Tài liệu Recent developments in forward osmosis processes

Recent Developments in Forward Osmosis Processes Edited by Rodrigo Valladares Linares, Zhenyu Li, Menachem Elimelech, Gary Amy and Hans Vrouwenvelder Recent Developments in Forward Osmosis Processes Recent Developments in Forward Osmosis Processes Edited by Rodrigo Valladares Linares, Zhenyu Li, Menachem Elimelech, Gary Amy and Hans Vrouwenvelder Published by IWA Publishing Alliance House 12 Caxton Street London SW1H 0QS, UK Telephone: +44 (0)20 7654 5500 Fax: +44 (0)20 7654 5555 Email: [email protected] Web: www.iwapublishing.com First published 2017 © 2017 IWA Publishing Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the UK Copyright, Designs and Patents Act (1998), no part of this publication may be reproduced, stored or transmitted in any form or by any means, without the prior permission in writing of the publisher, or, in the case of photographic reproduction, in accordance with the terms of licenses issued by the Copyright Licensing Agency in the UK, or in accordance with the terms of licenses issued by the appropriate reproduction rights organization outside the UK. Enquiries concerning reproduction outside the terms stated here should be sent to IWA Publishing at the address printed above. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for errors or omissions that may be made. Disclaimer The information provided and the opinions given in this publication are not necessarily those of IWA and should not be acted upon without independent consideration and professional advice. IWA and the Editors and Author will not accept responsibility for any loss or damage suffered by any person acting or refraining from acting upon any material contained in this publication. British Library Cataloguing in Publication Data A CIP catalogue record for this book is available from the British Library ISBN 9781780408118 (Paperback) ISBN 9781780408125 (eBook) Cover image: Ana Mabel López Villanueva Contents Additional Image credits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii List of Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xvii Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix Part 1:  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  1 Chapter 1.1 Population distribution and water scarcity  . . . . . . . . . . . . . .  3 1.1.1 Osmotic Membrane Processes  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5 1.1.2 Forward Osmosis (FO)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6 1.1.3 FO System for Wastewater Recovery and Seawater Desalination  . . . . . . .  8 1.1.4 Concentration Polarization in FO Membranes  . . . . . . . . . . . . . . . . . . . . .  9 1.1.5 FO Membrane Fouling  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  10 1.1.6 Energy Demand in Desalination and Water Treatment Processes  . . . . . . .  11 1.1.7 Scope and Outline  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11 1.1.8 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  13 Part 2:  Water Recovery  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17 Chapter 2.1 The management of urban runoff in coastal regions  . . . . .  19 2.1.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.2 Materials and Methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.2.1 Synthetic urban runoff and seawater  . . . . . . . . . . . . . . . . . . . . 2.1.2.2 FO membrane and simulated osmotic detention pond  . . . . . . . 2.1.2.3 Analytical methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.3 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.3.1 Effects of feed water condition on flux patterns  . . . . . . . . . . . .  19  22  22  22  24  25  25 vi Recent Developments in Forward Osmosis Processes 2.1.3.2 Salt leakage and NOM fouling  . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.3.3 Rejection of trace metals and nutrients  . . . . . . . . . . . . . . . . . . . 2.1.3.4 Environmental and economic implications  . . . . . . . . . . . . . . . . 2.1.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  27  29  31  32  33 Chapter 2.2 Water harvesting from municipal wastewater  . . . . . . . . . . .  37 2.2.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2 Experimental  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2.1 Feed water and draw solution  . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2.2 FO membrane and experimental set-up  . . . . . . . . . . . . . . . . . . 2.2.2.3 Analytical methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.3 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.3.1 Flux patterns  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.3.2 Salt leakage and retention of nutrients and trace metals  . . . . . 2.2.3.3 Fouling characterization and osmotic backwash  . . . . . . . . . . . 2.2.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37  39  39  40  40  41  41  42  46  48  48 Chapter 2.3 Indirect desalination of seawater  . . . . . . . . . . . . . . . . . . . . .  53 2.3.