1、BRITISH STANDARD BS EN 12255-15:2003 Wastewater treatment plants Part 15: Measurement of the oxygen transfer in clean water in aeration tanks of activated sludge plants The European Standard EN 12255-15:2003 has the status of a British Standard ICS 13.060.30 BS EN 12255-15:2003 This British Standard
2、, was published under the authority of the Standards Policy and Strategy Committee on 17 December 2003 BSI 17 December 2003 ISBN 0 580 43094 4 National foreword This British Standard is the official English language version of EN 12255-15:2003. The UK participation in its preparation was entrusted t
3、o Technical Committee B/505, Waste water engineering, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this
4、document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contr
5、act. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals fo
6、r change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 16, an inside back cover and a back cover. The BSI copyrig
7、ht notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN1225515 December2003 ICS13.060.30 Englishversion WastewatertreatmentplantsPart15:Measurementofthe oxygentransfe
8、rincleanwaterinaerationtanksofactivated sludgeplants StationsdpurationPartie15:Mesuredeperformances desarateurs KlranlagenTeil15:MessungderSauerstoffzufuhrin ReinwasserinBelftungsbeckenvonBelebungsanlagen ThisEuropeanStandardwasapprovedbyCENon3November2003. CENmembersareboundtocomplywiththeCEN/CENEL
9、ECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthree
10、officialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,Fra
11、nce,Germany,Greece, Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Slovakia,Spain,Sweden,SwitzerlandandUn ited Kingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2003CEN Allri
12、ghtsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN1225515:2003EEN1225515:2003(E) 2 Contents page Foreword. 3 1 Scope . 4 2 Normativereferences . 4 3 Termsanddefinitions. 4 4 Symbolsandabbreviations . 5 5 Principleandprocedures . 6 6 Aerationtanks,testwater,equ
13、ipmentandchemicals 7 6.1 Aerationtanksandaerationinstallations . . 7 6.2 MeasuringEquipment . . 7 6.2.1 Dissolvedoxygenprobes(DOprobes) . . 7 6.2.2 Recordingofthedissolvedoxygenconcentration . 8 6.2.3 Temperaturemeasurement. . 8 6.3 Chemicals 8 6.3.1 Sodiumsulphite . . 8 6.3.2 Cobaltcatalyst. 8 6.3.
14、3 Nitrogenandpureoxygengas 8 6.4 Testwater 8 7 Procedure 9 7.1 Planningoftesting. . 9 7.2 Advancepreparationandresponsibilities . 9 7.3 Fillingofthetankwithtestwater. . 10 7.4 InstallationoftheDOprobes. 10 7.5 Additionofchemicals. 11 7.5.1 Cobaltcatalyst. 11 7.5.2 Sodiumsulphite . . 11 7.6 Gasinject
15、ion. . 12 7.7 Datacollectionduringatest. . 12 7.8 Dataanalysis . 13 8 Precisionandaccuracyofresults. 13 8.1 Standardoxygentransferrate. 13 8.2 Standardaerationefficiency 13 8.3 Specificstandardoxygentransferefficiency 14 9 Presentationandinterpretationoftheresults .14 AnnexA (normative) Alternativet
16、estandevaluationprocedure . 15 A.1 Principle. 15 A.2 Measurementoftheoxygensaturationvalue 15 A.3 InsitucalibrationoftheDOprobes 15 A.4 Determinationoftheoxygentransfercoefficient 15 Bibliography . 16EN1225515:2003(E) 3 Foreword Thisdocument(EN1225515:2003)hasbeenpreparedbyTechnicalCommitteeCEN/TC16
17、5“Wastewater engineering”,thesecretariatofwhichisheldbyDIN. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofanidentical textorbyendorsement,atthelatestbyJune2004,andconflictingnationalstandardsshallbewithdrawnat thelatestbyJune2004. ItisthefifteenthPartpreparedbythe
18、WorkingGroupsCEN/TC165/WG42and43relatingtothegeneral requirementsandprocessesfortreatmentplantsforatotalnumberofinhabitantsandpopulationequivalents (PT)over50.EN12255withthegenerictitle“Wastewatertreatmentplants“consistsofthefollowingParts: Part1:Generalconstructionprinciples Part3:Preliminarytreatm
