EN 12255-13-2002 en Wastewater treatment plants - Part 13 Chemical treatment - Treatment of wastewater by precipitation flocculation《废水处理工厂 第13部分 化学处理 通过沉淀作用 絮凝作用处理废水》.pdf

1、RATIFIED EUROPEAN TEXT EN12255-13:2002 European Standards only exist formally as national transpositions (i.e. a BS EN for the UK) of a commonly agreed “ratified” text. This document will shortly be published as a British Standard. It is being made available in advance of its formal publication to g

2、ive interested parties early access to the technical information which the British Standard will contain. When the British Standard is formally published it will be supplied to you automatically, without any additional charge. Purchasers of this document should be aware of the following limitations

3、when using the document. The British Standard may contain additional information in the national foreword or national annex, Full rights conferred by compliance with the standard may only be granted by reference to the formal national transposition of the text as a British Standard. This document wa

4、s approved by CEN/CENELEC in its three official languages on the date given below. Under CEN/CENELEC rules, BSI is obliged to publish its national transposition within six months of this date. This ratified text was approved on 2002-11-01EUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN1225513 Decem

5、ber2002 ICS13.060.30 Englishversion WastewatertreatmentplantsPart13:Chemicaltreatment Treatmentofwastewaterbyprecipitation/flocculation StationsdpurationPartie13:Traitementchimique Traitementdeseauxusesparprcipitation/flocculation KlranlagenTeil13:ChemischeBehandlung AbwasserbehandlungdurchFllung/Fl

6、ockung ThisEuropeanStandardwasapprovedbyCENon1November2002. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational stand

7、ardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe officia

8、l versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROP

9、ISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2002CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN1225513:2002EEN1225513:2002(E) 2 Contents page Foreword3 1 Scope 4 2 Normativereferences 4 3 Termsanddefinitions. .4 4 Requirem

10、ents .5 4.1 General5 4.2 Chemicalbackgroundandprocessoptions. 5 4.2.1 Chemicalprocess 5 4.2.2 Precipitationprocesses . .6 4.2.3 Selectionofprecipitationchemicals .7 4.3 Storageofchemicals .7 4.3.1 General7 4.3.2 Aluminumsalts 8 4.3.3 Ironsalts .8 4.3.4 Calciumsalts. .8 4.4 Dosingequipment 8 4.4.1 Ge

11、neral8 4.4.2 Aluminiumsalts . 9 4.4.3 Ironsalts .9 4.4.4 Calciumsalts. .9 4.5 Silosandtanks. 10 4.6 Mixingsystems 10 4.7 Flocculators10 4.8 Sedimentationtanks. .10 4.8.1 General10 4.8.2 Designconsiderations . .10 4.8.3 Chemicalsludgewasting. .10 4.9 Flotation10 4.10 Physicalfiltration .11 4.11 Sludg

12、e .11 4.11.1 Sludgeproduction .11 4.11.2 Sludgecharacteristics. 11 AnnexA (normative) Precipitationchemicals 12 A.1 Aluminiumsalts . 12 A.2 Ironsalts .12 A.2.1 Ferroussalts. 12 A.2.2 Ferroussulphate,monohydrate. 12 A.2.3 Ferroussulphate,heptahydrate .12 A.2.4 Ferricsalts 12 A.3 Calciumsalts. .13 A.3

13、.1 General13 A.3.2 Calciumoxide. 13 A.3.3 Calciumhydroxide. 13 Bibliography 14EN1225513:2002(E) 3 Foreword Thisdocument(EN1225513:2002)hasbeenpreparedbyTechnicalCommitteeCEN /TC 165“Wastewater engineering“,thesecretariatofwhichisheldbyDIN. ThisEuropeanStandard shallbegiventhestatusofanationalstandar

14、d,eitherbypublicationofanidenticaltextor byendorsement,atthelatestbyJune2003,andconflictingnationalstandardsshallbewithdrawnatthelatestby June2003. ItisthethirteenthpartpreparedbytheWorkingGroupsCEN/TC165/WG42and43relatingtothegeneral requirementsandprocessesforwastewatertreatmentplantsforatotalnumb

15、erofinhabitantsandpopulation equivalents(PT)over50.Thepartsoftheseriesareasfollows: Part1:Generalconstructionprinciples Part3:Preliminarytreatment Part4:Primarysettlement Part5:Lagooningprocesses Part6:Activatedsludgeprocess Part7:Biologicalfixedfilmreactors Part8:Sludgetreatmentandstorage Part9:Odo

16、urcontrolandventilation Part10:Safetyprinciples Part11:Generaldatarequired Part12:Controlandautomation Part13:ChemicaltreatmentTreatmentofwastewaterbyprecipitation/flocculation Part14:Disinfection Part15:Measurementoftheoxygentransferincleanwaterinactivatedsludgeaerationtanks Part16:Physical(mechani