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.2 Materials, Methods and Experimental  . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.2.1 Membranes and equipment  . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.2.2 Draw solution and feed water  . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.2.3 Experimental protocol  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.3 Theoretical Background  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.4 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.4.1 Feed water and draw solution characterization  . . . . . . . . . . . . 2.3.4.2 Long-term forward osmosis experiments  . . . . . . . . . . . . . . . . . 2.3.5 Energy, Cost and Water Reuse Considerations  . . . . . . . . . . . . . . . . . . . 2.3.5.1 Comparison of energy use  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.5.2 Cost analysis  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.5.3 Alternative water reuse of diluted draw solutions  . . . . . . . . . . . 2.3.6 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.7 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  53  54  54  55  55  56  58  58  60  63  63  64  66  66  67 Part 3:  Fouling  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  69 Chapter 3.1 Fouling propensity during desalination of seawater  . . . . . .  71 3.1.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.2 Materials and Methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.2.1 Feed and draw solution  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.2.2 Forward osmosis set-up and fouling tests  . . . . . . . . . . . . . . . . 3.1.2.3 Analytical methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  71  73  73  74  76 vii Contents 3.1.3 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.3.1 Flux patterns during FO  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.3.2 Identification of major foulants  . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.3.3 Salt and foulant rejection  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  76  76  80  85  86  87 Chapter 3.2 NOM and TEP fouling  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  91 3.2.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  91 3.2.2 Experimental  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  92 3.2.2.1 FO membranes and cell configuration  . . . . . . . . . . . . . . . . . . .  92 3.2.2.2 Water samples  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  93 3.2.2.3 FO membrane fouling procedure  . . . . . . . . . . . . . . . . . . . . . . .  93 3.2.2.4 NOM characterization  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  95 3.2.2.5 FO membrane cleaning  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  96 3.2.3 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  97 3.2.3.1 FO membrane process  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  97 3.2.3.2 Fouling of the active layer of FO membrane  . . . . . . . . . . . . . . .  98 3.2.3.3 Fouling of the support layer of FO membrane  . . . . . . . . . . . .  101 3.2.3.4 Cleaning of the FO membrane – active layer  . . . . . . . . . . . . .  103 3.2.3.5 Cleaning of the FO membrane – support layer  . . . . . . . . . . .  104 3.2.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  104 3.2.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  105 Chapter 3.3 Draw solute induced calcium carbonate scaling  . . . . . . . .  107 3.3.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3.2 Materials and Methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3.2.1 FS, DS and FO set-up  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3.2.2 FO membrane, and the measurement of intrinsic permeability and separation properties  . . . . . . . . . . . . . . . . . . 3.3.2.3 Experimental protocol for FO testing  . . . . . . . . . . . . . . . . . . . 3.3.2.4 Analytical methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3.3 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3.3.1 Characterization of FO membrane  . . . . . . . . . . . . . . . . . . . . . 3.3.3.2 Water and reverse solute flux  . . . . . . . . . . . . . . . . . . . . . . . . . 3.3.3.3 Characterization of scaling in seawater desalination using NH3/CO2 FO process  . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3.3.4 Reversibility of scaling and recovery of permeate water flux by hydraulic flushing  . . . . . . . . . . . . . . . . . . . . . . . . 3.3.3.5 Mechanism of scaling formation in seawater desalination  using NH3/CO2 FO process  . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  107  108  108  109  109  110  110  110  112  114  117  117  121  122 viii Recent Developments in Forward Osmosis Processes Chapter 3.4 Impact of spacer thickness on biofouling in forward osmosis  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  125 3.4.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.2 Materials and Methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.2.1 Membrane, spacers and cell configuration  . . . . . . . . . . . . . . 