Environmental Biotechnology知到智慧树期末考试答案题库2024年秋哈尔滨工业大学

EnvironmentalBiotechnology知到智慧树期末考试答案题库2024年秋哈尔滨工业大学Theretentionandaccumulationofbiomassinbiofilmsystemmainlyrelyon(

).

A:biomasssettlingB:flocformationC:attachtosolidsurfaceD:therecyclingprocess

答案:C:attachtosolidsurfaceWhichofthefollowingistheuniqueoperatingparameterinrotatingbiologicalcontactors(RBC)?(

)

A:thepercentsubmergenceB:BODsurfaceloadingC:hydraulicloadingD:volumetricloading

答案:thepercentsubmergenceThefundamental“law”ofthesteady-statebiofilmhavingthefollowingpropertiesexcept.(

)

A:Neartheoutersurface,isnegative.B:Neartheattachmentsurface,isnegative.C:Thelocationswithpositivegrowthratesareexportingbiomasstothelocationswithnegativebiomass.D:itsaysthatthegrowthofnewbiomassperunitarea（YJ）

isjustbalancedbythelossesperunitarea.

答案:Thehalf-saturationcoefficientKfordissolvedoxygenisgenerallylessthan1mg/L,therefore,dissolvedoxygenshouldbekeptatlesswhatvaluetokeepoxygennon-limiting?(

)

A:0.5mg/LB:1mg/LC:4mg/LD:2mg/L

答案:2mg/LWhichofthefollowingorganismsownsthehighesttrueyieldintheirtypicaloperatingconditions?(

)

A:MethanogensB:DenitrifiersC:NitrifyingautotrophsD:Aerobicheterotrophs

答案:AerobicheterotrophsWhich

ofthefollowinghasarelativelyshortdetentiontime(

).

A:PlugFlow(Conventional)

B:CompletelyMixedC:ContactStabilizationD:StepAeration

答案:ContactStabilizationThevolatilesuspendedsolidsconcentrationfollowsthetrendof(

).

A:BAPB:inertbiomassC:SMPD:activebiomass

答案:activebiomassThepresenceofabundantof

whichisgenerallyconsideredasignofasystemthatisoperatingwellnowandhasbeenstableforsometime.(

)

A:predatorsB:ciliatedprotozoawithstalksC:freeswimmingprotozoaD:predatoreukaryotes

答案:ciliatedprotozoawithstalksWhichofthefollowingstatementsisincorrect?(

)

A:Stoichiometrydefineshowmuchproductandbiomassisproduced.B:NitriteisconsideredinASM1.C:Anabolismisrelatedtotherateofsubstrateuptakebyayield.D:TheinhibitioncausedbyLCFAisignoredinADM1.

答案:NitriteisconsideredinASM1.Themembranebioreactorofferssomeadvantagesincluding:(

).

A:Lowoperatingcost.B:Themembraneeliminatesthepossibilityofuncontrolledbiomasslosstotheeffluent.C:Effluentqualityisimproved.D:Thevolumetricloadingcanbeincreasedtoveryhighlevels.

答案:Effluentqualityisimproved.;Themembraneeliminatesthepossibilityofuncontrolledbiomasslosstotheeffluent.;Thevolumetricloadingcanbeincreasedtoveryhighlevels.Whataretheadvantagesofanaerobicammoniumoxidation(ANAMMOX)comparedtotraditionalnitrogenremovalprocess（

）.

A:NoneedfororganiccarbonB:HighernitrogenremovalrateC:LowersludgeproductionD:Significantsavingsinaerationenergy

答案:Highernitrogenremovalrate###Significantsavingsinaerationenergy###Lowersludgeproduction###NoneedfororganiccarbonWhenusingthepseudo-analyticalprocedureforasteady-statebiofilm,fcanbecomputedtodetermineifthebiofilmisdeeporshallow.Whichofthefollowingstatementiscorrect(

).

A:thebiofilmisdeepwhenf=

1.0.B:thebiofilmisdeepwhenf≠1.0.C:thebiofilmisdeepwhenf<1.0.D:thebiofilmisdeepwhenfapproaches1.0.

答案:thebiofilmisdeepwhenf=

1.0.###thebiofilmisdeepwhenfapproaches1.0.Thefollowingkeythingstousingthesteady-state-biofilmmodelaredescribedcorrectly(

).