19、ent Part4:Primarysettlement Part5:Lagooningprocesses Part6:Activatedsludgeprocess Part7:Biologicalfixedfilmreactors Part8:Sludgetreatmentandstorage Part9:Odourcontrolandventilation Part10:Safetyprinciples Part11:Generaldatarequired Part12:Controlandautomation Part13:ChemicaltreatmentTreatmentofwaste
20、waterbyprecipitation/flocculation Part14:Disinfection Part15:Measurementoftheoxygentransferincleanwaterinaerationtanksofactivatedsludgeplants Part16:Physical(mechanical)filtration NOTE Forrequirementsonpumpinginstallationsatwastewatertreatmentplants,providedinitiallyas Part2: Pumpinginstallationsfor
21、wastewatertreatmentplants ,seeEN7526 Drainandsewer systemsoutsidebuildingsPart 6:Pumpinginstallations . ThepartsEN122551,EN122553toEN122558andEN1225510andEN1225511wereimplemented togetherasaEuropeanpackage(ResolutionBT152/1998). AnnexAisnormative. AccordingtotheCEN/CENELECInternalRegulations,thenati
22、onalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,CzechRepublic,Denmark, Finland,France,Germany,Greece,Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands, Norway,Portugal,Slovakia,Spain,Sweden,SwitzerlandandtheUnitedKingdom.EN1225515:20
23、03(E) 4 1Scope ThisEuropeanStandardspecifiesthenonsteadystatemeasurementoftheoxygentransferrateandthe oxygentransferefficiencyofaerationsystemsinactivatedsludgeaerationtanks(seeEN12 2556)whenfilled withcleanwater. NOTE1 Thisisknownasthecleanwatertest. NOTE2 Sincethemethodisbasedoncompletelymixedtank
24、sortankswithevenlydistributedaeratorsordiffusers testresultsfromcertainaerationinstallationscanbeincorrect. NOTE3 Underprocessconditionswithmixedliquortheoxygentransferrateandtheoxygentransferefficiencycanbe differentfromthecleanwatertestresults.Thisisexpressedbythe a factor. 2 Normativereferences T
25、hisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromotherpublications. Thesenormativereferencesarecitedattheappropriateplacesinthetext,andthepublicationsarelisted hereafter.Fordatedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicationsapplyto thisEuropeanStandardonly
26、whenincorporatedinitbyamendmentorrevision.Forundatedreferencesthe latesteditionofthepublicationreferredtoapplies(includingamendments). EN1085, WastewatertreatmentVocabulary. EN25814, Water quality Determination of dissolved oxygen Electrotechnical probe method (ISO5814:1990). 3 Termsanddefinitions F
27、orthepurposesofthisEuropeanStandard,thetermsanddefinitionsgiveninEN1085andthefollowing apply. 3.1 standardoxygentransferrate(SOTR,kg/h) massofoxygentransferredperhouratstandardconditions(watertemperature T=20 C,barometric pressurep=1013hPa,zerodissolvedoxygenconcentration),toanaerationtankfilledwith
28、cleanwater (Volume V,m)equippedwithanaerationdeviceorsystemandoperatedataspecifiedaerationsetting.Itis obtainedas: 1000 20 , 20 S L C a k V SOTR = (1) 3.2 standardaerationefficiency(SAE,kg/kWh) ratioofstandardoxygentransferrateandtotalwirepoweruptake( P,kW)measuredduringthetest 3.3 specificstandardo
29、xygentransferefficiency (SSOTE,%/m) percentoxygenabsorbedpermetrediffusersubmergence( h D ,m).SSOTEmayalsobeexpressedin g/(mm) 1 1 Thevolumeexpressedinm 3 isapplicabletostandardconditions(dryair,zerohumidity,p=1013hPa,T=0C),seealso 3.9.EN1225515:2003(E) 5 () m % 299 , 0 100 A D = Q h SOTR SSOTE (2)
30、or () m) g/(m h Q SOTR SSOTE 3 D A = 1000 (3) 3.4 oxygentransfercoefficient( k L a T ,h 1 ) determinedbyevaluationofanoxygentransfertestincleanwateratacertainaerationsettingandatacertain temperature.Itisconvertedtothestandardtemperatureof T=20Casfollows: () T 20 T L 20 L 024 , 1 = a k a k (4) 3.5 st
31、andardoxygensaturationvalue( C S,St,T ,mg/l) aslistedinEN25814for p St =1013hPa,e.g.: C S,St,20 =9,09mg/l 3.6 testoxygensaturationvalue( C S,p*,T ,mg/l) oxygensaturationvalueofanoxygentransfertestincleanwaterataspecificwatertemperature( T,C)anda specificbarometricpressure( p*,hPa).Thetestoxygensatur