3.4.2.2 Water sources  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.2.3 Biofilm formation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.2.4 Analytical methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.3 Results  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.3.1 Effect of spacer thickness on performance  . . . . . . . . . . . . . . 3.4.3.2 Effect of spacer thickness on biomass accumulation  . . . . . . 3.4.3.3 Effect of spacer thickness on fouling localization  . . . . . . . . . . 3.4.3.4 Effect of spacer thickness on fouling composition  . . . . . . . . . 3.4.4 Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.4.1 Thickest spacer provides the best performance  . . . . . . . . . . 3.4.4.2 FO and RO show similar biofouling patterns  . . . . . . . . . . . . . . 3.4.4.3 Future studies  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.5 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.6 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  125  126  126  127  129  129  130  130  132  134  134  136  136  137  138  138  139 Chapter 3.5 Effect of cleaning methods to remove organic fouling 3.5.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5.2 Materials and Methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5.3 Results  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  143  143  145  146  147 Part 4:  Rejection of Pollutants  . . . . . . . . . . . . . . . . . . . . . . . . . . .  149 Chapter 4.1 Rejection of micropollutants by FO membranes  . . . . . . . .  151 4.1.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.2 Materials and Methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.2.1 FO membrane  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.2.2 RO membrane  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.2.3 Source waters  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.2.4 Experimental setup and procedure  . . . . . . . . . . . . . . . . . . . . 4.1.2.5 Micropollutants stock preparation and analyses  . . . . . . . . . . 4.1.2.6 FO membrane characterization  . . . . . . . . . . . . . . . . . . . . . . . 4.1.3 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.3.1 Zeta potential and contact angle  . . . . . . . . . . . . . . . . . . . . . . 4.1.3.2 Rejection of micropollutants by FO  . . . . . . . . . . . . . . . . . . . . .  151  152  152  153  153  153  154  156  156  156  157 Contents ix 4.1.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  162 4.1.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  162 Chapter 4.2 Rejection of boron  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  165 4.2.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.2 Materials and Methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.2.1 FO Membranes  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.2.2 Experimental setup and procedure  . . . . . . . . . . . . . . . . . . . . 4.2.3 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.3.1 Membrane characterization  . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.3.2 Membrane performance  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.3.3 Boron flux  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  165  166  166  167  167  168  169  171  173  173 Part 5:  Draw Solution and Membranes  . . . . . . . . . . . . . . . . . . . .  175 Chapter 5.1 Draw solution  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  177 5.1.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.2 Fundamentals of FO Processes  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.3 Ideal Draw Solution for the FO Process  . . . . . . . . . . . . . . . . . . . . . . . . 5.1.4 Literature Review About Draw Solutions  . . . . . . . . . . . . . . . . . . . . . . . 5.1.4.1 Commercially available compounds as draw solutes  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.4.2 Synthetic materials as draw solutes  . . . . . . . . . . . . . . . . . . . . 5.1.5 Applications of Typical Draw Solutions in Integrated FO Processes  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.5.1 Seawater desalination  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.5.2 Wastewater reclamation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.5.3 Protein enrichment  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.5.4 Power regeneration  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.6 Challenges and Prospects for the Future  . . . . . . . . . . . . . . . . . . . . . . . 5.1.7 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.8 Nomenclature  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.8.1 Greek symbols  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.9 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  177  179  182  184  184  195  198  198  200  201  202  203  205  205  206  206 Chapter 5.2 Cellulose acetate membrane: minimized internal concentration polarization  . . . . . . . . . . . . . . . . . . . . . . . . . .  