Review of Dioxins and Furan From Incineration CSR

ReviewofDioxinsandFuransfromIncinerationInSupportofaCanadawideStandardReview

AReportPreparedfor

TheDioxinsandFuransIncinerationReviewGroup

throughacontractassociatedwith

CCMEProject#3902007

&

A.J. Chandler Associates Ltd.

Environmental Management Consultants

12 Urbandale Avenue Willowdale Ontario Canada M2M 2H1 Telephone 416-250-6570 Facsimile 416-733-2588 e-mail: [email protected]

December 15, 2006

Canadian Council of Ministers of the Environment Inc. 2007

PN 1395

iTableofContents

Acronyms,Abbreviations,andMeasurementUnits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

EXECUTIVESUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x

1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 ScopeofReport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.3 ReportStructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.0 PCDD/FFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.1 CombustionControlPrinciples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.0 INCINERATIONPROCESSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123.2 MunicipalSolidWasteIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.2.1 AvailableMSWCombustionAlternatives . . . . . . . . . . . . . . . . . . . . . . . . . 163.2.1.1 MassBurningSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

EUROPEANTYPESYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17MODULARINCINERATIONSYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . 20OTHERMASSBURNVARIANTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

3.2.1.2 RefuseDerivedFuelSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23SEMISUSPENSIONBURNINGSYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . 23STOKERFIREDSYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24OTHERRDFVARIANTSFLUIDISEDBED . . . . . . . . . . . . . . . . . . . . . . 24

3.3 HazardousWasteIncinerationEquipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243.3.1 RotaryKilns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253.3.2 LiquidInjectionIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273.3.3 FluidizedBedIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283.3.4 FixedHearthIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.4 SewageSludgeIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313.4.1 MultihearthIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

3.5 BiomedicalWasteIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333.5.1 RetortFurnaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333.5.2 InLineFurnaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

3.6 OtherSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363.7 ProcessSummaryandPCDD/FGenerationPotential . . . . . . . . . . . . . . . . . . . . . 38

4.0 AIREMISSIONCONTROLSTRATEGIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404.1 PostCombustionControl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404.2 PCDD/FControlAlternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

4.2.1 ActivatedCarbonBedFilters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

ii

4.2.2 PACInjectionSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454.2.3 CatalyticDestruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464.2.4 OtherRemovalTechniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

5.0 PCDD/FSAMPLINGMETHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505.2 RegulatoryMethods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

5.2.1 SampleCollectionAlternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525.2.2 SampleExtractionandCleanup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 565.2.3 IdentificationandQuantification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585.3.4 MinimumDetectionLimits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 605.3.5 MeasurementUncertainty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

5.4 LongTermSampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 675.4.1 AMESA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 675.4.2 DMS(DioxinMonitoringSystem) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

5.5 AlternativeAnalysisProcedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 685.5.1 SurrogateProcedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 685.5.2 Immunoassays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

6.0 REPORTINGMEASUREMENTRESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 706.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 706.2 ExpressionofPCDD/FasToxicEquivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 716.3 TreatmentofLowValues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 746.4 ConversionProceduresforSamplingConditions . . . . . . . . . . . . . . . . . . . . . . . . . 756.5 ReportingProceduresforthisReport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

7.0 PCDD/FEMISSIONREGULATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 777.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 777.2 Japan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 807.4 Australia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 817.5 NewZealand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 827.6 EuropeanUnion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 837.7 UnitedStates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 857.8 SummaryofEmissionStandards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

8.0 EMISSIONDATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 918.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 918.2 BackgroundofHistoricalIncineratorInstallationsinCanada . . . . . . . . . . . . . . . 93

8.2.1 CanadaWideStandardsBasic2000Inventory . . . 948.2.3 CCME2005Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

8.3 UpdatingtheIncineratorsInventoryto2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 998.3.1 MSWIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1018.3.2 MedicalWasteIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

iii

8.3.3 HazardousWasteIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1088.3.4 SewageSludgeIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1128.3.5 IncineratorsOperatedbyFederalEntitiesoronFederalLands . . . . . . 1158.3.6 OtherIncineratorsinRemoteLocations . . . . . . . . . . . . . . . . . . . . . . . . . . 121

8.4 PCDD/FEmissionsinExhaustGasStream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1248.4.1 MSWIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1258.4.2 MedicalWasteIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1278.4.3 HazardousWasteIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1298.4.4 SewageSludgeIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1318.4.5 IncineratorsOperatedbyFederalEntities . . . . . . . . . . . . . . . . . . . . . . . . 1338.4.6 IncineratorsOperatedinRemoteLocationsonFederalLandsor

elsewhere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1348.5 PCDD/FEmissionsinSolidandLiquidStreams . . . . . . . . . . . . . . . . . . . . . 137

