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Biofouling of Spiral Wound Membrane Systems

Biofouling of Spiral Wound Membrane Systems

Johannes Simon Vrouwenvelder | Joop Kruithof | Mark C. M. van Loosdrecht

(2011)

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Book Details

Abstract

The study of membrane biofouling has increased strongly in the past four years, compared to the previous twenty two years, indicated by the more than doubling of the number of scientific papers. However, no single source gives an updated overview of biofouling. Biofouling of Spiral Wound Membrane Systems gives a complete and comprehensive overview of all aspects of biofouling, bridging the gap between microbiology, hydraulics and membrane technology. 
High quality drinking water can be produced with membrane filtration processes like reverse osmosis (RO) and nanofiltration (NF). As the global demand for fresh clean water is increasing, these membrane technologies are increasingly important. One of the most serious problems in RO/NF applications is biofouling – excessive growth of biomass – affecting the performance of the RO/NF systems. This can be due to the increase in pressure drop across membrane elements (feed-concentrate channel), the decrease in membrane permeability or the increase in salt passage. These phenomena result in the need to increase the feed pressure to maintain constant production and to clean the membrane elements chemically. 
Biofouling of Spiral Wound Membrane Systems relates biomass accumulation in spiral wound RO and NF membrane elements with membrane performance and hydrodynamics and determines parameters influencing biofouling. It focuses on the development of biomass in the feed-concentrate (feed-spacer) channel and its effect on pressure drop and flow distribution. It can be used to develop an integral strategy to control biofouling in spiral wound membrane systems. Most past and present methods to control biofouling have not been very successful. An overview of several potential complementary approaches to solve biofouling is given and an integrated approach for biofouling control is proposed.   

