Water Treatment for Purification from Cyanobacteria and Cyanotoxins

List of Contributors xi

Preface xvii

Acknowledgments xix

1 Introduction to Cyanobacteria and Cyanotoxins 1
Armah A. de la Cruz, Neill Chernoff, James L. Sinclair, Donna Hill, Deacqunita L. Diggs, and Arthur T. Lynch

1.1 An Overview of Cyanobacteria 1

1.1.1 Evolution and Worldwide Occurrence 2

1.1.2 Physical Characteristics 3

1.1.3 Metabolites of Cyanobacteria 6

1.2 General Environmental Impact: Ecological and Human Health Effects 6

1.2.1 Climate Change and Water Demand 7

1.2.2 Risk to Humans from Cyanobacterial Toxins 8

1.3 Health Effects of Cyanotoxins 8

1.3.1 Sources and Routes of Exposure in Humans and Animals 8

1.3.2 Hepatotoxins: Microcystins, Nodularins 9

1.3.3 Cytotoxin: Cylindrospermopsins 10

1.3.4 Neurotoxins: Anatoxin-a, Anatoxin-a(s), Homoanatoxin-a, Saxitoxins 10

1.3.5 Irritant and Dermal Toxins: Lipopolysaccharides, Lyngbyatoxins, Aplysiatoxins 11

1.3.6 Gill-Bearing Vertebrate Toxins: Euglenophycin, Prymnesins 12

1.3.7 Mixtures, Bioaccumulation, and Unknown Toxins 13

1.4 Current Guidelines for Cyanotoxins 14

1.4.1 WHO Microcystin-LR Provisional Drinking Water Guideline Value 14

1.4.2 National Cyanotoxin Drinking Water Regulations or Guideline Values 15

1.4.3 National Regulation of Unspecified Harmful Substances 17

1.4.4 Non-national Cyanotoxin Drinking Water Guideline Values 17

1.4.5 United States Cyanotoxin Drinking Water Guideline Values 17

1.5 Taste and Odor Compounds Related to Cyanobacteria 18

1.6 Management Strategies of Cyanobacteria, Cyanotoxins, and Related Compounds in Water Treatments 19

References 21

2 Cyanobacteria, Cyanotoxins, and Human Health 37
Geoffrey A. Codd, Emanuela Testai, Enzo Funari, and Zorica Svircev

2.1 Introduction 37

2.2 Exposure Routes, Exposure Media, and Human Health 39

2.2.1 Drinking Water 40

2.2.2 Diet 40

2.2.3 Bathing and Recreational Waters 42

2.2.4 Aerosols 42

2.2.5 Terrestrial Cyanobacteria 42

2.2.6 Human Gut Colonization Hypothesis 43

2.3 Cyanobacterial Cells and Cyanotoxins as Human Health Hazards and Risks 43

2.3.1 Hepatotoxins 44

2.3.2 Cytotoxins 46

2.3.3 Neurotoxins 47

2.3.4 LPS Endotoxins 48

2.3.5 Reference Values for Cyanotoxins and WHO Guidelines 49

2.3.6 Further Sources of Risk to Human Health 50

2.3.7 Data Gaps and Research Needs 51

2.4 Reported Investigations of Roles of Cyanobacteria and Cyanotoxins in Human Health Incidents 52

2.4.1 Raw (Untreated) Water 52

2.4.2 Treated Water 54

2.4.3 Aerosols and Dust 56

2.4.4 Food and Dietary Supplements 56

2.5 Recognition and Reporting of Role(s) of Cyanobacteria/Cyanotoxins in Health Incidents 57

2.6 Role of Human Health Incidents in Contributing to Cyanobacterial and Cyanotoxin Risk Management Policies 58

2.7 Importance of Contingency Plans and Outreach Activities 58

References 59

3 Removal of Cyanobacteria and Cyanotoxins by Conventional Physical-chemical Treatment 69
Margarida Ribau Teixeira, Maria João Rosa, Sabrina Sorlini, Michela Biasibetti, Christophoros Christophoridis, and Christine Edwards