8.5.1 MSWIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1378.5.2 MedicalWasteIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1388.5.3 HazardousWasteIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1408.5.4 SewageSludgeIncinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1428.5.5 IncineratorsOperatedbyFederalEntitiesoronFederalLands . . . . . . 144

8.6 SummaryofEstimatedPCDD/FEmissionsfromIncinerators . . . . . . . . . . . . . 148

9.0 ALTERNATIVEEQUIVALENCYFACTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1519.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1519.1 DataforAnalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1529.2 AffectofApplyingDifferentTreatmentsforLowConcentrationData . . . . . . 1599.3 AffectofApplyingWHO98TEF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

10.0 FINDINGSandCONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

11.0 RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16511.1 NumericalStandard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16511.2 Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16511.3 AnnualThroughputCalculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16611.4 SiteDisposalCapacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16611.5 ImplementationMeasures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

11.5.1 BatchEquipmentCertification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16711.5.2 ContinuousMonitoringofBatchSystems . . . . . . . . . . . . . . . . . . . . . . . . 16811.5.3 OperatorTraining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16911.5.4 IncineratorsEquippedwithHeatRecoverySystems . . . . . . . . . . . . . . . 169

11.6 ExistingIncineratorInstallations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17011.7 PCDD/FIncineratorInventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

iv

APPENDIXA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172TheRelationshipbetweenAnalyticalResultsandMeasurementUncertainty . . . . . . . 172

AnalyticalLaboratoryResults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172UncertaintyinStackMeasurementResults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

vListofTables

Table3.1 SummaryofIncineratorTypes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Table4.1 ComparisonofOperatingFeaturesofVariousAPCAlternatives . . . . . . . . . . . . 43Table5.1 ComparisonofRegulatorySamplingMethods . . . . . . . . . . . . . . . . . . . . . . . . . . . 56Table5.2 LimitsofCongenerQuantificationbasedupona5.5m3samplevolume . . . . . . 62Table5.3 SummaryInternalVariabilityDatafromValidationTestsforCEN . . . . . . . . . . 65Table7.1 JapaneseEmissionStandardsforIncinerators[ngTEQDFP/Nm3] . . . . . . . . . . . . . 81Table7.2 USEPANSPSforNonHazardousWasteIncineratorSystems . . . . . . . . . . . . . . 87Table7.3 SummaryofPCDD/FEmissionStandardsforIncineratorsintheUnitedStates

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88Table7.4 InternationalIncineratorPCDD/FEmissionRegulations . . . . . . . . . . . . . . . . . . . 90Table8.1 SummaryofCWS2000IncineratorInventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95Table8.2 SummaryofIncineratorslistedinNPRIData . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98Table8.3 SummaryofMunicipalSolidWasteIncineratorsinCanada . . . . . . . . . . . . . . . 102Table8.4 SummaryofMedicalWasteIncineratorsinCanada . . . . . . . . . . . . . . . . . . . . . . 105Table8.5 SummaryofHazardousWasteIncineratorsinCanada . . . . . . . . . . . . . . . . . . . 109Table8.6 SummaryofSewageSludgeIncineratorsinCanada . . . . . . . . . . . . . . . . . . . . . . 114Table8.7 SummaryofCanadianIncineratorslocatedatFederalFacilities . . . . . . . . . . . . 116Table8.8 SummaryofCanadianIncineratorslocatedinRemoteAreasonFederalLand

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117Table8.9 TypicalResidentialWasteComposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119Table8.10 SummaryofMiscellaneousSmallWasteIncineratorsinCanada . . . . . . . . . . . 123Table8.11 SummaryofAirEmissionsfromLargeMSWIncineratorsinCanada . . . . . . . 126Table8.12 SummaryofAirEmissionsfromMedicalWasteIncineratorsinCanada . . . . 128Table8.13 SummaryofAirEmissionsfromHazardousWasteIncineratorsinCanada . . 130Table8.14 SummaryofPCDD/FEmissionsfromSewageSludgeIncineratorsinCanada

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132Table8.15 EstimateofPCDD/FEmissionsfromIncineratorslocatedatFederal

Establishments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135Table8.16 PCDD/FEmissionsfromIncineratorslocatedinRemoteAreasoronFederal

Lands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136Table8.17 PCDD/FinResiduesfromLargeScaleMunicipalSolidWasteIncinerators . . 139Table8.18 PCDD/FinResiduesfromMedicalWasteIncineratorsinCanada . . . . . . . . . . 141Table8.19 PCDD/FinResiduesfromHazardousWasteIncineratorsinCanada . . . . . . . 143Table8.20 PCDD/FinResiduesfromSewageSludgeIncineratorsinCanada . . . . . . . . . . 145Table8.21 PCDD/FinResiduesEmissionsfromIncineratorslocatedatFederal

