Edited byAnil K. PabbySyed S.H. RizviAna Maria SastrePabbyRizviSastreHandbook of Membrane SeparationsChemical, Pharmaceutical, Food, and Biotechnological ApplicationsS E C O N D E D I T I O NSecondEditionISBN: 978-1-4665-5556-3978146655556390000K15379The Handbook of Membrane Separations: Chemical, Pharmaceutical, Food, and BiotechnologicalApplications,SecondEditionprovidesdetailedinformationon membrane separation technologies from an international team of experts. The handbook lls an important gap in the current literature by providing a compre-hensivediscussionofmembraneapplicationsinthechemical,food,pharmaceutical, and biotechnology industries as well as in the treatment of toxic industrial efuents.This revised second edition has been updated and expanded with discussions of new membrane products and processes and novel applications in engineering, life sciences, and energy conversion. Italsoincludesnewchaptersintheeldofmembranescienceandtechnology coveringrecentadvancesinROandUF,ionicliquids,nanotechnology,rolesof membraneinpowergeneration,updatesonfuelcells,newmembraneextraction conguration, and other important topics. Thehandbookisequallysuitedforthenewcomertotheeldasitisforprocess engineersandresearchscientists(membranologists/membraneexperts)whoare interestedinobtainingmoreadvancedinformationaboutspecicapplications.It provides readers with a comprehensive and well-balanced overview of the present state of membrane science and technology. CHEMI CALENGI NEERI NGHandbook of Membrane SeparationsChemical, Pharmaceutical, Food,and Biotechnological ApplicationsK15379_Cover_PubGr.indd All Pages 2/25/15 3:07 PMHandbook of Membrane SeparationsHandbook of Membrane SeparationsEdited byAnil K. PabbySyed S.H. RizviAna Maria SastreChemical, Pharmaceutical, Food, andBiotechnological ApplicationsSecond EditionCRC PressTaylor & Francis Group6000 Broken Sound Parkway NW, Suite 300Boca Raton, FL 33487-2742 2015 by Taylor & Francis Group, LLCCRC Press is an imprint of Taylor & Francis Group, an Informa businessNo claim to original U.S. Government worksVersion Date: 20150212International Standard Book Number-13: 978-1-4665-5558-7 (eBook - PDF)This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use. The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged please write and let us know so we may rectify in any future reprint.Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers.For permission to photocopy or use material electronically from this work, please access www.copyright.com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged.TrademarkNotice:Productorcorporatenamesmaybetrademarksorregisteredtrademarks,andareusedonlyforidentificationandexplanation without intent to infringe.Visit the Taylor & Francis Web site athttp://www.taylorandfrancis.comand the CRC Press Web site athttp://www.crcpress.comvContentsForeword ...................................................................................................................................................................................... ixPreface.......................................................................................................................................................................................... xiEditors ........................................................................................................................................................................................xiiiContributors ................................................................................................................................................................................ xvSECTION I Membrane Applications in Chemical and Pharmaceutical Industries and in Conservation of Natural ResourcesChapter 1Membrane Applications in Chemical and Pharmaceutical Industries and in the Conservation of Natural Resources: Introduction ........................................................................................................................................... 3Anil K. Pabby, Syed S.H. Rizvi, and Ana Maria SastreChapter 2Advanced Materials in Ultrafltration and Nanofltration Membranes ................................................................... 7W.J. Lau, A.F. Ismail, T. Matsuura, N.A. Nazri, and E. YuliwatiChapter 3Reverse Osmosis Membrane ................................................................................................................................. 35Dipak Rana, Takeshi Matsuura, Mohd Azraai Kassim, and Ahmad Fauzi IsmailChapter 4Industrial Applications of Membrane Contactors ................................................................................................. 53Anil K. Pabby, J.V. Sonawane, Ana Maria Sastre, and Y. KulkarniChapter 5Membrane Applications in Oil Refning and Petrochemical Industry .................................................................. 77A. Brunetti, G. Barbieri, and Enrico DrioliChapter 6Membrane and Monolithic Convective Chromatographic Supports....................................................................101M.E. Avramescu, Zandrie Borneman, and M. WesslingChapter 7Membranes in Gas Separation .............................................................................................................................143May-Britt Hgg and Liyuan DengChapter 8Pervaporation: Theory, Practice, and Applications intheChemical and Allied Industries ................................181Vishwas G. Pangarkar and Samit Kumar RayChapter 9Ceramic Membranes Technology: Current Applications and Future Development ........................................... 215Christian Guizard and Adam StevensonChapter 10Techniques to Enhance Performance of Liquid-Phase Membrane Processes by Improved Control ofConcentration Polarization.............................................................................................................................. 259S. Chang and A.G. Fanevi ContentsChapter 11Zeolite Membranes: Synthesis, Characterization, Important Applications, and Recent Advances ................... 293M.P. Pina, Manuel Arruebo, and Reyes MalladaChapter 12Current Challenges in Reducing Membrane Fouling ......................................................................................... 355Mattheus F.A. GoosenChapter 13Membrane Extraction in Preconcentration, Sampling, and Trace Analysis ....................................................... 377Jan ke Jnsson and Estelle LarssonChapter 14Advancements in Membrane Processes for Pharmaceutical Applications ......................................................... 403Ralf Kuriyel, Masatake Fushijima, and Gary W. JungChapter 15Membranes in Drug Delivery...............................................................................................................................419Simona Maria Fiorentino, Rossella Farra, Barbara Dapas, Bruna Scaggiante, Federica Tonon, GabrieleGrassi, and Mario GrassiChapter 16Chitosan and Its Derivatives as Potential Materials for Membrane Technology ................................................ 465Rajesha Kumar and Arun M. IsloorSECTION II Membrane Applications in Biotechnology, FoodProcessing, LifeSciences, and Energy ConversionChapter 17Membrane Applications in Biotechnology, Food Processing, LifeSciences, and Energy Conversion: Introduction ......................................................................................................................................................... 483Anil K. Pabby, Ana Maria Sastre, and Syed S.H. RizviChapter 18Membranes in Power Generation: A Review of Current Uses and Emerging Applications ............................... 485Dhaval Bhandari, Anthony Y. Ku, and Surinder SinghChapter 19Applications of Membrane Technology in the Dairy Industry ........................................................................... 505Philipina A. Marcelo and Syed S.H. RizviChapter 20Transporting and Separating Molecules Using Tailored Nanotube Membranes ................................................ 539Kexin Jiao, Punit Kohli, and Charles R. MartinChapter 21Proton-Conducting Membranes for Fuel Cells ................................................................................................... 567Vineet Rao, Norbert Kluy, Wenbo Ju, and Ulrich StimmingChapter 22On the Use of Ionic Liquid Technology for the Selective Separation of Organic Compounds and Metal Ions ....615A. Prez de los Ros, F.J. Hernndez-Fernndez, L.J. Lozano, C. Godnez, S. Snchez-Segado, F.J.Alguacil, F. Toms-Alonso, and S. GalaiChapter 23A Critical View on Separation Processes by Membrane Technology Applied in Vegetable Oil Refning ......... 629Cesar de Morais Coutinhovii ContentsSECTION IIIMembrane Applications in Industrial Waste Management (Including Nuclear), Environmental Engineering, and Future Trends in Membrane ScienceChapter 24Membrane Applications in Industrial Waste Management (Including Nuclear), Environmental Engineering, and Future Trends in Membrane Science: Introduction ................................................................ 663Anil K. Pabby and Ana Maria SastreChapter 25Advancement in Membrane Methods for Liquid Radioactive Waste Processing: Current Opportunities, Challenges, and the Global Scenario .................................................................................................................. 665Grazyna Zakrzewska-KoltuniewiczChapter 26Overview and the Current Status of Membrane-Based Processing of Radioactive Nuclear Plant Waste: Evaluation of Some Case Studies ........................................................................................................................ 709Anil K. Pabby, J.V. Sonawane, S.K. Gupta, S.R. Sawant, N.S. Rathore, and Y. KulkarniChapter 27Polymer Inclusion Membranes ............................................................................................................................ 723Spas D. Kolev, M. Ins G.S. Almeida, and Robert W. CattrallChapter 28Membrane Bioreactors forWastewater Treatment ...............................................................................................741Eoin Syron and Eoin CaseyChapter 29Concentration-Driven Membrane Processes for the Recovery of Valuable Compounds from Industrial Wastes ........................................................................................................................................ 759Eugenio Bringas, M. Fresnedo San Romn, Ana M. Urtiaga, and Inmaculada OrtizChapter 30Membrane Contactors for the Absorption of Carbon Dioxide from Gaseous Streams: State of the Art on Membrane Improvements ..................................................................................................... 773Alessandra Criscuoli and Enrico DrioliChapter 31Liquid Membranes for Studies Involving Nuclear Waste Remediation Using Hollow-Fiber Contactors ........... 787Seraj A. Ansari, Pankaj Kandwal, and Prasanta K. MohapatraChapter 32Hollow-Fiber Renewal and Strip Dispersion Liquid Membrane Techniques: Application for Metal Separation, Recovery, and Wastewater Treatment .............................................................................................. 