FILTRATION & PROCESSING SOLUTIONS
FRESHPOINT® ULTRAFILTRATION SYSTEM APPLICATIONS GUIDE
PENTAIR®
FRESHPO INT® U LTRAF I LTRAT ION GU IDE 32 P ENTA IR
PENTEK®
TABLE OF CONTENTS2 USING THIS GUIDE
3 HOW ULTRAFILTRATION WORKS MEMBRANE CONSTRUCTION FILTRATION OPERATION FLOW DIRECTION
5 ULTRAFILTRATION APPLICATIONS
6 WATER QUALITY BASICS WATER SOURCES SEASONAL VARIATIONS WATER IMPURITIES WATER ANALYSIS
7 FEED WATER QUALITY AND PRETREATMENT REQUIREMENTS
GENERAL FEED WATER SURFACE WATER WELL WATER PURE WATER
9 FILTERED WATER QUALITY TYPICAL FILTERED WATER QUALITY
9 SYSTEM SIZING MEMBRANE FLUX RATES TEMPERATURE CORRECTION
FACTOR
10 OPERATING GUIDELINES
11 SYSTEM CONFIGURATIONS AUTOMATIC FLUSHING OPERATION STORAGE TANKS
13 SHIPPING AND HANDLING CAREFUL TRANSPORT AND HANDLING STORAGE
13 SYSTEM STARTUP GUIDELINES PIPING FLUSHING SYSTEM DISINFECTION
13 MEMBRANE RINSING
14 SYSTEM SANITIZING
15 MEMBRANE INTEGRITY TEST GENERAL TEST INFORMATION EQUIPMENT PROCEDURE
16 MEMBRANE CLEANING MONITORING MEMBRANE
PERFORMANCE FOR FOULING NORMALIZING FLOW DATA BEFORE CLEANING CLEANING PROCEDURE
18 MEMBRANE STORAGE AFTER USE
18 BASICS OF FOULING
19 ULTRAFILTRATION TERMS
20 FREQUENTLY ASKED QUESTIONS
22 TROUBLESHOOTING GUIDE
23 MEMBRANE DATA SHEET FRESHPOINT® MODEL U440
USING THIS GUIDEThis guide is intended to provide general guidance to users regarding installation, operation, and maintenance of ultrafiltration systems including:
•Applications •Feedwaterrequirements •Pretreatmentrequirements •Systemsizing •Performance •Membranemaintenance
Thisguideisintendedforusebywatertreatmentprofessionalswhohavesomefamiliaritywithmembranesusedforwatertreatment.ItisrecommendedforuserstohavecompletedtheWQA® Reverse Osmosis/Ultrafiltration Specialty Exam,orhaveequivalentexperiencewithmembranetreatmentbasics.
For detailed information on specific ultrafiltration systems, please refer to its corresponding operating and maintenancemanualandproductdatasheet.
Fulvic Acids
Atomic Mass(Dalton DA)
Particle Size, µm
100
0.0001 0.001 0.01 0.1 1.0 10 100
10,000 1,000,000 108 109
Humic Acids
CellFragments
Bacteria
Virus
Ultrafiltration
Clay ParticlesHuman
Hair
CryptosporidiumCysts
Giardia LambliaCysts
Suspended Solids Test (TSS)
Organic Debris and Bacterial Flocs
Silt Particles
AqueousSalt
SugarMolecule
MetalIon
Colloidal Silica
Colloidal Material
HOW ULTRAFILTRATION WORKSUltrafiltration(UF)isamembraneseparationprocessthatallowsforremovalofsuspendedsolidsincludingparticles,colloids,cysts,bacteria,andviruses.UFmembranesremovesuspendedsolidsbasedonporesize.TheporesizefilteredbyUFmembranesvarieswidelydependingonthematerial,manufacturingprocess,andtheintendeduse/applicationofthespecificmembrane. (Seechartbelow).
Membrane Construction Ultrafiltrationmembranesareavailableinanumberofconfigurationsincluding:Flat sheet –Membranesformedinflatsheets,andconfiguredeitherinplate-and-framemembranestacksorspiralwoundcartridges.Typicallyusedforwatersuppliesthatdonothaveahighpotentialforfoulingandconfiguredforcross-flowfiltrationwithacontinuousrecirculation/wasteflow.Hollow fiber –Membranesformedintohollowfibersandconfiguredinmodulescontainingmultiplefibers.Typicallyoperatedinadeadendmode(i.e.nocontinuouswasteflow).Flowcanbeeitherfromthefiberboretotheexterior(insideout)orfromthefiberexteriortothebore(outsidein).Multi-bore hollow fiber –Similartohollowfibermembranesexceptthatthefibersarelargerandeachfibercontainsmultiplebores(typicallyfourtosevenbores).Tubular –Membranessimilartohollowfiberbutwithtubesthataremuchlarger(0.5"to1"ID).Typicallyusedforwastewaterapplicationsandconfiguredforcross-flowfiltrationwithacontinuousrecirculation/wasteflow.NOTE: Thisguidecoversonlyhollowfiberandmulti-borehollowfibermembranes.Thesetwotypesoffibermembranesarepreferredduetotheirrobustdesignandtheabilitytobecleaned“online”byperiodicflushing.
FRESHPO INT® U LTRAF I LTRAT ION GU IDE 54 P ENTA IR
PENTEK®
Particles, colloids,etc. are retained bythe membrane wall
Waterstream
Particles,colloids, etc.
Water freely passes through membrane wall
Simplified UF Fiber Diagram
Thefigurebelowdepictsanindividualultrafiltrationhollowfibermembraneflowinginsideout. Waterandparticulatesenterthecenterofthehollowfiber.Waterpassesthroughthemembranewallwhereitiscollectedasfiltrate,whileparticleslargerthanthemembraneporesareretainedbythemembrane.Theseparticlesareretainedinsidethefiberboreuntilaflushcycleisactivated.
ULTRAFILTRATION APPLICATIONS
Ultrafiltration(UF)isusedformanyapplicationsrequiringtheremovalofsuspendedsolidsincludingparticles,colloids,cysts,bacteriaandviruses.Typicalapplicationsinclude:
Surface Water TreatmentUFisusedaspartofamulti-barriersurfacewatertreatmentforthereductionof:•Turbidity•Finesiltnoteasilyfilteredbyconventionalmediafilters•TotalOxidizableCarbon(TOC)associatedwithhighmolecularweightorganics•Cystsnoteasilyfilteredbyconventionalmediafiltersorinactivatedbychlorine
Well Water Under the Influence of Surface WaterUFcanbeusedtotreatshallowwellsforreductionof:•Turbidity•Finesiltnoteasilyfilteredbyconventionalmediafilters•TotalOxidizableCarbon(TOC)associatedwithhighmolecularweightorganics•Cyststhatarenoteasilyfilteredbyconventionalmediafiltersorinactivatedbychlorine
Pretreatment of Reverse Osmosis (RO) Feed WaterPretreatingROfeedwaterwithUFincreasesmembranelifeandlowersoperatingcosts:•LowersfeedwaterSiltDensityIndex(SDI)–byremovingturbidityandcolloids•Removessuspendedsolidsthat“breakthrough”conventionalpressurefilters•Increasescartridgefilterlife•ReducesbiofoulingbyreductionofTotalOxidizableCarbon(TOC)andbacteria
Prefiltration of Water Feeding Sensitive EquipmentUFcanbeinstalledpriortoone-time-usespecializedfiltersandothersensitiveequipmenttoloweroperating costs: •Foodservice–prefiltrationoftasteandodorandcystfiltersgreatlyextendsservicelife•Laboratory,pharmaceutical,lifescience–extendsthelifeofdisposablemembranefilters
Postfiltering High Purity Water in Special ApplicationsUFcanbeinstalledafteranRO/deionizedwater(DI)systemtoimprovethequalityoftheultrapurewaterandloweroperatingcosts:•Pharmaceutical,lifescience–installinthepurewaterrecirculationlooptoextendthelifeofdisposablepoint-of-usefilters
•Ultrapurewater–installinthepurewaterrecirculationlooptoreducebacteria,TOC;extends thelifeofdisposablepoint-of-usefilters
Point-of-Entry Filtration for Residential and Commercial InstallationsInstalledaspartofmulti-barriersystem,UFoffers“peaceofmind”byprovidinganadditionalbarrieronpotablewatersuppliesagainstcompromisestothewatersystem,reducing:•Cysts •Bacteria•Turbidity •Viruses
Industrial and Municipal Waste WaterUFforwastewatertreatmentisbeyondthescopeofthisguide.
CAUTION:Onlysystemsthatarethirdpartycertifiedaswaterpurifiers,andmeetstateandlocalregulations,canbeusedtopurifyunsafedrinkingwatersupplies.
