membrane bioreactors state of the art.original

7/28/2019 Membrane Bioreactors State of the Art.original

1/54

Membrane Bioreactors:Membrane Bioreactors:

State of the Art andState of the Art andTechnology ExchangeTechnology Exchange

R. Shane Trussell, Ph.D., P.E.R. Shane Trussell, Ph.D., P.E.

Seminar for DOW Chemical

Midland, MI

June 21, 2007


2/54

OutlineOutline

IntroductionIntroduction

Membrane IssuesMembrane Issues

Other IssuesOther Issues


3/54

OutlineOutline IntroductionIntroduction

Brief historyBrief history

Configurations andConfigurations and

manufacturersmanufacturersMBR vs. ConventionalMBR vs. Conventional

Membrane IssuesMembrane Issues

Other IssuesOther Issues


4/54

IntroductionIntroduction

An MBR is not aAn MBR is not a

membrane processmembrane process

An MBR is aAn MBR is a

biologicalbiologicalprocess thatprocess that

uses membranesuses membranes

for solidfor solid--liquidliquidseparationseparation


5/54

IntroductionIntroductionMBRMBRss RootsRoots

Dorr Oliver (1960s)Dorr Oliver (1960s)

SuccessfullySuccessfully

coupled activatedcoupled activatedsludge (AS) tosludge (AS) tomembrane separationmembrane separationby early 1970sby early 1970s(sold 27 units(sold 27 unitsbetween 1974 andbetween 1974 and1982)1982)

EMBR process withEMBR process with

flatsheetflatsheet

UFUF

membranesmembranes

Cost prohibitiveCost prohibitive

Capital and O&MCapital and O&M


6/54

IntroductionIntroduction SMBR configurationSMBR configuration

University of TokyoUniversity of TokyoProfessorsProfessorsAyaAya andand

YamamotoYamamoto 19891989WatWat.. SciSci. Tech.. Tech.

JapanJapan

Kubota developed flatKubota developed flat--

sheet SMBRsheet SMBR

Mitsubishi developedMitsubishi developedhorizontal hollowhorizontal hollowfiber SMBRfiber SMBR

CanadaCanada

ZenonZenon developeddevelopedvertical hollow fibervertical hollow fiber

SMBRSMBR


7/54

IntroductionIntroduction SMBR configurationSMBR configuration

Breakthrough forBreakthrough forcommercialized MBRcommercialized MBRtechnologytechnology

Reduced energy by 90%Reduced energy by 90%

JapanJapan

Kubota dominates withKubota dominates with

6060MBRsMBRsby 1996 (totalby 1996 (total1.5 MGD)1.5 MGD)

UK, Canada, and USAUK, Canada, and USA

Milton, Ontario, CAMilton, Ontario, CA

19971997Arapahoe, CO, USA 1998Arapahoe, CO, USA 1998

Kingston Seymour, UKKingston Seymour, UK19921992


8/54

IntroductionIntroduction SMBR manufacturers in theSMBR manufacturers in the

USAUSA-- firstsfirsts

ZenonZenonwas 1.0 MGD inwas 1.0 MGD inArapahoe, CO in 1998Arapahoe, CO in 1998

Mitsubishi was 0.10 MGD inMitsubishi was 0.10 MGD inByfieldByfield, MA in 2000, MA in 2000

Kubota was 0.6 MGD in RunningKubota was 0.6 MGD in RunningSprings, CA in 2002Springs, CA in 2002

US Filter was 0.16 MGD inUS Filter was 0.16 MGD in

LakeLake OconoceeOconocee, GAG in 2003, GAG in 2003 Zenon is the predominantMBR manufacturer with themost experience andcapacity

Kubota is the runner-upwith significantknowledge andinstallation capacity


9/54

Submerged MBR (SMBR)Submerged MBR (SMBR)Q

Primary Treated

Wastewater

WASTE

EffluentEffluentEffluentEffluentAeration Basin

Waste Activated SludgeWaste Activated SludgeWaste Activated SludgeWaste Activated Sludge