17、cal)filtration 1) NOTE Forrequirementsonpumpinginstallationsatwastewatertreatmentplants,providedinitiallyaspart2“Pumping installationsforwastewatertreatmentplants“,seeEN7526“DrainandsewersystemsoutsidebuildingsPart6:Pumping installations. ThepartsEN122551,EN122553toEN122558andEN1225510andEN1225511we

18、reimplemented togetherasaEuropeanpackage(ResolutionBT152/1998). WARNING TheuseofthisEuropeanStandardmayinvolvehazardousmaterials,operationsand equipment.ThisEuropeanStandarddoesnotpurporttoaddressallofthesafetyproblemsassociatedwith itsuse.ItistheresponsibilityoftheuserofthisEuropeanStandardtoestabl

19、ishappropriatesafetyand healthpracticesanddeterminetheapplicabilityofregularitylimitationspriortouse(seealsoEN1225510). AnnexAisnormative. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,Cze

20、chRepublic,Denmark,Finland, France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Spain, Sweden,SwitzerlandandtheUnitedKingdom. 1) inpreparationEN1225513:2002(E) 4 1Scope ThisEuropeanStandardspecifiestherequirementsforchemicaltreatmentofwastewaterby precipitation/f

21、locculationforremovalofphosphorusandsuspendedsolids. TheapplicationofpolymersisnotdescribedinthisEuropeanStandard. DifferencesinwastewatertreatmentthroughoutEuropehaveledtoavarietyofpracticesbeingdeveloped.This standardgivesfundamentalinformationaboutthepractices;thisstandardhasnotattemptedtospecify

22、allavailable practices. Detailedinformationadditionaltothatcontainedinthisstandardmaybeobtainedbyreferringtothebibliography. 2 Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromotherpublications.These normativereferencesarecitedattheappropriateplacesinthetex

23、t,andthepublicationsarelistedhereafter.For datedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicationsapplytothisEuropean Standardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthelatesteditionofthe publicationreferredtoapplies(includingamendments). EN7526, Drainands

24、ewersystemsoutsidebuildingsPart6:Pumpinginstallations. EN1085:1997, WastewatertreatmentVocabulary. EN100882, StainlesssteelsPart2:Technicaldeliveryconditionsforsheet/plateandstripforgeneralpurposes. EN122551, WastewatertreatmentplantsPart1:Generalconstructionprinciples. EN122556, Wastewatertreatment

25、plantsPart6:Activatedsludgeprocess. EN1225511, WastewatertreatmentplantsPart11:Generaldatarequired. EN12518:2000, ChemicalsusedfortreatmentofwaterintendedforhumanconsumptionHighcalciumlime. 3 Termsanddefinitions ForthepurposesofthisEuropeanStandard,thetermsanddefinitionsgiveninEN1085:1997andEN12518:

26、2000 andthefollowingapply. 3.1 chemicaltreatmentofwastewater treatmentofwastewaterbychemicalcoagulation/precipitationwithmetalsalts(includinglime)ororganicpolymers inordertoremoveinorganicandorganicphosphoruscompoundsandsuspendedsolidsandcolloidsEN1225513:2002(E) 5 4Requirements 4.1General Chemicalt

27、reatmentofwastewatercanbedividedintotwoprocesses:areactionphase,thatconsistsof precipitationofdissolvedphosphates,destabilisationofcolloidsandtheformationofflocs,andaseparationphase, inwhichtheflocsareseparatedfromthewater. Thereactorsandflocseparators(sedimentationtanks,flotationunitsetc.)fortheche

28、micaltreatmentcanbe integratedwiththeotherpartsofthewastewatertreatmentplant(preprecipitation,simultaneousprecipitation,see 4.2.2.2and4.2.2.3)orbeaseparatepartofthetreatmentplant(postprecipitation,directprecipitation). Thewaterlevelinthechemicalreactorsandtanksmaybecontrolledbyfixedoradjustableweirs

29、.Itisparticularly importantwheretherearemultipleparallelreactors. ThedesignoftheprocessshalltakeintoaccountvariationsinflowandloadasstipulatedinEN122551and EN1225511. 4.2 Chemicalbackgroundandprocessoptions 4.2.1 Chemicalprocess Inordertoobtaincoagulation/precipitationacationicchemicalhastobeaddedto

30、thewastewater.Mostcommonly thisisasaltofaluminiumoriron.Limemayalsobeused.Ifonlycoagulation(removalofparticles)isaimedat,a cationicpolymermaybeaddedaloneorinadditiontoametalsalt. Phosphoruscanbepresentinthewastewaterinthefollowingforms: a) organicallyboundphosphorus, b)inorganic phosphorus, polyphos