Establishments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146Table8.22 PCDD/FinResiduesfromIncineratorslocatedinRemoteAreasoronFederal

Lands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147Table8.23 SummaryofInstalledCanadianIncinerators2005/2006 . . . . . . . . . . . . . . . . . . . 150Table8.24 SummaryofPCDD/FEmissionstoAirfromOperatingIncinerators2005/2006

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

vi

Table8.25 SummaryofPCDD/FinResiduesfromOperatingIncinerators2005/2006 . . . 150Table8.26 SummaryofPCDD/FEmissionsfromOpeatingCanadianIncinerators2005/2006

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150Table9.1 RawAnalyticalData[pg]fromStackTestingProgramsVariousFacilities . . . 153Table9.2 StackTestingDataCongenerConcentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154Table9.3 LOQValuesDerivedfromTestDataandITEF . . . . . . . . . . . . . . . . . . . . . . . . . . 155Table9.4 LOQValuesDerivedfromTestData&WHO98TEF . . . . . . . . . . . . . . . . . . . . . 156Table9.5 StackTestingDataTotalEmissionasToxicEquivalentsVariousMethods . . . 157Table9.6 PercentageIncreaseProducedbyUsingWHO98TEF . . . . . . . . . . . . . . . . . . . . 158TableA1 ExpandedUncertaintyRangeofAcceptableConcentrations* . . . . . . . . . . . . . . 176TableA2 SummaryInternalVariabilityDatafromValidationTestsforCEN . . . . . . . . . 186

ListofFigures

Figure1.1 SchematicDiagramsofPCDD,PCDFandPCBs . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Figure3.1 GeneralizedSchematicofanIncinerationSystem . . . . . . . . . . . . . . . . . . . . . . . . . 12Figure3.2 SchematicofFixedHearth,TwoStageIncinerator(fromUSEPA) . . . . . . . . . . . 21Figure3.3 SchematicofRotaryKilnIncinerator(fromUSEPA) . . . . . . . . . . . . . . . . . . . . . . 23Figure3.4 SchematicofLiquidWasteIncinerator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Figure3.5 SchematicofFluidizedBedIncinerator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Figure3.6 TypicalMultiHearthIncineratorfromUSEPAAP42 . . . . . . . . . . . . . . . . . . . . . 32Figure3.7 RetortIncineratorfromAP40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Figure3.8 TypicalInLineFurnacefromAP40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35Figure4.1 ComparisonofAirPollutionControlSystemOptions . . . . . . . . . . . . . . . . . . . . . 42FigureA1 DiagrammaticIllustrationoftheEffectofMeasurementUncertaintyandthe

Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

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Acronyms,Abbreviations,andMeasurementUnits

Thefollowingdefinitions,acronyms,andmeasurementunitsareprovidedtoclarifythediscussionthatfollows.

AcronymsACR activatedcharreactorAMESA adsorptionmethodforsamplingPCDD/FAPC airpollutioncontrolsystemASME AmericanSocietyofMechanicalEngineersCB chlorobenzenesCCME CanadianCouncilofMinistersoftheEnvironmentCEN ComitEuropendeNormalisation(EuropeanCommitteefor

Standardization)CEMS continuousemissionsmonitoringsystem(s)CFR CodifiedFederalRegulations(UnitedStatesofAmerica)CWS CanadaWideStandardsDIN DeutschesInstitutfrNormung(GermanInstituteforStandardization)DMS dioxinmonitoringsystemDRE DestructionRemovalEfficiencyECT evaporativecoolingtowerEN EuropeanNormals(StandardsissuedbyCEN)EPA(U.S.) U.S.EnvironmentalProtectionAgencyESP electrostaticprecipitatorEU EuropeanUnionGC/MS gaschromatography/massspectrometryHAP hazardousairpollutantHRSG heatrecoverysteamgeneratorITEQbasis 2,3,7,8tetrachlorinateddibenzopdioxintoxicequivalentbasedonthe

1989InternationaltoxicequivalencyfactorsLDR landdisposalrestrictions(USRegulations)LOD levelofdetectionLOQ levelofquantificationLWAK lightweightaggregatekilnMACT maximumachievablecontroltechnologyMHF multihearthfurnaceMOE MinistryoftheEnvironment(Ontario)MRR MaterialResourceRecoverymetalrecoveryoperationinCornwall,ONMSW municipalsolidwasteMTEC maximumtheoreticalemissionconcentrationNITEP NationalIncineratorTestingandEvaluationProgramNESHAP NationalEmissionStandardsforHazardousAirPollutantsNPRI NationalPollutantReleaseInventory