813Anil K. Pabby, Suman C. Roy, J.V. Sonawane, N.S. Rathore, C.B. Patil, Ana Maria Sastre, and Y. KulkarniChapter 33Future Progress in Membrane Engineering ........................................................................................................ 825Enrico Drioli and Gianluca Di ProfoixThe term membrane covers a large variety of materials and structureswithverydifferentproperties.Thesameistrue for membrane processes and their applications. Today, mem-branes are used to produce potable water by reverseosmosis seawaterdesalinationatbearablecosts.Membranesare keycomponentsinmedicaldevicesandintheseparation ofmolecularmixturesinthechemicalandpetrochemical industryaswellasinbiotechnologyandfoodprocessing. Membranesciencehasbecomeaninterdisciplinaryaffair withcontributionsfromphysicalchemistry,materialsand lifesciences,andprocessengineering.Theliteraturecov-eringmembraneprocessesandtheirapplicationsishighly fragmented and contained in a large number of different sci-entifc journals. This makes it diffcult to gain a reasonably complete overview of membrane technology and its applica-tions without an extensive study of a fair number of articles in scientifc journals and books, or even company brochures.Thereareanumberofexcellentmembrane-relatedtext-books and reference books available. However, most of these bookstreatonlycertainaspectsofmembranescienceand technologyindepthwhileotherfeaturesrelatedtomem-branes are only briefy mentioned or not covered at all. The fundamentalsofmembranefunctionsandmembranepro-cesses are described in detail in a number of publications in themembrane-relatedliterature.Theapplicationofmem-branes,however,ismuchlesscomprehensivelycoveredin such books. A large number of interesting membrane appli-cationsinthefoodanddrugindustry,electrochemicalsyn-thesisorbiomedicaltreatment,andenergyconversionare published in journals specifc for certain industries, which are beyond the interest of many membrane scientists. Therefore, asmentionedearlier,itisdiffculttoobtainareasonably complete overview of the very large and heterogeneous feld of membrane applications without reading a number of very different journals in which the bulk of the publications is not really membrane related.Itiscertainlynotaneasytasktoprovideacomplete overviewofsyntheticmembranesandtheirapplications inasinglemonograph.However,theseweretheobjectives oftheHandbookofMembraneSeparations:Chemical, Pharmaceutical,Food,andBiotechnologicalApplications. Whenthefrsteditionofthehandbookbecameavailable in 2008, it was received with great interest by the scientifc communityandtheprocessindustrysinceitprovideda rather comprehensive and well-balanced overview of the fun-damentals of synthetic membranes and their large number of applications in the modern industrialized society.However, membrane technology, as well as its application, isnotonlyfragmentedandwidelyspread,itisalsorapidly increasing with newly developed products and processes. To meet its objective to provide the most complete description of membranes and their technical and commercial relevance, the handbook has been updated and expanded with a discussion of new membrane products, processes, and novel applications in engineering, life sciences, and energy conversion. As with its well-received predecessor, it provides a comprehensive and well-balanced overview of the present state of membrane sci-ence and technology and its extensive application. It is equally suited for the newcomers in the feld as well as for engineers and scientists who have basic knowledge in membrane tech-nology but are interested in obtaining more information about specifc future applications.Heiner StrathmannUniversity of StuttgartStuttgart, GermanyForewordxiThisnew,revisedsecondeditionoftheHandbookof MembraneSeparations:Chemical,Pharmaceutical,Food, andBiotechnologicalApplicationsaddressesthelatest developmentsandimportantmilestonesthathaveappeared in the literature since the frst edition was published. Newer technologiesthathaveemergedandnovelapplicationsor trends for future applications along with relevant references arethehallmarkofthenewedition.Asanexpandedand updatedversionofitswell-receivedpredecessor,thishand-book includes new chapters in the feld of membrane science andtechnologydealingwithionicliquids,nanotechnology, new membrane extraction confguration, roles of membrane in power generation, updates on fuel cells, etc.Thehandbookisdividedintothreemainsections: Section Idealswithmembraneapplicationsinthechemi-cal and pharmaceutical industries and in the conservation of naturalresources.SectionIIcoversmembraneapplications inbiotechnology,foodprocessing,lifesciences,andenergy conversion.Finally,membraneapplicationsinindustrial wastemanagement(includingnuclear),environmentalengi-neering, and future trends in membrane science are presented in Section III. Each section is divided into chapters that deal withthesubjectmatterindepthandfocusoncutting-edge advancementsinthefeld.Severalauthorswerealsocom-missionedtowritenewchaptersunderthesupervisionof theeditors,andeachchapterwaspeer-reviewedforcontent and style before it was accepted for publication. Some of the previous editions chapters dealing with emerging areas were also updated by authors in order to record the latest advances in those felds. The aim was to maintain the perspective of a practical handbook rather than merely a collection of review chapters.Theeditorsacknowledgethecontributionsofanumber ofauthorsandinstitutionsthathaveplayedamajorrolein draftingthehandbook,fromconceptiontopublication.The handbookwouldnothavebeenpossiblewithouttheirinput. These contributors are leading experts in their felds and bring agreatwealthofexperiencetothisbook.Theeditorsalso acknowledgetheeffortsofthereviewerswhodevotedtheir valuable time in critically evaluating the chapters before the setdeadlinesandsuggestedimprovementstomaintainthe high standard of the handbook. Finally, the editors acknowl-edge the support of their home institutions at every stage in the handbooks conception: the Bhabha Atomic Research Centre (Mumbai, India), Cornell University (Ithaca, New York), and the Technical University of Catalonia (Barcelona, Spain).PrefacexiiiDr. Anil K. Pabby is scien-tifcoffcerinoneofthe pioneerresearchcentersin India,BhabhaAtomic ResearchCentre(BARC), andisassociatedwiththe activities of the Department ofAtomicEnergy(DAE), includingresearchand developmentwork.He receivedhisPhDfromthe UniversityofMumbai,India,andsubsequentlycarriedout hispostdoctoralworkattheTechnicalUniversityof Catalunya, Barcelona, Spain. Dr.Pabbyhasmorethan170publicationstohiscredit, including 20 chapters and 2 patents on nondispersive mem-brane technology. He was invited to join as an associate editor of the international journal Journal of Radioanalytical and NuclearChemistryduring20022005.Hehasalsoserved asconsultanttotheInternationalAtomicEnergyAgency (IAEA),Vienna,Austria,fordevelopingatechnicalbook volume,ApplicationofMembraneTechnologiesforLiquid Radioactive Waste Processing.Dr.Pabbyhasbeenaregularreviewerforseveralnational andinternationaljournalsandalsoamemberoftheeditorial board of a few reputed international journals. His research inter-est includes pressure-driven membrane processes, nondispersive membrane technology and its modeling aspects, solvent extrac-tion, and macrocyclic compounds. Dr. Pabby was elected as a fellowoftheMaharashtraAcademyofSciences(FMASc)in 2003 for his outstanding contribution in membrane science and technology. Also, he was awarded the prestigious Tarun Datta MemorialAward(institutedbyIndianAssociationofNuclear Chemists and Allied Scientists) in 2005 for his contribution in nuclear and radiochemistry. Dr. Pabby also received three dif-ferent group achievement awards (instituted by the Department ofAtomicEnergy)forhiscontributionstothereprocessing plant. He was appointed as assistant professor and PhD guide by Homi Bhabha National Institute, Mumbai. He is serving as sec-retary of the Indian Association of Nuclear Chemists and Allied Scientists, Tarapur Chapter, since 2008. He has delivered sev-eral keynote/plenary/invited talks atnational and international conferences.Hehasalsoservedaschairmanofthedifferent sessions in conferences on membrane science and technology.Syed S.H. Rizvi is interna-tionalprofessoroffood pro cess engineering andhas served as director ofgraduate studies at the Cornell Institute of Food Science, Ithaca, New York.HereceivedhisPhD fromOhioStateUniversity, Columbus, Ohio, ME in chemicalengineeringfrom theUniversityofToronto, Toronto, Ontario, Canada, and BTech from Panjab University, Chandigarh,India.Heteachescoursesdevotedtoengineer-ingandprocessingaspectsoffoodscienceandrelated biomaterials. Hislaboratoryisengagedinresearchonexperimental andtheoreticalaspectsofbioseparationprocessesusing supercritical fuids and membranes, high-pressure extrusion withsupercriticalcarbondioxide,physicalandengineering propertiesofbiomaterials,andnovelfoodprocessingtech-nologies.Hismajorlong-termgoalistodevelopnewand improved unit operations for value-added processing of food andbiomaterials.Hisderivativegoalsincludenewtech-niques for measurement and control of processes and proper-ties for industrial applications. Dr.Rizvihaspublishedover160technicalpapers, coauthored/edited6books,servesontheeditorialboard ofseveraljournals,andholds7patents.Hehasbeena visitingprofessoratseveraluniversities,includingBogor AgriculturalUniversity(Indonesia),theInstituteof FoodTechnology(Brazil),andtheUniversityofToronto (Canada).Therecognitionofhiscontributionshaspro-videdhimampleopportunitiestocollaborate,present talks,andinteractwithprofessionalsinnumerousother countries,includingAustralia,Chile,Ghana,Germany, India,Indonesia,Ireland,Japan,Malaysia,Mexico, Pakistan,Peru,Portugal,Russia,Sweden,Switzerland, and Turkey, to name but a few, under various sponsorships (FAO,UNIDO,WorldBank,NATO,amongothers).He isafellowoftheInternationalAcademyofFoodScience andTechnology(IAFoST)andtheInstituteofFood Technologists.HehasalsoservedasaJeffersonScience Fellow and senior science adviser in the U.S. Department of State in Washington, DC.Editorsxiv EditorsAnaMariaSastreisa professorofchemical engineeringatUniversitat PolitcnicadeCatalunya, Barcelona,Spain,where shehasbeenteaching chemistryformorethan 35 years.Shereceivedher PhD from the Autonomous University of Barcelona in 1982andhasbeenwork-ing for many years in the feld of solvent extraction, solvent impregnated resins, and membrane technology. She was a visiting fellow at the Department of Inorganic Chemistry, TheRoyalInstituteofTechnology,Sweden,during 19801981andcarriedoutpostdoctoralresearchwork from October 1986 to April 1987 at Laboratoire de Chimie Minerale,delEcoleEuropeennedesHautesEtudesdes Industries Chimiques dEstrasbourg, France. ProfessorSastrehaspublishedmorethan200journal articlesandmorethan80papersininternationalconfer-ences. She holds six patent applications. She has advised 13 PhDstudentsand16masterstheses,andisareviewerof manyinternationaljournals.ShewasawardedtheNarcis