215 5.2.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  215 x Recent Developments in Forward Osmosis Processes 5.2.2 Experimental  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.2.1 Materials  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.2.2 Membrane preparation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.2.3 Forward osmosis and fouling tests  . . . . . . . . . . . . . . . . . . . . . 5.2.2.4 Pure water permeability, salt rejection and salt permeability tests  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.2.5 Pore size and pore size distribution  . . . . . . . . . . . . . . . . . . . . 5.2.2.6 Water contact angle  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.2.7 Porosity P  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.2.8 Field emission scanning electronic microscopy (FESEM)  . . . 5.2.2.9 Atomic force microscope (AFM)  . . . . . . . . . . . . . . . . . . . . . . . 5.2.2.10 Positron annihilation spectroscopy (PAS)  . . . . . . . . . . . . . . . 5.2.3 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.3.1 Morphology influenced by different substrates and phase inversion conditions  . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.3.2 Morphology characterized by PALS  . . . . . . . . . . . . . . . . . . . . 5.2.3.3 Pore size and pore size distribution  . . . . . . . . . . . . . . . . . . . . 5.2.3.4 PWP, NaCl rejection and FO performance of different  membranes  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.3.5 Modeling of FO performance and structural parameter St  . . . 5.2.3.6 Single vs. double dense-layer structure in the FO-MBR integrated system  . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  217  217  218  218  219  219  220  220  221  221  221  222  222  226  227  228  232  238  240  240 Part 6:  Modeling  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  245 Chapter 6.1 Modeling water flux  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  247 6.1.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1.2 Governing Equations for Permeate Flux  . . . . . . . . . . . . . . . . . . . . . . . 6.1.2.1 External concentration polarization  . . . . . . . . . . . . . . . . . . . . 6.1.2.2 Internal concentration polarization  . . . . . . . . . . . . . . . . . . . . . 6.1.2.3 Model parameters  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1.3 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1.3.1 Dense symmetric membrane  . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1.3.2 Asymmetric membrane in PRO mode  . . . . . . . . . . . . . . . . . . 6.1.3.3 Asymmetric membrane in FO mode  . . . . . . . . . . . . . . . . . . . . 6.1.3.4 Implications for improved membrane design  . . . . . . . . . . . . . . 6.1.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  247  249  249  251  253  253  254  255  258  261  263  263 Chapter 6.2 Biofouling in FO systems: an experimental and numerical study  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  265 6.2.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  265 Contents 6.2.2 Experimental  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.2.1 Experimental setup  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.2.2 Model description  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.3 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.3.1 Evaluation of the forward osmosis model  . . . . . . . . . . . . . . . . 6.2.3.2 Biofilm effect on FO performance  . . . . . . . . . . . . . . . . . . . . . . 6.2.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi  267  267  268  274  275  278  286  286 Part 7:  Outlook  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  291 Chapter 7.1 Emerging applications for greater sustainability  . . . . . . .  293 7.1.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1.2 Osmotic Dilution for Energy Conservation  . . . . . . . . . . . . . . . . . . . . . . 7.1.3 Osmosis Engineered for Protection of the Environment  . . . . . . . . . . . 7.1.4 Membranes at Sea: Fuel from Waste  . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1.5 Osmotic Augmentation of Water Resources for Agriculture  . . . . . . . . 7.1.6 Outlook  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1.7 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1.8 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  293  294  297  299  301  303  304  304 Chapter 7.2 Life cycle cost assessment  . . . . . . . . . . . . . . . . . . . . . . . . .  307 7.2.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2.2 Methodology  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2.2.1 Life cycle cost methodology  . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2.2.2 Technologies analyzed  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2.2.3 OPEX and CAPEX calculations  . . . . . . . . . . . . . . . . . . . . . . . 7.2.3 Results and Discussion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2.3.1 Life cycle cost analysis and sensitivity evaluation  . . . . . . . . . . 