Membrane Fouling by Marine Algae in Seawater Desalination

131 Pages·2010·4.6 MB·English

by  David A. Ladner

Arsenic Water Technology Partnership

Membrane Fouling by Marine Algae
in Seawater Desalination

©2010 Water Research Foundation and Arsenic Water Technology Partnership. ALL RIGHTS RESERVED.
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©2010 Water Research Foundation and Arsenic Water Technology Partnership. ALL RIGHTS RESERVED.
Membrane Fouling by Marine Algae
in Seawater Desalination

Prepared by:

David A. Ladner
University of Illinois at Urbana-Champaign
Department of Civil and Environmental Engineering

Esvina Litia Choo Mei Seng
University of Illinois at Urbana-Champaign
Department of Civil and Environmental Engineering

and

Mark M. Clark
Northwestern University
Department of Civil and Environmental Engineering

Jointly Sponsored by:
Water Research Foundation
6666 West Quincy Avenue, Denver CO 80235-3098

and

U.S. Department of Energy
Washington, D.C. 20585-1290

Published by:

WERC, a Consortium for Water Research Foundation
Environmental Education and
Technology Development at
New Mexico State University
U NM DINÉ
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SANDIALOSALAMOS A CONSOANRTDIU TMEC FHONRO ELNOVGIRYO DNEVMEELNOTPAML EENDTUCATION

©2010 Water Research Foundation and Arsenic Water Technology Partnership. ALL RIGHTS RESERVED.
DISCLAIMER

This study was jointly funded by the Water Research Foundation and the U.S. Department of
Energy (DOE) under Grant No. DE-FG02-03ER63619 through the Arsenic Water Technology
Partnership. The comments and views detailed herein may not necessarily reflect the views of
the Water Research Foundation, its officers, directors, affiliates or agents, or the views of the
U.S. Federal Government and the Arsenic Water Technology Partnership. The mention of trade
names for commercial products does not represent or imply the approval or endorsement of the
Foundation or DOE. This report is presented solely for informational purposes.

Copyright ©2010
by
Water Research Foundation
and Arsenic Water Technology Partnership
All Rights Reserved
Printed in the U.S.A.

©2010 Water Research Foundation and Arsen ic Water Technology Partnership. ALL RIGHTS RESERVED.
CONTENTS

TABLES ........................................................................................................................................ ix 
FIGURES ....................................................................................................................................... xi 
FOREWORD .............................................................................................................................. xvii 
ACKNOWLEDGMENTS ........................................................................................................... xix 
EXECUTIVE SUMMARY ......................................................................................................... xxi 
CHAPTER 1: INTRODUCTION ................................................................................................... 1 
Membrane fouling ............................................................................................................... 1 
Cake-enhanced concentration polarization ............................................................. 2 
Algal Blooms and Membrane Fouling ................................................................................ 3 
Marine algal blooms ............................................................................................... 3 
Industry experience with algal fouling ................................................................... 4 
Algal fouling laboratory studies.............................................................................. 5 
Effects of shear on algal fouling ............................................................................. 6 
Clay Flocculation For Algal Removal ................................................................................ 7 
Project Hypotheses.............................................................................................................. 7
Figures..................................................................................................................... 8 
CHAPTER 2: METHODS AND MATERIALS ............................................................................ 9 
Seawater .............................................................................................................................. 9 
Algal culture........................................................................................................................ 9 
Reverse osmosis .................................................................................................................. 9 
Bench-scale RO testing apparatus .......................................................................... 9 
RO Membranes ..................................................................................................... 10 
Algal fouling experiments ..................................................................................... 10 
Microfiltration and ultrafiltration ...................................................................................... 11 
Dead-end cell setup ............................................................................................... 11 
MF and UF Membranes ........................................................................................ 12 
Hydrodynamic shear ......................................................................................................... 12 
Cell breakup characterization ........................................................................................... 13 
Size fractionation .............................................................................................................. 14 
Jar tests and clay ammendment experiments .................................................................... 14 
Analytical methods ........................................................................................................... 15 
Algal and bacterial enumeration ........................................................................... 15 
Flow cytometry ..................................................................................................... 16 
Bulk fluorescence .................................................................................................. 17 
Ultraviolet absorbance .......................................................................................... 17 
Total organic carbon ............................................................................................. 17 
v