MonturiolMedalforScientifcandTechnologicalMerits in 2003 by the Generalitat de Catalunya for her outstanding contribution in science and technology.ProfessorSastrewastheheadofthechemicalengineer-ingdepartmentfrom1999till2005andthevicepresident foracademicpolicyfrom2006to2013attheUniversitat Politcnica de Catalunya.xvF.J. AlguacilCentro Nacional de Investigaciones MetalrgicasCiudad UniversitariaMadrid, SpainM. Ins G.S. AlmeidaSchool of ChemistryThe University of MelbourneMelbourne, Victoria, AustraliaSeraj A. AnsariRadiochemistry DivisionBhabha Atomic Research CentreMumbai, Maharashtra, IndiaManuel ArrueboDepartment of Chemical and Environmental EngineeringUniversity of ZaragozaZaragoza, SpainM.E. AvramescuLydall Performance MaterialsHeerlen, the NetherlandsG. BarbieriInstitute on Membrane TechnologyNational Research CouncilUniversity of CalabriaCosenza, ItalyDhaval BhandariGE Global ResearchNiskayuna, New YorkZandrie BornemanFaculty of TechnologyUniversity of TwenteEnschede, the NetherlandsEugenio BringasDepartment of Chemical and Biomolecular EngineeringUniversity of CantabriaSantander, SpainA. BrunettiInstitute on Membrane TechnologyNational Research CouncilUniversity of CalabriaCosenza, ItalyEoin CaseySchool of Chemical and Bioprocess EngineeringUniversity College DublinDublin, IrelandRobert W. CattrallSchool of ChemistryThe University of MelbourneMelbourne, Victoria, AustraliaS. ChangSchool of EngineeringUniversity of GuelphGuelph, Ontario, CanadaCesar de Morais CoutinhoDepartment of Food Science and Technology ResearchFederal University of Santa MariaSanta Maria, BrazilAlessandra CriscuoliInstitute on Membrane TechnologyNational Research CouncilUniversity of CalabriaCosenza, ItalyBarbara DapasDepartment of Life ScienceCattinara HospitalUniversity of TriesteTrieste, ItalyA. Prez de los RosFaculty of ChemistryDepartment of Chemical EngineeringUniversity of MurciaMurcia, SpainLiyuan DengDepartment of Chemical EngineeringNorwegian University of Science and TechnologyTrondheim, NorwayGianluca Di ProfoInstitute on Membrane TechnologyNational Research CouncilUniversity of CalabriaCosenza, ItalyEnrico DrioliInstitute on Membrane TechnologyNational Research CouncilandDepartment of Chemical Engineering and MaterialsUniversity of CalabriaCosenza, ItalyA.G. FaneSchool of Chemical Sciences and EngineeringUNESCO Centre for Membrane Science and TechnologyUniversity of New South WalesSydney, New South Wales, AustraliaRossella FarraDepartment of Engineering and ArchitectureUniversity of TriesteTrieste, ItalySimona Maria FiorentinoDepartment of Engineering and ArchitectureUniversity of TriesteTrieste, ItalyMasatake FushijimaScientifc and Laboratory ServicesPall CorporationPort Washington, New YorkS. GalaiLaboratory of Protein Engineering and Bioactive MoleculesNational Institute of Applied Sciences and TechnologyUniversity of CarthageCarthage, TunisiaC. GodnezDepartment of Chemical and Environmental EngineeringTechnical University of CartagenaMurcia, SpainContributorsxvi ContributorsMattheus F.A. GoosenOffce of Research and Graduate StudiesAlfaisal UniversityRiyadh, Saudi ArabiaGabriele GrassiDepartment of Life ScienceCattinara HospitalUniversity of TriesteTrieste, ItalyMario GrassiDepartment of Engineering and ArchitectureUniversity of TriesteTrieste, ItalyChristian GuizardCeramic Synthesis and Functionalization LaboratorySaint-Gobain CREECavaillon, FranceS.K. GuptaNuclear Recycle BoardBhabha Atomic Research CentreTarapur, Maharashtra, IndiaMay-Britt HggDepartment of Chemical EngineeringNorwegian University of Science and TechnologyTrondheim, NorwayF.J. Hernndez-FernndezDepartment of Chemical and Environmental EngineeringTechnical University of CartagenaMurcia, SpainArun M. IsloorMembrane Technology LaboratoryDepartment of ChemistryNational Institute of Technology KarnatakaMangalore, Karnataka, IndiaA.F. IsmailAdvanced Membrane Technology Research CentreUniversity of Technology, MalaysiaSkudai, MalaysiaKexin JiaoDepartment of Chemistry and BiochemistrySouthern Illinois UniversityCarbondale, IllinoisJan ke JnssonDepartment of ChemistryCenter for Analysis and SynthesisLund UniversityLund, SwedenWenbo JuDepartment of Physics E19Technische Universitaet MuenchenMunich, GermanyGary W. JungMembrane Technology ConsultantLos Angeles, CaliforniaPankaj KandwalRadiochemistry DivisionBhabha Atomic Research CentreMumbai, Maharashtra, IndiaMohd Azraai KassimAdvanced Membrane Technology Research CentreUniversity of Technology, MalaysiaJohor, MalaysiaNorbert KluyDepartment of Physics E19Technische Universitaet MuenchenMunich, GermanyPunit KohliDepartment of Chemistry and BiochemistrySouthern Illinois UniversityCarbondale, IllinoisSpas D. KolevSchool of ChemistryThe University of MelbourneMelbourne, Victoria, AustraliaAnthony Y. KuGE Global ResearchNiskayuna, New YorkY. KulkarniNuclear Recycle BoardBhabha Atomic Research CentreTarapur, Maharashtra, IndiaRajesha KumarMembrane Technology LaboratoryDepartment of ChemistryNational Institute of Technology KarnatakaMangalore, Karnataka, IndiaRalf KuriyelBiopharm Applications R&DPall Life SciencesPall CorporationNew York, New YorkEstelle LarssonDepartment of Water and Waste WaterTrelleborg MunicipalityTrelleborg, SwedenW.J. LauAdvanced Membrane Technology Research CentreUniversity of Technology, MalaysiaJohor, MalaysiaL.J. LozanoDepartment of Chemical and Environmental EngineeringTechnical University of CartagenaMurcia, SpainReyes MalladaDepartment of Chemical and Environmental EngineeringUniversity of ZaragozaZaragoza, SpainPhilipina A. MarceloFaculty of EngineeringDepartment of Chemical EngineeringThe Research Center for the Natural and Applied SciencesUniversity of Santo TomasManila, PhilippinesCharles R. MartinDepartment of ChemistryCenter for Research at the Bio/Nano InterfaceUniversity of FloridaGainesville, FloridaT. MatsuuraDepartment of Chemical and Biological EngineeringUniversity of OttawaOttawa, Ontario, CanadaPrasanta K. MohapatraRadiochemistry DivisionBhabha Atomic Research CentreMumbai, Maharashtra, IndiaN.A. NazriAdvanced Membrane Technology Research CentreUniversity of Technology, MalaysiaJohor, Malaysiaxvii ContributorsInmaculada OrtizDepartment of Chemical and Biomolecular EngineeringUniversity of CantabriaSantander, SpainAnil K. PabbyNuclear Recycle BoardBhabha Atomic Research CentreTarapur, Maharashtra, IndiaVishwas G. PangarkarFormerly Professor of Chemical Engineering and Head of ChemicalEngineering DepartmentInstitute of Chemical TechnologyUniversity of MumbaiMumbai, IndiaC.B. PatilNuclear Recycle BoardBhabha Atomic Research CentreTarapur, Maharashtra, IndiaM.P. PinaDepartment of Chemical and Environmental EngineeringUniversity of ZaragozaZaragoza, SpainDipak RanaDepartment of Chemical and Biological EngineeringUniversity of OttawaOttawa, Ontario, CanadaVineet RaoDepartment of Physics E19Technische Universitaet MuenchenMunich, GermanyN.S. RathoreNuclear Recycle BoardBhabha Atomic Research CentreTarapur, Maharashtra, IndiaSamit Kumar RayDepartment of Polymer Science and TechnologyUniversity of CalcuttaKolkata, West Bengal, IndiaSyed S.H. RizviInstitute of Food ScienceCornell UniversityIthaca, New YorkSuman C. RoyNuclear Recycle BoardBhabha Atomic Research CentreTarapur, Maharashtra, IndiaM. Fresnedo San RomnDepartment of Chemical and Biomolecular EngineeringUniversity of CantabriaSantander, SpainS. Snchez-SegadoDepartment of Chemical and Environmental EngineeringTechnical University of CartagenaMurcia, SpainAna Maria SastreDepartment of Chemical EngineeringUniversitat Politcnica de CatalunyaBarcelona, SpainS.R. SawantNuclear Recycle BoardBhabha Atomic Research CentreTarapur, Maharashtra, IndiaBruna ScaggianteDepartment of Life ScienceCattinara HospitalUniversity of TriesteTrieste, ItalySurinder SinghGE Global ResearchNiskayuna, New YorkJ.V. SonawaneNuclear Recycle BoardBhabha Atomic Research CentreTarapur, Maharashtra, IndiaAdam StevensonCeramic Synthesis and Functionalization LaboratorySaint-Gobain CREECavaillon, FranceUlrich StimmingDepartment of Physics E19Technische Universitt MnchenMunich, GermanyEoin SyronSchool of Chemical and Bioprocess EngineeringUniversity College DublinDublin, IrelandF. Toms-AlonsoFaculty of ChemistryDepartment of Chemical EngineeringUniversity of MurciaMurcia, SpainFederica TononDepartment of Life ScienceCattinara HospitalUniversity of TriesteTrieste, ItalyAna M. UrtiagaDepartment of Chemical and Biomolecular EngineeringUniversity of CantabriaSantander, SpainM. WesslingMembrane Technology GroupUniversity of TwenteEnschede, the NetherlandsE. YuliwatiAdvanced Membrane Technology Research CentreUniversity of Technology, MalaysiaJohor, MalaysiaGrazyna Zakrzewska-KoltuniewiczInstitute of Nuclear Chemistry and TechnologyCentre of Radiochemistry and Nuclear ChemistryWarsaw, PolandSection IMembrane Applications in Chemical and Pharmaceutical Industries and in Conservation of Natural Resources31Focusingontherecentadvancesandupdates,thissection addresses new development in chemical andpharmaceutical industriesandintheconservationofnaturalresources. Included in this edition are newer practices and technologies and their applications or trends for future applications with rel-evant references that have appeared in the literature since the frst edition was published. Several new chapters on emerging areas such as membrane separation in petrochemical oil refn-ery, chitosan as new material for membrane preparation, new membrane material for ultrafltration (UF) and nanofltration (NF),andpotentialapplicationofreverseosmosis(RO)in chemical industry have been added in the second edition.As a new strategy, process intensifcation is gaining par-amountimportanceandslowlybecomingpartofalready establishedandnewlydevelopedtechnologicalprocesses. Drioli et al. [1] defne process intensifcation as the strategy tobringdrasticimprovementsinmanufacturingandpro-cessingbydecreasingcapitalcost,equipmentsize,energy consumption,wasteproduction,environmentalimpact,etc. Inthiscontext,membraneoperationshavethepotentialto replaceconventionalenergy-intensivetechniques,accom-plish the selective and effcient transport of specifc compo-nents,improvetheperformanceofreactiveprocesses,and, ultimately,providereliableoptionsforsustainablegrowth [2]. In addition, membrane processes can be benefcially inte-grated at different levels because of their several advantages overconventionalprocesses:compactness,easyscale-up, and automation [34]. Pressure-driven processes such as UF, NF, and microfltration are already established, and various applications have been commercialized in the felds of food, pharmaceutical,andbiotechnology.Thedevelopmentofa meansofcharacterizing,controlling,andpreventingmem-branefoulinghasprovenvitalinrecentyears.Engineering tailored membranes, fouling prevention, and optimization of chemical cleaning will ensure a high level of membrane pro-cessperformance.Inthelast5 years,developmentsofnew techniques for membrane characterization and improvements inexistingtechniqueshaveincreasedourknowledgeofthe mechanismsinvolvedinmembranefouling.Theadvanced