7.2.3.2 Biogas production  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2.3.3 Water quality versus public perception  . . . . . . . . . . . . . . . . . . 7.2.3.4 Wastewater recovery and reuse: successful projects  . . . . . . 7.2.3.5 Co-location  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2.5 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  307  310  310  311  312  315  315  321  322  324  325  325  326 Chapter 7.3 Niches in seawater desalination and wastewater reuse 7.3.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3.1.1 Increasing need for fresh water along coasts  . . . . . . . . . . . . . 7.3.1.2 Current membrane systems in the water industry: reverse osmosis  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3.1.3 Forward osmosis hybrid systems: an opportunity  . . . . . . . . . .  331  331  331  332 xii Recent Developments in Forward Osmosis Processes 7.3.2 Desalination Applications  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  334 7.3.2.1 Direct desalination  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  334 7.3.2.2 Indirect desalination  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  339 7.3.3 Impaired-Quality Water Treatment and Reuse Applications  . . . . . . . .  342 7.3.3.1 Water harvesting from municipal wastewater  . . . . . . . . . . . . .  342 7.3.3.2 Industrial wastewater reclamation and reuse  . . . . . . . . . . . . .  348 7.3.3.3 Other applications for impaired-quality water treatment  . . . . . .  349 7.3.4 Energy and Economics of FO Systems  . . . . . . . . . . . . . . . . . . . . . . . .  350 7.3.5 Pressure Retarded Osmosis: Special FO Application for Energy Recovery in Water Industry  . . . . . . . . . . . . . . . . . . . . . . . . . . .  352 7.3.5.1 Generating power with PRO  . . . . . . . . . . . . . . . . . . . . . . . . . .  352 7.3.5.2 Large-scale applications of PRO  . . . . . . . . . . . . . . . . . . . . . .  354 7.3.5.3 PRO membranes  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  356 7.3.6 Major Challenges for Commercialization  . . . . . . . . . . . . . . . . . . . . . . .  357 7.3.7 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  359 7.3.8 References  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  360 Supplementary material  . . . . . . . . . . . . . . . . . . . . . . . . . . . .  369 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  371 Additional Image credits Part 1 – Spring-fed pool, “Ojo de Agua” ranch, Villa Unión, Coahuila, Mexico. Photograph taken by Rodrigo Valladares Linares Part 2 – Recycle for clean water, Photographer: serrnovik. Photo ID: csp9783511 http:// www.canstockphoto.com/recycle-for-clean-water-9783511.html Part 3 – Scanning electron microscopy image of a biofouled membrane showing bacterial cells and exopolymeric substances. Photograph taken by Szilard Bucs and Rodrigo Valladares Linares Part 4 –  3-D representation of Bisphenol A and Paracetamol molecules. Paracetamol molecule – Author: Ben Mills – Benjah-bmm27. Public Domain. Available from https://en.wikipedia.org/wiki/Paracetamol#/media/File:Paracetamol-from-xtal3D-balls.png, Author: Bisphenol A molecule – Author: Edgar181. Public Domain. Available from https://commons.wikimedia.org/wiki/File:Bisphenol_A.png Part 5 – Scanning electron microscopy cross-section image of a clean cellulose triacetate forward osmosis membrane. Photograph taken by Szilard Bucs and Rodrigo Valladares Linares Part 6 – Visualization of membrane and feed spacer fouling process using computational fluid dynamics software. Simulation image created by Szilard Bucs Part 7 – Water. Photographer: ifong. Photo ID: csp4605553 http://www.canstock​photo.com/​ water-4605553.html List of Contributors We want to acknowledge the contribution of our co-authors in the various chapters. Muhannad Abu-Ghdaib King Abdullah University of Science and Technology, Saudi Arabia. Laura A. Hoover Yale University, New Haven, United States. Gary L. Amy King Abdullah University of Science and Technology, Saudi Arabia. Yan-Ching Jean University of Missouri-Kansas City, United States. Cyril Aubry King Abdullah University of Science and Technology, Saudi Arabia. TorOve Leiknes King Abdullah University of Science and Technology, Saudi Arabia. Szilard S. Bucs King Abdullah University of Science and Technology, Saudi Arabia. Qingyu Li King Abdullah University of Science and Technology, Saudi Arabia. Hongmin Chen University of Missouri-Kansas City, United States. Zhenyu Li King Abdullah University of Science and Technology, Saudi Arabia. Tai-Shung Neal Chung National University of Singapore, Singapore. Menachem Elimelech Yale University, New Haven, United States. Qingchun Ge National University of Singapore, Singapore. Noreddine Ghaffour King Abdullah University of Science and Technology, Saudi Arabia. Rodrigo Valladares Linares King Abdullah University of Science and Technology, Saudi Arabia. Mingming Ling