31、phate, orthophosphate. Polyphosphatesareeventuallyconvertedtoorthophosphatesandtheorganicallyboundphosphorusisconverted toorthophosphateduringbiologicaltreatment. Inprimarytreatment,phosphorusfixedtosettleableparticlesisremoved(5 %to15 %ofthetotalinfluent phosphorusdependingonthecharacterofthewastew

32、ater).Inthebiologicaltreatmentacertainamountof phosphorusisconsumedatthemicrobialsynthesisofnewcellularmaterial(10 %to30 %oftheinfluent phosphorus).Byintroducingananaerobicstagewherevolatilefattyacidsareproducedandphosphatesare releasedanincreasedbiologicalremovaloftotalphosphoruscanbereachedwithout

33、additionofchemicals (60%to90%oftheinfluentconcentration). Inthechemicalprecipitation,aprecipitationagent(suchasaluminiumsulphate,ferroussulphate,ferricchlorideor calciumhydroxide)isaddedtothewastewater.Theorthophosphatephosphorusisprecipitatedasmetal orthophosphate.Al 3+ andFe 3+ alsoformcolloidalhy

34、droxides.ThesolubilityoftheprecipitatesispHdependent. Organicpolyelectrolytesareusedasflocculationagentsforcolloidalandsuspendedmatter. Chemicalcoagulation/precipitationcanbecarriedoutinsixdifferentways,namely direct precipitation, preprecipitation,EN1225513:2002(E) 6 simultaneous precipitation, pos

35、tprecipitation, multipoint precipitation, precipitation on filters. 4.2.2 Precipitationprocesses 4.2.2.1 Directprecipitation Directprecipitationisusedinwastewatertreatmentplantswithoutabiologicalstage. Inadirectprecipitationplant,theprecipitationagentshouldbeaddedafterthepreliminarystage(screen,grit

36、 chamberandpossiblyaprimarysettlementtank). Theprecipitationagentshouldbeaddedinawaythatassuresrapidandcompletemixingofthechemical. Aftermixingflocculationtakesplaceinaflocculationtank.Thechemicalflocsarethenseparatedinafinal sedimentationtankoranotherflocseparationdevice. 4.2.2.2Preprecipitation Pr

37、eprecipitationcanbeusedinwastewatertreatmentplantshavingbothmechanicalandbiologicaltreatment. Withpreprecipitation,theadditionoftheprecipitationagentiseffectedbeforethebiologicalstage,oftenbeforethe aeratedgritchamber,preaerationtanks,orflocculationtanks.Thechemicalflocsareseparatedtogetherwiththe p

38、rimarysludgeintheprimarysettlementtanks. Chemicalflocswhicharenotremovedintheprimarysettlementtankaretransportedwiththewastewaterand separatedinthesecondarysettlementtanktogetherwiththebiologicalsludge. 4.2.2.3 Simultaneousprecipitation Simultaneousprecipitationcanbeusedinwastewatertreatmentplantswi

39、thbiologicaltreatmentdependingonthe activatedsludgeprocessused. Withsimultaneousprecipitationtheadditionoftheprecipitationagentiseffectedintheaerationtank,attheendof theaerationtankortogetherwiththereturnsludge,wherebothabiologicalandachemicalprocesstakesplace. Themixedbiologicalandchemicalsludgeiss

40、eparatedinthesecondarysettlementtankoraflotationunit.The returnsludge,theexcesssludgeandthemixedliquorsuspendedsolidscontainalargerpartofinorganicmaterial ascomparedtothesludgesinanormalactivatedsludgeplant. 4.2.2.4Postprecipitation Postprecipitationcanbeusedinwastewatertreatmentplantswithbiological

41、treatment(activatedsludge,trickling filteretc.). Withpostprecipitationtheadditionoftheprecipitationagentisdoneinamixingtankafterthesecondary settlement.Flocformationtakesplaceinaflocculationtankfollowedbyafinalclarificationtankwherethechemical sludgeisseparated.Alternativelylamellasedimentationorflo

42、tationcanbeusedforseparation. 4.2.2.5 Multipointprecipitation Theefficiencyoftheprecipitationmaybeincreasedbyaddingthechemicalsattwoorthreedifferentpoints,e.g. thegritchamber,theaerationtank,thefinalsandfilter.EN1225513:2002(E) 7 4.2.2.6 Precipitationonphysicalfilters Precipitationonfiltersisnormall

43、yacomplementtobiologicalphosphorusremovalortoapreprecipitationora simultaneousprecipitation.Thechemicalisaddedinthechannelorpipeleadingtothefilter.Aneffectivemixing shallbearranged. 4.2.3 Selectionofprecipitationchemicals DetailsofchemicalsoftenusedaregiveninannexA.Apartfromthatsomewasteproductsorbyproductsand productsreadyforusecanbeusedasprecipitationorflocculationchemicals. Carefulconsiderationoftheheavymetalconcentrationandotherpollutantsshallbemade. NOTE Detailsaboutlimitscanbeobtainedfromrelevan