Dimensional Effect 158 5.5.2 Surface Oxygen Functionalities 159 5.5.3 Edging and Structural Defects 160 5.5.4 Heteroatom Dopants 162 5.6 Active Sites on Supported Nanocarbons 164 5.7 Methods to Probe the Active Sites on Nanocarbons 164 5.8 Oxidation Pathways in Metal-free Nanocarbon Catalyzed Ozonation 166 5.8.1 Radical-based Oxidations 166 5.8.2 Nonradical Oxidations 169 5.8.3 Identification of the Types of ROS and Evaluation of Their Roles 172 5.8.4 Critical Issues in Determination of the Oxidation Pathways 176 5.9 Conclusions and Perspectives 176 Acknowledgements 177 References 177 Chapter 6 UVA Photocatalytic Ozonation of Water Contaminants 183 6.1 Introduction 183 6.2 Ozonation of Water Contaminants 184 6.3 Photocatalytic Oxidation of Water Contaminants 185 6.4 Photocatalytic Ozonation 187 6.5 UVA Photocatalytic Ozonation 188 6.5.1 Catalysts 188 6.5.2 Radiation Sources 204 6.5.3 Reactor Type 206 6.5.4 Organics Studied and Water Matrices 208 6.5.5 AOP Comparison, Influence of Variables 212 6.5.6 Ozone Consumption, Rct, RHOO3, Scavengers 215 6.5.7 Synergism 218 6.5.8 Mechanisms of Reactions 219 6.5.9 Kinetics 220 6.5.10 Energy and Cost 224 6.5.11 Other Aspects 226 6.6 Conclusions 228 Acknowledgements 229 References 229 Chapter 7 Visible-light-driven Photocatalytic Ozonation of Aqueous Organic Pollutants 235 7.1 Introduction 235 7.2 Overview of the Catalysts and Their Performances 236 7.3 Reaction Mechanism 241 7.4 Structure–Performance Relationship of Catalysts 245 7.4.1 WO3 245 7.4.2 g-C3N4 248 7.4.3 Future Design and Optimization of g-C3N4 250 7.5 Stability of g-C3N4 Catalysts 252 7.6 Present State and Challenges for Practical Application 253 7.7 Conclusions 254 Acknowledgements 255 References 255 Chapter 8 Catalytic Peroxone Process and the Coupled Processes 258 8.1 Introduction 258 8.1.1 Mechanism 259 8.1.2 Application 260 8.1.3 Drawbacks 263 8.2 Catalysts in Peroxone Process 263 8.2.1 Traditional Metal Catalysts 263 8.2.2 Single-atom Catalysts 267 8.3 Enhancement by Other Processes 269 8.3.1 Photolysis and Photocatalysis 270 8.3.2 Sonolysis 271 8.3.3 Plasma 272 8.4 Conclusions 272 References 273 Chapter 9 Promising Electrocatalytic Ozonation Processes for Water and Wastewater Treatment 275 9.1 Introduction 275 9.2 Mechanisms of Electrocatalytic Ozonation 279 9.2.1 Mechanisms of OH Generation 279 9.2.2 Mechanisms of Pollutant Abatement 281 9.3 Cathode Studies During the E-peroxone Process 281 9.3.1 Cathode Materials 281 9.3.2 Cathode Configuration 282 9.3.3 Cathode Stability 284 9.4 Water and Wastewater Treatment by the E-peroxone Process 285 9.4.1 Removal of Organic Pollutants 285 9.4.2 Control of Harmful Oxidation By-products 285 9.4.3 Disinfection and Removal of Antibiotic Resistance Genes (ARGs) 295 9.4.4 Pilot-scale Study 296 9.5 Integration of the E-peroxone Process with Other Technologies 297 9.5.1 Combination with UV Photolysis 297 9.5.2 Combination with Adsorption 298 9.5.3 Combination with Membrane 299 9.5.4 Combination with Electrocoagulation 300 9.6 Challenges and Prospects 301 9.6.1 Challenges 301 9.6.2 Prospects 302 Acknowledgements 303 References 303 Chapter 10 Catalytic Ozonation with Ultrasound 310 10.1 Introduction 310 10.2 Fundamental Characteristics of Ultrasound 311 10.2.1 Generation of Ultrasound 311 10.2.2 Typical Reactors Applied 312 10.3 Reactivity of Compounds 317 10.3.1 Phenols 317 10.3.2 Aromatics 320 10.3.3 Dyes 320 10.3.4 Antibiotics 322 10.3.5 Industrial Wastewater 322 10.4 Reaction Kinetics 323 10.5 Influencing Factors 323 10.5.1 Ultrasonic Power Density 323 10.5.2 Frequency 323 10.5.3 The Concentration of Ozone 325 10.5.4 pH 325 10.5.5 Temperature 325 10.6 Combined Processes 326 10.6.1 Homogeneous 326 10.6.2 Heterogeneous 327 10.7 Enhanced Mechanism 327 References 328 Chapter 11 Hybrid Ceramic Membrane Catalytic Ozonation 330 11.1 Introduction 330 11.2 Coupling of Ceramic Membranes with Ozonation 331 11.2.1 Effect of Ozone Coupling Mode on EfOM Removal 332 11.2.2 Effects of Pre-O/F and In-situ-O/F on Membrane Fouling 333 11.2.3 Membrane Fouling Mitigation Mechanism 333 11.3 Coupling of Catalytic Ceramic Membranes with Ozonation 335 11.3.1 Kinds of Catalytic Ceramic Membranes and Corresponding Fabrication Methods 335 11.3.2 Reaction Mechanism 340 11.3.3 Fe-based Catalytic Ceramic Membranes 342 11.3.4 Mn-based Catalytic Ceramic Membranes 346 11.3.5 Ce-based Catalytic Ceramic Membranes 349 11.3.6 Cu-based Catalytic Ceramic Membranes 350 11.3.7 Hybrid Metal-oxide-based Catalytic Ceramic Membranes 351 11.3.8 Carbon-based Catalytic Ceramic Membranes 355 11.4 Conclusions and Outlook 363 Acknowledgements 364 References 364 Chapter 12 Ozonation Nanobubble Technology 370 12.1 Introduction to Water Disinfection and Ozonation Disinfection 370 12.1.1 Principles of Ozonation Disinfection 370 12.1.2 Limitations of Traditional Ozonation Disinfection 371 12.2 Nanobubbles and Generation Principles of Ozone Nanobubbles 372 12.2.1 Nanobubbles and Their Applications 372 12.2.2 Ozone Nanobubble Generation Methods 373 12.3 Ozone Nanobubble Properties and Applications 375 12.3.1 Stability and Disinfection Characteristics of Ozone Nanobubbles 375 12.3.2 Mass Transfer of Ozonation 376 12.3.3 Enhanced Reactivity of Ozone Nanobubbles 378 12.3.4 Applications of Ozone Nanobubbles 378 12.4 Future Research Directions 379 12.4.1 Industrialized Ozone Nanobubble Generator Development 379 12.4.2 Safety Concerns of Ozone Nanobubbles 380 Acknowledgements 381 References 381 Subject Index 388