HOW ULTRAFILTRATION WORKSFiltration Operation
Ultrafiltrationsystemsmaybeconfiguredtooperateinoneofthreebasicfiltrationmodes:•Cross-flow–Aportionofthefeedwateriscontinuouslyrecirculatedand/orflowstowastetopreventretainedsolidsfrombuildinguponthemembranesurface.
•Deadend–Thereisnowasteflowfromthesystem.Whenthefilterbecomespluggeditiscleaned orreplaced.
•Deadendwithperiodicflushing–Thereisnocontinuouswasteflow.Themembraneisperiodicallyflushedtoremoveretainedsolidsfromthemembranesurface.
NOTE: Thisguidefocusesonsystemsconfiguredfordeadendfiltrationwithperiodicflushingonly.
Flow DirectionHollowfibermembranescanbeconstructedtoallowinsideoutoroutsideinflowinadeadendmode.Inside out flow:Feedwatertravelsdowntheboreofthefiberandpassesthroughthefibertotheoutsidewhereitiscollectedastreated(filtrate)water.Outside in flow:Feedwaterisontheoutsideofthefiberandpassesthroughtotheinsideofthefiberwhereitiscollectedastreated(filtrate)water.Thepreferredmembraneconfiguration(insideoutoroutsidein)isdependentupontheconstructionmethodandintendeduse.Outsideinmembranesarepreferredforwaterswithveryhighsuspendedsolidsandareprimarilyappliedinwastewaterapplicationssuchasmembranebioreactorsusedforsewagetreatment.Insideoutmembranesaremoreefficientandrequirelowervolumesofwaterforflushing,sotheyarepreferredforapplicationswithlowerlevelsofsuspendedsolidssuchasprefilteredwellorsurfacewater.NOTE: ThisguidefocusesoninsideoutUFmembraneconfigurationsonly.
FRESHPO INT® U LTRAF I LTRAT ION GU IDE 76 P ENTA IR
PENTEK®
WATER QUALITY BASICSWater Sources
Watersmaybecategorizedbytheirsource–groundwaterorsurfacewater.Thisclassificationdefinesthebasichistoryofthefeedwater,anddeterminesthelikelytypeandlevelofitsimpurities–andthereforeitsquality.Evenrainwatercontainssomeimpuritiesfromtheatmosphere.Surfacewaterisdrawnfromlakes,ponds,streams,andrivers.Itgenerallycontainsagreaterdegreeoforganicmaterialthangroundwatercausedmainlybydecayingvegetation.Surfacewaterisalsolikelytocontainsubstancesfromindustrialdischarge,agriculturalrunoff,andotherhumanactivities.Highconcentrationsofmicrobessuchasbacteria,viruses,andcystsaremorecommoninsurfacewaterthangroundwater.Groundwater,whichisdrawnfromwells,comesfromrainwaterthathaspercolatedthroughtheearthandcollectedinundergroundaquifers.Waterwellsvarygreatlyindepth,butgenerallydeeperwellshavelessorganicmaterialduetothenaturalfiltrationofthewaterpercolatingthroughtheground.Groundwatermayalsobedischargedtothesurfacefromnaturalsprings.Groundwatertendstohavehigherconcentrationsofinorganiccompounds.Groundwaterinshallowand/ordisruptedlocationsmaybeconsideredgroundwaterundertheinfluenceofsurfacewater,andhavesubstancesnormallyassociatedwithsurfacewatersupplies.Forexample,shallowwellwatermaycontainnitratesand/orcoliformbacteriafromnearbyagriculturalactivity.Shallowwellwater,likesurfacewater,maybeturbid(i.e.hazyinappearanceduetoparticlesfloatingwithin).
Seasonal VariationsSurfacewatertendstochangeinqualityduetoseasonalandweatherinfluences.Forexample,algaebloomsinlakesandriversmayoccurinlatesummer.Lakesandreservoirsinareaswithsubstantialtemperaturevariation“turnover”twiceayear,whichcandrasticallychangethewatercomposition.Snowmeltandspringrainrunoffaddmoresuspendedsolidsandimpuritiestorivers,andtheirconcentrationincreasesduringdryperiods.Evenmunicipallytreatedsurfacewaterqualitywillvarywiththeseasons.Asaresult,membranefoulingmaybemoresignificantinsomemonthsversusothers.
Water ImpuritiesWatermaycontainawiderangeofforeignmaterial.Mattermaybedissolvedorsuspendedinwater(presentassolutesorparticles).Solutesareatoms,moleculesorcompoundsthatcompletelydissolveinwater(i.e.completelyhydrated).Examplesincludeinorganicsaltionssuchassodium,calcium,chloridesandsulfates,andorganicmoleculeslikesugarsandtannicacid.Particulate matter is that material that is not dissolved and remains a discrete particle suspended in water.Examplesincludeclays,sand,dust,andsolutesthatreachtheirsaturationpointandprecipitateoutofsolution.Dissolvedorganicmatterincludesawiderangeofmaterialfromverysmalltolargemolecules. Examples of naturally occurring organics include tannins, lignin, humic and fulvic acids, proteins and thestarchesandcelluloseofplantcellwalls.Surfacewateroftencontainssubstantiallymoreorganicmatterthangroundwater.LargerorganicmoleculesmaybepartiallyremovedbyUFmembranes.Colloidsarechargedparticlestypicallymadeupofacombinationofmoleculesbothorganicandinorganic.Theyareheldinsuspensionbyelectrochemicalforcesthatputtheminacategorybetweenatruesoluteandsuspendedparticles.Theyaregenerallyviewedasverysmallparticles.Colloidsinwaterincludesilicaandiron(incertainforms).Virtuallyallparticulatematter(includingcolloids)largerthanthemembraneporesizewillberemovedbytheUFmembrane.Sincethesuspendedmaterialsaretrappedbythemembrane,theyconcentrateonthesurfaceofthemembraneandhavethepotentialtofoulit.Duetotheelectricalchargeassociatedwithcolloids,theycanbeespeciallyproblematicwithrespecttofouling.Microbesinwaterincludeviruses,bacteria,andsingle-cellprotozoa.Virusesareverysmallandcannotreproduceifsuspendedinwater–theyrequireahostorganism.UFremovesmostviruses, dependingontheporesizeandtypeofvirus.Bacteriaarelargerthanvirusesandmanydifferenttypesmaybepresentinwater.Bacteriareproduceinwaterespeciallyinstagnantwater.Mosttypesofbacteriaareharmlesstohumans,butsomebacteriatypes,especiallyE. coli fromanimalwaste,maycauseillness.ProtozoaincludemanyspeciesincludingGiardia Lamblia and Cryptosporidium cysts whichareknowntocausegastrointestinalillness.
Water Analysis Anunderstandingofthefeedwatersource,includingpriortreatmentandanalysisofthefeedwater,isessentialtodeterminethebestconfigurationandoperationalsettingsforaUFsystem.Ataminimum,thefollowingtestsarerecommended:SiltDensityIndex(SDI)–AnSDItestmustberunon-site.Thistestentailsrunningwaterthrougha0.45umfilterataconstantpressureandrecordingthereductioninflowratebymeasuringthetimeittakestofilla500mLbeakerinitiallyandthenafter5,10and15minutesofcontinuousflow.Thistestprovidesagoodindicationofthefoulingtendencyofthewaterduetosuspendedsolidsandcolloids.TotalOxidizableCarbon(TOC)–OrganicmattertypicallyismeasuredasTotalOxidizableCarbon(TOC),alsocalledTotalOrgaincCarbon.TOCisatypicalmeasurementforcarbonaceousmaterialinwater.Turbidity–Turbidityisameasureofhazinessorlackofclarityinwater,causedbylightdiffraction.Althoughnottechnicallythesameassuspendedparticulatematter,particulatesusuallycauseturbidity.TotalandDissolvedIron(TDI)–Totalironmeasuresbothdissolved(ferrousorclearwater)andoxidized(ferricorprecipitated)formsofiron.UFmayremoveferricironwhichmayfoultheUFmembrane.
Otherteststhatmaybehelpfulinclude:DissolvedOrganicCarbon(DOC)–AsubsetofTOC,DOCmeasuresorganicmatterthatwillpassthroughananalyticalmembranetoremoveparticulatematterbeforetesting.Tannins,Lignin,HumicAcid,andFulvicAcid–Oftenfoundinsurfacewatersandrequirespecializedtests.Allmaycontributetocolor.TotalSilica–Measuresallsilicainthewater,includingdissolvedandcolloidalforms.