Solids RecycleSolids RecycleSolids RecycleSolids Recycle

QR = 3-5xQ


10/54

External MBR (EMBR)External MBR (EMBR)

Primary TreatedPrimary TreatedPrimary TreatedPrimary Treated

WastewaterWastewaterWastewaterWastewater


EffluentEffluentEffluentEffluentAeration BasinAeration BasinAeration BasinAeration Basin

Q

QR = 20-30xQ



11/54

AirAir--liftlift EMBREMBR

Primary TreatedPrimary TreatedPrimary TreatedPrimary Treated

WastewaterWastewaterWastewaterWastewater


EffluentEffluentEffluentEffluent

Aeration BasinAeration BasinAeration BasinAeration Basin

Q

QR = 5-10xQ


DiffuserDiffuserDiffuserDiffuser


12/54

ZENONZENON Hollow fiberHollow fiber

membranemembrane

configurationconfiguration

ProprietaryProprietary

polymerpolymer

UltrafiltrationUltrafiltration 1998 First MBR1998 First MBR

Installation inInstallation in

the USA wasthe USA was

operational atoperational at

1.0 MGD in1.0 MGD in

Arapahoe, COArapahoe, CO


13/54

ZENONZENON 48 modules combine48 modules combine

to form a cassetteto form a cassette

One common headerOne common header

Permeate drawnPermeate drawn

from top andfrom top and

bottombottom

IntermittentIntermittent

coarse bubblecoarse bubble

aeration (10s on/aeration (10s on/

10s off)10s off)


14/54

ZENONZENON

Membranes submerged at end of aeration basinMembranes submerged at end of aeration basin

System capable of operating withSystem capable of operating with backpulsebackpulse

oror relaxrelax


15/54

Kubota /Kubota / EnviroquipEnviroquip Flat sheet membraneFlat sheet membrane

configurationconfiguration PolyethylenePolyethylene

MicrofiltrationMicrofiltration

2002 First MBR2002 First MBRInstallation in theInstallation in theUSA was operationalUSA was operationalat 0.6 MGD inat 0.6 MGD in

Running Springs, CARunning Springs, CA


16/54

Kubota /Kubota / EnviroquipEnviroquip

100 flat sheets100 flat sheets

combine to formcombine to formcassettecassette

Each sheet hasEach sheet hastube connectiontube connectionto headerto header

Constant coarseConstant coarsebubble aerationbubble aeration

to mitigateto mitigatemembrane foulingmembrane fouling


17/54

Kubota /Kubota / EnviroquipEnviroquip

Cassette submerged in aeration basinCassette submerged in aeration basin DoubleDouble deckerdecker (DD) configuration(DD) configuration

System operates with membrane relax, noSystem operates with membrane relax, no

backpulsebackpulse


18/54

US Filter/US Filter/ MemJetMemJet Hollow fiberHollow fiber

membranemembraneconfigurationconfiguration

PVDFPVDF


2003 First MBR2003 First MBRInstallation in theInstallation in theUSA was operationalUSA was operational

at 0.16 MGD in Lakeat 0.16 MGD in LakeOconee, GAOconee, GA


19/54

US Filter/US Filter/ MemJetMemJet Bundles of 4Bundles of 4

membrane modulesmembrane modules Common header for 4Common header for 4modulesmodules

Combination ofCombination of

air/liquid jetair/liquid jet JetJetTechTech is used tois used to

provide crossprovide cross--flowflowto the membraneto the membranesurfacesurface


20/54

US Filter/US Filter/ MemJetMemJet Separate tankSeparate tank

for membranesfor membranes BackwashingBackwashing

cycle:cycle:

45 s relax45 s relax

15 s permeate15 s permeate

backflushbackflush

15 s coarse15 s coarse

bubble airbubble air


21/54

Mitsubishi / GE IonicsMitsubishi / GE Ionics

Hollow fiber membraneHollow fiber membrane

configurationconfiguration(horizontal)(horizontal)

