1、BRITISH STANDARD BS EN 12255-14:2003 Wastewater treatment plants Part 14: Disinfection The European Standard EN 12255-14:2003 has the status of a British Standard ICS 13.060.30 BS EN 12255-14:2003 This British Standard, was published under the authority of the Standards Policy and Strategy Committee
2、 on 14 January 2003 BSI 14 January 2003 ISBN 0 580 43221 1 National foreword This British Standard is the official English language version of EN 12255-14:2003. The UK participation in its preparation was entrusted to Technical Committee B/505, Wastewater engineering, which has the responsibility to
3、 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 document may be found in the BSI Catalogue under the section entitled “International
4、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 contract. Users are responsible for its correct application. Compliance with a British Sta
5、ndard 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 for change, and keep the UK interests informed; monitor related international and Europ
6、ean 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 copyright notice displayed in this document indicates when the document was last issued. Ame
7、ndments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN1225514 December2003 ICS13.060.30 Englishversion WastewatertreatmentplantsPart14:Disinfection StationsdpurationPartie14:Dsinfection KlranlagenTeil14:Desinfektion ThisEuropeanStandardwasapprovedbyC
8、ENon11September2003. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCent
9、ralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationa
10、lstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Slovakia,Spain,Sweden,SwitzerlandandUn ited Kingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRN
11、ORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2003CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN1225514:2003:EEN1225514:2003(E) 2 Contents page Foreword3 1 Scope 4 2 Normativereferences 4 3 Termsanddefinitions. .4 4 Design .6 5 Requirement
12、s .13 Bibliography 15EN1225514:2003(E) 3 Foreword Thisdocument(EN1225514:2003)hasbeenpreparedbyTechnicalCommitteeCEN/TC 165“Wastewater engineering”,thesecretariatofwhichisheldbyDIN. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofanidenticaltextor byendorsement,atth
13、elatestbyJune2004,andconflictingnationalstandardsshallbewithdrawnatthelatestby June2004. ThisisthefourteenthPartpreparedbytheWorkingGroupsCEN/TC165/WG42andWG43relatingtothegeneral requirementsandprocessesfortreatmentplantsforatotalnumberofinhabitantsandpopulationequivalents(PT) over50.EN12255withthe
14、generictitle“Wastewatertreatmentplants”consistsofthefollowingParts: Part1:Generalconstructionprinciples Part3:Preliminarytreatment Part4:Primarysettlement Part5:Lagooningprocesses Part6:Activatedsludgeprocesses Part7:Biologicalfixedfilmreactors Part8:Sludgetreatmentandstorage Part9:Odourcontrolandve
15、ntilation Part10:Safetyprinciples Part11:Generaldatarequired Part12:Controlandautomation Part13:ChemicaltreatmentTreatmentofwastewaterbyprecipitation/flocculation Part14:Disinfection Part15:Measurementoftheoxygentransferincleanwaterinaerationtanksofactivatedsludgeplants Part16:Physical(mechanical)fi
16、ltration NOTE Forrequirementsonpumpinginstallationsatwastewatertreatmentplants,providedinitiallyas Part2:Pumping installationsforwastewatertreatmentplants ,seeEN7526 DrainandsewersystemsoutsidebuildingsPart6:Pumping installations. EN122551,EN122553toEN122558andEN1225510andEN1225511wereimplementedtog
17、etherasa Europeanpackage(ResolutionBT152/1998). AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,CzechRepublic,Denmark,Finland, France,Germany,Greece,Hungary,Iceland,Ireland,Italy,Luxembourg,
18、Malta,Netherlands,Norway,Portugal, Slovakia,Spain,Sweden,SwitzerlandandtheUnitedKingdom.EN1225514:2003(E) 4 1Scope ThisEuropeanStandardspecifiesperformancerequirementsforthedisinfectionofeffluentsfromwastewater treatmentplants. Theprimaryapplicationisforwastewatertreatmentplantsdesignedforthetreatme