techniquesusedformembranefoulingdetectionwillnot only provide useful insights into the fouling mechanism but alsoaugmentourunderstandingofthefactorsthataffect membrane fouling.Inthenewdevelopments,anovelmethodforCO2 separationfromthegasphasebyapplyingnanofuidsof nanosilica and carbon nanotube as absorbents was achieved in a gasliquid hollow fber membrane contactor. Nanofuids ofsilicaandcarbonnanotubes(CNT)werepreparedfrst from their nanoparticles and were fed into the lumen side of themembranemodule[5].Similarly,developmentofadif-ferent and potentially advantageous geometry for membranes called microcapillary flm (MCF) was recorded by Bonyadi andMackley[6].MCFsareflmswithembeddedmultiple hollow capillaries and can be considered as a hybrid geom-etry between fat sheets andhollow fbers. Compared to fat sheetmembranes,MCFsareself-supportedandprovidea higher surface area per unit volume. Compared to single cap-illary membranes, MCFs offer several advantages including improvedmechanicalstrength,easeofhandling,andmore effcient module fabrication.The extraction of metals based on a membrane contactor systemwithconventionalsolventsisaprocesswidelystud-ied using different confgurations, extractants, and extraction solvents.Oneoftheupcomingapplicationsofmembrane contactorsissupercriticalextraction.Thisprocessiscalled porocriticalextraction.Porocriticalprocessorporocritical extraction is a commercial supercritical fuid extraction (SFE) techniquethatutilizesanhollowfbermembranecontactor (HFMC) to contact two phases for the purpose of separation. As an improvement, the extraction of Cu2+ from aqueous solu-tions by means of dense gas extraction was achieved by using ahollowfbermembranecontactordevice[7].Theauthors Membrane Applications in Chemical and Pharmaceutical Industries and in the Conservation of Natural ResourcesIntroductionAnil K. Pabby, Syed S.H. Rizvi, and Ana Maria SastreCONTENTReferences ..................................................................................................................................................................................... 54 Handbook of Membrane Separations: Chemical, Pharmaceutical, Food and Biotechnological ApplicationsclaimedthattheuseofdenseCO2asextractionsolventof Cu(II)ionsreachesextractioneffcienciesofupto98.7%. This process offers several advantages over the conventional contactordevicesgenerallyusedinSFEinwhichonefuid phaseisdispersedinanotherinacolumn.Inthiscase,the modularityofthemembranecontactorapplicationisvery important,consideringthatinatypicalporocriticalextrac-tion application large and expensive vessels are not used.Membrane materials are continuously undergoing modif-cations for achieving better performance. In this direction, the extrahigh free volume glassy polymer poly[1-(trimethylsilyl)-1-propyne](PTMSP)isaperspectivemembranematerial for two inherently different applications: (1)organic solvent NF(OSN), when a high solvent fux through the membrane isexpected,and(2)high-pressuremembranecontactorsfor CO2capturethatrequirestheabsenceofliquidpermeation (noliquidleakage)throughthemembrane.Asuccessful applicationofthissinglepolymerfortwodifferentmem-brane systems has been reported in the literature [8].Thecombinationofmolecularseparationwithchemical reactions (membrane reactors) offers important opportunities forimprovingtheproductioneffcienciesinbiotechnology andinthechemicalindustry.Withregardtothefutureof biotechnologyandpharmaceuticalprocesses,theavailabil-ity of new, high-temperature-resistant membrane contactors offers an important tool for the design of alternate production systems appropriate for sustainable growth.Afewrecentpublications[58]outlinetheverylatest advancements in the feld of membrane science and technol-ogy. Since these are only updates and the systems are yet to be established on large scales, no dedicated chapter in these felds was included in this edition. This section of the book outlines several established applications of membranes in the chemicalandpharmaceuticalindustries,reviewsthemem-branesandmembraneprocessesavailableinthefeld,and discussesthehugepotentialofthesetechnologies.Inaddi-tion, other important topics dealing with conservation of nat-ural resources (zeolite membranes) are also presented in this section. Each chapter has been written by a leading interna-tional expert with extensive industrial experience in the feld.This chapter presents an overview of different membrane processes and a description of all of the chapters presented in this edition. Chapter 2 focuses on updated information of utility to UF and NF membrane research and development, particularly in the preparation of new types of UF/NF mem-braneswithimprovedperformances.Chapter3presentsa comprehensivereviewonROmembrane,thelatestdevel-opmentsinthefeld,importantinstallationsdemonstrating this technology, and future scope of RO processes. Chapter 4 presents the potential of membrane contactors, especially hollow fber contactors in the feld of chemical and nuclear industryalongwiththeirapplications,performance,and current challenges faced by industry. Thischapter also gives an introduction to membrane contactors, their principles of operation and associated mechanisms (where chemical reac-tionsareinvolved),andfuturescopeofthesecontactors. Chapter5presentsthelatestadvancesinmembranespro-cessesforrefneryandpetrochemicalfelds.Thischapter describes the important applications, current status of tech-nology, and future perspectives. Chapter 6 deals with mem-brane and monolithic convective chromatographic supports. This chapter discusses the latest developments in membrane-basedstationaryphases(affnitymembranesandmixed matrixmembraneadsorbers)andmonolithicseparation media (organic and inorganic). It also provides information on new types of chromatographic support, focusing on mem-brane materials, properties, and preparation. Finally, it con-siders possible applications of chromatographic membranes under various process conditions. Chapter 7 focuses on the important aspects of membrane applications in gas separa-tion. It deals with the subject comprehensively, providing an introductionand discussingtransportmechanisms,differ-ent membrane materials for gas separation, module design, currentandpotentialapplications,andnoveldevelopments inthefeld.Chapter8presentsnewdevelopmentsinper-vaporation(PV).Itfrstgivesabriefintroductiontothe theoryofPVandthen discussessorption thermodynamics inpolymers,thesolutiondiffusionmodel,thecriteriafor membranepolymerselection,andtheimportantlatest applications of PV in different cases of aqueous and organic separations.Chapter9focusesonadvancesinthefeldof ceramicmembranes,coveringinterestingapplicationsin thisarea.Chapter10presentsthevariousmethodologies or techniques for improving the membrane performance of liquid-phasemembraneprocessesbyimprovedcontrolof concentration polarization. Chapter 11 describes some of the main characteristics of the use of zeolite membranes in sep-aration applications. Zeolite membranes separatemolecules accordingtodifferencesintheiradsorptionanddiffusion propertiesinthemixture.Theyare,therefore,suitablefor separating gas and liquid-phase mixtures by gas separation and PV, respectively. This chapter reviews the basic mecha-nisms of gas separation and PV through zeolite membranes and presents examples of industrial applications. Chapter12 focusesonmembranefoulingandthestrategiesusedto reduceitrelativetopressure-drivenprocesses.Thischap-ter highlightsrecentstrategiesforminimizingmembrane fouling.Inparticular,itdiscussesthelatestliteratureon thefoulingphenomenainpressure-drivenmembranesys-tems,analyticaltechniquesemployedtoquantifyfouling, preventivemethods,andmembranecleaningstrategies. Specifc recommendations are also made on how membrane usersmayfndithelpfultoimprovetheperformanceof thesesystemsbyminimizingthemembranefoulingphe-nomena.Chapter 13describesmembraneextractionand itsuseinpreconcentration,sampling,andtraceanalysis. Chapter 14 providesanintroductiontomembraneapplica-tionsandrecentadvancesinthepharmaceuticalindustry, its current status, and future potential in this very important area.Chapter15isdevotedtomembraneapplicationsand its recent advances in the drug delivery feld with emphasis onthemechanismsgoverningmasstransporttomodulate 5 Membrane Applications in Chemical and Pharmaceutical Industries and in the Conservation of Natural Resourcesthe release kinetics. Chapter 16presents studies in emerging area dealing with new materials for developing membranes, thatis,chitosananditsderivativesaspotentialmaterials. This chapter also elaborates on the latest applications, cur-rent status, and future challenges in this feld.REFERENCES1.E.Drioli, A.I.Stankiewicz,F.Macedonio,Membraneengi-neeringinprocessintensifcationAnoverview,Journalof Membrane Science 380 (2011):18.2.E. Drioli, E. Curcio, G. Di Profo, State of the art and recent progresses in membrane contactors, Transactions of IChemE, Part A: Chemical Engineering Research and Design 83(A3) (2005):223233.3.P. Bernardo, G. Clarizia, Potential of membrane operations in redesigning industrial processes. The ethylene oxide manufac-ture, Chemical Engineering Transactions 25 (2011):617622.4.A.K.Pabby, A.M.Sastre,State-of-the-artreviewonhollow fbrecontactortechnologyandmembrane-basedextraction processes, Journal of Membrane Science 430 (2013):263303.5.A.Golkhar,P.Keshavarz,D.Mowla,InvestigationofCO2 removal by silica and CNT nanofuids in microporous hollow fber membrane contactors, Journal of Membrane Science 433 (2013):1724.6.S.Bonyadi,M.Mackley,Thedevelopmentofnovelmicro-capillary flm membranes, Journal of Membrane Science 389 (2012):137147.7.H. Valds, R. Seplveda, J. Romero, F. Valenzuela, J. Snchez, Near critical and supercritical fuid extraction of Cu(II) from aqueoussolutionsusingahollowfbercontactor,Chemical Engineering and Processing 65 (2013):5867.8.A. Volkov, A. Yushkin, A. Grekhov, A. Shutova, S. Bazhenov, S.Tsarkov,V.Khotimsky,T.J.H.Vlugt,V.Volkov,Liquid permeationthroughPTMSP:Onepolymerfortwodiffer-entmembraneapplications,JournalofMembraneScience 440(2013):98107.722.1INTRODUCTIONThe historic announcement of the Loeb and Sourirajan asym-metric membrane in the 1960s is generally acknowledged as themajorscientifcbreakthroughinthefeldofmembrane science and technology. Over a half century has passed since theconceptfrstemerged. Today,fltrationseparationusing membrane-basedtechnologyhasbeensuccessfullyadopted in various industrial felds around the world, such as seawa-terdesalination,municipal/industrialwastewatertreatment, food and beverage industry, and pharmaceutical industry. In these industrial processes, membrane technology offers many distinct advantages over the conventional treatment methods.In general, membrane science research can be divided into sevenmajorareas,thatis,materialselection,materialchar-acterization, membrane fabrication, membrane characteriza-tion and evaluation, transport phenomena, membrane module design, and process performance. Among these areas, materi-als chosen for membrane fabrication are the most