A:thereisauniqueXfLf

foranyS>Smin.B:alargeS*min

indicatesthatbiofilmaccumulationstronglylimitssubstrateutilization.C:JhasanuncertainvalueforallS>Smin.D:asmallK*

valueindicatesthatexternalmasstransportisamajordeterminantofsubstrateflux.

答案:A,DWhichofthefollowingstatementsiscorrectaboutthecharacteristicsoftwo-stageanaerobictreatment:(

).

A:Theoverallvolumeofthetwo-phasesystemislessthanforaconventionalone-reactorCSTR.B:Thelimitingstepinbiomassconversiontomethaneisthehydrolysis.C:ThesludgeorothercomplexorganicsubstrateisfirsttreatedinaCSTRthathasashortdetentiontime,1to2d.D:Theliquidretentiontimeofthesecondreactornormallyis8to10d.

答案:ThesludgeorothercomplexorganicsubstrateisfirsttreatedinaCSTRthathasashortdetentiontime,1to2d.###Theliquidretentiontimeofthesecondreactornormallyis8to10d.###Theoverallvolumeofthetwo-phasesystemislessthanforaconventionalone-reactorCSTR.Whichofthefollowingstatementsaboutnitrificationistrue?（

）

A:Thecontentofdissolvedoxygeninnitrificationshouldbelessthan0.5mg/LB:ThesludgeageofnitrificationmustbegreaterthanitsminimumgenerationperiodC:Nitrifyingbacteriaareautotrophicbacteria,toohighconcentrationoforganicmatterinthereactionprocesswillcausetoxicitytotheactivityofnitrifyingbacteriaD:NitrificationconsumesalkalinityandlowersthepHofthesystem

答案:Thesludgeageofnitrificationmustbegreaterthanitsminimumgenerationperiod###NitrificationconsumesalkalinityandlowersthepHofthesystemTheselectionofmixed-liquorsuspendedsolidsconcentrationdependsupon(

).

A:settlingcharacteristicsoftheactivatedsludgeB:SolidsRetentionTimeC:thedesignofthesettlingtankD:therateofrecycleofsludgefromthesettlingtankbacktotheaerationtank

答案:settlingcharacteristicsoftheactivatedsludge;SolidsRetentionTime;thedesignofthesettlingtank;therateofrecycleofsludgefromthesettlingtankbacktotheaerationtankWhichofthefollowingcanbeusedasindicatorstoindicatethesystemhasalongSRT.(

)

A:ProtozoaB:RotifersC:othermulticellularformsD:nematodes

答案:Rotifers###othermulticellularforms###nematodesWhichfactorscouldaffectthesubstratefluxinbiofilmsystem(

).

A:PresenceofinhibitorsB:pHC:TemperatureD:Mediumtexture

答案:Temperature;pH;PresenceofinhibitorsDisadvantagesofanaerobictreatmentinclude

(

)

.

A:Lowgrowthrateofmicroorganisms.B:Lowproductionofwastebiologicalsolids.C:Poorremovalefficiencywithdilutewastes.D:HighbufferrequirementforpHcontrol.

答案:Lowgrowthrateofmicroorganisms.###HighbufferrequirementforpHcontrol.###Poorremovalefficiencywithdilutewastes.Theperformanceofananaerobicsludgedigestercan

measuredby:(

).

A:Themethane-gasyield.B:Biodegradablesolidsdestruction.C:Thenetsludgeproduction.D:StabilizingtheBODtomethane.

答案:Thenetsludgeproduction.###Biodegradablesolidsdestruction.Whichofthefollowingmeasurescouldpreventmassivedetachmentofbiofilm(

).