FEED WATER QUALITY AND PRETREATMENT REQUIREMENTSTheperformanceofanymembranesystemishighlydependentonfeedwaterquality.Itinfluencesmembranelife,flushingfrequency,cleaningfrequency,recommendedflowrate,andfiltratequality.Itisvirtuallyimpossibletopredictthepreciseperformanceofasystemduetothewiderangeoffoulantsthatcanbepresentinwatersupplies,andbecausewatersuppliesvaryfromseasontoseasonandevendaytoday.However,apilotstudyisthemosteffectivewaytodeterminethelong-termperformanceofamembranesystem.Itisimportantthatthepilotstudyincludetheexpectedextremesinfeedwaterqualityifitistoprovidemeaningfulresults.Wewillconsiderseveral“typical”watersupplieswhenofferingguidelinesforUFsystemsapplicationsinthisguide.Therecommendedoperatingconditions,systemconfiguration,suggestedpretreatmentequipment,andexpectedperformancearealldependentuponinitialfeedwaterquality.
General Feed Water•Temperature–34°to104°F.•pH–3to10.•Iron–Dissolvedironwillnotfoulthemembranenorwillthemembraneremovedissolvediron.Lowconcentrationsofprecipitatedironcanberemovedbutmaycausefoulingatconcentrationsabove1mg/l.
•Chlorine–4.0mg/lcontinuous(200.0mg/lshortterm).•Ozone–0.0mg/l.•Turbidity–5.0NTUcontinuous(20.0NTUintermittent).•Silicone/SiliconeLubricants–Mustnotcomeincontactwithmembraneinconcentrationsthatcausefouling.
•OrganicSolvents/ChlorinatedSolvents–Mustnotcomeincontactwithmembrane.•Polyelectrolytes–Mustnotcomeincontactwithmembraneinconcentrationsthatcausefouling.•FreeOilandGrease–Mustnotcomeincontactwithmembraneinconcentrationsthatcausefouling.
FRESHPO INT® U LTRAF I LTRAT ION GU IDE 98 P ENTA IR
PENTEK®
Surface Water (Municipally Pretreated)•Suggestedminimumpretreatment: –Flocculation,settling/clarificationandfiltration(bymunicipality). –Disinfection(bymunicipality). –200-micronprefilter(optional).
•Chlorine–<4.0mg/l.•Turbidity–<5.0NTU.•TOC–<2.0mg/l.•SDI15–<6.67.•Metals(Fe,Mn,Cu,etc.)–<1.0mg/l.
Surface Water (Private Multi-Barrier System)•Suggestedminimumpretreatment: –In-linecoagulationandfiltrationwithmultimediafilter. –Disinfectionwithchlorine. –200-micronprefilter(optional).
•Chlorine–>2.0mg/l,<4.0mg/l.•Turbidity–<5.0NTU.•TOC–<10.0mg/l.•SDI5–<20.0.•Metals(Fe,Mn,Cu,etc.)–<1.0mg/l.CAUTION:DosageofcoagulantmustbecontrolledtopreventfoulingoftheUFmembranes.
Well Water (Municipally Treated Deep Well)•Suggestedminimumpretreatment: –Ironremovalfiltration(ifironover1mg/l). –Disinfection(bymunicipality). –200-micronprefilter(optional).
•Chlorine–<4.0mg/l.•Turbidity–<5.0NTU.•TOC–<2.0mg/l.•SDI15–<6.67•Metals(Fe,Mn,Cu,etc.)–<1mg/l
Well Water (Private Deep Well > 100 ft.)•Suggestedminimumpretreatment:–Ironremovalfiltration(ifironover1mg/l)–Disinfection–optional–200-micronprefilter–optional•Chlorine–<4.0mg/l•Turbidity–<5.0NTU•TOC–<2.0mg/l•SDI15–<6.67•Metals(Fe,Mn,Cu,etc.)–<1mg/l
NOTE:Wellsundertheinfluenceofsurfacewater(suchasthoselessthan100ft.deep)mayrequiretreatmentsimilartosurfacewater.
Pure Water (UF used to post-treat high purity RO/DI water)•Suggestedminimumpretreatment: –RO –MixedbedDIorContinuousDIsystem
•Chlorine–0.0mg/l•Turbidity–<0.1NTU•TOC–<1.0mg/l•SDI15–<1•Metals(Fe,Mn,Cu,etc.)–<0.1mg/lNOTE:ThefeedwaterlimitsshownareforwaterenteringtheUFmembranes(i.e.afteranyprefiltration,chemicaladdition,etc).
FILTERED WATER QUALITY
Thequalityoffiltrate(filteredwater)willvarydependinguponfeedwaterquality,operatingconditionsandtheconditionofthemembrane(s).Thefiltrationperformanceshownbelowrepresentstypicalresults.Pilottestingisrequiredtodeterminesite-specificresults.
Typical Filtered Water Quality•Particleremoval–99%+removalefficiencyforparticles1micronandlarger•Turbidity–<5NTU•Cystreduction–99.95%•Bacteriareduction–4to6logreduction(astestedwithKlebsiellaterrigena)•Virusreduction–1to4logreduction(astestedwithMS2coliphage)•SDI15–<2
SYSTEM SIZING
Ultrafiltrationsystemshavepeakflowandcontinuousflowratings.Thepeakflowratingisbasedbothonstandardoperatingconditionsandmembranesthatarein“asnew”condition(i.e.notfouledordegraded).Thepeakflowratingistypicallyusedtosizesystemsforresidentialapplications.Flowsinresidentialapplicationsareintermittent,andthereareveryfewtimesthathomesactuallyexperiencehighflowrates.Forexample,Aquacraft,Inc.WaterEngineeringandManagementpreparedastudyforWQAin2001toidentifyindoorflowratedemandsin1,188homesacrossvariousregionsoftheU.S.andCanada.Findings included:•70%ofallflowswere2.5gpmorless•92%ofallflowswere5gpmorless•99%ofallflowswere7.5gpmorless•99.9%ofallflowswere10gpmorlessCommercialapplications,however,aremorelikelytoexperiencesustainedperiodsofcontinuous flow.Systemsforcommercialapplicationsshouldbesizedbasedonthecontinuousflowratingof themembrane.
Membrane Flux RatesMembranemanufacturerstypicallyrecommendmembraneflowratesintermsofspecificfluxrates(i.e.gallonsperdaypersquarefootofmembranesurface[gfd]).Theserecommendedfluxratesshouldbeusedforsystemsizingguidance.However,fluxrates/systemflowsmayneedtobeadjustedbasedonlocaloperatingconditionsandfeedwaterquality.Pilotstudiesarethebestwaytodetermineanappropriatefluxrate. (Continued on next page)
FRESHPO INT® U LTRAF I LTRAT ION GU IDE 1110 P ENTA IR
PENTEK®
Membrane Flux Rates (continued)
Recommendedfluxratesforvariousfeedwatersources/qualityareshowninthetablebelow. Toobtainrecommendedflowrates,multiplythefluxratetimesthemembranearea.(Seemembranedatasheets).
NOTE:MetalsincludeFe,Mn,Cu,etc.
Temperature Correction FactorUFmembranecapacityisdependentupontemperature.Membraneflowdropsabout2%to3%foreach1°C(1.8°F)decreaseinfeedwatertemperature.Thislossinflowcanbecounteractedbyincreasingthepressure,providedthatmaximumtrans-membranepressureisnotexceeded.Thistable(seeright)showsthelossinflowassociatedwithfeedwatertemperaturesbelowstandardtestconditions25°C(77°F).Thistableassumesthattrans-membranepressureisheldconstantandonlywatertemperature ischanged.
OPERATING GUIDELINES
TEMPERATURE CORRECTION FACTOR°C °F
25 77 122.5 72.5 0.9320 68 0.86
17.5 63.5 0.8015 59 0.74
12.5 54.5 0.6910 50 0.647.5 45.5 0.605 41 0.55
2.5 36.5 0.51
Feed Water QualityRefertotheFeedWatersectionofthisguide(pages7-9).IftheUFisinstalledaspartofamulti-barriersystem,thewaterqualityshouldbecheckedattheinlettotheUFmembranes(i.e.afterallchemicaladditionandprefiltration).PrefiltrationA200-micronprefilter/strainerisrecommended.Membrane PressureFollowtheguidelinesinthemembranedatasheetwithregardtoallowabletrans-membranepressure.Scaling/FoulingPreventprecipitationintheUFsystem(e.g.Fe,Mn,CaCO3).Water HammerPreventionofwaterhammerisrequiredtoavoidmembranedamage.Protection from Abrupt Variations in TemperatureAvoidabruptvariationsintemperature.Themaximumoperatingtemperatureis40°C(104°F). Temperatureequalizationshouldberealizedslowly.Protection from Abrasive MaterialsThemembranemustbeprotectedfromabrasivematerials(e.g.machiningshavings,constructiondebris)whichcancauseirreversibledamagetothemembrane.Silicone or Lubricants Containing SiliconeLubricants/materialscontainingsiliconecancauseirreversibleblockageofthemembraneandmustnotcontactthemembranesurface.Useglycerinasalubricantforseals,o-rings,etc.
