Elvis Fosso-Kankeu, PhD, has a doctorate degree from the University of Johannesburg in South Africa. He is currently a Full Professor in the Department of Electrical and Mining Engineering, Pretoria, South Africa. His research focuses on the prediction of pollutant dispersion from industrial areas and the development of effective and sustainable methods for the removal of inorganic and organic pollutants from polluted water. He has published more than 220 journal articles, books, book chapters, and conference proceeding papers. Sadanand Pandey, PhD, is a Research Professor in the School of Chemistry and Biochemistry, Yeungnam University, South Korea. He was a Kothari fellow at the world-prestigious Indian Institute of Science (2011–2013) and NRF scientist at the University of Johannesburg, South Africa (2014–2018). His research activities span the disciplines of polymer chemistry, nanotechnology, and sustainable and advanced materials. He has published more than 100 SCI Journal articles, and 10 book chapters as well as co-edited a number of books. Suprakas Sinha Ray, PhD, is a chief researcher in polymer nanocomposites at the CSIR, India with a PhD in physical chemistry from the University of Calcutta (2001), and director of the DST-CSIR National Centre for Nanostructured Materials. Ray’s current research focuses on polymer-based advanced nanostructured materials and their applications. Prof. Ray is the author of 4 books, co-edited 3 books, 30 book chapters on various aspects of polymer-based nanostructured materials & their applications, and the author and co-author of more than 300 articles in high-impact international journals. He has also 6 patents and 7 new demonstrated technologies (commercialized) shared with colleagues, collaborators, and industrial partners.

• Preface xiiiPart 1: Advances in Photocatalysts Synthesis 11 Advancement and New Challenges in Heterogeneous Photocatalysts for Industrial Wastewater Treatment in the 21st Century 3Sadanand Pandey, Tanushri Chatterji, Edwin Makhado, Abbas Rahdar, Elvis Fosso-Kankeu and Misook Kang1.1 Introduction 41.2 Development of Heterogeneous Photocatalysts 61.3 Mechanism of Action of Heterogeneous Photocatalysis 81.4 Recent Advances in Heterogeneous Photocatalyst 111.5 Heterostructure Photocatalysts for the Degradation of Organic Pollutants 171.6 Photoreactors 191.7 Photoreactors for the Degradation of Volatile Organic Compounds 201.7.1 Annular Reactors 201.7.2 Plate Reactor 211.7.3 Packed Bed Reactors 221.7.4 Honeycomb Monolith Reactors 221.7.5 Fluidized Bed Reactors 231.7.6 Batch Reactors 231.7.7 Parabolic Trough Photoreactors 261.7.8 Inclined Flat Photoreactors 261.7.9 Gas Phase Photoreactors 261.8 Advantages and Disadvantages of Heterogeneous Photocatalysis 271.9 Conclusion 28Acknowledgment 28References 292 Role of Heterogeneous Catalysts for Advanced Oxidation Process in Wastewater Treatment 37Rupali Mishra, Sadanand Pandey and Elvis Fosso-KankeuAbbreviations 382.1 Introduction 382.1.1 Advanced Oxidation Processes (AOPs) 412.1.2 AOPs Classification 412.1.2.1 Catalytic Oxidation 412.1.2.2 Heterogeneous Catalytic Oxidation 422.2 Effect of Pollutant 432.3 Type of Catalysts 432.3.1 Metal Organic Frameworks 432.3.1.1 Hydro (Solvo) Thermal Technique 452.3.2 Metal Oxides 462.3.2.1 Coprecipitation Method 462.3.2.2 Hydrothermal Synthesis 472.3.2.3 Sol-Gel Process 472.3.2.4 Bioreduction Method 472.3.2.5 Solvent System-Based Green Synthesis 482.3.3 Perovskites 492.3.3.1 Ultrasound-Assisted Synthesis of Perovskites 492.3.3.2 Microwave-Assisted Synthesis of