A:decreasetheairventilationB:aproperspeedofrotarydistributionarmsC:keepadequateairventilationD:decreasethehydraulicloading

答案:decreasethehydraulicloading###decreasetheairventilation###aproperspeedofrotarydistributionarmsAllmicrobialreactionsareassumedtooccurinthebiofilmandsuspendedflocswhenwewanttoapplythesteadystatebiofilmmodelinInthecompletelymixedbiofilmreactor(CMBR).(

)

A:错B:对

答案:错Theearlyliteratureindicatedaerationbasinsforsewagetreatmentshouldhavea6hhydraulicdetentiontime,aBODloadingof1.6kg/m3.doraMLSSconcentrationbetween1,200and3,000mg/L.（

）

A:对B:错

答案:错Fornormalbiofilmprocessoperation,theoperatingfluxliesinthehigh-loadregion.(

)

A:错B:对

答案:对Aspecialcaseofshallowiscalledfullypenetratedwhenthesubstrateconcentrationhasnegligiblegradient.(

)

A:对B:错

答案:对Threedistinctcausesofsludgebulking:lowdissolvedoxygen,shortSRT,andinputreducedsulfur.（

）

A:错B:对

答案:错Biomassitselfcanbeusedaselectrondonorindenitrification.

(

)

A:错B:对

答案:对Sulfatereducersdivertelectronequivalentsawayfrommethanewhentheyproducesulfides.(

)

A:对B:错

答案:对Nitrogensourceistheonlyfactorthataffectscellsynthesisequation(RC).(

)

A:对B:错

答案:B:错Denitrificationcanonlybecarriedoutinanaerobiccondition.(

)

A:对B:错

答案:错TheremovalofBODL

orwastestabilizationtotallydependsonmethaneformation.(

)

A:错B:对

答案:对Oneofthecharacteristicsofthedeepbiofilmsisthesubstrateconcentrationapproacheszeroatsomepointinthefilm.(

)

A:对B:错

答案:A:对Anaerobictreatmentisgenerallyanetproducerofenergy.(

)

A:对B:错

答案:对Theclosejuxtapositionofcellsinabiofimisimportantfortheexchange.(

)

A:错B:对

答案:对S*min,K*,andS*ofthesteady-state-biofilmsolutionarethreedimensionlessvariablesconsolidatingtheinformationofeightvariables(,K,Y,b’,Df,D,L,S).

(

)

A:错B:对

答案:对Inthecompletelymixedbiofilmreactor(CMBR)，activebiomassinthereactorandtheeffluentisatconcentrationXa

andcomessolelyfromdetachmentfromthebiofilm.(

)

A:错B:对

答案:对Trytoestablishthestoichiometrymatrixusingthefollowingcomponentsandprocesses.Components:Particlesubstrate(XP),Solublesubstrate(SS),Acetate(Sac),Solublemethane(Sch4),fermenter(Xf),andmethanogen(Xm).Processes:1.

HydrolysisofXP

withaparameterofkhyd,p;2.

ConsumptionofSS

toproduceacetatebyfermenters(maximumspecificuptakeratekm,S,semi-saturationconstantKS,S);3.

ConsumptionofSac

toproducemethanebymethanogens(maximumspecificuptakeratekm,ac,semi-saturationconstantKS,ac,yieldYm);4.

DecayofXf

(kdec,Xf);5.

DecayofXm(kdec,Xm);

答案:StoichiometryMatrix:|Processes|XP|SS|Sac|Sch4|Xf|Xm||---|---|---|---|---|---|---||HydrolysisofXP|-1|1|0|0|0|0||ConsumptionofSSbyfermenters|0|-1|1|0|0|0||ConsumptionofSactoproducemethanebymethanogens|0|0|-1|1|0|0||DecayofXf|0|0|0|0|-1|0||DecayofXm|0|0|0|0|0|-1|Pleasedrawtheschematicdiagramoffivebasicprocessconfigurationsandintroducethecharacteristicsofeachconfiguration.

