Ecotechnologies for the Treatment of Variable Stormwater and Wastewater Flows (eBook)

Preface 6
Contents 8
1 Introduction 11
Abstract 11
General Scope 12
Variation Driven by Precipitation 13
Ecotechnologies 14
References 15
2 Treatment Techniques for Variable Flows 17
Abstract 17
Treatment Systems 18
Stormwater Ponds and Basins 18
Constructed Wetlands 21
Surface-Flow Constructed Wetlands 22
Floating Treatment Wetlands 23
Subsurface-Flow Constructed Wetlands 27
Bioretention Filters 30
Swales and Buffer Strips 34
References 35
3 Nutrient Removal from Variable Stormwater Flows 41
Abstract 41
Treatment Mechanisms for Nutrient Removal 42
Concentrations of Nutrients from Stormwater, CSOs and Agricultural Diffuse Pollution 46
Stormwater from Separate Sewer Systems and Highway Runoff 46
Combined Sewer Overflows 46
Agricultural Diffuse Pollution 49
Treatment Systems 51
Stormwater Sedimentation Ponds and Basins 51
Constructed Wetlands 52
Surface-Flow Wetlands 52
Floating Treatment Wetlands 54
Subsurface-Flow Constructed Wetlands 55
Bioretention Filters 58
Swales and Buffer Strips 60
References 60
4 Microbial Loads and Removal Efficiency Under Varying Flows 66
Abstract 66
Introduction 67
Treatment Mechanisms 67
Concentrations of Pathogens from Stormwater, Combined Sewer Overflows and Agricultural Diffuse Pollution 69
Stormwater from Separate Sewer Systems 69
Combined Sewer Overflows 71
Agricultural Diffuse Pollution 72
Treatment Systems 74
Stormwater Ponds and Basins 74
Constructed Wetlands 75
Surface-Flow Constructed Wetlands 75
Subsurface-Flow Constructed Wetlands 77
Bioretention Filters 77
References 79
5 Metals: Occurrence, Treatment Efficiency and Accumulation Under Varying Flows 84
Abstract 84
Introduction 84
Treatment Mechanisms 85
Metals in Stormwater from Separate Sewer Systems and Combined Sewer Overflows 86
Seasonal Variations 86
Variation Between Catchments 87
Variations Over Time 87
Treatment Systems 89
Stormwater Ponds and Basins 89
Constructed Wetlands 91
Surface-Flow Constructed Wetlands 91
Floating Treatment Wetlands 92
Subsurface-Flow Constructed Wetlands 92
Bioretention Filters 93
Swales and Buffer Strips 96
References 96
6 Emerging Contaminants: Occurrence, Treatment Efficiency and Accumulation Under Varying Flows 101
Abstract 101
Introduction 102
Concentrations of Selected Emerging Contaminants 104
Treatment Systems 108
Stormwater Ponds and Basins 108
Constructed Wetlands 109
Bioretention Filters 112
Swales and Buffer Strips 113
References 113
7 Modelling Under Varying Flows 118
Abstract 118
Modelling of Treatment Systems 118
Modelling Hydraulics of Variable-Flow Constructed Wetlands 119
Modelling Treatment Performance of Variable-Flow Constructed Wetlands 122
Design-Oriented Models for CSO-CWs 122
First-Order Kinetic Model 124
Process-Based Model 126
Future Perspectives 127
Novel Approaches for Design of Variable-Flow Constructed Wetlands 127
Process-Based Models as Design Tools 127
Limitations of the Wider Application of Models for Variable-Flow Constructed Wetlands 131
References 133