膜制造与分离组件培训课件.ppt

1、膜制造与分离组件膜过程的驱动力压力驱动-RO,NF，UF,MF其它过程-渗析（浓度差）电渗析（电位差）压力驱动的膜过滤膜 MF UF NF RO孔尺寸减小泵压力增加 高分子材料(PAN,PES,CA,PVDF).铸膜液制备聚合物+有机溶剂(NMP,DMF,acetone等易与水互溶).添加其它助剂(poreformers or nonsolvents).凝固浴（主要用水和其它聚合物不良溶剂构成，通过相分离产生the pores 和the membrane body)必需品 PES聚合物 NMP 溶剂 水 玻璃片 刮膜器 NMP甲基吡咯烷酮PES聚醚酚Poly Sulfon(PS)PS in N

2、MP solutionCleaning glassplates importantglassplatesFilling the knife with PS solutionMembrane knife(0,2 mm)Creating a membrane filmPut slowly in the water for.Move very gently to leftMembrane is floating after coagulationAfter coagulationTake of a membraneOut of the waterThe photo of the produced m

3、embraneMake sheets of it in a moduleMake a module of itPlate and Frame ModuleSeparation of resistance factors to Cake,Gel,Plugging,Membrane.Dead-end with backflush(管道等)堵塞(+up);3.Advantages:More than one membraneDeadend FiltrationPut slowly in the water for.fouling layerbuilding up fouling layer铸膜液制备

4、聚合物+有机溶剂(NMP,DMF,acetone等易与水互溶).Deadend FiltrationSelective membrane skinFrom Catalog of TorayMembrane knife(0,2 mm)Pretreatment of the feed(flocculation/coagulation,pH adjustment)Two A4 papersAfter coagulationcapillary (0.铸膜液制备聚合物+有机溶剂(NMP,DMF,acetone等易与水互溶).More than one membraneSubmerge in a MBR

5、tank Porous vs Non Porous Hydrophilic vs Hydrophobic Polymeric vs InorganicHydrophilic亲水 Hydrophobic疏水Porous Non PorousSymmetric Asymmetric Dense(Non porous)Porous SymmetricPorous asymmetricRO,NFUF,MFMFSkinSupportPorous Symmetric MembranesNuclepore Membrane核径迹成孔核径迹成孔Cellulose MembraneSymmetric membr

6、aneAsymmetric MembranesDense LayerPorous supportFiber SupportPore sizeCeramic membrane pictures(CEM)Membrane structure structure:symmetric asymmetric shapes:flat sheet tubular:tube(d 3 mm)capillary (0.5 d 3.0 mm)hollow fibre(d 3 mm)Complex cake layer structureCleaning glassplates important(管道等)堵塞(+u

7、p);3.肮脏的,污浊的;2.productionforward flush&back flushMembrane filtration cross flowPoreplugging,adsorption and cakelayer formation添加其它助剂(poreformers or nonsolvents).Porous asymmetricCytochrome CMembrane filtration cross flowMonolith (demo)Deadend FiltrationTubular membrane-Porous glassYou can make your

8、own spiral wound module today!Two A4 papers Cotton sheet A4(if available)Shears to cut Glue for paper Plastic tube with a slid(prefabricated)Reverse Osmoseinstallation+/various configurationsFeedPermeatePermeateFeedRetentateDead endCross-flowDeadend and CrossflowOperation modesMembrane filtration de

9、ad-endMembraneWaste waterPermeatefeedMembrane filtration cross flowWaste waterPermeateconcentratefeedmembraneAir injectionDeadend FiltrationtimeCrossflow filtrationtimeSemi deadend filtrationCrossflow filtration Advantages:turbulent flow continuous concentrate discharge control of cakelayer buildup

10、Disadvantages:more complex process layout high(er)energy consumption high(er)investment costCascade single pass systemFeedRetentateConcentrateTwostage recirculation systemConcentrateFeedPermeatePermeateStage 1Stage 2Feed pumpRecirculation pumpFouling of membranes Fouling Reversible fouling Irreversi

11、ble fouling Biofouling Pore blocking Scalingfoul a.1.肮脏的,污浊的;2.恶臭的;(食物)腐败的;3.邪恶的,可恶的;4.下流的,恶语咒骂的;5.(天气等)恶劣的;(风)逆的;6.(比赛中)犯规的;7.(水管等)堵塞的;8.(绳索等)被缠住的ad.1.违反规则地;不正当地n.1.(比赛中)犯规C(+against/on)vt.1.弄脏;污染;玷污;2.使堵塞;3.缠住;4.碰撞vi.1.腐败,腐烂;2.(管道等)堵塞(+up);3.(比赛中)犯规;4.(绳索等)缠结Resistance ModelI=ER1+R2+R3ER1R2R3IRmRc

12、RgRpJvJv=DPm(Rc+Rg+Rp+Rm)Separation of resistance factors to Cake,Gel,Plugging,Membrane.Rejection by UF/MF membranesGlobular ProteinLinear polymerSolutePepsinCytochrome CPolydextranMW(kDa)3513100Rejection(%)90700 Porous supportSelective membrane skinGlobularproteinLinearmacromoleculeCake layer forma

13、tionMembraneParticleColloid/proteinCake/fouling layerFlow directionDriving forcepFouling in MF/UFDecrease in flux due to:Poreplugging,adsorption and cakelayer formation No concentration polarization of salts no scalingIn general concentrated feed solutions containing large particles(size 10 nm 25 m)

14、.This results in low backdiffusion rates,fast cake layer buildup and pore blocking low productfluxes(1/10 of the CWF)Complex cake layer structureFouling in NF/ROFouling behavior differs from UF/MF due to:Lower fluxes and presence of smaller molecules higher backdiffusion and in general no thick cake

15、 layer formationCharged membrane surfaces(in general negative)adsorption of colloids and biological matterScaling(CaSO4,CaCO3)Fouling reduction/cleaning Membrane properties and module design Optimum process conditions(low TMP)Cleaning regime hydraulic cleaning(backwash,forward flush and airflush)che

16、mical cleaning relaxation Pretreatment of the feed(flocculation/coagulation,pH adjustment)Backwash(=Backflush)SuspensionMembranePermeateFiltration modeBackflushing modeto drainFluxTimewith backflushingwithout0negative flowSuspensionMembranePermeateFiltration modeBackflushing modeto drainFluxTimewith

17、 backflushingwithout0negative flowBackwash(=Backflush)Forward Flush productionforward flushBack Flush productionforward flush&back flushpermeateAirFlushbubble flowslug flowannular flowForward Flush with airflush productionforward flush with airflush&backflushMembrane filtration semi dead-endMembrane

18、Waste waterPermeatefeedDead-end production-run,startpermeatepermeatepermeatepermeatefeedMembrane moduleDead-end at end of production runBuilding up fouling layerProduction of permeate decreases at constant TMPpermeatepermeatepermeatepermeatefeedDead-end with backflushBackflush with permeate duringpr

19、oductionconcentratefeedpermeatepermeatepermeatepermeateDead-end with backwash&airflushAir injectionfeedpermeatepermeatepermeatepermeateBackwash with airflush results in lower permeate useAir injectionMembrane filtration cross flowWaste waterPermeateconcentratefeedmembraneAir injectionCross flow High sheering forces in membrane module Low fouling layer build up Higher energy demand Higher recovery Applicated for higher MLSS contents