答案:1.Theoriginalorconventionalactivatedsludgesystemshadlongnarrowaerationtanksinwhichthewastewaterentersatoneendexitsthroughtheother.Intuitively,plugflowwouldappeartobethebestapproach,asitshouldhavethegreatestcontaminantremovalwithinadefinedtreatmenttime.Contaminantconcentrationishighestattheentrancetotheaerationtankanddecreaserapidlywithinthefirstlengthoftheaerationtank.Oxygendemandisherethehighest.2．Step-aeration,alsocalledstepfeeding(amoreaccuratedescriptor),wasdevelopedasameanstocircumventsomeoftheproblemoftheplug-flowapproach.Sincethetwoproblemsresultfromhighconcentrationsofcontaminantsattheheadendofaerationbasin,highconcentrationatanyonelocationareavoidedbydistributingtheinfluentalongthelengthofthereactorinsteps.Theconcentrationofaninfluentcontaminantisdilutedmuchmore,andtheoxygen-uptakerateisspreadout.3.Acomplete-mixsystemismostfavorablewithwastewaterscontainingbiodegradablematerialsthatalsoaretoxictomicroorganismsatmodestconcentrations.Theeffluentsolublecontaminantconcentrationisuniformandlowthroughoutthereactor,themicroorganismsneverareexposedtotheinfluentconcentrationofacontaminant.4.ContactStabilizationWastewaterismixedwithreturnactivatedsludgeinacontacthavingarelativelyshortdetentiontime.Thetreatedwastewaterthenflowsintothefinalsettlingtank,wheretheactivatedsludgeandtreatedwastewaterareseparatedfromoneanother.Thewastewaterisdischarged,andthesettledandconcentratedactivatedsludgeissenttoasecondreactortermedthestabilizationtank,whereaerationiscontinued.Here,adsorbedorganicparticles,storedsubstrates,andbiomassareoxidized.Thebiggestadvantageofcontactstabilizationsystemisthereductioninoverallreactorvolume.Onedisadvantageofcontactstabilizationisthatitrequiressubstantiallymoreoperationalskillandattention.5.ActivatedsludgewithaselectorThemostfrequentcauseoffailureofactivatedsludgesystemsissludgebulking,orasludgethatdoesnotcompactwellinthesettlingtank.Oneoftheinnovationsistoaddaselectortankpriortotheaerobicreactor.Returnactivatedsludgeiscontactedwiththewastestreamforonly10to30minunderconditionsinwhichcompleteBODoxidationisimpossible.Thefunctionoftheselectoristochangeorselecttheecologyoftheactivatedsludgesystemtowardsorganismswithgoodsettlingcharacteristics.Whatisthesteady-statebiofilm?

答案:Thebiomassperunitsurfaceareaisconstantinthetime,eventhoughthebiomassatanyonelocationisnotsteadystate.或者/zhs/teacherExam_h5/COMMONUEDITOR/202103/d7e12b582b6e44a9b68228d1dc23146c.png

答案:Describethethreebasicstrategiesforpreservingorganicelectrondonorsduringnitrification.

答案:1.LimitingOxygenExposure2.TemperatureControl3.pHManagementWhymostbiofilmsystemsworkwellfordenitrification

?

答案:Denitrificationisoneoftheeasiestapplicationsforawidevarietyofbiofilmsystems.BrieflydescribeASM1,ASM2,ASM2d,andASM3.

答案:ASM1:ActivatedSludgeModelNo.1(ASM1)ASM2:ActivatedSludgeModelNo.2ASM2d:ActivatedSludgeModelNo.2withDynamicGrowthRateASM3:ActivatedSludgeModelNo.3Pleaseexplainwhytheintroductionofbiofilmmediainactivatedsludgeprocesswouldpromotethewastewatertreatmentcapacity.