PolyethylenePolyethylene


2000 First MBR2000 First MBRInstallation in theInstallation in theUSA was operationalUSA was operational

at 0.10 MGD inat 0.10 MGD inByfieldByfield, MA, MA


22/54

Mitsubishi / GE IonicsMitsubishi / GE Ionics 50 membrane modules50 membrane modules

for 1 membrane bankfor 1 membrane bankModules connect toModules connect to

common headercommon header

Permeate drawn fromPermeate drawn fromboth sides (L and R)both sides (L and R)

Constant coarseConstant coarse

bubble aerationbubble aeration


23/54

Mitsubishi / GE IonicsMitsubishi / GE Ionics

Membranes submerged in aeration basinMembranes submerged in aeration basin

System operates with membrane relax, noSystem operates with membrane relax, no

backpulsebackpulse


24/54

Membrane ComparisonMembrane Comparison

--0.50.50.40.4MitsubishMitsubish

ii

170170--0.40.4KubotaKubota

4004000.20.20.080.08US FilterUS Filter

2902900.10.10.0350.035ZenonZenon

MembraneMembrane

Area/Footprint,Area/Footprint,

ftft22

/ft/ft22

AbsoluteAbsolute

MWCO,MWCO,

mm

NominalNominal

MWCO,MWCO,

mm

ManufacturerManufacturer


25/54

KochKoch PuronPuron


26/54

EMBREMBRss ReRe--BirthBirth--Air PumpsAir Pumps


27/54

How does MBR compareHow does MBR compareto what isto what is commoncommon

wastewater practice?wastewater practice?


28/54

Drivers for ProcessDrivers for Process

SelectionSelection Intended use of treated waterIntended use of treated water

Effluent limitsEffluent limits ScalabilityScalability

Site constraintsSite constraints

Flexibility withFlexibility withexpansions/retrofitsexpansions/retrofits

Capital costCapital cost

O&M costO&M cost

Training/Expertise requirementTraining/Expertise requirement


29/54

TechnologiesTechnologies

Goal is to remove COD, TN, TSS,Goal is to remove COD, TN, TSS,and Pathogensand Pathogens

Small to medium capacity < 5 MGDSmall to medium capacity < 5 MGD

Oxidation DitchOxidation Ditch

Sequencing Batch Reactor (SBR)Sequencing Batch Reactor (SBR)

Membrane Bioreactor (MBR)Membrane Bioreactor (MBR)

Large capacity > 5 MGDLarge capacity > 5 MGD

Conventional activated sludgeConventional activated sludge Pure oxygen activated sludgePure oxygen activated sludge

Membrane Bioreactor (MBR)Membrane Bioreactor (MBR)


30/54

Flow Scheme for ConventionalFlow Scheme for Conventional

Activated Sludge ProcessActivated Sludge Process

Backwash

Water

Secondary

Clarifier

Secondary

Clarifier

WASTE

ToDisinfection

Microfiltration

ConventionalConventional

Aeration BasinAeration Basin

Primary Treated

Wastewater

Fl S h f th MBR dFl S h f th MBR d


31/54

Flow Schemes for the MBR andFlow Schemes for the MBR andConventional Activated SludgeConventional Activated Sludge