19、ntofdomesticandmunicipal wastewaterforover50PT. DifferencesinwastewatertreatmentthroughoutEuropehaveledtoavarietyofsystemsbeingdeveloped.This standardgivesfundamentalinformationaboutthesystems,thisstandardhasnotattemptedtospecifyallavailable systems. Detailedinformationadditionaltothatcontainedinthi
20、sstandardcanbeobtainedbyreferringtothebibliography. 2 Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromotherpublications.These normativereferencesarecitedattheappropriateplacesinthetext,andthepublicationsarelistedhereafter.For datedreferences,subsequentamen
21、dmentstoorrevisionsofanyofthesepublicationsapplytothisEuropean Standardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthelatesteditionofthe publicationreferredtoapplies(includingamendments). EN1085:1997, WastewatertreatmentVocabulary . EN122551, WastewatertreatmentplantsPart1:Gene
22、ralconstructionprinciples. EN122555, WastewatertreatmentplantsPart5:Lagooningprocesses. EN1225510, WastewatertreatmentplantsPart10:Safetyprinciples. EN1225512, WastewatertreatmentplantsPart12:Controlandautomation. 3 Termsanddefinitions ForthepurposesofthisEuropeanStandard,termsanddefinitionsgiveninE
23、N1 085:1997 andthefollowingapply. 3.1 residualconcentration concentrationofadisinfectantinthefinaleffluentofthewastewatertreatmentplant 3.2 UVradiation(UVdose) thereceivedUVdoseoverthedurationoftheUVirradiationalongthepathwayofaninfinitesimalsmallwater volumeexpressedinJ/m 3.3 UVintensity quotientof
24、theenergyfluxoftheUVradiationreceivedonthesurfaceofaninfinitesimalsmallareadividedbythe sizeofthearea.TheunitofUVintensityisW/m 3.4 UVreactor aclosedvesselreactororanopenchannelsectionwithanassemblyofUVlampsirradiatingthewaterpassing throughtheUVreactorEN1225514:2003(E) 5 3.5 bioassay methodtodeterm
25、inetheeffectiveUVradiationofanUVsystemusingacalibratedtestorganism.Calibrationoftest organismsisdoneinalaboratorydevicewithanUVradiationofahomogeneousandmeasuredintensity(see15, 20) 3.6 ozonedemand amountofozonerequiredtoattainacertainresidualozoneconcentrationintheeffluentofatreatmentstage.The ozon
26、edemandincludestheozoneconsumptionduetothedecayoftheozoneandduetoreactionsofozonewith anyofthepollutantsinthewater 3.7 chlorinator equipmentfordosingchlorinegasintowater 3.8 contactbasin tankforprovidingtherequireddetentiontimeforcertainreactionstotakeplace 3.9 membrane semipermeablematerialusedasfi
27、ltermediainmembranefiltrationprocesses.Membranesnormallyareflat sheets,tubesorhollowfibrescomposedofathinsemipermeablelayeronastructuralmaterial 3.10 module unitcontaininganassemblyofmembranesandsystemsfordistributingtherawwaterinflow,andsystemsfor collectingpermeateandtheconcentrate 3.11 permeate f
28、luidspassingthroughthemembraneinmembranefiltrationprocesses 3.12 concentrate fluidsenrichedwithsubstancesnotpassingthemembranesinmembranefiltrationprocesses 3.13 flux membranesurfaceareaspecificrateoffluidspassingthroughthemembraneinmembranefiltrationprocesses normallyindicatedinl/(m h).Thefluxismai
29、nlydeterminedbythewastewaterquality,thetypeofmembraneused, themodeoffiltrationandthetransmembranepressure 3.14 transmembranepressure pressuredifferencebetweenconcentrateandpermeatesideofthemembrane 3.15 crossflowfiltration filtrationwithasignificantflowparalleltothemembranesurface,whichisintendedtop
30、reventsubstancesfrom accumulatingonthesurfaceofthemembrane 3.16 deadendfiltration filtrationwithoutasignificantflowparalleltothemembranesurface 3.17 perpendicularmixing mixingverticaltofloatingdirectionEN1225514:2003(E) 6 4Design 4.1General Disinfectionprocessesareusedtoimprovethemicrobiologicalqual
31、ityofeffluents,ifrequired,e.g.becauseofsensitive usesofthereceivingwatersdownstream.Adisinfectionofeffluentsfromwastewatertreatmentplantscanbe requiredtocontributetopublichealthtopreventacontaminationbyhumanpathogensof: watersusedforbathingandotherrecreationalactivitiesinvolvingimmersion; shellfishe