SYSTEM CONFIGURATIONSAutomatic Flushing Operation Systemsmaybeconfiguredtoflushinoneoracombinationofthreebasicmodes.Thetablebelowdescribesthevalvesequencingrequired.
Forward-flush –Thedrainvalveisopenedsothattheflowthroughtheboreofthefibersissignificantly increased.Retainedsolidsareflushedfromthemembranesurfaceduetothevelocityofthewater.Back-flush – Thedrainvalveisopened,thefeedwaterisshutoff,andthefiltrateisallowedtoreverseflowthroughthemembrane.This“lifts”retainedsolidsfromthemembranesurface,flushingthemtodrain.Thefiltrateusedforback-flushingcanbeprovidedbyastoragetankorbyotherUFmembranesthatremaininservice.Combined flush – Combinesbothback-flushandforward-flushsimultaneously.Thisnormallyoccursbyopeningthedrainvalve,whilethefeedwatersupplyremainsopenandback-flushwaterissuppliedbyothermembranesoranexternalsource.
Flush Valve SequencingSYSTEM
FLUSH TYPE CYCLE INLET VALVE DRAIN VALVE FILTRATE VALVE NOTES
Forward-Flush Only Forward-Flush None Open None Filtrate check valve required if
storage tank is used
Back-Flush Only Back-Flush Closed Open NoneBack-flush water provided by
storage tank or other membranes (no filtrate check valve)
Sequential Back- Then
Forward-Flush
Back-Flush Closed Open Open (if used)
If back-flush provided by tank and filtrate valve is not used,
then backflow prevention during forward-flush is requiredForward-Flush Open Open Closed
(if used)Combined
Forward- and Back-Flush
Combined Forward- and Back-Flush None Open None Back-flush water provided by
other membranes
Therequiredflushfrequencyisdependentuponlocaloperatingconditionsandmayrequireadjustmentafterinstallation.Furthermore,feedwaterqualitymayvaryseasonallyorwhenalternatewatersuppliesareused.Adjustmentstoflushingfrequencymayberequiredtoaccommodatechangesinfeedwaterquality.
Initial Recommended Flushing Parameters by Water Source and Treatment
WATER SOURCE FORWARD-FLUSH BACK-FLUSH
SEQUENTIAL BACK- THEN
FORWARD-FLUSH
COMBINED FORWARD- AND
BACK-FLUSH
FLUSH FREQUENCY (GALLONS
THROUGHOUT)
Surface Water Municipally Treated Minimum Minimum Recommended Recommended 100
Surface Water Private Multi-Barrier
Treatment
Not Recommended
Not Recommended Recommended Minimum 50
Well Municipally Treated Minimum Minimum Recommended Recommended 200
Well Private Minimum Minimum Recommended Recommended 100
Pure Water Recommended Recommended Recommended Recommended 500
NOTE: Themaximumrecommendedtimebetweenflushcyclesis24hours.Wellsthatareundertheinfluenceofsurfacewater(suchasthoselessthan100ftdeep)mayrequiretreatmentsimilartosurfacewater.
OPERATING CONDITION UNITS FLUX RATE TURBIDITY (NTU) SDI METALS (mg/l)
TOC (mg/l)
Peak/Initial (@ 25°C) gfd 280 < 0.1 < 1 < 0.1 < 1
Pure Water gfd 180 < 0.1 < 1 < 0.1 < 1
Well Water gfd 85 < 1 < 6.67 < 1 < 2
Surface Water gfd 35 < 20 < 20 < 1 < 10
FRESHPO INT® U LTRAF I LTRAT ION GU IDE 1312 P ENTA IR
PENTEK®
Storage TanksSomesystemsmayutilizeasingleUFmembrane,whileothersmayusemultiplemembranestoprovidetherequiredflowrateandfeatures.Systemsmaybeconfiguredwithafiltratestoragetankorconfiguredasadirectfeedsystemwithnofiltratestoragetank.Onsomesystems,itmaybebeneficialtoprovideastoragetanktomaintainwaterpressureduringthe flushcycles,toprovidewaterforback-flushingoftheUFmembrane,andtoprovideadditionalwaterpressureduringshortperiodsofhighflowdemand.Thestoragetankmayalsobeusedinback-flushing systemstostorefiltratefortheflushcycle.Thefiltratestoragetankcanbeanatmospherictankoraclosedhydropneumatictank.Theadvantages oftheclosedhydropneumatictankisthatthewaterisnotexposedtoairborneimpuritiesandnopumpisneededtorepressurizethewater.NOTE:Forthepurposesofthisguide,itisassumedthatthestoragetankisaclosedhydropneumatictankunlessotherwisespecified.Thefigurebelowshowsasystemwithastoragetankusedformaintainingevenwaterpressure,butnotusedforflushing.
SHIPPING AND HANDLINGCareful Transport and Handling
Mechanicaldamage/ruptureofthemembraneshellandconnectionscanresultifthemembranesaredroppedorcollide.Therefore,membraneunitsmustbehandledwithcareatalltimesduringtransportation,installation,andstartup.
StorageMembranesshouldbestoredinadrysettingwithnormalventilation,removedfromanydirectsunlight,heatorignitionsources.Storagetemperatureshouldbebetween4°and30°C(40°and86°F).Membranemodulesshouldnotbesubjectedtoanyfreezingconditions.Topreventdehydrationandcontrolbacterialgrowth,membranesaresaturatedwithawater/glycerin/sodiumbisulfitesolution(74.75%water,25%glycerin,0.25%sodiumbisulfite)andsealedinplasticbagsorindividualmembranehousingspriortoshipment.Sealedmembranes(inoriginalpackaging)canbestoredforuptoeightmonthsafterdeliveryifstoredbetweenatemperatureof4°-30°C(40°and86°F).Whenexceedingeightmonthsofstorage,theindicatedsolutionmustberefreshed.ROorDIwaterisrecommendedforthesaturationsolution.Beforestorage,membranemodulesshouldbesealedinplasticbags.Ifprocessedaccordingly,membranemodulescanbestoredforanothertwomonthsbeforethesolutionwouldhavetoberefreshed.
SYSTEM STARTUP GUIDELINESPiping
SystemandinstallationpipingshouldbecleanedbeforetheUFsystemisstartedsothatnoimpurities, abrasivematerials,oroilymaterialsarewashedintothemembranes.Pipingmustbepurgedofairtopreventwaterhammerwhichcandamagethesystem.
FlushingFlushthemembranetoremovethemembranestoragesolutionpriortoplacingtheUFsysteminservice.
System DisinfectionThesystemshouldbedisinfectedafterflushingbutpriortouse.Seethisguide’sdisinfection/sanitizingguidelines(pages14-15).
MEMBRANE RINSINGTopreventdehydrationandbiologicalgrowth,membranesareshippedandstoredinawater/glycerin/sodiumbisulfitesolution.Thefollowing3-cyclemembranerinseproceduremustbeperformedinorder to remove the storage solution prior to use:
Rinse Cycle 1A.Slowlyfilltheinflowsideofthesystemwithuntreatedwaterinordertoavoidwaterhammer.B.StartaForward-FlushCycle(directionofflowfromthebottomtothetop)atareducedflushflow
rateforaminimumofthreeminutesorlongerifrequiredtopurgeallairfromthesystem(observethedrainflowforair).
C.Operatetheunitinthenormalfiltrationmodeatalowflowrate—providearangeofflow2.0-2.5GPM—foraminimumof20minutes.Makesurethefiltrateoutletisopenandallwaterproducedisdischargedtothedrain.
D.Ifastoragetankisused,makesurethatitisdrainedcompletelyafterthefirstrinsecycle.
FRESHPO INT® U LTRAF I LTRAT ION GU IDE 1514 P ENTA IR
PENTEK®
Rinse Cycle 2A.Operatetheunitinthenormalfiltrationmodeatalowflowrate—providearangeofflow2.0-2.5
GPM—for20minutes.Makesurethefiltrateoutletisopenandallwaterproducedisdischargedtothedrain.
B.Initiateastandardflushcycle(whichmayincorporateback-andforward-flushcycles).Ensure thatthesystemflushesforaminimumof60seconds,whichmayrequiretwoflushcyclesinitiatedback-to-back.
C.Ifastoragetankisused,makesureitisdrainedcompletelyafterthesecondrinsecycle.
Rinse Cycle 3A.Operatetheunitinthenormalfiltrationmodeatalowflowrate—providearangeofflow2.0-2.5
GPM—for20minutes.Makesurethefiltrateoutletisopenandallwaterproducedisdischargedtothedrain.
B.Initiateastandardflushcycle(whichmayincorporateback-andforward-flushcycles).Ensure thesystemflushesforaminimumof60seconds,whichmayrequiretwoflushcyclesinitiated back-to-back.
