Nitrification and Denitrification - Indigo Water Group, Classes/Nitrification and...Agenda yUnit Processes forfor Nitrification yDefine Biological Denitrification 9Chemical equations

  • View
    218

  • Download
    0

Embed Size (px)

Text of Nitrification and Denitrification - Indigo Water Group, Classes/Nitrification and...Agenda yUnit...

  • SidneyInnerebner,PhD,PESidneyInnerebner,PhD,PEIndigoWaterGroupIndigoWaterGroup

    sidney@indigowatergroup.comsidney@indigowatergroup.comwww.indigowatergroup.comwww.indigowatergroup.com

    30330348948992269226

  • AgendaAgendaSourcesandTypesofNitrogenSourcesandTypesofNitrogen

    NeedforNitrogenRemovalNeedforNitrogenRemovalgg

    Physical/ChemicalNitrogenRemovalPhysical/ChemicalNitrogenRemoval

    DefineBiologicalNitrificationDefineBiologicalNitrificationChemicalequations(stoichiometry)Chemicalequations(stoichiometry)

    OrganismsinvolvedOrganismsinvolved

  • AgendaAgendaUnitProcessesforNitrificationUnitProcessesforNitrification

    DefineBiologicalDenitrificationDefineBiologicalDenitrification

    ChemicalequationsChemicalequations(stoichiometry)(stoichiometry)(stoichiometry)(stoichiometry)

    OrganismsinvolvedOrganismsinvolvedUnitProcessesforDenitificationUnitProcessesforDenitification

  • S d f iSourcesandTypesofNitrogen

  • Quantities16 grams/cap/day.g p y20 to 85 mg/L influent concentrations typical.

    Recycle StreamsDigester supernatantBelt press filtrate

    T i l FTypical Forms40% organic 60% ammonia

    Ammonification60% ammonia

  • RuleofThumbRuleofThumbRatioofTKN/BODRatioofTKN/BOD55 fordomesticfordomesticwastewateris0.1to0.2wastewateris0.1to0.2wastewateris0.1to0.2wastewateris0.1to0.2HigherratiosmayindicateHigherratiosmayindicate

    RecycleStreamsRecycleStreamsS i d/S i d/

    If BOD5 is 250 mg/L, then TKN should be

    Septic,and/orSeptic,and/orIndustrialIndustrialWasteWaste

    TKN/NH3TKN/NH3Nisabout0.65Nisabout0.65(250)(0.1) = 25 mg/L

    (250)(0.2) = 50 mg/LTKN = Total Kjedahl Nitrogen

    / 3/ 3 55

    (250) (0.2) 50 mg/L

    Ammonia = 16 33 mg/L

  • Nitrogen Gas (N2)Nitrogen Gas (N2)

    Nitrate (NO3 ) AnalysisAnalysisNitrate (NO3 )

    Nitrite (NO2 )TIN

    Analysis MethodsAnalysis Methods

    Nitrite (NO2 )

    Ammonia (NH3)

    TIN

    Ammonia (NH3)

    Organic NitrogenTKN

    Organic Nitrogen

  • Need for Nitrogen RemovalNeed for Nitrogen RemovalNeedforNitrogenRemovalNeedforNitrogenRemoval

  • TypesofAmmoniaTypesofAmmoniaTransfer,Transfer,Removal,andConversionRemoval,andConversion,,

    NHNH33NStrippingNStripping

    IonExchangeIonExchange

    B k i tChl i tiB k i tChl i tiBreakpointChlorinationBreakpointChlorination

    NaturalWetlandsNaturalWetlands

    BiologicalNitrificationBiologicalNitrification

  • NHNH33NStrippingNStrippingll l d d l lll l d d l lReallyonlyusedinindustrialapplications.Reallyonlyusedinindustrialapplications.

    AmmoniumionpredominantinWastewaterAmmoniumionpredominantinWastewater

    ConverttogaseousNHConverttogaseousNH33NNbyraisingpHupto10.5byraisingpHupto10.5 11.5S.U.11.5S.U.

  • NHNH33NStrippingNStripping

    AtpH11and25AtpH11and25C,C,gaseousformis~98%gaseousformis~98%gaseousformis~98%gaseousformis~98%

    StrippingtowerwithStrippingtowerwithh h fl h h fl highairflowtostriphighairflowtostrip

    Same principal behind ion Same principal behind ion selective electrode test.selective electrode test.

