Table of Contents
Preface ix
Acknowledgments xii
1 Membrane Integrity Testing in the Drinking Water Industry: A Historical Perspective 1
Coming of Age: Low-Pressure Membranes in Drinking Water Filtration 1
Membrane Integrity Testing in Drinking Water-A Brief History 2
ASTM Standard Practice for Integrity Testing of Water Filtration Membrane Systems (ASTM 6908-03) 4
AwwaRF Research Project on Integrity Monitoring of Low-Pressure Membranes (RFP 2861) 5
LT2ESWTR and MFGM 7
2 Background: What Is Membrane Integrity Testing and Why Do It? 11
Low-Pressure Membranes and Membrane Systems-A Primer 11
Low-Pressure Membranes 11
Membrane Filter Module and Membrane System 15
Membrane Integrity, Integrity Breach, and Integrity Testing 16
Membrane Integrity 16
Types of Integrity Breach 18
Causes of Integrity Breach 19
Manufacturing Defects 19
Improper Design, Installation, and Operation and Maintenance 19
Long-term Wear and Tear 20
Significances of Conducting Membrane Integrity Testing 25
Regulatory Compliance 25
Quality Control for Manufacturers 25
Monitoring and Diagnosis Tool for Plant Operators 26
3 Important Criteria of Membrane Integrity Testing 27
Introduction 27
Resolution 28
Sensitivity 29
Testing Frequency 35
Define the Risk 36
Determine the Probability of Occurrence of Membrane Integrity Breach 36
Determine Consequence of Integrity Breach 39
Reliability 43
Traceability 47
Implementability 47
Summary 47
Appendix 3-A: Derivation of Equations 3-12 Through 3-19 48
4 Types of Membrane Integrity Testing 53
Introduction 53
Integrity Testing Based on Fluid Flow 54
Integrity Testing Based on Measuring Filtrate Quality 56
Comparison of Integrity Methods 58
5 Membrane Integrity Testing Methods Based on Fluid Flow 61
Introduction 61
Determination of Method Resolution 63
Diffusion of Air in Water Across an Integral Membrane Module 66
Calculation of LRV 70
ASTM D-6908-03 Method 70
MFGM Method 72
An Alternative Method to Calculate LRV-Pall Equation 75
Sensitivity Analysis 80
Validation of LRV Calculation 86
Validate LRV Calculation via Challenge Test 86
Validate LRV Calculation via Measuring Water and Air Flow 87
Comparison of Different Methods for LRV Calculation 95
Conclusion 98
Appendix 5-A: Derivation of Equation 5-31 100
Appendix 5-B: Derivation of Equation 5-35 103
Appendix 5-C: Derivation of Equation 5-39 104
6 Membrane Integrity Testing Based on Monitoring Filtrate Quality 107
Introduction 107
Turbidity 108
Impact of Particle Size 108
Impact of Reflectivity of Particles 109
Impact of the Color of Water Matrix 110
Impact of Particle Concentration 110
Using Nephelometric Turbidimeter to Monitor Membrane Integrity 111
Liquid Particle Counters 113
Types of Liquid Particle Counters 113
Light-Blocking Particle Counter 114
Light-Scattering Particle Counter 116
Using Particle Counters to Monitor Membrane Integrity 117
Laser Nephelometer 121
Comparison to Standard Nephelometer 121
Using Laser Nephelometer to Monitor Membrane Integrity 121
Particle Monitor 122
Using Particle Monitor to Monitor Membrane Integrity 124
Multiple-Sensing Monitoring 126
Using Multiple-Sensing to Monitor Membrane Integrity 128
Marker-Based Integrity Monitoring 128
Description of the Method 130
Using Marker-Based Method to Monitor Membrane Integrity 130
Evaluation of Different Methods Based on Monitoring Water Quality 131
Sensitivity 132
Reliability 134
Conclusion 136
7 Other Integrity Testing and Monitoring Methods 139
Introduction 139
Acoustic Integrity Monitoring (AIM) 139
How AIM Works 139
Using Hydrophone to Monitor Membrane Integrity 145
Particle Amplifier 146
Method Description 146
Using Particle Amplifier to Monitor Membrane Integrity 147
Relative Trans-Membrane Pressure Monitoring 149
How Does the Method Work? 149
Use of Relative TMP Monitoring for Membrane Integrity 150
8 Implementing an Integrity Verification and Monitoring Program in Low-Pressure Membrane Plants 153
Introduction 153
Define Regulatory Requirements 153
Issues in Implementing an Integrity Verification Plan 159
Appendix 8-A: Resolution and LRV Calculation Using the MFGM Method for Water Treatment Plant 168
9 The Future of Membrane Integrity Testing 173
Introduction 173
Particle Imaging 174
Biosensor 178
Biological Recognition 178
Signal Transducers 182
Microcantilevers 186
Conclusion 189
Appendix A Metric Conversion Factors 191
Appendix B Physical Properties of Water 193
Appendix C Excerpts From USEPA's Membrane Filtration Guidance Manual 195
References 237