3.1 Introduction 69

3.2 Chemical Treatment 71

3.2.1 Copper-based Algicides 71

3.2.2 Other Metal-based Algicides 72

3.2.3 Photosensitizers 72

3.2.4 Herbicides 74

3.2.5 Algicides Derived from Natural Compounds 75

3.3 Coagulation and Flocculation 75

3.4 Dissolved Air Flotation 76

3.5 Rapid Sand/Gravity Filtration 80

3.6 Slow Sand Filtration 81

3.7 Bank Filtration 83

3.8 Activated Carbon Adsorption 85

3.8.1 General 85

3.8.2 GAC/BAC Filtration 85

3.8.3 PAC Adsorption 86

3.8.4 Case Study 87

3.9 Conclusions 88

References 89

4 Removal of Cyanobacteria and Cyanotoxins by Membrane Processes 99
Mike B. Dixon, Lionel Ho, and Maria G. Antoniou

4.1 Introduction 99

4.2 Microfiltration and Ultrafiltration 100

4.3 Nanofiltration 101

4.4 Nanofiltration for the Combined Removal of Various Cyanobacterial Metabolites 102

4.4.1 Membrane Fouling 103

4.4.2 Removal of MIB and GSM 105

4.4.3 Cylindrospermopsin Removal 106

4.4.4 Microcystin Removal 107

4.5 Reverse Osmosis 108

4.6 Integrated Studies: Ultrafiltration Combined with PAC and Coagulants 108

4.6.1 Ultrafiltration - Integrated Membrane System Test 108

4.6.2 Effect of Cyanobacterial Species and Coagulant Type on Membrane Flux 109

4.6.3 Removal of Cyanobacterial Cells and Metabolites with Membranes and Coagulants 109

4.6.4 Summary of Results 112

Acknowledgement 114

References 114

5 Biological Treatment for the Destruction of Cyanotoxins 117
Dariusz Dziga, Sonja Nybom, Ilona Gagala, and Marcin Wasylewski

5.1 Introduction 117

5.2 Overview of Microbial Degradation 118

5.2.1 Microorganisms Capable of MC-degradation 118

5.2.2 Microbial Degradation of Other Cyanotoxins 122

5.2.3 Degradation Efficiency and Factors Affecting Degradation 123

5.3 The Mechanisms of Biodegradation 124

5.3.1 Biochemistry of Degradation 124

5.3.2 Enzymes Involved in Biodegradation 125

5.3.3 Alternative Mechanisms of Biodegradation 126

5.3.4 Methodology of Analysis of Degradation Pathways 128

5.4 Biological Methods of Cyanotoxin Elimination 129

5.4.1 Most Common Proposals of Microbial Removal of Cyanotoxins 129

5.4.2 Microbial Strains 132

5.4.3 The Efficiency of Described Methods and Future Challenges 132

5.5 Guide to Evaluating Biodegradation 133

5.5.1 Environmental Samples 137

5.5.2 Bacterial Strains 138

5.5.3 Indication of Biodegradation Activity 139

5.5.4 Enzymatic and Genetic Aspects of Biodegradation 140

5.6 Microbial Water Treatment - Application and Case Studies 142

5.6.1 Real-life Application of MC-degrading Bacteria 142

5.6.2 Potential of Existing Water Treatment Infrastructure for MC-removal 144

5.7 Conclusions 145

Acknowledgements 145

References 146

6 Conventional Disinfection and/or Oxidation Processes for the Destruction of Cyanotoxins/Cyanobacteria 155
Sylvain Merel, Shuwen Yan, and Weihua Song

6.1 Reaction of Chlorine and its Derivatives with Cyanotoxins 155

6.1.1 Microcystins and Nodularins 156

6.1.2 Cylindrospermopsin 159

6.1.3 Anatoxin-a 160

6.1.4 Saxitoxins 160

6.1.5 Other Cyanotoxins 161

6.1.6 Summary 162

6.2 Reaction of Ozone with Cyanotoxins 162

6.2.1 Microcystins 162

6.2.2 Nodularins 163

6.2.3 Cylindrospermopsin 163

6.2.4 Anatoxin-a 165

6.2.5 Saxitoxins 165

6.2.6 Summary 165

6.3 Reaction of Permanganate (KMnO₄) with Cyanotoxins 166

6.3.1 Microcystins 166

6.3.2 Cylindrospermopsin 167

6.3.3 Anatoxin-a 167

6.3.4 Saxitoxins 167

6.3.5 Summary 167

References 167

7 Advanced Oxidation Processes 173
Geshan Zhang, Xuexiang He, Xiaodi Duan, Ying Huang, Changseok Han, Mallikarjuna N. Nadagouda, Kevin O'Shea, Duk Kyung Kim, Virender K. Sharma, Natalie Johnson, Bangxing Ren, Vasileia Vogiazi, Theodora Fotiou, Christophoros Christophoridis, Anastasia E. Hiskia, and Dionysios D. Dionysiou