Table of Contents

Section Title Page Action Price
Half title page 2
Title page 4
Copyright page 5
Contents 6
Preface 14
Contributors 16
Summary 18
Biofouling of spiral wound membrane systems 18
Problem analysis 19
Method development 19
Basic studies 19
Control studies 20
Outlook 21
Chapter 1 22
Introduction 22
INCREASING DEMAND FOR CLEAN FRESHWATER 22
MEMBRANE FILTRATION 25
Membrane element 29
Membrane fi ltration system 31
Membrane fouling 32
BIOFILMS AND BIOFOULING 34
Biofouling in membrane systems 35
SCOPE AND OUTLINE 37
Chapter 2 42
Biofouling studies in NF and RO installations* 42
INTRODUCTION 42
MATERIALS AND METHODS 44
Test rig experiments 44
Full-scale experiments 44
Normalized pressure drop 46
Sampling and study of membranes 46
Biomass in membrane elements 47
Biological parameters of feed water 48
Effect of cleaning 48
Statistical evaluation 48
RESULTS 48
Biomass in membrane elements 48
Dose-effect studies 50
Fouling of membrane plants: use of biomass parameters 52
Use of biological parameters of water to predict fouling 54
Pretreatment and cleaning 55
DISCUSSION 56
Selection of a suitable parameter for biofouling 56
Use of feed water parameters as process parameters 59
Practical implications 60
Chapter 3 68
Membrane fouling simulator development* 68
INTRODUCTION 68
MATERIALS AND METHODS 72
Membrane Fouling Simulator 72
Membranes and spacers 73
Experimental set-up for operation/monitoring of MFS and test rig 74
Sampling and analysis of membrane coupons 75
RESULTS 75
Relationship between linear velocity and pressure drop 75
Flow distribution 76
Sensitivity for fouling detection 76
Reproducibility of MFS experiments 78
Comparison of fouling in MFS and membrane elements 79
DISCUSSION 81
Evaluation of the Membrane Fouling Simulator 81
Potential fi elds of application for the Membrane Fouling Simulator 83
DEVELOPMENT OF A SET OF NEW MONITORS 85
MFS operation 88
MFS use 90
SUMMARY 91
Chapter 4 94
Sensitive pressure drop measurement* 94
INTRODUCTION 94
MATERIALS AND METHODS 95
Experimental set-up 95
Pressure drop measurements 96
Sampling and study of membranes modules 97
Feed water 100
RESULTS 100
UF pretreatment 102
Development of pressure drop 105
Comparison of pressure drop measurements 106
Fouling analysis 106
DISCUSSION 107
Pretreatment effect 107
Biofouling mechanism in lead membrane elements 107
Biofouling monitoring 109
Selection of pressure transmitter 110
Potential fouling control 111
SUMMARY 112
Chapter 5 114
Nuclear magnetic resonance measurement* 114
INTRODUCTION 114
METHODOLOGY 115
Membranes systems 115
Membrane module 115
Flow cell 115
BIOFOULING PROCEDURE 116
Membrane module 116
Flow cell 118
Nuclear magnetic resonance (NMR) microscopy 118
Membrane module 118
Flow cell 119
RESULTS AND DISCUSSION 119
Membrane 119
Flow cell 122
SUMMARY 127
Chapter 6 130
Three-dimensional numerical model development* 130
INTRODUCTION 130
MODEL DESCRIPTION 133
Model geometry and computational domains 133
Momentum balance (hydrodynamics) 134
Mass balance for soluble substrate 135
Mass balance for biomass 136
Model solution 138
MODEL RESULTS AND DISCUSSION 139
Interaction between hydrodynamics and biofi lm growth 141
Effect of biofi lm formation on the residence time distribution 155
Effect of mass transport limitations on the biofi lm development 160
Model evaluation 162
SUMMARY 165
Chapter 7 168
Effect of flux* 168
INTRODUCTION 168
MATERIALS AND METHODS 169
Experimental set-up 169
Laboratory study 169
Monitors, test rigs and full-scale plant 170
NF pilot plant: membrane elements with/without fl ux 171
Pressure drop 172
Calculation of the ratio of diffusive and convective fl ux 173
RESULTS 176
Fouling in monitor without fl ux 176
Fouling in monitors, test rigs and full-scale plant 178
Fouling in membrane elements with/without fl ux in NF pilot plant 180
DISCUSSION 182
Flux and critical fl ux 182
Nutrient rejection 184
Biofouling is a feed spacer problem 184
SUMMARY 185
Chapter 8 186
Effect of feed spacer* 186
INTRODUCTION 186
MATERIALS AND METHODS 187
Terminology 187
Experimental set-up 188
Full-scale and test-rig investigations with different feed water types 189
Comparison full-scale, test-rig and MFS studies 190
NF pilot plant: membrane elements with/without permeate production 190
Laboratory study 190
MRI study 191
Pressure drop 194
Membrane autopsy 194
RESULTS 195
Full-scale and test-rig investigations with different feed water types 195
Comparison full-scale, test-rig and MFS studies 196
Infl uence of permeate production on biofouling 196
In-situ visual observations on fouling accumulation 198
In-situ MRI observations of fouling accumulation and velocity distribution profi les 198
Feed spacer impact on biofouling 202
DISCUSSION 203
Biomass accumulates on the location with highest impact on feed channel pressure drop 204
Biofouling is a feed spacer problem 204
Reduction of biofouling by adaptation of spacer geometry and hydrodynamics 206
SUMMARY 207
Chapter 9 208
Three-dimensional numerical model based evaluation of experimental data* 208
INTRODUCTION 208
MATERIALS AND METHODS 210
Feed spacer characterization 210
Model description 211
Experimental set-up 214
MRI study 215
Pressure drop 216
Membrane autopsy 216
RESULTS 217
Inventory of feed spacers used in practice 217
Biomass growth parameters and pressure drop increase 217
Comparison model with experimental data 218
Infl uence feed spacer: model and experimental data 224
DISCUSSION 230
Comparison model with practice 230
Spacer relevance 232
Future studies and practical implications 233
SUMMARY 234
Chapter 10 238
Effect of substrate load and linear fl ow velocity* 238
INTRODUCTION 238
MATERIALS AND METHODS 240
Membrane fouling simulator 240
Experimental set-up 241
Sampling and study of membranes 241
RESULTS 242
Linear fl ow velocities applied in practice 247
Effect of substrate concentration at constant linear velocity 247
Effect of linear fl ow velocity at constant substrate concentration 248
Effect of linear velocity and substrate concentration at constant substrate load 248
Effect of fl ow velocity 249
Effect of substrate load reduction 250
DISCUSSION 252
Plant performance 252
Biomass parameters 252
Linear fl ow velocities applied in practice 253
Biofi lm accumulation 254
Pressure drop increase monitoring 256
Biofouling analysis 256
Biofouling control 257
Linear fl ow velocity adaptation: possible consequences 258
SUMMARY 259
Chapter 11 260
Effect of fl ow regime on biomass accumulation and morphology* 260
INTRODUCTION 260
MATERIALS AND METHODS 262
Experimental set-up 262
Membrane fouling simulator (MFS) 262
Pressure drop 264
Bubble fl ow studies 264
Feed water and substrate dosage 265
Relative friction factor 267
RESULTS 267
Effect substrate concentration at constant linear fl ow velocity 268
Effect linear fl ow velocity at constant substrate concentration 269
Effect linear fl ow velocity at constant substrate load 269
Effect bubble fl ow at constant substrate load and linear fl ow velocity 273
Effect fl ow regime on biofi lm cohesion strength 276
DISCUSSION 276
Analogy biofi lm formation in RO/NF and other systems 276
Manipulation of biofi lm morphology 277
Quantifi cation of biofouling effect 278
Future studies and practical implications 278
SUMMARY 280
Chapter 12 282
Effect of phosphate limitation* 282
INTRODUCTION 282
MATERIALS AND METHODS 284
Experimental set-up 284
Plant description 284
Membrane fouling simulator 287
Pressure drop 291
Membrane autopsy from elements and MFSs 291
RESULTS 292
Full-scale RO investigations 292
Comparison of antiscalants 294
Growth limiting conditions in RO installation 295
Low phosphate concentrations during water treatment 298
DISCUSSION 299
Biofouling control 299
Follow up 301
SUMMARY 301
Chapter 13 306
Integrated approach for biofouling control* 306
INTRODUCTION 306
PROBLEM ANALYSIS 307
EARLY DETECTION 309
BIOFOULING CONTROL 310
Strategy 310
Potential approaches 311
Cleaning strategies 312
Advanced cleaning strategies 314
Biofouling inhibitor dosage 316
Chemical selection and use 317
Low flow velocities 317
Feed flow reversal 318
Feed spacer modifi cation 319
Total membrane system 320
Growth limiting conditions 320
Repetitive stress conditions 321
Biofi lm morphology engineering 321
Combined approaches 324
MOST PROMISING SCENARIOS FOR BIOFOULING CONTROL 325
Biofouling tolerant conditions in spiral wound membrane systems 325
Capillary membranes 325
Phosphate limitation 326
SUMMARY 326
References 328
Nomenclature 348
Abbreviations 348
List of symbols 349
Greek 350
Index 352