32、ationvalueisconvertedtostandardconditions asfollows: ) / ( ) / ( , * St T St, S, St,20 S, T p S, S,20 * p p C C C C = (5) 3.7 middepthoxygensaturationvalue( C S,md,20 ,mg/l) fordiffusedairaerationthemiddepthoxygensaturationvalueforstandardconditionsiscalculatedasfollows (10,35mofwaterisequivalentto1
33、013hPa): () 10,35) 2 ( / 1 D St,20 S, md,20 S, + = h C C (6) 3.8 diffusersubmergence( h D ,m) depthbelowthewaterlevelofairreleasefromthediffuserwithoutaerationoperating 3.9 normalairflowrate( Q A ,m/h) airflowratedeliveredtotheaerationtank,correctedforstandardconditions(dryair,zerohumidity, p=1013hP
34、a, T=0C) 3.10 aerationsetting fordiffusedairaeration:aspecifiedairflowrateataspecifieddiffuserdepthwithorwithoutadditionalmixing; forsurfaceaerators:aspecifiedfreeboardoraspecifiedimmersiondepthataspecifiedrotaryspeedandwith orwithoutbafflesand/oradditionalmixing 4 Symbolsandabbreviations h D diffus
35、ersubmergence,inmetre(m) C 0 oxygenconcentrationat t=0,inmilligrammeperlitre(mg/l)EN1225515:2003(E) 6 C i initialconcentrationofdissolvedoxygeninthetankwithoutsodiumsulphite,inmilligrammeperlitre (mg/l) C S,20 testoxygensaturationvalueatstandardconditions,inmilligrammeperlitre(mg/l) C S,md,20 middep
36、thoxygensaturationvalue,inmilligrammeperlitre(mg/l) C S,p*,T testoxygensaturationvalue,inmilligrammeperlitre(mg/l) C S,p,T, oxygensaturationvalueafteraprolongedaerationperioddeterminedbyWinklertitration(see EN25813),inmilligrammeperlitre(mg/l) C S,St,T standardoxygensaturationvalue,inmilligrammeperl
37、itre(mg/l) C S,St,T, standardoxygensaturationvalueatthetemperatureatwhichthesaturationvaluehasbeen determinedbyWinklertitration,inmilligrammeperlitre(mg/l) C t oxygenconcentrationattime t,inmilligrammeperlitre(mg/l) k L a 20 oxygentransfercoefficientat T=20C,in1/h k L a T oxygentransfercoefficientat
38、testtemperature,in1/h M So massofsodiumsulphiteneededforonetest,inkilogramme p barometricpressureduringsamplingforWinklertitration,inhectopascal(hPa) p* barometricpressureduringatest,inhectopascal(hPa) p St barometricstandardpressure(1013hPa),inhectopascal(hPa) Q A normalairflowrate,incubicmetreperh
39、our(m 3 /h) 2 t M mixingperiodatoxygenconcentration C=0,inminutes(min) V tankvolume,incubicmetre 3 (m 3 ) 5 Principleandprocedures Afterdecreasing(absorptiontest)orincreasing(desorptiontest)thedissolvedoxygenconcentrationofan aerationtankatconstantmixingandacertainaerationsettingtheincreasingordecre
40、asingdissolvedoxygen concentrationismonitored.Thisisdescribedbythefollowingequation: ) ( exp ) ( , t a k C C C C - - - = T L 0 T , p S, T p S, t * * (7) Byanonlinearregressionmethodequation(7)isfittedtothemeasuredvaluesofC t .Thevaluesfor C 0 , C S,p*,T andk L a T areobtained.Theresidues( C t (measu
41、red) C t (calculated)plottedversustimeshallberandomly distributed.Iftheyfollowacurveanewevaluationshallbeperformedatwhichoneormorevaluesof C t from thebeginningand/orendofthecurvearetobeneglected.Anycomputerprogramfornonlinearparameter 2 Thevolumeexpressedincubicmetre isapplicabletostandardcondition
42、s(dryair,zerohumidity,p=1013hPa,T=0C), seealso3.9.EN1225515:2003(E) 7 estimationmaybeused,e.g.Stenstrometal.1981.ThedisksprovidedbyASCE1992,byATV1996or byFUL1995maybeusedaswell. Thevalueofk L a T isnotaffectedbythecalibrationoftheDOprobes.TheexactdeterminationofC S,p*,T requiresaccuratelycalibratedD
43、OprobesorWinklertitration,seeEN25813andEN25814. ExperiencedInstitutionsmayapplylinearestimation(logdeficitmethod)of k L a T usingameasuredoxygen saturationvalue C S,p,T ,seeannexA. Theoxygentransferabsorptiontestisthemostcommontestmethodbywhichthedissolvedoxygen concentrationoftheaerationtankisatfirstdecreasedbyadditionofsodiumsulphiteorbyinjectionofnitrogen gasandthenaeratedclosetooxygensaturation.Fromtheincreasingdissolvedoxygenconcen