答案:Biofilmmediaintroductioninactivatedsludgeprocessenhanceswastewatertreatmentcapacitydueto:1.**Increasedsurfaceareaformicrobialattachment**:Biofilmmediaprovidealarge,structuredsurfaceformicroorganismstocolonize,formingdensebiofilms.Thissignificantlyincreasestheoverallsurfaceareaavailableforbiologicalreactionscomparedtosuspendedbiomassalone,allowingforhighermicrobialpopulationsandthusgreatersubstrateuptakeandpollutantdegradation.2.**Improvedretentionofbiomass**:Biofilmsystemshelpretainbiomasswithinthereactor,reducingwashoutof微生物underhighhydraulicloadsorvariationsinflowconditions.Thisensuresastableandconcentratedmicrobialcommunitycontinuouslyworkingonwastewatertreatment,evenathigherorganicloadingrates.3.**Enhancedsubstrateutilizationandmetabolicdiversity**:Biofilmsharbordiversemicrobialcommunitieswithdifferentphysiologicalcapabilities,whichcanutilizeabroaderrangeofsubstratesmoreefficiently.Thisleadstobetterdegradationofcomplexorrefractorycompoundsandimprovednutrientremoval(e.g.,nitrogenandphosphorus).4.**Protectionfromenvironmentalstress**:Thebiofilmmatrixshieldsmicroorganismsfromtoxicsubstances,fluctuationsintemperature,pH,anddissolvedoxygenlevels,enablingthemtowithstandadverseconditionsthatmightotherwiseinhibittheiractivityinsuspendedgrowthsystems.Thisresiliencecontributestomoreconsistenttreatmentperformance.5.**Potentialforsimultaneousnitrification-denitrification(SND)**:Incertainbiofilmconfigurations,aerobicandanaerobiczonescancoexistwithinthesamebiofilm,facilitatingSNDwithouttheneedforseparatereactorsoroperationalstages.Thiscanleadtoenhancednitrogenremovalefficiencyandreducedenergyconsumptionforaeration.6.**Reducedsludgeproduction**:Biofilmprocessesoftengeneratelessexcesssludgecomparedtoconventionalactivatedsludgesystems,asbiomassgrowspredominantlyonthemediaratherthanbeingproducedasfreelysuspendedflocs.Lowersludgeproductiontranslatestolowersludgehandling,treatment,anddisposalcosts.Insummary,theintroductionofbiofilmmediainanactivatedsludgeprocesspromoteswastewatertreatmentcapacitybyincreasingavailablesurfaceareaformicrobialgrowth,improvingbiomassretention,fosteringmetabolicdiversity,providingenvironmentalprotectiontomicroorganisms,enablingsimultaneousnitrification-denitrification,andpotentiallyreducingsludgeproduction.Canyouintroducetheeffectofairsparginginthree-phasesystemoffluidizedbed?

答案:Enhancedgas-solidcontact,improvedmasstransfer,andenhancedfluidizationqualityTreatinganindustrialwastewaterwithaflowof104

m3/dandBODL

of20000mg/L.Computingthevolumeofmethanegasgeneratedifthewastestabilizationis90precent.Also,computingtheenergyvalueofthatmethane.

答案:Volumeofmethanegasgenerated:56.7m³/dayEnergyvalueofthatmethane:84,.pngkWh/dayPleasebrieflydescribethecrucialstepsduringanaerobicreactorstart-up.

答案:Thecrucialstepsduringstart-upare:Beginwithasmuchgoodanaerobicseedaspossible;Fillthedigesterwiththisseedandwater;Bringthesystemtotemperature;AddbufferingmaterialintheformofachemicalsuchassodiumbicarbonatetoprotectagainstpHdrop;Addasmallamountoforganicwastesufficienttolettheorganicacidcontentfromfermentationreachnomorethanabout2000to4000mg/L,whilekeepingpHbetween6.8and7.6.Whatisthebiofilm?

答案:Biofilmisacomplex,structuredcommunityofmicroorganisms,typicallybacteriaorfungi,embeddedwithinaself-producedextracellularmatrixthatadherestoalivingornon-livingsurface.PointoutthekeyfeaturesofSMP.

答案:SymmetricMultiprocessing(SMP)referstoacomputerarchitecturewheretwoormoreidenticalprocessors,connectedthroughasharedmemorybus,worksimultaneouslyandindependentlyondifferenttasksorpartsofatask.ThekeyfeaturesofSMPinclude:1.MultipleProcessors:SMPsystemsincorporatetwoormoreidenticalprocessors,typicallyofthesametypeandspeed.2.SharedMemory:Allprocessorshaveequalaccesstoacommonphysicalmemory,allowingthemtoreadfromandwritetoanylocationinthememorywithoutrestrictions.3.CacheCoherence:Tomaintaindataconsistency,SMPsystemsemploycachecoherenceprotocols,ensuringthatwhenoneprocessorupdatesamemorylocation,allotherprocessors'cachesreflectthischangepromptly.4.SymmetricNature:EachprocessorinanSMPsystemhasequivalentcapabilitiesandresponsibilities,executingbothuser-levelapplicationsandoperatingsystemcode.Theycanrunanyprocessorthread,andthereisnodistinctionbetweena"master"or"slave"processor.5.Inter-ProcessorCommunication(IPC):SMPsystemsusevariousmechanismsforinter-processorcommunication,suchasinterrupts,sharedmemoryflags,andmessagepassing,tocoordinatetasks,s