Perovskites 492.3.3.3 Mechanosynthesis of Perovskites 502.3.4 Layered Double Hydroxides 502.3.4.1 Coprecipitation by the Addition of Base 512.3.5 Graphene 512.3.5.1 Electrochemical (EC) Processes 522.3.5.2 Water Electrolytic Oxidation 532.4 Some Recent Heterogeneous Catalysts for Advanced Oxidation Process 532.5 Conclusions and Future Prospect 58Acknowledgement 60References 603 Green Synthesis of Photocatalysts and its Applications in Wastewater Treatment 71Premlata Kumari and Azazahemad Kureshi3.1 Introduction 713.2 Photocatalysts and Green Chemistry 723.2.1 Nanophotocatalysts (NPCs) 743.2.2 Plant-Mediated Green Synthesis of NPCs 763.2.3 Biopolymer-Mediated Synthesis of NPCs 773.2.3.1 Alginic Acid 783.2.3.2 Carrageenan 793.2.3.3 Chitin and Chitosan 793.2.3.4 Guar Gum 793.2.3.5 Cellulose 803.2.3.6 Xanthan Gum 803.2.4 Green Synthesis of NPCs Using Bacteria, Algae, and Fungus 803.2.5 Characterization of NPCs Using Various Analytical Techniques 813.2.5.1 UV-Visible Spectroscopy 813.2.5.2 Xrd 823.2.5.3 SEM, HR-TEM, EDX, and AFM 823.2.5.4 Fourier Transform Infrared Spectroscopy 843.2.5.5 Dynamic Light Scattering 853.2.5.6 Brunauer-Emmett-Teller (BET) 883.2.5.7 Barrett-Joyner-Halenda 883.2.6 Application of Green Synthesized NPCs in Wastewater Treatment 883.3 Limitations and Future Aspects 983.4 Conclusion 99References 994 Green Synthesis of Metal Ferrite Nanoparticles for the Photocatalytic Degradation of Dyes in Wastewater 109Aubrey Makofane, David E. Motaung and Nomso C. Hintsho-MbitaAbbreviations 1104.1 Introduction 1104.2 Metal Ferrite Nanoparticles 1124.3 General Synthesis Methods of Metal Ferrites and Their Limitations 1134.4 Biological Synthesis of Metal Ferrite Nanostructures 1154.4.1 Synthesis of Metal Ferrite Nanostructures Using Bacteria 1164.4.2 Synthesis of Metal Ferrites Nanostructures Using Fungi 1184.4.3 Synthesis of Metal Ferrites Nanostructures Using Plant Extracts 1214.5 Plant-Derived Metal Ferrites as Photocatalysts for Dye Degradation 1234.5.1 Effect of Depositing Noble and Transition Metal on Metal Ferrites for Photodegradation 1294.5.2 Effect of Carbon Deposited on Metal Ferrites for Photocatalytic Degradation 1314.5.3 Effect of Coupling Metal Oxide Semiconductors with Metal Ferrites for Photocatalytic Degradation 1334.5.4 Biological Applications of Plant-Derived Metal Ferrites 1374.6 Challenges of these Materials and Photocatalysis 1404.7 Conclusion: Future Perspectives 141References 142Part 2: Advanced Oxidation Processes 1515 Selected Advanced Oxidation Processes for Wastewater Remediation 153Nhamo Chaukura, Tatenda C. Madzokere and Themba E. Tshabalala5.1 Introduction 1535.2 Photocatalysis and Ozonation 1545.2.1 Photocatalysis 1545.2.2 Ozonation 1565.3 Hybrid AOP Technologies 1575.3.1 Hydrodynamic Cavitation 1575.3.2 Hybrid AOP Systems Based on Hydrodynamic Cavitation 1595.3.3 Hybrid AOP Systems Based on Ultrasound Radiation 1605.3.3.1 Sonoelectrochemical Oxidation 1615.3.3.2 Sonophotocatalytic Degradation 1625.4 Membrane-Based AOPs 1655.5 Conclusion and Future Perspectives 168References 1696 Advanced Oxidation Processes-Mediated Removal of Aqueous Ammonia Nitrogen in Wastewater 175Mohammad Aslam, Ahmad Zuhairi Abdullah, Mukhtar Ahmed and Mohd. RafatullahAbbreviations 1766.1 Introduction 1776.2 Basic Chemistry and Occurrence of Ammonia Nitrogen 1796.2.1 Basic Chemistry of Ammonia Nitrogen 1796.2.2 Sources of Ammonia Nitrogen 1796.2.3 Effects of Ammonia Nitrogen on Aquaculture Species 1806.3 Photocatalytic Technique for Removal of Aqueous Ammonia Nitrogen From Wastewater 1876.3.1 TiO 