important partinthemembranetechnologyandthisphenomenoncan berefectedbythesignifcantamountoftechnicalarticles published in the literature.Over the past decade, many attempts have been reported to enhanceseparationperformancesofultrafltration(UF)and nanofltration (NF) membranes through variation of different parametersinvolvedduringthemembranepreparationpro-cesssuchasdopeformulation,casting/spinningconditions, andposttreatment[15].Oftheparametersstudied,itis found that the utilization of advanced materials in preparing membraneofimprovedpropertiesstillremainstoppriority amongthecommunityofmembranescientistsworldwide, whether in the past or present. In view of this, the main focus of this chapter is to review the role of these advanced materi-als used in preparing UF and NF membranes as a sustainable technologicalsolutiontowaterandwastewaterseparation andpurifcationprocess.Thisupdatedinformationisof great importance and timely to provide good insights to UF andNFmembraneresearchanddevelopment,particularly inthepreparationofnewtypesofUF/NFmembraneswith improved performances.2.2 ADVANCED MATERIALS USED IN THE RECENT DEVELOPMENT OF THE UF MEMBRANEAmarketreportpublishedbyBCCResearchindicated thattheUFmarketiscurrentlyexperiencingaccelerated growthwithacompoundannualgrowthrateof5.7%,and this growth is expected to be sustained over the next decade [6].Generally,theUFmembranehasfoundamultitudeof applications in the treatment of industrial wastewater, in the sewage treatment process, in the food andchemical industry, and in the biotechnology to separate, concentrate, and purify molecular mixture. This section does not intend to provide a reviewofalltheUFmembranesdevelopedtodatebecause a study on the basic factors governing membrane properties can be found in the book written by Mulder [4]. The follow-ingsectionwillinsteadcovertherecentresearchactivities that focus on the improved properties of UF membranes pre-pared from the use of advanced materials such as copolymer, polymeric additive, and inorganic fller.Advanced Materials in Ultrafltration and Nanofltration MembranesW.J. Lau, A.F. Ismail, T. Matsuura, N.A. Nazri, and E. YuliwatiCONTENTS2.1Introduction ......................................................................................................................................................................... 72.2 Advanced Materials Used in the Recent Development of the UF Membrane .................................................................... 72.2.1Polymer/Polymer Membrane ................................................................................................................................... 82.2.1.1Amphiphilic Copolymer Membrane ......................................................................................................... 82.2.1.2Polymer/Polymer Blend Membrane ........................................................................................................ 112.2.2Polymer/Inorganic Composite Membrane ............................................................................................................. 132.3 Advanced Materials Used in the Recent Development of the TFC-NF Membrane .......................................................... 152.3.1Monomer ................................................................................................................................................................ 162.3.2Surfactant/Additive ................................................................................................................................................ 222.3.3Nanofller ............................................................................................................................................................... 232.3.4Microporous Polymeric Substrate ......................................................................................................................... 262.4Concluding Remarks ......................................................................................................................................................... 30References ................................................................................................................................................................................... 308 Handbook of Membrane Separations: Chemical, Pharmaceutical, Food and Biotechnological Applications2.2.1POLYMER/POLYMER MEMBRANE2.2.1.1Amphiphilic Copolymer MembraneSelf-assemblyamphiphiliccopolymerisseeminglyavery promisingapproachinpreparingUFmembraneasitoffers modifcation on membrane surface and internal pores while maintainingdesirablebulkpropertiesandeliminatesextra modifcation step. Amphiphilic copolymer can be purposely designedtoselectivelyself-migratetothepolymerwater interface during the phase inversion process to impart mem-branesurfacehydrophilicity,offeringafacileoperationfor theseparationprocess.Generally,thefabricationoftheUF membraneutilizinganamphiphiliccopolymercanbeper-formedbyaddinganamphiphiliccopolymerasanaddi-tiveintothepolymericdopesolutionorusingitasamain membrane-forming material [7]. In this section, an introduc-tionofamphiphiliccopolymerwillbebriefydiscussedto develop a basic understanding of how an amphiphilic copoly-mer can be synthesized from different types of polymer fol-lowedbyadiscussionontheeffectsofnewlysynthesized copolymer on the performances of UF membranes.Amphiphiliccopolymersareresultedfrompolymeriza-tionofoneormoremonomers.Copolymerpolymerization introducesspecifcpropertiestoamaterialwhilemaintain-ingtheuniquecharacteristicsoftheparentpolymer. These copolymersareusuallyinvolvedinthecovalentbonding betweenhydrophobicandhydrophilicblocks,havingdif-ferentchemicalnaturesandmolecularinteractionandalso different affnities in an aqueous solvent [8]. In this regard, anamphiphiliccopolymercanbefexiblysynthesizedinto variousarchitecturesandthecommonarchitecturesare random(r),block(b),andgraft(g).Figure2.1showsthe schematicrepresentationofvariouscopolymerarchitec-tures[9]. Theuseofanamphiphiliccopolymerwhetheras anadditiveormembrane-formingmaterialisundoubtedly anattractivemethodasitinvolvesasurfacesegregation stepduringthephaseinversionprocess,whichcanimpart hydrophilicity of the membrane, leading to outstanding anti-fouling performance [10].AsreportedbyHesteretal.[11],therearetwomecha-nisms involved in surface segregation. The frst is the phase inversion process in a coagulation bath, during which a thin flmofacastingsolutionisimmersedinawaterbathand waterreplacesthesolventinthecastingsolution,resulting in the formation of an asymmetric membrane consisting of a dense skin layer and a porous sublayer. For a polymer blend composedofhydrophilicandhydrophobiccomponents,the differenceinthechemicalpotentialbetweenthesecompo-nents and water would further lead hydrophilic components to migrate slowly to the membrane surface, causing its sur-face to be enriched with hydrophilic components. Figure2.2 depictsthemigrationofanamphiphiliccopolymertothe polymerwaterinterfaceandformationofadensebrush ofhydrophilicsidechainonthemembranesurface[12]. Hydrophobic segments on the other hand aid the stability of the hydrophilic part by anchoring on the hydrophobic mem-brane matrix.However, there is a main concern with the addition of an amphiphiliccopolymerasanadditiveintothemembrane matrix.Incertaincases,thepoorcompatibilitybetween hydrophobic segment and membrane matrix may lead to bad phaseseparation,producingundesirablemembraneproper-ties. In view of this, the use of an amphiphilic copolymer as a membrane-forming material is attempted and has received attention from membrane researchers in recent years [1315]. Besides enhancing membrane hydrophilicity and water per-meability, the use of amphiphilic copolymer in UF membrane fabrication can also offer exceptional advantages such as tun-able membrane structure and higher degree of compatibility.Table2.1presentssomeoftheamphiphiliccopolymers that have been synthesized and used as either a membrane-forming material or an additive in UF membrane fabrication andtheirimpactsonmembraneproperties[10,1220].As can be seen from the table, most of the copolymer-based UF AABBB B A BAA(a) (b) (c)(d) (e) (f )FIGURE 2.1Various possible architectures for amphiphilic copolymer: (a) linear block copolymers with different numbers of A and B blocks, (b) cyclic block copolymers, (c) star block copolymers, (d) graft block copolymers, (e) block copolymers with dendritic or hyper-branched blocks, and (f) semitelechelic polymer (upper), telechelic polymer (middle), and asymmetrical telechelic polymer with different hydrophobic chain ends [9].9 Advanced Materials in Ultrafltration and Nanofltration Membranesmembranes were fabricated in the fat sheet confguration. It is found that studies on hollow fber copolymer membranes have been scarcely reported. In 2011, Chen et al. [13] investigated theantifoulingperformanceofthepolyacrylonitrile-block-polyethylene glycol (PAN-b-PEG) copolymer membrane by varying the content of polyethylene glycol (PEG) in the copo-lymer. The results revealed that with increasing PEG content in copolymer from 5.5 to 11.1 mol%, the water permeability and protein adsorption (tested using 1000 ppm bovine serum albumin (BSA) solution) of membranes were enhanced from 2087L/m2hMPaand38g/cm2to3189L/m2hMPaand 24.34g/cm2,respectively.Theenhancedperformanceis attributed to the enrichment of PEG segments on membrane surface and its pores as a result of the self-migration of the hydrophilic segments. On the other hand, Su et al. [15] stud-ied the effect of different molecular weights (MWs) of PEG (ranging between 400 and 6000 Da) on the preparation of the PEG-g-PANcopolymermembraneandfoundthat2000Da PEG was the best candidate in producing highly hydrophilic membrane with the lowest protein adsorption rate. Although PEG segment content in copolymer and chain length of PEG could alter membrane hydrophilicity and its separation per-formance,Choetal.[14]howeverexperiencedanoticeable fuxdeclineandlowersoluterejectionwhenthemembrane waspreparedfromcopolymerofhighhydrophiliccontent, owing to reduced mechanical stability.Instead of using a copolymer as a main membrane-forming material,thereareanumberofpapersreportingtheuseof acopolymerasanadditiveinpolymericmembranefabrica-tion in an effort to modify membrane surface properties, par-ticularlythedegreeofhydrophilicityandfoulingresistance [10,12,15,16]. PAN-based membrane with the incorporation of apolyacrylonitrile-graft-poly(ethyleneoxide)(PAN-g-PEO) amphiphiliccopolymerhasbeensuccessfullydevelopedby Asatekin et al. [10] in 2007, and fux as high as 1590 L/m2 h and complete fux recovery were achieved using the resultant membrane when it was tested using 1000 ppm BSA solution at 10 psi. It is also reported that the membrane permeability was mainly dependent on the PEO content in copolymer and the copolymer composition in dope solution in which the higher the PEO content and/or copolymer concentration, the greater the water fux and the higher the fouling resistance of mem-brane. Sun et al. [18] in another study have experienced pure waterfux(PWF)ofPANmembranetodeclinefrom497.0 to276.6L/m2hwithincreasingpolyacrylonitrile-random-N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl)(PAN-r-DMMSA) copolymer content from zero to 100 wt% in PAN dope solution. The result is likely due to the decrease in mem-braneporosityandincreaseinskinthicknessasaresultof increasing DMMSA segment content in membrane matrix. In thisstudy,permeationratewascompromiseduponaddition of copolymer into dope solution, but membrane fux recovery rate was signifcantly increased.Incorporationofself-assemblyamphiphiliccopolymer into polyethersulfone (PES)-based membrane has also been widelystudiedbyseveralresearchgroups.Forinstance, Lohetal.