32、ries; treatedwastewatertobereusedforunrestrictedirrigationorasprocesswaterorgreywater; sourcesusedforpotablewatersupply. Adisinfectionofeffluentsfromwastewatertreatmentcanbeattainedbytwopossiblemechanisms: inactivationofmicroorganismsrenderingmicroorganismsincapableofreproduction; removingthemicroor
33、ganismsfromaneffluent(e.g.byfiltration)butnotnecessarilyinactivatingthem. Processesmostcommonlyusedfordisinfectingwastewaterbyremovinginactivatingmicroorganismsare: Ultraviolet (UV)radiation; Chlorination; Ozonation. Processesmostcommonlyusedfordisinfectingwastewaterbyremovingrespectivelyreducingmic
34、roorganisms are: membrane filtration; effluent maturation ponds; soilfiltration. 4.2Planning 4.2.1General Disinfection,ifrequired,shouldbethelaststageinthewastewatertreatmentprocess.Poorperformanceby upstreamprocesseswillaffecttheperformanceofthedisinfectionprocess.Ifaneffluenthastobestoredpriorto d
35、ischargee.g.incaseofdischargetotidalwaterorirrigationitshouldbepreferablydisinfectedafterstorage directlypriortodischargeinordertolimitregrowthhazards. Whenplanningdisinfectionsystemsconsiderationshallbegivento: a) levelofdisinfectionrequired; b) stabilityandefficiencyofdisinfectionprocess; c) techn
36、ologicallevelofdisinfectionprocess; d)operational requirements; e)safety hazards;EN1225514:2003(E) 7 f) environmentalimpacts,e.g.: effectsonthequalityoftheeffluents(reductionofBOD 5 ,COD,SS,P tot ); deleteriouseffectsofresidualdisinfectants; productionoftoxicorbioaccumulatingbyproducts; g)power requ
37、irements. 4.2.2 Levelofdisinfection Disinfectionprocessesshallreduceorinactivatehumanpathogenstoalevelthattheriskofthedisinfected wastewaterbeingasourceofinfectionsisminimised.Disinfectionprocessesarenotintendedtoremoveallmicro organisms,orevenremoveallhumanpathogens. Thelevelofdisinfectionisspecifi
38、edbynationalandlocalauthorities. Thespecificationofthelevelofdisinfectionshallincludeproceduresforsampling,analysisandevaluation. Statisticalcriteriaforcomplyingwiththelevelofdisinfectionrequiredshallbenamedexplicitlye.g.fordryweather andstormwaterconditions. 4.3Process Design 4.3.1General Adisinfec
39、tionsystemhastobedesignedandsizedtoensurethat therequiredtreatment(minimumdisinfectantdose)isappliedtoallwastewater; therequiredlevelofdisinfectionismaintainedatthemaximumeffluentflowrateanddisinfectantdemand (worstcasecondition). Withrespecttothehighrequiredreductionratenoshortcircuiting,bypassing,
40、orincompletetreatmentis permitted.Therequiredtreatmenthastobeappliedtoallwastewaterbecausethemicrobiologicalqualityof disinfectedwastewaterreactsverysensitivelytoanywastewaternotbeingdisinfectedproperly. NOTE Thisisduetothefactthattherequiredreductionofindicatororganismsisusuallyinthemagnitudeof99,9
41、to 99,99%.Aleakageorshortcircuitingof0,01%to0,1%ofthewastewaterorareducedreductionrateofonly99%in1%to 10%ofthewastewaterduetoincompletetreatmentcancausegermcountsthatalreadyexceedtheeffluentstandards. 4.3.2 UVradiation UVdisinfectionistheapplicationofUVradiationartificiallygeneratedinUVlampsinUVrea
42、ctorstothewastewater tobedisinfected.AnappropriatedoseofUVradiationwillcauseanirreversibleinactivationofmicroorganismswith noothersignificanteffectsonthewastewater. NOTE ThedisinfectionbyUVradiationisduetoaphotochemicaleffect.UVradiationofgermicidalwavelengthcausesthe formationofdimersofneighbouring
43、thyminebasesinnucleicacids.Thesedimersdisturbthereplicationofthenucleicacidsa nd causeanirreversibleinactivationofthemicroorganisms,ifduetotheUVdosetheformationofdimersistoonumeroustobe repairedbythecellsrepairmechanisms. UVradiationsystemsforwastewaterdisinfectioncanbeclassifiedasfollows: typeofUVreactor(openchannelgravityflowsystems,closedvesselsystems); typeofUVlamps(lowpressureormediumpressuremercurydischargelamps); configurationofUVlamps(inwastewate