ProcessProcess

Primary Treated

Wastewater

Backwash

Water

Secondary

Clarifier

WASTE

ToDisinfection

Microfiltration

Conventional

Aeration Basin

WASTE

MBR

Aeration Basin

To

Disinfection


32/54

Sequencing BatchSequencing BatchReactorsReactors

SBR is a fillSBR is a fill--and draw typeand draw type

activated sludge systemactivated sludge system

Equalization, aeration andEqualization, aeration and

clarification all performed in theclarification all performed in the

same batch reactorsame batch reactor

React Settle Decant


33/54

Retrofitting SBR with MBR

Capacity increases by 8-fold Batch becomes Continuous

MLSS increases from 3 to 10 g/L

DisinfectionPrimary TreatedWastewater

Waste

Activate

Sludge

Membrane TankAeration Tank

Solids RecycleQR = 3-5Q

Q


34/54


Oxidation ditch is an activated sludge process

that utilizes long solids retention times

CAS SRT = 5 avg. days

Oxidation ditch SRT = 20 avg. days


35/54


Double Ditch

Triple Ditch

Mechanical aerators

More capacity, more ditches

Typical HRT is 24 h


36/54

TechnologiesTechnologiesAll conventional technologies that

compete with MBR use gravity forsolid-liquid separation

Additional filtration process required toAdditional filtration process required toattain recycled water statusattain recycled water status

Membrane filtration required to attain aMembrane filtration required to attain asimilar water qualitysimilar water quality

MBR has great potential to reduceMBR has great potential to reducedisinfection requirementsdisinfection requirements

Commercial MBRs to date are not marketedin in a manner that allows operationsimilar to pure oxygen plants

Low SRT operation to prevent nitrificationLow SRT operation to prevent nitrificationand significantly reduce oxygen requirementsand significantly reduce oxygen requirements

This is because membrane fouling rates areThis is because membrane fouling rates areincreased with low SRT designsincreased with low SRT designs


37/54

TechnologiesTechnologiesObvious winner for MBR

Space limitationsSpace limitations

High quality effluent requiredHigh quality effluent requiredDebate amongst practicing engineers in

USA as to the economics of MBRcompared to membrane filtration of

secondary effluents for largewastewater treatment facilities

Less aeration required on settledLess aeration required on settledeffluent because less solids presenteffluent because less solids present

Higher flux and reduced capital costHigher flux and reduced capital cost

Reality is established cleaningReality is established cleaningintervals are different (2intervals are different (2ndnd effluenteffluentevery 3 to 4 weeks while MBR every 1every 3 to 4 weeks while MBR every 1to 3 months)to 3 months)


38/54

TechnologiesTechnologiesLarge membrane facilities treating secondaryLarge membrane facilities treating secondary

effluenteffluent

Orange County Water District 85 MGDOrange County Water District 85 MGD

West Basin Municipal Water District 40West Basin Municipal Water District 40MGDMGD

Clark County Water Reclamation DistrictClark County Water Reclamation District30 MGD30 MGD

Large MBR facilitiesLarge MBR facilities

Traverse City 17 MGD facilityTraverse City 17 MGD facility

Tempe 10 MGD facilityTempe 10 MGD facility

King CountyKing County BrightwaterBrightwater 38 MGD38 MGD

Irvine Ranch Water District 20 MGDIrvine Ranch Water District 20 MGD

MBRsMBRs economic viability depends on theeconomic viability depends on theentire picture of a given locationentire picture of a given location

Cost of land and availabilityCost of land and availability

Total present worth costsTotal present worth costs

Overall project goalsOverall project goals


39/54

Principle Advantages ofPrinciple Advantages ofMBR ProcessMBR Process

High qualityHigh qualityeffluenteffluent

CompactCompact

FootprintFootprint

High MLSSHigh MLSS

concentrationsconcentrations


40/54

Some obvious benefitsSome obvious benefits

ofofMBRsMBRs areare

MBR produces an excellentMBR produces an excellent

effluent qualityeffluent quality

MBR has a much smallerMBR has a much smaller

footprintfootprint

smaller aeration tankssmaller aeration tanks no clarifiersno clarifiers

no filtersno filters

MBR has great potential forMBR has great potential for

being highly automated andbeing highly automated and

requiring little operatorrequiring little operator

attentionattention

MBR AdvantagesMBR Advantages


41/54

MBR eliminates the needMBR eliminates the need

for monitoring sludgefor monitoring sludge

settleability as ansettleability as anoperational parameteroperational parameter

Effluent quality is notEffluent quality is not

dependent on operationsdependent on operationsNot necessary to determineNot necessary to determine