[12]performedastudybyaddingPluronicinto PES-basedmembranematrix.Atoptimumconcentration ofPluronic(10wt%)andPEOmasscontentincopolymer (70wt%),optimizedmembranepropertieswithmolecular weight cutoff (MWCO) of 9 kDa and fux of 113 L/m2 h bar couldbeproduced.Itmustbepointedoutthatmembrane fux tended to decline upon addition of higher Pluronic con-centrationintomembranematrix,owingtotheformation PES membrane matrixPPO chainPore filled with waterApparent pore diameterActual pore diameterPEO chainFIGURE 2.2Poly(ethylene oxide) layer formation during surface segregation of Pluronic [12].10 Handbook of Membrane Separations: Chemical, Pharmaceutical, Food and Biotechnological ApplicationsTABLE 2.1Summary of Amphiphilic Copolymers and Their Effects on UF Membrane PropertiesCopolymer Membrane/ConfgurationaCopolymer Synthesis MethodOptimized Dope Formulation (in wt%)Optimized Membrane Properties RemarksMain polymer: PSF-r-PEOConfguration: FS [14]Polycondensation reaction via nucleophilic substitutionPSF-r-PEO/NMP15/85PEO composition in copolymer: 10 mol%PWFb: 135 L/m2 h barMWCOb: 20 kDaContact angle: 60Oil rejection: 94.7%The presence of 20 mol% PEO content in the copolymer could lead to fux decline and decrease in mechanical strength of the membrane.Main polymer: PEG-g-PANConfguration: FS [15]Water phase precipitationPEG-g-PAN/DMF15/85Type of PEG: 2000 DaPWFc: 294.4 L/m2 hContact angle: 38.8Protein adsorption: 5.8 g/cm2Protein rejection: 93.5%Flux recovery rate: 91.6%The authors studied the effect of different MWs of PEG (ranging from 400 to 6000Da) in preparing the PEG-g-PAN copolymer and found that the MW of PEG is crucial in controlling membrane properties and performance.Main polymer: PAN-b-PEGConfguration: FS [13]Combined redox polymerization and reversible addition fragmentationPAN-b-PEG/NMP10/90PEG composition in copolymer: 11.1 mol%.Type of PEG: 10,200 DaPWF: 2189 L/m2 h MPaContact angle: 45bBSA rejection: >98.4%Protein adsorption: 24 g/cm2The authors reported that the membrane properties were strongly governed by copolymer composition, while the MW of PEG played negligible role in affecting membrane morphology and performance.Main polymer: PESCopolymer additive: PBMA-b-PMAA-b-PHFBMConfguration: FS [16]Free radical polymerizationPES/DMF/PEG/copolymer16/66.2/17/0.8Monomer molar ratio in copolymer: BMA:MAA:HFBM, 5:5:1PWF: c150 L/m2 h (pH 4.8)c75 L/m2 h (pH 6.2)Pore size: 821 nmContact angle:78.0BSA rejection: >95%The copolymer with fuorine-containing segment made the resulting membrane exhibiting fouling release property. Besides, the presence of PMAA segments in the copolymer could also induce the pH-responsive property of the membrane prepared.Main polymer: PPESKCopolymer additive: PPESK-g-PEGConfguration: FS [17]Modifed Williamson etherifcation(PPESK+copolymer)/NMP15/85PEG composition in copolymer: 37.2 wt%PWF: c138.9 L/m2 h (pH 4.9)c186.5 L/m2 h (pH 7.4)BSA rejection: 90%BSA adsorption:1011 g/cm2Total fouling layer resistant:12.06 1012 m1Irreversible fouling resistant:00.75 1012 m1In order to enrich the membrane surface with the PEG component, the authors increased the casting temperature from 20C to 60C, and the results revealed that the membrane casted at higher temperature displayed greater fouling resistance against BSA.Main polymer: PANCopolymer additive: PAN-r-DMMSAConfguration: FS [18]Water phase suspension polymerizationPAN-r-DMMSA/DMSO13/87DMMSA composition in copolymer: 5.8 mol%PWF: c276.6 L/m2 hContact angle: 42.5Protein retention: 70%Flux recovery rate: 95%The authors suggested that increasing the DMMSA content in the copolymer tend to reduce porosity and increase membrane thickness, hence resulting in PWF decline but low susceptibility to fouling.Main polymer: PESCopolymer additive: (1) PEO-PPO-PEO, (2) PPO-PEO-PPOConfguration: HF [12]N/A PES/PEO-PPO-PEO/NMP18/10/72PEO composition in copolymer: 70 wt%PWF: 113 L/m2 h barMWCO: 9 kDaThe molecular architecture of PEO-PPO-PEO is more favorable than PPO-PEO-PPO. The larger mass fraction of Pluronic enhanced membrane hydrophilicity. Furthermore, the longer PEO and PPO chain could signifcantly improve rejection performance and block stability.Main polymer: PANCopolymer additive: PAN-g-PEOConfguration: FS [10]Free radical polymerizationPAN/PAN-g-PEO/DMF8/90/2PEO composition in copolymer: 50 wt%PWF: 1590 L/m2 h MPaBSA retention: 89%Sodium alginate retention: 12%Humic acid retention: 84%Flux recovery rate: 100%The membrane fabricated from the copolymer with 50 wt% PEO exhibited 100% fux recovery, indicating its low irreversible fouling. Further increasing the PEO content in the copolymer could affect severely the membrane performance.(Continued)11 Advanced Materials in Ultrafltration and Nanofltration Membranesof a spongelike structure. On the contrary, Wang et al. [20] foundthatPluronicadditivehadlittleeffectonPESmem-branepermeabilitybutpossessedremarkableinfuenceto fouling resistance, recording as low as 3.0 g/cm2 of protein adsorption.Experimentalworkshavealsobeenconductedtostudy the possibility of adding other potential copolymer additives intoPES-basedmembranes.Forexample,incorporationof 4.5wt%polystyrene-block-PEG(PSR-b-PEG)copolymer into18wt%PESdopesolutioncouldproducemembrane with PWF of around 140.96 L/m2 h (measured at 100 kPa), low protein adsorption (0.5 g/cm2), and high fux recovery rate(88.2%)[19].Thestudyhasrevealedthattheaddition ofacopolymeradditiveshowednegligibleeffectonmem-brane permeability but tended to improve membrane protein resistance,whichwasinagreementwiththeworkreported by Wang etal. [20]. Zhao et al. [16] on the other hand high-lightedthepH-responsivepermeabilityandfoulingrelease propertyuponadditionofapoly(butylmethacrylate)-b-poly(methacrylic acid)-b-poly(hexafuorobutyl methacrylate) (PBMA-b-PMAA-b-PHFBM)additiveintothePESmem-brane matrix. Interestingly, the authors experienced a unique pH-dependentfuxandfoulingreleasepropertyduetothe characteristics of hydrophilic PMAA and fuorine- containing segments in the copolymer. These promising results indicated the tunable membrane properties with the use of amphiphilic copolymer as additive.The outstanding characteristics of copolymer membranes andmembranesincorporatedwiththecopolymeradditive especiallyonfoulingresistanceduetoproteinadsorption haveattractedconsiderableinterestinpreparingUFmem-brane for industrial adoption. In order to achieve the status, severalvariables,forexample,thechainlengthofhydro-philicsegments,massfractionofhydrophilicsegmentsin the copolymer, and composition of the copolymer additive in dope solution, need to be carefully studied during the mem-brane preparation process in order to produce a high-quality membranetocompetewiththecommerciallyavailable membranes. It must be pointed out that fabricating a hollow fber copolymer membrane is one of the subjects deserving a better level of understanding to take full advantage of hollow fber membranes, that is, high packing density and relatively low system footprint.2.2.1.2Polymer/Polymer Blend MembranePolymericadditiveisfrequentlyusedinthemembrane formationprocessasitcanplayavitalroleinsuppressing macrovoid formation in the membrane, promoting pore for-mation,improvingporeinterconnectivity,and/ormodify-ingmembranesurfacehydrophilicity.Forinstance,adding hydrophilic additive into a hydrophobic polyvinylidene fuo-ride (PVDF) dope solution can make the resultant membrane suitableforUFmembrane,improvingwaterpermeability and reducing fouling propensity.Overthelast15 years,therearemanyresearchworks reported using polymeric additives of different MWs at vari-ous concentrations during dope preparation. Of the additives (usually hydrophilic polymers) studied, PEG and polyvinyl-pyrrolidone (PVP) are among the two most frequently stud-ied materials. These two additives are signifcantly different in terms of MW in which PEG displays average MW in the range of 20020,000 Da, while PVP shows much higher MW, ranging between 10,000 and 360,000 Da. It must be pointed outthatinadditiontoadditives,otherparameterssuchas membrane-formingmaterial(e.g.,MWandconcentration in dope solution), solvent (e.g., solubility parameter and vis-cosity), fabrication conditions (e.g., shear rate/take up speed, coagulationmedium,evaporationtemperature,humidity), andposttreatment(e.g.,dryingprocedure)canalsoplaya role in infuencing the morphology of the membrane and thus itsseparationperformance.Therefore,incertaincases,the opposite effects of adding an additive might also be observed inmembraneproperties,dependingondopeformulation, preparation condition, and post treatment method used.Table2.2summarizesthepolymericadditivesthathave beenusedinUFmembranepreparationoverthepastfew TABLE 2.1 (Continued)Summary of Amphiphilic Copolymers and Their Effects on UF Membrane PropertiesCopolymer Membrane/Confgurationa Copolymer Synthesis Method Optimized Dope Formulation (in wt%) Optimized Membrane PropertiesRemarks Main polymer: PESCopolymer additive: PS-b-PEGConfguration: FS [19]Anionic living polymerizationPES/PS-b-PEG/PEG2000/DMF18/4.5/15/62.5PWF: c140.96 L/m2 hContact angle: 40.5BSA rejection: 100%BSA adsorption: 0.5 g/cm2Flux recovery rate: 88.2%The addition of an amphiphilic copolymer has little effect on membrane permeability but it promoted excellent antifouling property.Main polymer: PESCopolymer additive: Pluronic F127Confguration: FS [20]N/A PES/Pluronic/PEG2000/solvent18/1.78/15/65.22PWF: c105 L/m2 hContact angle: 47.0BSA rejection: 98%Protein adsorption: 2 g/cm2The addition of Pluronic into the PES membrane has little impact on membrane permeability, but it could contribute greatly to excellent fouling resistance.a Membrane confguration; FS, fat sheet; HF, hollow fber.b PWF, pure water fux; MWCO, Molecular weight cutoff; BSA, bovine serum albumin.12 Handbook of Membrane Separations: Chemical, Pharmaceutical, Food and Biotechnological Applicationsyears[2127].In2009,SusantoandUlbricht[22]madean attempt to investigate the infuence of using three polymeric macromolecularadditiveswithsimilarMW,thatis,PVP (MW~10kDa),PEG(MW~10kDa),andPluronicF127 (MW~12.6kDa)inPESUFmembranepreparation.By adding10wt%additiveintoPES/NMP(15/75)system,the results revealed that PES-Plu membrane achieved the highest hydraulic permeability compared to PES-PVP and PES-PEG membrane and was able to maintain similar rejection curves of dextran mixture. In addition