  • H

    IonExchangeIonExchangeH N H

    H

    Typicallyusedforsmallflows.Typicallyusedforsmallflows.

    WastewaterpassesoverresinbedWastewaterpassesoverresinbedWastewaterpassesoverresinbedWastewaterpassesoverresinbedcontainingionsofsamecharge.containingionsofsamecharge.

    h d h dAmmoniaionsareexchangedAmmoniaionsareexchangedforionsonresin,typicallyforionsonresin,typicallysodiumsodium Nasodium.sodium.

    Resinbedsmustberegenerated.Resinbedsmustberegenerated.

    +

  • IonExchangeIonExchange

  • BreakpointChlorinationBreakpointChlorination

    NHNH33NcanbeconvertedNcanbeconvertedtoNtoN withClwithCltoNtoN22 withClwithCl22

    ClCl22/NH/NH33NratioofNratioof 10:110:122// 33neededneeded

    EXPENSIVEEXPENSIVE EXPENSIVEEXPENSIVE useauseapolishingsteppolishingstep

  • NaturalWetlandsNaturalWetlandsPlantssuchashyacinthorPlantssuchashyacinthorduckweedgrowninlagoonduckweedgrowninlagoonsystems.systems.yy

    PlantsuseammoniaasaPlantsuseammoniaasanitrogensource(fertilizer).nitrogensource(fertilizer).

    NitrogenisincorporatedintoNitrogenisincorporatedintobiomass.biomass.

    PeriodicharvestingofplantsPeriodicharvestingofplantsremovesnitrogenfromtheremovesnitrogenfromthesystemsystemsystem.system.

  • NaturalWetlands FreeSurface

    Assimilative nutrient removal onlyAssimilativenutrient removalonly Removes verylittleammonia

  • NaturalWetlands:Subsurface FlowSubsurfaceFlow

    Nitrifying bacteriagrowhere Removes ammonia well when warm Removesammonia wellwhenwarm

  • Duckweed

  • DefineBiologicalNitrificationDefineBiologicalNitrificationTwoTwostepconversionofNHstepconversionofNH33NtoNtoNONO NNNONO33N.N.

    NitrificationiscarriedoutbytwoNitrificationiscarriedoutbytwounrelatedgroupsoforganisms.unrelatedgroupsoforganisms.

    AmmoniaAmmoniaoxidizingbacteria oxidizingbacteria AmmoniaAmmonia oxidizingbacteria,oxidizingbacteria,NitrosomonasNitrosomonas

    NitriteNitrite oxidizingbacteria oxidizingbacteria NitrobacterNitrobacterNitriteNitriteoxidizingbacteria,oxidizingbacteria,NitrobacterNitrobacter

  • DefineBiologicalNitrificationDefineBiologicalNitrification

    NitrosomonasNitrosomonas convertammoniatoconvertammoniatonitrite.nitrite.nitrite.nitrite.

    NitrobacterNitrobacter covertnitritetonitrate.covertnitritetonitrate.

    OverallOverallStoichiometricStoichiometric Equation:Equation:1 0NH1 0NH ++ +1 8O+1 8O +0 8CO+0 8CO1.0NH1.0NH44 +1.8O+1.8O22 +0.8CO+0.8CO220.02C0.02C44HH77OO22N+1.0HN+1.0H22O+1.0NOO+1.0NO33 ++2.0H2.0H++

  • BiologicalNitrificationBiologicalNitrificationC fOC fO d fd fConsumes4.33gramsofOConsumes4.33gramsofO22 and7.14gramsofand7.14gramsofalkalinitypergramofNHalkalinitypergramofNH33NoxidizedNoxidized

    Forms0.15gramsofnewcellspergramofNHForms0.15gramsofnewcellspergramofNH33NoxidizedNoxidized

    Consumes0.08gramsofinorganicCarbonperConsumes0.08gramsofinorganicCarbonpergramofNHgramofNH33NoxidizedNoxidizedgg 33

    Organicloadingtoprocessalsoafactor.Organicloadingtoprocessalsoafactor.NitrifierscantcompetewithheterotrophsNitrifierscantcompetewithheterotrophsNitrifierscan tcompetewithheterotrophs.Nitrifierscan tcompetewithheterotrophs.