National University of Singapore, Singapore. Jeffrey R. McCutcheon Yale University, New Haven, United States. Yong-Gyun Park GS Engineering and Construction, Seoul, South Korea. xvi Recent Developments in Forward Osmosis Processes William A. Phillip University of Notre Dame, United States. Kai Yu Wang National University of Singapore, Singapore. Cristian Picioreanu Delft University of Technology, The Netherlands. Chunhai Wei King Abdullah University of Science and Technology, Saudi Arabia. Sarper Sarp GS Engineering and Construction, Seoul, South Korea. Victor A. Yangali-Quintanilla King Abdullah University of Science and Technology, Saudi Arabia; Grundfos Holding A/S, Bjerringbro, Denmark. Alberto Tiraferri Yale University, New Haven, United States. Johannes S. Vrouwenvelder King Abdullah University of Science and Technology, Saudi Arabia; Delft University of Technology, The Netherlands; Wetsus, The Netherlands. Ngai Yin Yip Yale University, New Haven, United States. Tong Zhan King Abdullah University of Science and Technology, Saudi Arabia. Sui Zhang National University of Singapore, Singapore. Preface A constant and reliable source of fresh water is essential for the development of modern economies and settlements around the world. It has been projected that by 2025, between 2.4 billion and 3.2 billion people could live under water-scarce or water-stressed conditions, a four-fold increase in the number of people that lived under these situations at the beginning of the century. Research has identified the potential of forward osmosis (FO) systems to produce high quality water from seawater, while recovering impaired water from wastewater sources. The study of FO has increased strongly in the past five years, compared to the previous fifteen years, as indicated by a more than tripling of the number of scientific papers. However, no single source has given an updated overview of FO. This book gives a complete and comprehensive overview of all aspects of forward osmosis: (i) introduction, (ii) water recovery, (iii) fouling, (iv) rejection of micropollutants, (v) draw solutions and membranes, (vi) numerical modelling, and an (vii) outlook with an overview on low-energy applications, a life cycle cost assessment, and the possible niches in the water industry for forward osmosis processes and hybrids. Rodrigo Valladares Linares [email protected] [email protected] Zhenyu Li [email protected] [email protected] Menachem Elimelech [email protected] Gary L. Amy [email protected] [email protected] Johannes S. Vrouwenvelder [email protected] [email protected] Summary Since more than 97% of the water in the world is seawater, desalination technologies have the potential to solve the fresh water crisis. The most used desalination technology nowadays is seawater reverse osmosis (SWRO), where a membrane is used as a physical barrier to separate the salts from the water, using high hydraulic pressure as the driving force. However, the use of high hydraulic pressure imposes a high cost on operation of these systems, in addition to the known persistent fouling problems associated with reverse osmosis (RO) membrane filtration systems. Forward osmosis (FO) is an alternative membrane process that uses an osmotic pressure difference as the driving force. FO uses a concentrated draw solution to generate high osmotic pressure, which extracts water across a semi-permeable membrane from a feed solution. Afterwards, fresh water can be obtained when the diluted draw solution is regenerated in a second treatment step, e.g., low pressure reverse osmosis (LPRO). Research has identified the potential for hybrid forward osmosis/low-pressure reverse osmosis (FO/ LPRO) systems for several applications, including seawater desalination, and to reduce the cost and fouling propensity of producing fresh water from impaired-quality water sources, compared to conventional high pressure RO systems. One of the main advantages of FO is the limited amount of external energy required to extract water from the feed solution, using only a very low amount of energy to recirculate the draw solution on one side of the membrane, while the feed solution is passively in contact with the other side of the membrane. The objective of this book is the evaluation of the recent developments in FO processes for wastewater recovery and seawater desalination, characterization of membrane fouling and cleaning, pollutant rejection capabilities of FO membranes, state-of-the-art FO membranes and draw solutions, modeling the effect of concentration polarization, reverse salt flux and fouling on water flux through the FO membrane, and the analysis of FO applications/niches and the life cycle cost of a large-scale system compared to conventional desalination and water recovery alternatives. WATER RECOVERY Forward osmosis membrane processes can be adapted to the existing urban runoff collection system in coastal regions for the management of urban runoff (Chapter 2.1). During testing,