to this, Pluronic is also found to improve resistance against fouling due to protein adsorp-tion by showing >70% of the water fux recovery after a water cleaning process.It is generally agreed that the higher the MW of the PEG used into dope solution, the larger the pores of the membrane, leading to increase in water permeation [28]. Besides creating larger membrane pores, increase in membrane porosity (pore number) was also reported with increasing PEG molar mass [29]. In the recent past, Ma et al. [21] studied the effect of PEG of six different MWs (i.e., 400 Da, 800 Da, 1.5 kDa, 4 kDa, 10kDa,and20kDa)onthemorphologyandperformance of polysulfone (PSF) membrane. The results obtained in this work were in line with the previous data reported where water fux and porosity of membranes were increased with increase intheMWofPEG.PWFwasincreasedremarkablyfrom 340 to 1390 L/m2 h bar when the MW of PEG was increased TABLE 2.2Summary of the Polymeric Additives Used in UF Membrane Preparation over the Past Few YearsDope Formulation Characteristics of AdditiveEffect on Membrane PerformanceMain Polymer (wt%) aPolymeric Additive (wt%)PSF (18%) [21] PEG 400/800/1500/4000/10,000/20,000 (8%)HydrophilicWater solubleIncreasing the MW of PEG resulted in increase in membrane water fux. A high MW of PEG (10 and 20 kDa) however would weaken the membrane mechanical strength due to increasing porosity. A PEG of 1.5 kDa was recommended as a suitable additive in the UF making process.PES (15%) [22] PVP 10,000/PES 10,000/bPluronic F127 12,600 (10%)HydrophilicWater solubleCompared to the PES membrane (control), all membranes blended with additives displayed lower contact angle value and signifcantly higher resistance toward adsorptive fouling due to protein. Water fux and protein rejection of blended membranes however were relatively lower than the control membrane.PSF (14.875%17.5%) [23]SPEEK (0%2.625%) HydrophilicTunable degree of sulfonationThe fux of PSF/SPEEK blend membranes increased from 71 to 126 L/m2 h (at 414 kPa) with increasing SPEEK loading from 0% to 2.625%. Signifcant increase in MWCO was obtained when 2.625% SPEEK was added. The results were supported by SEM results.PVDF (18%) [24]cSMM (0%4.5%) HydrophilicThermodynamically compatible with the main polymerMacromoleculesThe addition of 1.5% L2MM(PEG-600) and 3% L2MM(PEG-200) into an 18% PVDF membrane showed 5.6 and 5.5 times higher fuxes than the control PVDF membrane, respectively. Fluxes of the modifed membranes were largely improved but their rejection of 100 kDa PEO remained more or less the same (88%96%).PPSU (10%40%) [25]PEI (0%30%) HydrophilicPositively chargedGood thermal and chemical stabilityMembrane pore size and porosity increased as the PEI concentration increased, leading to signifcant fux enhancement. The membrane with low PEI content possessed a strong negative charge that allowed the membrane to signifcantly resist humic acid adsorption.PVC (14%) [26] PSR (0%6%) Hydrophobic The water fux of the blend membrane was kept almost unchanged, while rejection of PVP K-90 was highly improved from 76% to 99% upon addition of 1% PSR into the PVC membrane. The mechanical strength of the membranes was randomly improved with the PSR content due to the difference in membrane porous structure.CA (12.25%17.5%) [27]PAI(0%5.25%)HydrophilicHigh thermal stabilityGood chemical stabilityThe morphology, hydraulic resistance, and thermal and mechanical properties of the blend membranes were improved signifcantly by the incorporation of PAI into CA membrane matrix.a The value followed by polymeric additive indicates the MW of the polymer used.b Pluronic F127 = poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO).c SMM, surface modifying macromolecule. Type of SMM used = L2MM.13 Advanced Materials in Ultrafltration and Nanofltration Membranesfrom 400 Da to 20 kDa. It must be noted that the mechanical strength of the membrane would be weakened upon addition of a high MW of PEG, that is, 10 and 20 kDa, which is the resultofrapidincreaseinmembraneporosity.Considering the effect of the MW of an additive on membrane properties and performances, the authors suggested that 1.5 kDa PEG is a suitable additive for making an asymmetric UF membrane.Aspolymerichydrophilicadditivesmayleachoutfrom resultingmembranetoaquaticsolutionduringthephase inversion process due to their relatively small sizes and high affnitytowater,Pezeshketal.[24]in2012developeda novel type of macroscale additives called L2MM to address the defciency. Compared to the hydrophilic surface modify-ing macromolecule (LSMM) reported in their previous work [30], this novel type of L2MM could signifcantly make the PVDF membrane more hydrophilic by decreasing its contact angle by up to 19%. With respect to water fux, the modifed PVDF membranes showed up to 6.5 times that of the control membrane. This was a very large improvement as the rejec-tion rate of 100 kDa PEO was not changed very signifcantly.Apartfromusingneutralpolymericadditiveforthe fabricationofUFmembrane,theintroductionofcharged additive into membrane matrix via blending method is also generatinggreatinterest.Todate,polymerssuchascellu-lose acetate (CA), PSF, and PES have already been reported bymembranescientiststhatcouldbewellblendedwith sulfonatedpoly(etheretherketone)(SPEEK)toobtaina newtypeofmembranewithdiverseproperties[3134]. Moreover, SPEEK shows unique characteristics with respect tohydrophilicityandchargedpropertiesduetoitseasily tunablepropertiesthatarerelatedtothedegreeofsulfo-nation.Amongtheresearchgroupsstudyingthepotential ofusingSPEEKasadditiveinmakingUFmembranes, Arthanareeswaranandhisgroup(fromNationalInstitute ofTechnology,Tiruchirappalli,India)canbeconsidered contributing the most to this area. In their recent work [23], asymmetric UF membranes were prepared from dopes com-prisedofPSF/SPEEK/PEG600/DMF.Resultsrevealedthat thePSF/SPEEKblendmembranesrequiredatleast4 hof compaction before attaining steady-state water fux, and with increasingSPEEKconcentrationfromzeroto2.6%(based on total weight of dope), the PWF of membranes was steadily increasedfrom71to126L/m2hwhenitwasoperatedat 414kPa.UnliketheworksconductedbyLauandIsmail [33,34]inthepreparationofPES/SPEEKNFmembranes, Arthanareeswaran and his group did not consider the effect ofionicchargesintroducedbySPEEKonUFmembrane performance, particularly in fouling reduction.Otherthanthepolymericadditivesmentionedearlier, polymerssuchaspolyetherimide(PEI)[25],polyamide-imide (PAI) [27,35], PSR [26], PSF [36], andpolycarbonate (PC)[37]arealsoproposedoverthepastfewyearsas potential additives in UF membrane fabrication. The differ-encebetweenthesepolymersandwater-soluble additives, forexample,PEGandPVP,isthattheycanbeusedeither asthemainmembrane-formingmaterial(bydissolving inanappropriatesolvent)orasanadditivetoexploretheir positive properties in developing desired membrane proper-ties. For example, blending dope solution with PEI or PAI can enhancemembranepropertieswithrespecttomechanical strengthandchemicalandthermalstability.Otherpositive featuressuchasfuxenhancementandfoulingminimiza-tion can also be observed depending on the characteristics of additiveselectedinthepolymer/polymerblendingprocess. Nevertheless,onemustbeawareofthepoorcompatibility resultingfromoverdosageofpolymericadditivesadded, whichmayresultinpoorintegrityofmembranestructure, leading to undesirable membrane performance.2.2.2POLYMER/INORGANIC COMPOSITE MEMBRANEA variety of inorganic materials can be blended with PVDF, PES,PSF,andCAmembranesincludingtitaniumdiox-ide(TiO2),zirconiumoxide(ZrO2),silica(SiO2),alumina (Al2O3),carbonnanotube(CNT),andclay.Inrecentyears, incorporating inorganic fllers into the membrane matrix to prepareacompositemembraneforenhancingmembrane performancehasattractedalotofattentionowingtotheir smallparticlesizes,highsurfacearea,and/orhydrophilic nature.Foraparticulartypeofnanoparticles,forexample, TiO2,additionalfeaturessuchasphotocatalysismechanism andantibacterialpropertiescanalsobeexperiencedwhen the membrane process is integrated with UV/visible light.Ofthenanomaterialsstudied,theTiO2nanoparticleis themainresearchfocusofmembranescientistsinprepar-ing UF composite membranes. It is generally agreed that the addition of TiO2 into membrane matrix could play a key role in promoting membrane water permeation rate. As reported in the work of Hamid et al. [38], PSF membrane with 2 wt% TiO2incorporationcoulddemonstrate32%higherwater fuxthanthatofaneatPSFmembrane.Similarly,thefux ofpoly(phthalazinoneethersulfoneketone)(PPESK)/TiO2 compositemembranewasfoundtoincreaseapproximately 30% upon addition of 2 wt% TiO2 compared to neat PPESK membrane [39]. The increase in water permeability could be due to enhanced membrane hydrophilicity and/or increase in membrane pore size/porosity upon TiO2 addition. However, it has been reported that the composite membranes prepared fromhighconcentrationofTiO2(>2wt%)couldresultin poor membrane performances in which both water fux and soluterejectiontendedtodecrease[40].Thephenomenon ismostlikelyduetotheagglomerationofTiO2nanopar-ticles,whichreducesthecontactareaofhydroxylgroups carriedbyTiO2nanoparticles.Inordertopreventuneven distributionofparticlesinthemembranematrixresulting from agglomeration, Razmjou et al. [41] in the most recent yearproposedtomodifyTiO2propertiesusingasilane couplingagent3-aminopropyltriethoxysilane(APTES). Itisknown that using this mechanical and chemical modi-fcation method, the hydrophilic nature and surface energy ofnanoparticlescanbereduced,minimizingagglomera-tion and increasing matrixparticle interaction. The results showed that upon incorporation of these modifed nanofll-ers, the glass transition temperature, membrane porosity and 14 Handbook of Membrane Separations: Chemical, Pharmaceutical, Food and Biotechnological Applicationsporesize,stiffness,andhydrophilicityincreased,whereas mechanical strength decreased.In addition to TiO2 nanoparticles, other inorganic fllers that have been recently investigated include ZrO2 microparticles [42], mesoporous/nanoporous SiO2 [43], nano -Al2O3 [44], silver (Ag) nanoparticles [45,46], graphine oxide (GO) [47], andhydroxylfunctionalizedmultiwalledcarbonnanotubes (MWCNTs) [48]. Table 2.3 shows the characteristics of these potentialinorganicparticlesandtheirimpactsontheprop-ertiesofcompositeUFmembranes[38,39,41,42,44,4649]. In general, the main purposes of adding inorganic fller into polymeric membrane are to increase water fux and minimize fouling problem, prolonging its lifespan and reducing clean-ing frequency. Nevertheless, contradictory statements on the mechanicalpropertiesofcompositemembranescouldbe founduponincorporationofinorganicfllerintomembrane matrix. For instance, Wang et al. [47] reported a tremendous improvement on the tensile strength of the PVDF/GO com-posite membrane when 0.2 wt% GO was added into a cast-ing solution comprised of PVDF and DMAc. The noticeable trend is explained by the suitability of GO as an ideal fller for polymeric membrane, which is due to its excellent mechani-cal properties, high