  • BiologicalNitrificationProcessesBiologicalNitrificationProcessesS d dG hS d dG hSuspendedGrowthSuspendedGrowth

    ActivatedSludgeActivatedSludgeFi dFil Att h dG thFi dFil Att h dG thFixedFilmorAttachedGrowthFixedFilmorAttachedGrowth

    TricklingFilters(tertiary)TricklingFilters(tertiary)RotatingBiologicalContactors(RBCs)RotatingBiologicalContactors(RBCs)RotatingBiologicalContactors(RBCs)RotatingBiologicalContactors(RBCs)BiologicalAeratedFilters(BAFs)BiologicalAeratedFilters(BAFs)

    HybridProcessesHybridProcessesyyKaldnesKaldnes,,RinglaceRinglace,etc.,etc.

  • ConventionalActivatedSludgeConventionalActivatedSludgeNitrificationratesNitrificationratesrelativelylow.relativelylow.relativelylow.relativelylow.Air(andelectricalAir(andelectricaldemand)high.demand)high.) g) gOperatorintensive.Operatorintensive.Flexible.Flexible. EasytoexpandEasytoexpandFlexible.Flexible. EasytoexpandEasytoexpandforlaterforlaterdenitrificationdenitrification..

  • ActivatedSludgeNitrificationMCRT>5days

    MLSSincreaseswithMLSSincreaseswithMCRT

    Wh MLSSi hi h WhenMLSSistoohigh,clarifierisoverloaded.

    Reallyoldsludgecanhaveotherproblems!

  • ActivatedSludgeNitrificationActivatedSludgeNitrificationRequireshigherMCRT,>5daysRequireshigherMCRT,>5daysColdertempsmeanlongerMCRTsColdertempsmeanlongerMCRTsp gp gMaintainDOnear2mg/LMaintainDOnear2mg/LDangerofDangerofdenitrificationdenitrification inclarifierinclarifiergg

    ashingashingorpoppingblanketorpoppingblanketMostactivatedsludgeconfigurationsareMostactivatedsludgeconfigurationsareMostactivatedsludgeconfigurationsareMostactivatedsludgeconfigurationsarecapableofsupportingnitrificationcapableofsupportingnitrification

  • Ashing andFloating SludgeFloatingSludge

  • Fixed Film ProcessesFixed Film ProcessesFixedFilmProcessesFixedFilmProcesses

  • T ti Nit ifi tiTertiaryNitrification

    NHNH33NN

    NONO33NN

    Secondary Clarifier Effluent

  • WastewaterWastewaterCharacteristics That CanCharacteristics That CanCharacteristicsThatCanCharacteristicsThatCanImpactNitrificationImpactNitrification

  • MeanCellResidenceTimeMeanCellResidenceTimeH l h th ll b i th H l h th ll b i th HowlonghavethecellsbeenintheHowlonghavethecellsbeeninthesystem?system?

    l l bl l bCalculatebyCalculatebyTakethetotalamountofsolidsintheTakethetotalamountofsolidsinthesystem(aerationbasin+clarifier).system(aerationbasin+clarifier).DividebytheamountofsolidsDividebytheamountofsolidswastedperday.wastedperday.

    AerationBasin Clarifier

  • MeanCellResidenceTimeMeanCellResidenceTimeGenerallyanMCRT>5daysisGenerallyanMCRT>5daysisneededforstablenitrification.neededforstablenitrification.

    Nitrifyingbacteriagrowvery,veryNitrifyingbacteriagrowvery,veryslooowlyslooowly..

    Ni ifi i i fi dfil Ni ifi i i fi dfil NitrificationinfixedfilmprocessesNitrificationinfixedfilmprocessesfollowsadifferentsetofrules.followsadifferentsetofrules.

  • TemperatureTemperatureNitrificationcantakeplacebetweenNitrificationcantakeplacebetween10and35degreesC.10and35degreesC.RatesincreaseastemperatureRatesincreaseastemperatureincreases.increases.Below5degreesC,nitrificationBelow5degreesC,nitrificationessentiallystops.essentiallystops.ActivatedsludgeprocessesaremoreActivatedsludgeprocessesaremoresusceptibletotemperatureeffectssusceptibletotemperatureeffectsh f d f lh f d f lthanfixedfilmsystems.thanfixedfilmsys

View more >