C.Ifastoragetankisused,makesureitisdrainedcompletelyafterthethirdrinsecycle.D.Placethesysteminthenormalfiltrationmodeandfillthestoragetank,ifequipped.NOTE: Thisinformationisprovidedasageneralguideline.Alwaysrefertoaspecificsystem’soperatingandmaintenancemanualfordetailedprocedures.
SYSTEM SANITIZINGTheunitshouldbesanitized/disinfectedaftertheinitialstartuprinsingprocedureorincaseofbiologicalfouling.CAUTION: Sodiumhypochlorite(bleach)isusedfordisinfection.Theusershouldacquaintthemselveswiththeappropriatesafetyprecautionsforstorageandhandlingofthechemicalsbeingused.Useonlysodiumhypochlorite.Donotusebleachescontaininganyothercompounds.
Procedureifacleaningsystemisavailable:1. Prepareasolutioncontaining100mg/l(asCl2)ofchlorineusingUFfiltratewater.2. Removetheinlet,outlet,anddrainplumbingfromthemembrane(s).Connectthecleaningsystem
pumpoutlettothemembranefeedpiping.Connectthedrainandfiltratetothecleaningtank.3. Recirculatethesolutionforfiveminutes,returningthefiltrateanddraintothecleaningtank.4. Letthesystemsoakforonehour.5. Emptythecleaningtank.6. Refillthecleaningtankwithcleanwater(UFfiltrateifavailable).7. Pumpthewaterinthetankthroughthesystemwithbothfiltrateanddrainlinesdirectedtothedrain.8. Reconnectthepipingsystemfornormaloperation.9. Operatetheunitinthenormalfiltrationmodefortenminutes.Makesurethefiltrateoutletisopen
andallwaterproducedisdischargedtothedrain.10. Initiateastandardflushcycle(whichmayincorporatebothback-andforward-flushcycles).11. Ifastoragetankisused,makesureitisdrainedcompletelyaftertheflushcycle.12. Operatetheunitinthenormalfiltrationmodefortenminutes.Makesurethefiltrateoutletisopen
andallwaterproducedisdischargedtothedrain.13. Initiateastandardflushcycle(whichmayincorporatebothback-andforward-flushcycles).14. Ifastoragetankisused,makesureitisdrainedcompletelyaftertheflushcycle.15. Placethesysteminthenormalfiltrationmodeandfillthestoragetank(ifequipped).16. Samplethefiltratebycheckingthebacteriologicalquality.Iftestresultsarenotsatisfactory,
repeatthedisinfectionprocedure.NOTE: RefertotheCleaningSystemSchematicinthemembranecleaningsectionofthisguide(page17).
ProcedureifacleaningsystemisNOTavailable:1. Prepareasolutioncontaining100mg/l(asCl2)ofchlorineusingUFfiltratewater.2. Removetheinlet,outlet,anddrainplumbingfromthemembrane(s).3. Ifthesystemisfurnishedwithacartridgefilter(s)removethefilterelements.4. Fillthemembranehousing(s)andfiltersump(s)withthechlorinesolution.5. Letthesystemsoakforonehour.6. Reconnectthepipingsystemfornormaloperation.Donotinstallthefilterelementsyet.7. Operatetheunitinthenormalfiltrationmodeforfiveminutes.Makesurethefiltrateoutletis
openandallwaterproducedisdischargedtothedrain.8. Stoptheunitandreinstallthecartridgefilter(s)ifapplicable.9. Operatetheunitinthenormalfiltrationmodeforanadditionalfiveminutes.Makesurethefiltrate
outletisopenandallwaterproducedisdischargedtothedrain.10. Initiateastandardflushcycle(whichmayincorporatebothback-andforward-flushcycles).11. Ifastoragetankisused,makesureitisdrainedcompletelyaftertheflushcycle.12. Operatetheunitinthenormalfiltrationmodefortenminutes.Makesurethefiltrateoutletisopen
andallwaterproducedisdischargedtothedrain.13. Initiateastandardflushcycle(whichmayincorporatebothback-andforward-flushcycles).14. Ifastoragetankisused,makesureitisdrainedcompletelyaftertheflushcycle.15. Placethesysteminthenormalfiltrationmodeandfillthestoragetank(ifequipped).16. Samplethefiltratebycheckingthebacteriologicalquality.Ifthetestresultsarenotsatisfactory,
repeatthedisinfectionprocedure.Note:Thisinformationisprovidedasageneralguideline.Alwaysrefertoaspecificsystem’soperatingand maintenancemanualfordetailedprocedures.
MEMBRANE INTEGRITY TESTAllmembraneelementsarefactorytestedandpassintegritystandardspriortoshipment.However,afullsystemintegritytestshouldbeconducteduponstartupandperformedroutinelythereafter(onceperyearminimum).Theintegrityisusedtocheckfor: –Internalleaks,suchascutormisalignedo-rings –DamagedmembranesThepreferredintegritytestisapressuredecaytest.Thistestinvolvestheapplicationofairpressuretothemembranewhenitisfully“wet-out”(i.e.theporesarefullofwater,whichistheconditionofthemembranewhenithasbeenproperlyflushedafterstartup).Theamountofpressurelossismeasuredoverasetperiodoftime.Ifthepressuredeclinestoofast,thisindicatesthatthereisasealleakinthesystemormembranefiberdamage.
General Test Information•Thetestrequiresthatthemembranebefully“wet-out”(i.e.allporesfullofwater).•Themembraneassemblyshouldbedrainedofallexcesswater.•Thistestdoesnotrequirethevisualdetectionofabubble;insteaditmeasuresthelossofpressureorvacuumovertimeviaagauge.
•Acertainamountofpressurelosswilloccurinanintactsystemfromsimplediffusionofairthroughthewatertrappedinthemembranepores(“baselinedecay”).Butahigherpressurelosswilloccurfrommembraneflawsorbrokenseals.
•Topreventcontamination,useeitheracleanairsourceora0.2-micronfilterontheairsource.Equipment
•Pressurizedairsource(~20psig,3+scfmcapacitywithpressureregulator,typicallyasmallportableairtankorportablecompressor.
•Pressuregauge(0-20or0-30psig)withaccuracyto0.1psi.•Positiveshutoffvalve(abubble-tightballvalve)toisolatetheUFmembraneinlet,andonetoisolatetheairsource.
•Stopwatchorwatchwithasecondhand.
FRESHPO INT® U LTRAF I LTRAT ION GU IDE 1716 P ENTA IR
PENTEK®
Procedure1. Ensurethemembraneisfully“wet-out”;operatethesystem
atitsnormalflowrateforseveralminutesbyopeningthenearesttapdownstream.
2. Drainthefeedsideofthemembranefor10-15minutes.Ifpossible,drainthefiltratesideofthesystemfor10-15minutes.
3. Close supply and drain valves to isolate the feed side of the system.Thefiltratesideofthemembraneshouldbeopen toatmosphere.
4. Graduallypressurizethefeedsideofthefibersto15psig.NOTE: Donotoverpressurize;thiswillforcethewateroutoftheporesandthemembranewillnolongerbe“wet-out”,resultinginafalsefailure.
5. Closethevalvebetweentheairsourceandgauge;simultaneouslybeginmeasuringtime.
6. Notethepressureat60,120,and180secondsandrecordit.7. Relieveairpressureslowlybeforedisconnectingtheairlines.8. Ifsystempressureholdsbetween14.5and15.0psigafter
twominutes,thesystemintegrityisgoodandthuspassesthetest.
9. Ifsystempressureis14.5psigorlessaftertwominutes,checkconnectionsandplumbingforpossibleairleaks.
10. Ifsystempressuredropstolessthan14.5psigaftertwominutes,theo-ringsealmaybepinched,defective,orabsent,orthemembraneelementmaybedamaged.
NOTE: Theflushsolenoidmayneedtoberemovedandthelinecappedofftoensureagoodairseal.
MEMBRANE CLEANINGMembranecleaningisrequiredwhenthesurfaceofthemembraneandmembraneporesbecomefouled.Thisismostoftendetectedbyalossofflowrate.UFmembranesshouldbemaintainedinacleancondition,unfouledbyparticulatematter,precipitates,orbiologicalgrowth.
Monitoring Membrane Performance for FoulingMembranesareconsideredfouledif“normalized”filtrateflowdeclinesmorethan10percentwithin24hourswhenmeasuredimmediatelyafteraflushcycle.Normalizingthefiltrateflowisrequiredtoaccountforthedifferencesinfeedwatertemperatureandtrans-membranepressure.
Normalizing Flow DataNormalizethepermeateflowdataasfollows:•Operatethesystematthesametrans-membranepressurewhencomparingtwodatapoints.Ensurethepressuredropassociatedwithothersystemcomponentsisnotincludedinthedata.
