Biofouling of membrane systems / Szilárd Bucs [and three others].

Format:

Book

Author/Creator:

Bucs, Szilárd, author.

Language:

English

Subjects (All):

Fouling.

Reverse osmosis.

Water--Purification--Membrane filtration.

Water.

Physical Description:

1 online resource (xvi, 325 pages) : illustrations

Edition:

1st ed.

Place of Publication:

London, UK : IWA Publishing, 2018.

Summary:

Because of the uneven distribution of fresh water in time and space and the increasing human population, a large number of regions are experiencing water scarcity and stress. Membrane-based desalination technologies like reverse osmosis have the potential to solve the fresh water crisis in coastal areas. However, in many cases membraneperformance is restricted by biofouling.Biofouling of Membrane Systems gives a comprehensive overview on the state of the art strategies to control biofouling in spiral wound reverse osmosis membrane systems and point to possible future research directions. Despite the fact that much research and development has been done to overcome biofouling in spiral wound membrane systems used for water treatment, biofouling is still a major practical problem causing performance decline and increased energy demand. Biofouling of Membrane Systems is divided into three sections including modelling and numerical analysis, non-destructive characterization and feed spacer geometry optimization. It focuses on the development of biomass in the feed channel of the membrane module and its effect on pressure dropand hydrodynamics.This book can be used to develop an integral strategy to control biofouling in spiral wound membrane systems. An overview of several potential complementary approaches to solve biofouling is given and an integrated approach for biofouling control and feed spacer design is proposed.

Contents:

Cover

Copyright

Contents

Preface

List of authors

Chapter 1: New approaches to characterizing and understanding biofouling of spiral wound membrane systems

Introduction

Biofouling Studies

Recent Microbiological Research into Characterizing Biofouling

Flow Cell Studies

Mathematical Modelling

Conclusion

Chapter 2: Effect of flow velocity, substrate concentration and hydraulic cleaning on biofouling of reverse osmosis feed channels

Biofouling Model Description

Model assumptions and equations

Model solution

Results and Discussion

Effect of cross-flow velocity on biofilm development in the feed channel

Biofilm influence on the permeate flux and pressure drop

Hydraulic membrane cleaning

Effect of inlet substrate concentration on biofouling

Reproducibility of biofouling simulations

Conclusions

Chapter 3: Modelling the effect of biofilm formation on reverse osmosis performance: Flux, feed channel pressure drop and solute passage

Model Development

Model geometry

Model equations

Model parameters

Results

Biofilm development in the feed channel

Effect of biofouling on global membrane performance

Local effects of biofouling

Discussion

Concentration polarization and biofilm permeability

Spacer importance

Further model development and use

Chapter 4: Combined biofouling and scaling in membrane feed channels: A new modelling approach

Model Description

Geometry, phases, computational domains

Fluid flow and solute transport

Foulant development

Dynamics of combined fouling in the feed channel

Biofilm enhanced concentration polarization and scaling

Effect of combined fouling on process performance

Parameter sensitivity studies.

Discussion

Complexity of biofilm-precipitate interactions

Benefits, limitations and extensions of the model

Chapter 5: Effect of different commercial feed spacers on biofouling of reverse osmosis membrane systems: A numerical study

Spacer geometry

Computational domain

Liquid flow, substrate transport and biofilm formation

Effect of linear flow velocity

Effect of bacterial cell load

Biomass location

Spacer shape and channel porosity

Spacer thickness

Numerical model evaluation

Importance of feed spacer for biofouling

Chapter 6: In-situ biofilm characterization in membrane systems using Optical Coherence Tomography: Formation, structure, detachment and impact of flux change

Experimental set-up

Experiments and operational conditions

Effect of permeate flux variations

OCT and biofilm image data processing

Biofilm development

Biofilm detachment

Effect of permeate flux variation on biofilm thickness and resistance

Suitability of Optical Coherence Tomography

Biofilm compaction

Biofilm structures

Perspective of OCT studies

Application aspects

Chapter 7: Early non-destructive biofouling detection and spatial distribution: Application of oxygen sensing optodes

Biofouling in NF/RO membranes

Planar optodes

Materials and Methods

Experimental setup description

Operating condition

Dye and optode description

Imaging system

Image calculation and analysis

Analysis of spatial indicators

Cross-flow versus stop-flow imaging

Pressure drop

Oxygen concentration during cross-flow MFS operation

Oxygen concentration during stop-flow MFS operation.

Comparison of the three methods

Early detection of biofouling development

Spatially resolved biofouling development information

Effect of stop-flow imaging on biofouling development

Practical applications and future studies

Chapter 8: Chemical cleaning of biofouling in reverse osmosis membranes evaluated using magnetic resonance imaging

Material and Methods

Flow cells

Fouling

Cleaning

MRI

Results and Discussions

Fouling and image analysis

Different cleaning solutions

Cleaning mechanism

Effect of fouling time

Link to feed channel pressure drop

Chapter 9: Early non-destructive biofouling detection in spiral wound RO membranes using a mobile earth's field NMR

Background

Relevant nuclear magnetic resonance (NMR) theory

NMR and biofilms

Materials and Methodology

NMR methods employed

RO membrane module and test conditions

Visualisation of final fouled module

EF NMR relaxation measurements

Spin-echo measurements of total NMR signal

Practical implications and further studies

Chapter 10: Experimental and numerical characterization of the water flow in spacer-filled channels of spiral-wound membranes

Experimental

Numerical model

Flow pattern change over channel height

Spatial reproducibility

Steady and unsteady flow - effect of different flow velocities

Measurements compared with CFD model

Flow regimes

Solute transfer

CFD model

Further studies

Chapter 11: Spacer geometry and particle deposition in spiral wound membrane feed channels

Experiments

Results.

Development of deposition pattern in time

Effect of feed spacer orientation on particle deposition

Effect of cross-flow velocity

Effect of permeate production

Importance of hydrodynamic conditions and spacer geometry

Implications for practice

Chapter 12: Characterization of feed channel spacer performance using geometries obtained by X-ray computed tomography

Spacer types

Spacer geometry acquisition and processing

Experimental methods

Measures for evaluation of different spacer geometries

Geometric characteristics of feed channel spacers from CT scans

Hydraulic characterization

Feed channel spacer geometry

Pressure drop measurements compared to model solutions using CT scans

Friction due to strand shape and orientation

Local membrane shear distribution

Power input with respect to friction

Spatial velocity distribution

Mechanical deformation and membrane imprinting

Chapter 13: Development and characterization of 3D-printed feed spacers for spiral wound membrane systems

Numerical modelling

3D printed feed spacers

Microscopic observation

Experimental set up

Operating conditions

Sampling and biomass analyses

Numerical modeling and 3D printing of feed spacers

Comparison of feed spacer from practice and 3D printed spacer with same geometry

Comparison of feed spacer from practice and 3D printed spacer with modified geometry

3D printing technique to design modified geometry feed spacers

A novel strategy to modify feed spacer geometry

Suggestions for future studies

Conclusions.

Chapter 14: Strategies for biofouling mitigation in spiral wound membrane systems

Biofouling control strategies

Pre-treatment by water filtration and bacterial inactivation

Membrane modification

Feed spacer and hydrodynamics

Spiral wound membrane modules cleaning strategies

Future Research Directions

Biofilm structural characterization

Biofouling mitigation strategies

References

Index.

Notes:

Description based on print version record.

ISBN:

1-5231-2329-X