TSS/VSS concentrations toTSS/VSS concentrations to

maintain desired SRTmaintain desired SRT

Can use fixed waste rateCan use fixed waste rate

SRT=V/QSRT=V/QWASWAS


d


42/54

Higher MLSS concentrations (More bugHigher MLSS concentrations (More bugmass per volume)mass per volume)

Membrane provides solidMembrane provides solid--liquidliquidseparationseparation

SBR or Ox. Ditch 2SBR or Ox. Ditch 2

--4 g/L4 g/L

MBR 8MBR 8--12 g/L12 g/L

MBR makes longerMBR makes longerSRTsSRTs feasiblefeasible

Reduced solids handling costsReduced solids handling costsMore stable nitrogen removal processMore stable nitrogen removal process


d


43/54


Membrane provides an absolute barrierMembrane provides an absolute barrier

and effluent quality is no longer aand effluent quality is no longer a

concern.concern.

ND to 10ND to 101000 to1000 to

10,00010,000

FecalFecal

Coliform,Coliform,

#/100#/100mLmL


44/54

Public Health BenefitPublic Health Benefit

Membrane is anMembrane is anabsolute barrier thatabsolute barrier thatphysically removes allphysically removes allpathogenspathogens

ConventionalConventional

technologies depend ontechnologies depend onhighly selectivehighly selectivechemical orchemical or

photochemical reactionphotochemical reactionPathogens may repairPathogens may repair

themselves and reactivatethemselves and reactivate

Results from operatingResults from operating

MBR plants:MBR plants:



45/54

Total ColiformsTotal Coliforms

MitsubishiMitsubishi

ZenonZenon

1E+00

1E+01

1E+02

1E+03

1E+04

1E+05

1E+06

1E+07

1E+08

1E+09

0 250 500 750 1000 1250 1500 1750 2000 2250 2500

Time of Operation, h

Concentration

,MPN/100mL

Primary Eff luent Total Coliforms MBR Permeate Total Coliforms

open symbols denote below detection limit

1E+00

1E+01

1E+02

1E+03

1E+04

1E+05

1E+06

1E+07

1E+08

1E+09

0 250 500 750 1000 1250 1500 1750 2000 2250 2500


Concentration,MPN/100mL

Primary Eff luent Total Coliforms MBR Permeate Total Coliforms

open symbols denote below detection limit


46/54

Fecal ColiformsFecal Coliforms

MitsubishiMitsubishi

ZenonZenon

1E+00

1E+01

1E+02

1E+03

1E+04

1E+05

1E+06

1E+07

1E+08

1E+09

0 250 500 750 1000 1250 1500 1750 2000 2250 2500

Time of Operation. h

Concentration,

MPN/100mL

Primary Eff luent Fecal Coliforms MBR Permeate Fecal Coliforms

1E+00

1E+01

1E+02

1E+03

1E+04

1E+05

1E+06

1E+07

1E+08

1E+09

0 250 500 750 1000 1250 1500 1750 2000 2250 2500


Concentration,MP

N/100mL

Primary Effluent Fecal Coliforms MBR Permeate Fecal Coliforms

I di C li h


47/54

IndigenousIndigenous ColiphageColiphage

Mitsubishi

ZenonZenon

1.00E+00

1.00E+01

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

1.00E+08

1.00E+09

0 250 500 750 1000 1250 1500 1750 2000 2250 2500


Concentration

,PFU/100mL

Primary Eff luent Total Coliphage MBR Permeate Total Coliphage

1E+00

1E+01

1E+02

1E+03

1E+04

1E+05

1E+06

1E+07

1E+08

1E+09

0 250 500 750 1000 1250 1500 1750 2000 2250 2500


Concentration,PF

U/100mL

Primary Eff luent Total Coliphage MBR Permeate Total Coliphage

Wh MBR?Wh MBR?