•Correctfortemperaturedifferencesusingthetemperaturecorrectionfactor.
Exampleofasimplifiedmethodtonormalizeflowdata:•Day1filtrateflow=2.5gpm,watertemperature=20°C(68°F),trans-membranepressure=8psid•Day2filtrateflow=2.0gpm,watertemperature=17.5°C(63.5°F),trans-membranepressure=7psid•Day2datanormalizedtoDay1conditions: –2.0x8/7(pressure)x0.86/0.80(temperature)=2.46gpm –Therefore,thenormalizedfluxlossis2%
Drain
FlowControl
PressureGauge
Inlet
Filtr
ateIntegrity Test
Simplified Diagram
UFMembrane
Air Tank/Air Supply
TankTank
Drain
UFMembrane
FiltrateFiltrate
PumpPump
Cleaning SystemSchematic
FeedWaterFeed
Water
Before CleaningBeforecleaningthemembrane(s),makesurethemembrane(s)is/arebeingproperlyflushedduringnormalautomaticflushcycles.Ensurethatthereisadequatewaterpressureduringalloftheflushcyclesandthatthedesignflushflowsareachieved.Thenimplementseveralmanualflushcyclestoseeifthenormalizedflowisrestored.Ifflowcanberestoredbyadditionalflushcycles,itmaybebeneficialtoincreasethefrequencyofthetimedurationforautomaticflushcycles.
Cleaning Procedure1. Ifflushingdoesnotrestoremembraneflow/flux,cleanasfollows:2. Performtwocomplete,consecutive,automaticflushcycles.
Setupcleaningsystemasshownintheschematic.NOTE: Cleaningsystemcomponentsmustbecompatiblewiththecleaningchemicals.
3. Preparethecleaningsolutionperthetableatthebottomofthispage.Selectingthecleaningsolutionisdependentuponthetypeoffoulant,whichwilldependuponfeedwatersourceandquality.Somegeneralguidelines:
A.Sourceofwater •Ifthesourcewaterissurfacewater,thefoulingwilltendtobeorganic-based.
•Ifthesourcewaterisgroundwater,foulingtendstobeinorganic-based.
B.Inletwateranalysis •IftheinletwaterhasrelativelyhighlevelsofTOC,DOC, ortannin,focusonorganiccleaningmethods.
•Iftheinletwaterhasrelativelyhighlevelsofiron,manganese, or hardness, focus on inorganic cleaning methods.
4. Makeupthecleaningsolutionperthetablebelow.5. Connectcleaningsystemhosestothemembranemodule(s)asshownintheschematic.6. Startthepumpandcirculatethecleaningsolutionthroughthemembrane(s)inthenormalflow
directionatthenormalforward-flushflowrate.Returndrainandfiltratehosestothecleaningtank.7. Circulatethecleaningsolutionthroughthemembranefor15minutes.8. Stopthepumpandallowthesystemtosoakfor15minutes.9. Repeattherecirculate/soakcyclesuntilnoadditionalfoulantsarebeingremoved.NOTE: Observecleaningtankwaterclarityanddump/replacethecleaningsolutionifitisevidentthatthecleaningsolutionisfouled.MeasurethecleaningtankwaterpH,addingacidifrequiredtomaintainthepHbetween1to3,orcausticifrequiredtomaintainpHbetween11and13.
10. Flushthemembranes.(SeeMembraneFlushing).11. Disinfectthemembranes.(SeeDisinfection/Sanitizing).12. Determinethenormalizedmembraneflow/flux.13. Repeatasneeded.NOTE: Thisinformationisprovidedasageneralguideline.Alwaysrefertoaspecificsystem’soperatingandmaintenancemanualforthedetailedprocedure.
1. Usewaterwith50%NaOH.2. Use H2O25%solution.3. UseHCI(30%HCl).4. Usehouseholdorcommercial-gradebleachwithno
fragrancesoradditives.5. Usefood-gradecitricacid.CAUTION: Cleaningsystemwasteshouldbetreatedtocomplywithlocalregulations(pHneutralized)beforethespentcleaningsolutionisdischargedtodrain.
CLEANING SOLUTION
CLEANER FOULANT FINAL pH OR CONC.
Sodium Hydroxide Solution (NaOH) Organics 13
Bleach Solution (NaOCl)
Organics/ Biological 200 mg/l
Hydrogen Peroxide Solution (H2O2)
Organics/Biological 500 mg/l
Hydrochloric Acid Solution (HCl) Hardness 1
Citric Acid Iron 1
FRESHPO INT® U LTRAF I LTRAT ION GU IDE 1918 P ENTA IR
PENTEK®
MEMBRANE STORAGE AFTER USEAfterinitialuse,themembrane(s)needtobekeptwetatalltimes.Toavoidbiologicalgrowthduringshutdownsorstorage,wetmembranesshouldbetreatedwithacompatiblebiocide.
Downtimeupto24hours–NomeasuresrequiredDowntime1to7days–Automaticflushing
Systemsequippedwithautomatictime-basedflushsystems(withavailablefeedwater)cancontinuetoflushautomatically,providedtheflushcycleoccursatleastevery24hoursforaminimumof30seconds.
Downtime1to15days–AutomaticflushingSystemsequippedwithautomatictime-basedflushsystems(withavailablefeedwater)cancontinuetoflushautomatically,providedtheflushcycleoccursatleastevery24hoursforaminimumof60seconds.
Downtime>7days–Noautomaticflushing/membranesstoredinplaceMembrane(s)shouldbecleanedanddisinfectedthenfilledwitha0.1%sodiumbisulfitesolution.Leavemembrane(s)installedinthesystem.Replacethesodiumbisulfitesolutionevery15days.
Downtime>15days–Noautomaticflushing/membrane(s)storedinsealedcontainersMembrane(s)shouldbecleanedanddisinfectedthenfilledwitha0.1%sodiumbisulfitesolution.Themembraneshouldberemovedfromthesystemandstoredinindividuallysealed(airtight)containers.Replacethesodiumbisulfitesolutionevery60days.Inallcases,themembrane(s)mustbefilledwithwaterwhenstored.Anytimeastoragesolutionisused,themembrane(s)mustbeflushedpriortouse.Seemembranerinsingguidelines(page13).
BASICS OF FOULING Aswithallfiltrationmedia,aUFmembranebecomescoveredwiththematerialitremovesfromwater.Foulingreducesthefiltrateproducedatagiventrans-membranepressureandtemperature.UFsystemsaredesignedtoregularlyflushtominimizeaccumulationofthefoulingmaterial.Therearefourtypesoffouling,whichareunderstoodbytheirrelationshiptothemembranestructure.Cake Layering – Foulingoccursastheretainedmaterialbuildsintoalayerontopofthemembranesurface.This“cake”reduceswaterflowasitgrowsinthicknessanddensity.Pore Blockage – Occurswhenaparticleorgroupofcombinedparticleslocatedirectlyoveraporeopeningonthemembranesurface.Likeacorkinabottleneck,thisblocksthewaterfromenteringtheporeandreducestheflowrateinthesystem.Cakelayeringandporeblockagearetheeasiesttypesoffoulantstoremovebyflushing.Itisalsopossibleforaproblematic“sticky”materialtodevelop,causingatypeoffoulingthatmayberesistanttoremoval.Interior Pore Fouling – Materialentersthemembrane’spores,thenlodgesinsidetheremainingporousstructureinsteadofpassingallthewaythroughthemembrane.Asthistrappedmaterialbuildsup,itreducestheavailablechannelspaceforwaterflow,eventuallyblockingoffchannelsandseverelyreducingflow.Interiorporefoulantsareremovedmostefficientlybyback-flushingratherthanforward-flushing.NOTE: Operatingthemembraneathightrans-membranepressurepromotesinteriorporefoulingwhichmaynotbereversible.
Fiber Plugging – Thisisanextremelyseverefoulingcondition.Inthiscase,themembranefiber’sfeedchannelbecomesfilledeitherwithlargeparticlesorformseverecakelayerbuildupfrommembranefouling.Flowthroughboththefiberchannelandmembraneporesbecomesseverelyrestricted.NOTE: Fiberpluggingmayoccurwithhighconcentrationsofcolloidalmaterialsandiron.Ifhighconcentrationsofironorcolloidalmaterialsarepresent,aprefiltersystemsuchasabackwashingmultimediafilterorironremovalfiltershouldbeemployed.