2 /TiO 2 -Based Photocatalyst 1876.3.2 Modified TiO 2 Photocatalyst 1976.4 Ozonation Technique for Removal of Aqueous Ammonia Nitrogen From Wastewater 1996.4.1 Noncatalytic Ozonation of Ammonia Nitrogen 1996.4.2 Catalytic Ozonation of Ammonia Nitrogen 2016.5 Conclusion and Future Prospects 203Acknowledgments 204References 204Part 3: Design and Modelling of Photoreactors 2157 Recent Advances in Photoreactors for Water Treatment 217Jean Bedel Batchamen Mougnol, Shelter Maswanganyi, Rashi Gusain, Neeraj Kumar, Elvis Fosso-Kankeu, Suprakas Sinha Ray and Frans Waanders7.1 Introduction 2187.2 Photocatalysis Fundamentals and Mechanism 2197.3 Configuration of Photoreactor 2217.3.1 Source of Light Irradiation 2227.3.2 Geometry of Photoreactor 2237.3.3 Light Source Placement and Distribution 2247.3.4 Photoreactor Materials 2257.4 Types of Photoreactors 2267.4.1 Slurry Photoreactors 2267.4.2 Photocatalytic Membrane Photoreactors 2277.4.3 Rotating Drum Photoreactors 2307.4.4 Microphotoreactors 2317.4.5 Annular Photoreactor (APR) 2317.4.6 Closed-Loop Step Photoreactors 2327.5 Photocatalytic Water Purification Using Photoreactors 2337.6 Challenges for Effective Photoreactors 2377.7 Conclusion 238References 2398 Design of Photoreactors for Effective Dye Degradation 247Rajashree Sahoo and Arpan Kumar NayakAbbreviations 2478.1 Introduction 2488.1.1 Mechanisms and Theory of AOP 2498.1.2 Design of Photoreactors 2508.1.2.1 Source of Irradiation 2508.1.2.2 Wavelength/Lamp Selection 2518.1.3 Placement of Light Source and Light Distribution 2538.2 Different Photoreactors Are Used for Wastewater Treatment 2588.2.1 Some Typical Photoreactors Used for Wastewater Treatment Are Described Below 2598.2.2 Homogenous and Heterogenous Systems 2618.2.3 Heterogenous Photocatalyst Arrangement 2628.2.4 Amount of Photocatalyst 2638.3 Photoreactors Designed to Work Under Visible-Light Irradiation Toward Wastewater Treatment 2638.3.1 Limitations of the Currently Employed Photoreactors and Future Scope 2668.4 Current and Future Developments 266References 2679 Simulation of Photocatalytic Reactors 277John Akach, John Kabuba and Aoyi OchiengAbbreviations 2779.1 Introduction 2789.2 Modeling of Light Distribution 2799.2.1 Light Distribution 2799.2.2 Light Distribution Methods 2809.2.3 Simulation Parameters 2829.2.4 Influence of Bubbles on Light Distribution 2939.2.5 Validation of Light Distribution Models 2939.3 Photocatalysis Kinetics 2979.4 Conclusion 299References 29910 The Development of Self-Powered Nanoelectrocatalytic Reactor for Simultaneous Piezo-Catalytic Degradation of Bacteria and Organic Dyes in Wastewater 305Daniel Masekela, Nomso C. Hintsho-Mbita and Nonhlangabezo MabubaAbbreviations 30610.1 Introduction 30610.2 Degradation Techniques 30810.2.1 Electrochemical Advanced Oxidation Processes (EAOPs) 30910.3 Characteristics and Properties of Piezoelectric Materials 31010.3.1 Natural Piezoelectric Materials 31310.3.2 Synthetic Piezoelectric Materials 31410.4 Synthesis of Piezoelectric Materials 31610.4.1 Electrospinning Technique 31610.4.2 Template Synthesis 31710.4.3 Mixed Metal Oxide (MMO)/Solid State Synthesis 31710.4.4 Hydrothermal/Solvothermal Method 31810.4.5 Sol-Gel Method 31810.5 Challenges of Piezoelectric Nanomaterials/Nanogenerators 31910.6 Application of Piezoelectric Materials for Piezo-Electrocatalytic Degradation of Dyes and Bacteria in Wastewater 32310.6.1 Piezo-Electrocatalytic Degradation of Organic Dyes and Bacteria in Wastewater 32510.7 Conclusion and Future Perspectives 332Acknowledgments 332References 332Index 339