48/54

MBR Effluent Allows Modern Objectives to beMBR Effluent Allows Modern Objectives to be

RealizedRealized

Ideal for UV disinfectionIdeal for UV disinfection All particulate matter and suspended solids thatAll particulate matter and suspended solids that

can interfere with UV have been rejected atcan interfere with UV have been rejected at

membrane barriermembrane barrier

High percentHigh percent transmissivitytransmissivity (>70%)(>70%)

Dose of 80 mJ/cmDose of 80 mJ/cm22 adequate for MBR effluent,adequate for MBR effluent,

while 100 mJ/cmwhile 100 mJ/cm22 required for granular filteredrequired for granular filtered

wastewaterwastewater Ideal pretreatment process for reducing TDSIdeal pretreatment process for reducing TDS

Suitable for direct feed to ROSuitable for direct feed to RO

ChloramineChloramine residual is requiredresidual is required

Why MBR?Why MBR?

Aqua 2000 Bureau StudyAqua 2000 Bureau Study


49/54

0

25

50

75

100

125

150

175

200

0 250 500 750 1000 1250 1500 1750 2000


NetOperatingPre

ssure,psi

0

5

10

15

20

25

30

35

40

Temperatur

e,

C

Net Operating Pressure Temperature

Plant shutdow n

Feed TDS = 1200 mg/L

Aqua 2000 Bureau StudyAqua 2000 Bureau Study[[FilmtecFilmtec BW 30BW 30--4040, low pressure TFC RO membranes]4040, low pressure TFC RO membranes]

11 weeks

Principle Disadvantage of MBRPrinciple Disadvantage of MBR


50/54

Principle Disadvantage of MBRPrinciple Disadvantage of MBR

ProcessProcessAbility to maintain hydraulic capacityAbility to maintain hydraulic capacityAll treated wastewater exiting an MBRAll treated wastewater exiting an MBR

process must pass through the membraneprocess must pass through the membrane

Peak flows arePeak flows area particularlya particularly

significantsignificantissueissue

Cold weatherCold weather

can furthercan furthercomplicate thiscomplicate thisissueissue

Peaking StudiesPeaking Studies


51/54


Peaking studies are commonlyPeaking studies are commonly

performed to estimate the sustainableperformed to estimate the sustainable

flux under wet weather flow scenariosflux under wet weather flow scenarios

These peaking studies are frequentlyThese peaking studies are frequently

performed during dry weatherperformed during dry weather

conditions and not during a stormconditions and not during a stormeventevent

Typically, the flux is increased toTypically, the flux is increased to

mimic storm conditions for a periodmimic storm conditions for a periodof hours or daysof hours or days



52/54


Three significant issues to be aware of:Three significant issues to be aware of:

New membranes do not provideNew membranes do not provide

representative performancerepresentative performance

Temperature influence on TMP needs to beTemperature influence on TMP needs to be

accounted foraccounted forFlux @ 20C Overall Vacuum Pressure

SustainableSustainable

membrane fluxmembrane flux

isis greatlygreatly

influencedinfluencedbyby

mixed liquormixed liquorpropertiesproperties

h l iT h l i


53/54

TechnologiesTechnologiesManufacturers and design engineers are

still learning how to address peak

flows

Store peak flow in equalization tanksStore peak flow in equalization tanks Need adequate spaceNeed adequate space

Generally required for peaking factor >Generally required for peaking factor >

2.52.5

Economics will depend on the specificEconomics will depend on the specific

applicationapplication

Purchase additional membrane capacityPurchase additional membrane capacity

Generally more expensive solution forGenerally more expensive solution for

peaks > 2.5peaks > 2.5

Often preferred by the MBR manufacturerOften preferred by the MBR manufacturer

Design decisions need to be made withDesign decisions need to be made with

extra membranes (e.g. operate or store)extra membranes (e.g. operate or store)


54/54

Break/Questions?Break/Questions?

membrane bioreactors state of the art.original

Documents