ULTRAFILTRATION TERMS
Back-Flush (BF) –Cleaningtechniquewherefiltrateisrunoppositeofnormaldirectionthroughthemembrane,forthepurpose of flushing the foulant off the membranesurface.Bubble Point Test – Nondestructive filter testusedtodetermineamembraneelement’sintegrityandproperinstallation,basedonthepressurenecessarytodisplacealiquidheldbysurfacetensionforces from the largest pore in the membrane.Thepressureholdtestisbasedonthebubblepointpressure.Colloid –Matterwhichisheldinwaterinaformbetweenasoluteandadiscretesuspended particle, that does not precipitatebutremainsasadispersion.Concentrate –Portionofthefeedwaterthatdoesnotpassthroughthemembraneasfiltrate,butcarriesthematterthatisretainedbythemembraneawayfromthesystem(alsoknownasrejectordrain).Cross-Flow Filtration – Operation mode wherethefeedstreamflowsthroughboththemembrane(duetohydraulicpressure)andoverthemembrane.Oneinfluentfeedstreambecomestwoeffluentstreams(filtrateandconcentrate).Disinfection – Process of removing or inactivatingorganismsinawatersupply toasafelevel.Element –Membraneconfigurationthatformsadiscreteunitwhichisthenplacedinahousingforpressurizedoperation.Depth Filtration –Removalofsubstancesthroughout the thickness or depth of the media.Disposablefibrousandwoundfiltercartridgesareexamplesofdepthfilters.Feed (Feed Water) – Water source fed to theUFtobepurified.Filtrate –Purifiedwaterthathaspassedthroughthemembrane(SeePermeate).Forward-Flush or Fast Forward-Flush (FFF) –Cleaningtechniquewherefeedflowsoverthemembranesurfaceathighvelocity to drain, instead of through the membrane.Theshearforcecausedby the high velocity removes foulants from themembranesurface.Flux –Rateoffiltrateflowthroughamembrane(usuallyexpressedinvolumeofper unit time per unit area, such as gallons per day per ft2orgfd).Fouling – Accumulation of retained matteronthesurfaceorwithintheporesofthemembrane,resultinginaloss ofperformance–mostnoticeably reducedflux.
Foulant –Anywaterbornematerialthatcontributestomembranefouling.Housing –Pressure-bearingvessel thatcontainsthemembraneelementduringoperation.Humic Acid –Variouswater-solubleorganic compounds resulting from decayedvegetablematter.Ion –Chargedsoluteinwater,atan atomic or small molecular level (examples:sodiumorcarbonate).Integrity –ConditionofaUFmembraneelementwherenointernalbypassing offeedwaterintothefiltrateexistsdue tobrokenfibers,membranetearsor failedseals.Irreversible Fouling – When fouling materialcannotberemovedwithnormalcleaningtechniques,includingfastforward-flushing,back-flushingorchemicalcleaningwhichcanresultinalossofperformance.Membrane –Semi-permeablebarrierthat permits the passage of materials only uptoacertainsizeorelectrochemicalcharacter.Microbes/Micro-Organisms – Organism thatrequiresamicroscopetobeseen. Inwater,theseincludevirus,bacteria, andprotozoan.Microfiltration (MF) – Class of membranesthatremovesparticlesofasizeabovetheapproximaterangeof0.05microns,throughsieving(orsizeexclusion).Milligrams per Liter (mg/L) – Weight to volumeratioofconcentration,equivalenttopartspermillion(ppm).Multi-Barrier – Water treatment system thatincludesmultipletreatmentstages.Municipal Water –Drinkingwatertreatedbyamunicipalityandofpotablequality.TreatmenttechniquesandfinishedqualityarebothdefinedbyStateandUSEPAstandards.Natural Organic Matter (NOM) – Any organic matter of natural origin found inwater(asopposedto,forexample,pesticides).Normalization – Conversionofrawdata to reference conditions in order to “standardize”operationtoacomparablebaseline.Operating Pressure – Hydraulic gauge pressure in the system on the feed stream, orupstreamside,ofthemembrane.Parts per Million (ppm) – Volume to volumeratioofconcentration,equivalenttomilligramsperliter(mg/l).
Permeate – Purified feed stream after passingthroughamembrane.Alsoknownas“productwater”(SeeFiltrate).Pore –Openingorvoidinamembranethatdeterminesthesizeofasoluteorparticlepassingthroughtothefiltrate.Reverse Osmosis (RO) – Separation processwhereimpuritiesofasizedowntotheioniclevelareremovedbyasemi-permeablemembrane.Reversible Fouling – Fouling material thatcanberemovedwithnormalcleaningtechniques,suchasfastforward-flushing,back-flushingorchemicalcleaning.Sanitization –Reductioninthenumberofmicrobialimpuritiestosafelevels.(SeeDisinfection).Silt Density Index (SDI) – Value calculated fromtherateatwhichawatersourcewillpluga0.45-micronmembrane.TheSDI test procedure is defined in ASTM StandardD4189.TheSDIratingprovidesan indication of rating tendency of the feed watertofoulmembranes.Solutes –Anymatterdissolvedinwater(asopposedtosuspendedinwater).OftenreportedasTDS(totaldissolvedsolids).Surface Filtration –Removalofsubstancesmainlyatthetwodimensionalplanesofthemediasurface.Standardpolymermembranesaresurfacefilters.Suspended Solids – Particulate matter heldinsuspensioninwater(usuallyparticles,butcolloidsareoftenconsideredassuspendedbecausetheyarenotfullydissolved).OftenreportedasTSS(totalsuspendedsolids).Total Oxidizable Carbon (TOC) or Total Organic Carbon (based on how it is analyzed) – Measure of the level of organic matterinwater.Trans-Membrane Pressure (TMP) – Hydraulicdrivingpressuremovingwaterthroughthemembrane,measuredasthedifferencebetweenfeedandfiltrate(upstreamanddownstream)sidesofthemembrane.Alsotermed“effectivepressure”.Ultrafiltration (UF) – Process using hydraulicpressureandasemi-permeablemembranefortheseparationofcomponentsinsolutionsandsuspensions.Membraneporesareofasizethat allowspassageofwater,butwillretainnon-ionicsolutesbasedprimarilyontheirphysicalsize.
FRESHPO INT® U LTRAF I LTRAT ION GU IDE 2120 P ENTA IR
PENTEK®
FREQUENTLY ASKED QUESTIONSTheFAQsbelowarespecifictothePentair® FreshPoint® Ultrafiltration (UF) system, although they generally applytomostotherhollowfiber UFsystemsaswell.
Q. Is this device designed for use on microbiologically unsafe water?
A. FreshPointUFisbestusedaspartofamulti-barriersystemtotreatmicrobiologicallyunsafewaters.
CAUTION: Onlysystemsthatare3rdparty-certifiedaswaterpurifiersandmeetstateandlocalregulationscanbeusedtopurifyunsafedrinkingwatersupplies.
Q. Will UF remove cysts from my water?
A. Yes,cystswillberemovedbyFreshPointUF.
Q. How often does the FreshPoint UF membrane need to be replaced?
A. Membranelifevarieswidely andisdependentonfeedwaterqualityandoperatingconditions.A3-to5-yearmembranelifeisexpected for a properly applied, wellmaintainedsystem.
Q. What is the nominal pore size?A. TheFreshPointnominalporesize
is0.02microns.
Q. Is the pore size rating absolute?A. No,theporesizeisnominal.
Q. How do I know the FreshPoint UF System is working?
A. Amembraneintegritytestshouldbeperformedtodetermineifthemembraneisworking.
Q. How do I test the integrity of the membrane?
A. An air test is used to ensure thattheFreshPointmembraneintegrityismaintained.
Q. How long does a membrane integrity test take?
A. Theintegritytesttakesabout1/2hourtocomplete,butthenneedstobefollowedbysanitizing.
Q. How much water will the UF system use for flushing?
A. FreshPoint UF uses three to four gallonsperflushcycle.
Q. Can UF be used to remove iron from my water?
A. FreshPointUFwillremovesuspended iron particles and colloidsabovethemembraneporesize.However,itisonlyrecommended as a polishing iron filter as high concentrations of ironcouldplugthefiberbores.FreshPointwillnotremovedissolvediron.
Q. How frequently will the UF system flush?
A. Flushingfrequencyisprogrammable.Thedefaultsetting for FreshPoint UF is 100gallonsoronceperday,whicheveroccursfirst.
Q. Will my water flow be interrupted while the unit flushes?
A. Waterwillcontinuetobesuppliedwhilethesystemflushes,butyou may notice a reduction in pressure.Thisreductioninpressurecanbeminimizedbyinstallingaproductstoragetank.
Q. Do I have to do anything special with the FreshPoint UF System when I go on vacation?
A. If you are going to leave your waterturnedonwhileyouareonvacation,thesystemwillcontinueto flush daily and nothing needs tobedone.Ifyouwillbegoneforan extended period and shutting offthewatercompletely,thenpreservativesshouldbeaddedtothemembrane.
Q. What is the maximum flow rate? A. Maximumflowrateisdependent
onoperatingconditions.FreshPointModelU440isratedatamaximumof10gpmatstandardoperatingconditions.