7.1 Introduction 173

7.2 UV 174

7.3 UV/H₂O₂ 175

7.4 O₃/H₂O₂ 176

7.5 UV/O₃ 177

7.6 Catalytic Ozonation 178

7.7 Fenton/Photo-Fenton Reagent 179

7.8 TiO₂-Based Photocatalysis/Visible Light Sensitized TiO₂ 180

7.9 Radiolysis 182

7.10 Ultrasonic Degradation 184

7.11 Ferrate 186

7.12 Other Iron-based Processes 187

7.13 Sulfaten Radical-based AOPs 189

7.14 Polyoxometalate Photocatalysis 191

7.14.1 Photocatalytic Degradation of Organic Pollutants with POMs: Mechanistic Aspects 192

7.14.2 Photocatalytic Degradation of Cyanobacterial Metabolites with POM 193

7.14.3 Photocatalytic Degradation of CYN with POM 194

7.15 Conclusion 195

Acknowledgments 195

References 196

8 Removal and/or Destruction of Cyanobacterial Taste and Odour Compounds by Conventional and Advanced Oxidation Processes 207
Carlos J. Pestana, Linda A. Lawton, and Triantafyllos Kaloudis

8.1 Introduction 207

8.2 Conventional Water Treatment 210

8.2.1 Pretreatment and Preventative Measures 211

8.2.2 Coagulation, Flocculation, and Sedimentation 213

8.2.3 Filtration 213

8.2.4 Disinfection 215

8.2.5 Distribution System 215

8.2.6 Summary - Key Points 216

8.3 Advanced Treatment Methods 218

8.3.1 Advanced Oxidation Processes (AOP) 218

8.3.2 Air Stripping 220

8.3.3 Membrane Filtration 222

8.3.4 Variations of Conventional Treatment Techniques 223

8.3.5 Summary - Key Points 223

8.3.6 Key Findings 224

8.4 Side Note: T&O Compound Concentrations and Customer Perception 224

References 224

9 Transformation Products (TPs) of Cyanobacterial Metabolites During Treatment 231
Theodora Fotiou, Theodoros M. Triantis, Anastasia E. Hiskia, Dariusz Dziga, Sylvain Merel, Christine Edwards, and Maria G. Antoniou

9.1 Introduction 231

9.2 TPs Formed in the Natural Environment 233

9.2.1 Photolysis 233

9.2.2 Effect of pH and Temperature 234

9.3 Transformation Products of Microcystins and Nodularins with Advanced Oxidation Processes/ Technologies and Conventional Chemical Oxidation 236

9.3.1 Titanium Dioxide-based Photocatalysts 236

9.3.2 Other Photocatalysts (BiOBr and Bi2WO6) 264

9.3.3 Ultrasonic Degradation (Sonolysis) 268

9.3.4 Ozone 277

9.3.5 Chlorination 278

9.3.6 Sulfate Radical-based AOTs (SR-AOTs) 278

9.4 Transformation Products of Microcystins and Nodularins with Biological Treatment 279

9.5 Transformation Products of Cylindrospermopsin 287

9.6 Transformation Products of Odor Compounds 292

9.7 Conclusions 298

Acknowledgements 298

References 298

10 Integrated Drinking Water Processes: Case Studies 307
Tomasz Jurczak, Andrzej Jodlowski, Sabrina Sorlini, Michela Biasibetti, and Francesca Gialdini

10.1 Introduction 307

10.2 Pilot Plant Studies for Optimization of Water Treatment Processes in Microcystins Removal 308

10.3 Removal of Cyanobacterial Cells and Microcystin-LR with a Microfiltration Pilot Plant (Lake Garda, Italy) 312

10.4 Removal of Cyanobacterial Cells and Cyanotoxins in a Conventional Full-scale DWTP (Lake Vico, Italy) 314

10.5 Efficiency of Water Treatment Processes in Elimination of Microcystins - Polish Examples 317

10.6 Conclusions 324

References 324

Index 327