©2010 Water Research Foundation and Arsenic Water Technology Partnership. ALL RIGHTS RESERVED.
vi | Membrane Fouling by Marine Algae in Seawater Desalination

Carbohydrates ....................................................................................................... 17 
Proteins ................................................................................................................. 18 
Size-exclusion chromatography ............................................................................ 18 
Visual image analysis of fouled membranes ........................................................ 18 
Laser-scanning cytometry ..................................................................................... 19 
Infrared spectroscopy ............................................................................................ 19 
Scanning electron microscopy .............................................................................. 19 
Atomic force microscopy ...................................................................................... 19 
Tables .................................................................................................................... 20 
Figures................................................................................................................... 22 
CHAPTER 3: RESULTS AND DISCUSSION ............................................................................ 25 
Reverse osmosis fouling by marine algae ......................................................................... 25 
Design of experiments .......................................................................................... 25 
Flux decline caused by algae ................................................................................ 26 
AOM characterization ........................................................................................... 26 
Fouled membrane autopsy .................................................................................... 27 
Fouling Mechanisms ............................................................................................. 30 
Figures................................................................................................................... 35 
Fouling by direct algal filtration on MF and UF............................................................... 47 
Figures................................................................................................................... 50 
Shear and its effects on MF and UF .................................................................................. 54 
Effects of shear on algal cells ............................................................................... 54 
Effects of shear on flux ......................................................................................... 55 
Effects of shear on organic-matter rejection ......................................................... 55 
Fractionation Flux Results .................................................................................... 56 
Fractionation Analytical Results ........................................................................... 56 
Tables .................................................................................................................... 60 
Figures................................................................................................................... 60 
The importance of bacteria in MF and UF ........................................................................ 69 
Simulated algal bloom .......................................................................................... 69 
Membrane Filtration Tests .................................................................................... 69 
Algal bloom life cycle results ............................................................................... 70 
Figures................................................................................................................... 73 
Clay flocculation for algal removal and flux improvement .............................................. 81 
Figures................................................................................................................... 83 
CHAPTER 4: CONCLUSIONS AND FUTURE RESEARCH ................................................... 93 
Reverse osmosis membrane Fouling by marine algae ...................................................... 93 
Conclusions ........................................................................................................... 93 
Future research ...................................................................................................... 93 
Low-pressure membrane fouling by marine algae ............................................................ 94 
Conclusions ........................................................................................................... 94 
Future research ...................................................................................................... 95 
Clay flocculation as an algal-bloom mitigating strategy .................................................. 96 
Conclusions ........................................................................................................... 96 
Future Research .................................................................................................... 96 

©2010 Water Research Foundation and Arsenic Water Technology Partnership. ALL RIGHTS RESERVED.
Contents | vii
CHAPTER 5: RECOMMENDATIONS TO UTILITIES ............................................................ 97 
Mitigating algal-bloom problems in Reverse Osmosis ..................................................... 97 
Mitigating algal-bloom problems in MF and UF .............................................................. 97 
REFERENCES ............................................................................................................................. 99 
ABBREVIATIONS .................................................................................................................... 105 

©2010 Water Research Foundation and Arsenic Water Technology Partnership. ALL RIGHTS RESERVED.
©2010 Water Research Foundation and Arsenic Water Technology Partnership. ALL RIGHTS RESERVED.
TABLES

Table 2.1. Composition of San Diego Bay seawater ....................................................................20

Table 2.2. Components of bench-scale RO testing unit ................................................................21

Table 3.1. Feed concentrations and rejections calculated for total carbohydrates,
monosaccharides, UV, and fluorescence for four membrane pore sizes. ± indicates
standard error of triplicate measurements. ..........................................................................60

ix

©2010 Water Research Foundation and Arsenic Water Technology Partnership. ALL RIGHTS RESERVED.
©2010 Water Research Foundation and Arsenic Water Technology Partnership. ALL RIGHTS RESERVED.