Q. What is the pressure drop at the maximum flow rate?
A. Pressure drop is dependent on operating conditions and feed watertemperature.FreshPointUFhasapressuredropof<15psidatmaximumflowrate/standardoperatingconditions.
Q. What is the continuous flow rate?A. Thecontinuousflowrateis
dependentonoperatingconditions. TheFreshPointU440isratedatacontinuousflowof3gpmatstandardoperatingconditions.
Q. What is the pressure drop at the continuous flow rate?
A. The pressure drop is dependent on operating conditions and feedwatertemperature.TheFreshPointU440hasapressuredropof<10psidatcontinuousflowrate/standardoperatingconditions.
Q. What cleaning chemicals are recommended?
A. Cleaningsolutionsvarybyfoulantand include: chlorine, hydrogen peroxide, sodium hydroxide, citric acidandhydrochloricacid.
Q. Is any prefiltration recommended?A. The need for prefiltration is
dependentuponfeedwaterquality.SeetheFeedWaterQuality section of this guide (pages7-9)formoreinformation.
Q. What is the permitted operating pH range?
A. ApHrangeof3to10ispermissibleforFreshPointUF.
Q. What is the required operating pressure range?
A. FreshPoint®canbeoperatedatinletpressuresupto120psig.However,trans-membranepressureshouldbelimitedtopreventlongtermfouling.Seemembranespecificationsheetsformoreinformation.
Q. What is the permitted operating temperature range?
A. FreshPointUFcanbeoperatedwithtemperaturesfrom34°to104°F(1.1°to40°C).
Q. Can I install this unit outside?A. Outdoor installation is not
recommended due to the temperature limits for the FreshPointUFsystem.
Q. What is the drain flow rate?A. TheFreshPointU440drainflowis
7gpmmaximum.
Q. What size and length drain line is permitted?
A. Thesizeofthedrainlineshouldbeaminimumof0.75"tomeetcoderequirements.Drainlinelengthshouldbeminimizedtopreventwaterhammerwhentheflushvalvecloses.
Q. Does the module need to be installed vertically?
A. The FreshPoint UF module shouldbeinstalledverticallyforproperventing.
Q. What is the maximum inlet chlorine concentration allowed?
A. Maximum continuous inlet chlorine concentration for FreshPoint is 4mg/l.
Q. What is the maximum inlet turbidity?
A. Maximum recommended inlet turbidityforFreshPointUFis 5NTU.PleaserefertotheFeedWater Quality section of this guide formoreinformation.
Q. What outlet turbidity can be expected?
A. TheFreshPointoutletturbidityisexpectedtobe<1.0.
Q. What outlet SDI can I expect?A. The FreshPoint outlet SDI is
expectedtobe<2.0.
Q. What system flushing will be required after installation?
A. TheFreshPointmembrane(s)mustbeflushedforapproximatelyonehourpriortoinitialuse.
Q. Do membranes have a shelf life?A. Membranematerialisstable,
however,amaximummembraneshelf life of eight months is recommended (if maintained in itsoriginalpackaging).
Q. What flocculants could be used ahead of the membrane(s)?
A. Polyelectrolytescanbeusedaspartofanin-linecoagulation/ filtration process prior to the FreshPointUFmembrane(s),butgreatcaremustbeusedtoavoidoverdosingofthepolyelectrolyte.Overdosing polyelectrolyte can irreversiblyfoulUFmembranes.
Q. What lubricants should be used on seals?
A. Glycerin is the preferred lubricant.(Siliconewillfoulthe UFmembrane(s).)
Q. Is a dropped membrane safe to use?
A. Anydroppedmembrane(s)shouldbeintegrity-testedtoensurethatitwasnotdamaged.
Q. What is the preservative solution in a new membrane?
A. Sodiumbisulfiteandglycerin.
Q. Do UF systems have to be installed with a flush tank?
A. No,howeverflushtanksarepreferred for most applications tominimizepressurereductionduring flush cycles and periods ofhighflow.Theyalsoprovidewaterforback-flushingofthemembranes.
FRESHPO INT® U LTRAF I LTRAT ION GU IDE 2322 P ENTA IR
PENTEK®
TROUBLESHOOTING GUIDEThistroubleshootingguidefocusesonbasicmembrane/processissues.Seeaspecificsystem’soperatingandmaintenancemanualfortroubleshootinginformationforspecificUFsystems.
MEMBRANE DATAMembrane Data Sheet – FreshPoint® Ultrafiltration System (Model U440)
PROBLEM POTENTIAL CAUSE CORRECTION
Low flow / pressure available.
Unit is flushing.Wait for flush to be completed.
Install a pressure tank to maintain system pressure during flush cycles.
Prefilter(s) is plugged (if so equipped). Change prefilter(s) – disposable type.Regenerate back-washable filters.
Feed water pressure is too low. Increase UF feed water pressure.
Membrane is fouled.
Decrease the volume between flushes.Increase the flush time.
Decrease the time between flushes.Chemically clean/sanitize.
No product water flow.
Bypass valves are not in the correct position. Correct bypass valve position to restore flow.
Inlet water is shutoff. Open inlet valve(s).
Prefilter(s) is plugged (if so equipped). Change prefilter(s) – disposable type.Regenerate back-washable filters.
Membrane is fouled.
Decrease the volume between flushes.Increase the flush time.
Decrease the time between flushes.Chemically clean/sanitize.
Unpleasant taste and odor in the water.
Membranes were not sufficiently flushed following installation, disinfection, or cleaning.
Follow the system startup guide for flushing new membranes.
Water has become stagnant from low water use. Perform additional flushing of the system per operation manual.
Membrane is fouled.
Decrease the volume between flushes.Increase the flush time.
Decrease the time between flushes.Chemically clean/sanitize.
Suds in the water. Membranes were not sufficiently flushed following installation, disinfection, or cleaning.
Follow the system startup guide for flushing new membranes.
System not producing the expected water quality.
Impurities are unable to be removed by UF system.
Refer to UF application guide for approximate removal capabilities.
Add additional treatment steps to aid in impurity removal.
Seals/internal connections are leaking. Confirm with pressure decay test.Replace internal seals.
Membrane has an internal leak. Confirm with pressure decay test. Replace membrane.
System is flushing continuously.
Drain solenoid valve is stuck open. Remove debris from the valve.Replace the drain solenoid valve.
System controller circuit board is sending continuous flush signal.
Confirm the controller is programmed correctly.Contact your Water Specialist for service.
UF MEMBRANE SPECIFICATION UNIT OF MEASURE
SPECIFICATION VALUE
Membrane Model n/a Pentair® U440
Membrane Area sq. ft. 51.0
Peak Flux Rate gfd 280.0
Pure Water Continuous Flux Rate gfd 180.0
Well Water Continuous Flux Rate gfd 85.0
Surface Water Continuous Flux Rate gfd 35.0
Peak Flow Rate (Not Continuous) gpm 9.9
Pure Water Continuous Flow gpm 6.4
Well Water Continuous Flow gpm 3.0
Surface Water Continuous Flow gpm 1.2
Trans-Membrane Pressure – Continuous psid 11.5
Trans-Membrane Pressure – Maximum psid 36.0
Trans-Membrane Pressure – Back-Flush psid 36.0
Molecular Weight Cut-Off Dalton 150,000
Operating Temperature – Minimum °F 34
Operating Temperature – Maximum °F 104
Operation n/a Inside Out
Flush – Fluid n/a Water
Flush – Direction n/a Forward and Back
Membrane Type n/a Multibore Hollow Fiber
Capillaries per Fiber n/a 7
Hollow Fiber ID in. 0.04
Hollow Fiber OD in. 0.17
Diameter – Nominal in. 4
Length – Nominal in. 38
pH Range – Continuous pH 3 to 10
NaOCl – Continuous mg/l 4
pH Range – Intermittent (Cleaning) pH 1 to 13
NaOCl – Intermittent (Cleaning) mg/l 200
H2O2 – Intermittent (Cleaning) mg/l 500
NaOH – Intermittent (Cleaning) pH 13.0
HCl – Intermittent (Cleaning) pH 1.0
Citric Acid – Intermittent (Cleaning) pH 1.0
FILTRATION & PROCESS5730 NORTH GLEN PARK ROAD, MILWAUKEE, WI 53209P: 262.238.4400 | F: 262.518.4404 | WWW.PENTAIRAQUA.COM | CUSTOMER CARE: 800.279.9404
AllPentairtrademarksandlogosareownedbyPentair,Inc.oritsaffiliates.Allotherregisteredandunregistered trademarks and logos are the property of their respectiveowners.Becausewearecontinuouslyimprovingourproductsandservices,Pentairreservestherighttochangespecificationswithoutpriornotice.Pentairisanequalopportunityemployer.42680REVBMY13©2013PentairResidentialFiltration,LLC.AllRightsReserved.