surface area, and high aspect ratio. On the other hand, opposite effect on the mechanical stability of CA membraneuponadditionofZrO2wasreportedinthework ofArthanareeswaranandThanikaivelan[42].Itisfound thatthetensilestrengthofmembraneswasdecreasedfrom 2to1.4 N/mm2 with increasing ZrO2 loading from 0 to 7 wt% TABLE 2.3Summary of the UF Membranes Prepared from Different Types of Inorganic Materials in the Period of 20102012Composite MembraneProperties of Inorganic Material Dope Composition (wt%)Effects on Membrane Properties PSF-TiO2 [38]Aeroxide TiO2 P25, mean particle size = 20nmPSF/DMAc/PVP/TiO218/75/5/2With the addition of 2% TiO2, membranes were excellent in mitigating fouling due to humic acid and showed higher water fux than the control membrane.PES-modifed TiO2 [41]Aeroxide TiO2 P25, mean particle size = 20nmPES/NMP/PVP/modifed TiO223/63/12/2The mechanically and chemically modifed TiO2 was able to migrate toward the outer layer of the hollow fber, and there was a signifcant reduction in the size of agglomerates. Flux enhancement and bigger pore size were observed upon addition of modifed TiO2.PPESK-TiO2 [39]Aeroxide TiO2 P25, mean particle size = 20nmPPESK/NMP/PEG/SDS/TiO216/75.9/6/0.1/2Owing to the existence of the hydrogen bond between TiO2 and PPESK, the mechanical and thermal properties of the membrane were improved and suitable for high-temperature (80C) condensed water treatment.PVDF--Al2O3 [44]Alfa Aesars -Al2O3, mean particle size = 20nmaPVDF/NMP/Al2O315/85/2-Al2O3 particles were well dispersed in the membrane, and because of this, it enhanced membrane hydrophilicity. The membrane with 2% nanoparticles also has excellent fouling resistance for BSA adsorption.PSF-Ag [46] Ag from Nanoshop Company (Iran), particle size = 30nmPSF/DMAc/PVP/Ag16/78/4/2The membrane tended to have a dense and sponge structure when Ag was added during dope preparation. In addition to higher water fux and higher BSA rejection, the PES/Ag membrane also showed higher antibacteriality than the neat PES membrane.CA-ZrO2 [42] ZrO2 from SD Fine Chemical Ltd. (India), primary particle size = 19mCA/DMF/ZrO210.5/82.5/7The addition of ZrO2 microparticles was found to increase membrane fux for separation of different types of protein and to enhance membrane fouling resistance. The mechanical strength of the membrane however was affected due to aggregation of particles in the membrane matrix.PVDF/GO [47]bN/AcPVDF/DMAc/GO20/80/0.2With the addition of GO, the permeability and tensile strength of membrane was increased tremendously compared to the unblended PVDF membrane. With respect to BSA rejection, only a slight change was observed.PAN-MWCNT [48]Hydroxyl functionalized MWCNTs from FutureCarbon, average length = 1520mdPAN/DMF/MWCNT14/86/2The fux of the membrane was improved due to the hydrophilic nature of MWCNT. Improvement in tensile strength and resistance against compaction was also observed, mainly due to the decrease in porosity and good interaction between PAN and MWCNT.PSF-clay [49] Clay from Zhejiang AnjiTianlong Organic Bentonite Co. Ltd. (China), modifed montmorillonite (MMT)PSF/DMAc/LiCl/clay17.38/79.2/0.52/2.9Compared to the control membrane, the water fux of the PSF-clay membrane was increased signifcantly accompanied by a decrease in the contact angle value and increase in porosity. Rejection of protein remained almost unchanged.a The percentage of -Al2O3 was calculated based on the total amount of the PVDF solution.b Graphine oxide (GO) was self-synthesized by authors. No characterization on GO properties was conducted.c The percentage of GO was calculated based on the weight of DMAc.d The percentage of MWCNT was calculated based on the ratio between PAN and MWCNT (98:2).15 Advanced Materials in Ultrafltration and Nanofltration MembranesintopureCAmembrane.Otherstudiesreportedthatusing an optimized loading of inorganic fller (used to be in small concentration) during membrane preparation could improve mechanical strength of composite membrane [39,48].With respect to the effect of inorganic particles on the vis-cosityofthedopesolution,itisgenerallyknownthatthe viscosity of the dope solution increases with the increase in thecontentofinorganicparticles.Itmustbenotedthatthe viscosityofpolymerdopesolutionplaysanimportantrole to the morphological properties of the membranes prepared byaphaseinversionprocess. AsexperiencedbyMaetal. [49],theincreaseintheviscosityofPSFcastingsolution upontheadditionofclaycouldresultinlargerfngerlike pore formation in the sublayer of the membrane, mainly due tothedelayeddiffusionexchangeratebetweenthesolvent andnonsolventduringthedemixingprocess.Theslower precipitation rate is the main reason promoting polymer-lean phase growth and coalescence, which result in larger fnger-like pores formed and thus higher water permeation rate. On the other hand, increased in the size of macrovoids was also reported following the increase in solution viscosity. It hap-penedtoPANmembraneinwhichthesizeofmacrovoids increasedwithincreasingthecontentofMWCNTinthe dopesolution[48].Withrespecttoporesizeandporosity, theresultsshowedthattheincreaseinPANdopeviscosity uponadditionofMWCNTdidnotsignifcantlyalterthe surface morphology.Considerablescientifcefforthasbeendevotedinrecent yearstoinvestigateantibiofoulingandvirusremovalabil-ityofAgnanoparticlesaddedintopolymericmembranes. ThoughAg nanoparticles are known for their unique optical, electrical,andthermalproperties,itisactuallythebacteri-cidalabilityofAgthatbroughtthemtothefeldofmem-brane technology. In 2012, Mollahosseini et al. [46] studied theeffectofAgparticlesizeonmembranepropertiesand foundthatsmallAgparticlesize(30 nm)wasbetterthan largerAgparticlesize(70 nm).Incomparisontotheneat PSF membrane, the addition of 2 wt% Ag of 30nm into the membrane could enhance PWF from ~15 to ~48 L/m2 h bar, contactanglefrom81.2to60.9,andBSArejectionfrom ~63%to~84%andwasalsoabletoshowsignifcantanti-bacterialeffect.Ontheotherhand,Basrietal.[45]found that2,4,6-triaminopyrimidine(TAP)couldbepotentially usedascompatibilizerinpreparingPES/Aghybridmem-brane.TheresultsfromXPSanalysisrevealedthatTAP hascontributedtobettersilverentrapmentasevidencedby theintensepeakappearinginthespectra.Apartfromthis, asmoothermembranesurfacewasobtaineduponaddition ofTAP,whichmightprovidebetterpreventionofbacte-rial adhesion during the fltration process. Another possible method to introduce Ag element into membrane is by blend-ingitwithAg+-exchangedzeolite(AgNaY).Itisreported that Liao et al. [43] have made an attempt of adding 0.8 wt% ofAgNaYintoPVDFUFmembranes.Asexpected,the hybrid membrane with AgNaY showed long-lasting antibac-terial activity against E. coli in comparison to the neat mem-brane. Moreover, the mechanical property, thermal stability, andsurfacehydrophilicityofthehybridmembranewere improved as a result of AgNaY addition.The discovery of CNTs by Sumio Iijima [50] in 1991 has launched entirely new felds of materials research and devel-opmentinmanyapplications,includingmembranescience andtechnology.Oneoftheearliestmentionsoftheuseof CNTs in membrane fabrication for water separation process wasdisclosedbyChoietal.[51]in2006.Itwasreported inthisworkthatwiththeadditionofasmallquantityof MWCNTs,rangingbetween0.075and0.6wt%(basedon thetotalweightofdopesolution)intoPSFmembranes,the inorganic fllers could turn out to be good modifers for the formationoffunctionalmicroporousmembranes,control-lingthehydrophilicityofthemembraneandadjustingthe pore size and porosity. Recently in 2012, Majeed et al. [48] blendedPANdopesolutionwithhydroxylfunctionalized MWCNTs to prepare UF membrane with improved proper-ties. In comparison to the maximum amount of TiO2 added, the concentration of MWCNTs in the dope solution was rela-tively low, ranging only between 0.07 and 0.28 wt% (based on total weight of dope solution). Even though only 0.28 wt% MWCNTswasincorporatedintomembranes,ithowever showed36%improvementinmembraneresistanceagainst compaction,around60%enhancementinwaterfux,and 97%increaseintensilestrengthcomparedtotheneatPSF membrane. It must be pointed out that the greatest advantage ofutilizingCNTsinmembranepreparationistheirfunc-tionalized tips that can be easily manipulated and patterned, leading to a wide variety of possible applications.2.3 ADVANCED MATERIALS USED IN THE RECENT DEVELOPMENT OF THE TFC-NF MEMBRANEIntheearlydevelopmentofcompositemembrane,Morgan was the very frst researcher to propose the use of interfacial polycondensationapproachtoformathinpolymericlayer ontoasubstrate[52].Theapproachhoweverdidnotsuc-ceed in industrial fabrication until Cadotte and his cowork-ersdiscoveredthatthroughtheoptimizationofformation conditions,aseriesofcompositemembraneswithsurpris-inglyhighfuxcouldbemadebyinterfacialcross-linking ofpiperazine(PIP)withtrimesoylchloride(TMC)/isoph-thaloylchloride(IPC)mixture[53,54].Besideshighfux production,thesemembranesalsoexhibitedhighrejection to aqueous sulfate ions but low selectivity of aqueous chlo-ride ions. The contribution of this approach, which is widely knownasinterfacialpolymerization(IP),issosignifcant to membrane science and technology and marks a quantum leap toward the production of a high-fux/low-pressure mem-branewithagoodcombinationofsaltremoval.Usingthe method invented by Cadotte et al. [53,54], many companies succeededindevelopingavarietyofthin-flmcomposite (TFC)membranes,allowingtheapplicationofmembranes for many industrial separation processes. Compared to other industrialsectorssuchasfood,pharmaceutical,andbio-medical industry, NF in the water and wastewater treatment 16 Handbook of Membrane Separations: Chemical, Pharmaceutical, Food and Biotechnological Applicationsprocesses is growing at a faster rate, recording a compound annual growth rate of 27.4% [55].Ingeneral,polymerizationreactiontakesplaceatthe interface of the two liquids that are insoluble to each other. Figure 2.3 depicts the schematic diagrams of the TFC mem-branepreparationusingtypicalIPtechnique.Inorderto establishaverythinpolyamide(PA)activelayerontopof a supporting membrane, the substrate typically will be frst immersedintoanaqueoussolutionconsistingofbetween 0.1%and3%(w/v)aminemonomerpriortoimmersionin a second organic solution of between 0.05% and 0.3% (w/v) acyl chloride monomer. The membrane is then subject to heat treatment (preferably in the range of 70C90C) to densify the polymerization properties of the PA layer and/or enhance adhesionofthePAthinlayertothesurfaceofthesupport membrane. At last, the composite membrane will be under-going washing and drying processes before it is ready for use. It is well acknowledged that by employing IP technique, the properties of both bottom substrate and top barrier flm can beindividuallytailoredandoptimizedtoachievedesired water permeation and solute separation rate.This section intends to provide a review on the advanced materialsusedintherecentdevelopmentofTFC-NF membranes and the effects of the advanced materials on the improvement of composite membrane properties with respect to permeability/selectivity, chlorine tolerance,