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OPG OntarioPowerGenerationPAC powderedactivatedcarbonPAH polycyclicaromatichydrocarbonsPCBTotal CEPADefinitionissumoftritodecaisomersofpolychlorinated

byphenylsPCDD/F polychlorinateddibenzopdioxinsandpolychlorinateddibenzofuransPIC productsofincompletecombustionPM particulatematterPOHC principalorganichazardouscomponentRCRA ResourceConservationandRecoveryAct(USRegulations)RDF refusederivedfuelRSI RcupreSolinc.BennettSoilRemediationfacilityinSt.Ambroise,PQSCR selectivecatalyticreactorSVOC semivolatileorganiccompoundTEF toxicityequivalencefactorTEQ toxicequivalentquantityTCLP toxiccharacteristicsleachingprocedureTSMP ToxicSubstancesManagementPolicyUCL UpperConfidenceLimit(definitionofupperboundoftestresults)U.S.EPA UnitedStatesEnvironmentalProtectionAgencyWHO WorldHealthOrganizationWHO98TEQ 2,3,7,8tetrachlorinateddibenzopdioxintoxicequivalentthatincludes

coplanarPCBtoxicequivalencyfactors

DEFINITIONSAPPLIEDTOCHARACTERISEINCINERATORS

Batch incineratorsthatareloadedwithwastebeforethewasteisignitedandthedoorremainscloseduntiltheashhascooledinsidethefurnace

Commercial meansthosethatchargeatippingfeefordisposingofwasteContinuous incineratorsthatareloadedperiodicallyduringoperationandashis

removedduringtheburningphase(typicallyoperateforperiodsfromweekstomonths)

SemiContinuous incineratorsthatareloadedperiodicallyduringoperationbutashisonlyremovedafteracooldownphase(typicallyoperateforperiodsofdays)

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AbbreviationsandMeasurementUnits

Btu =BritishThermalUnit(measureofenergy)oC =degreesCelsius(degreesFahrenheit=(oC*9/5+32)dscf =drystandardcubicfeet(at14.7poundspersquareinch,68oF)dscm =drystandardcubicmeters(at14.7poundspersquareinch,68oF)g =gram(454gramsperpound)g/a =gramsperannumgr =grains(7,000grainsperpound)MJ =megajoules(energyinput,1MJ=947.82Btu=0.27778kW.h)kg =kilogram(0.454kilogramsperpound)kg/a =kilogramsperannumkW =kilowatt(measureofenergy)m3 =cubicmeter(35.3cubicfeetpercubicmeter)mg =milligrams(103grams)Mg =megagram(1.1tons)Mg/d =megagramsperdayMg/a =megagramsperannumng =nanogram(109grams)Nm3 =normalcubicmetre(at0oC,101.3kPa)ppmv =partspermillionbyvolumeRm3 =dryReferencecubicmetre(at25oC,101.3kPaand11%O2)

totalmassbasis =totalmassoftetrathroughocta(dioxins/chlorinateddibenzopdioxinsandfurans)dibenzofurans

MetricPrefixes TheSIPrefixesusedtoformnamesandsymbolsofdecimalmultiplesandsubmultiplesofSIunitsare:

Prefix Symbol Magnitude Factor

exa E 1000000000000000000 1018

peta P 1000000000000000 1015

tera T 1000000000000 1012

giga G 1000000000 109

mega M 1000000 106

kilo k 1000 103

milli m 0.001 103micro 0.000001 106nano n 0.000000001 109pico p 0.000000000001 1012femto f 0.000000000000001 1015atto a 0.000000000000000001 1018

EXECUTIVESUMMARY

AspartofthereviewstipulatedintheCWSPCDD/Fstandard,thisreportexaminesthewasteincinerationsectorandtheprogressthatsectorhasmadeinreducingthereleaseofPCDD/Ftotheenvironment.TheCWSPCDD/Fstandarddefinesincinerationintermsoftheequipmentasfollows:

Waste incinerator: a device, mechanism or structure constructed primarily to thermally treat(e.g., combust or pyrolyze) a waste for the purpose of reducing its volume, destroying ahazardous chemical present in the waste, or destroying pathogens present in the waste.

Thisimpliesthatthestandardappliestoanythermalprocess,eventhoughthedefinitionlistscombustionandpyrolysisasexamplesofthermaltreatment.Thisinnowayrestrictsapplicationofthestandardtoanyalternativemethodofheatingandtreatingwastetoreduceitsvolumeorbreakingdowncompoundswithinthewaste.Assuch,thePCDD/FWasteIncinerationCWSwouldapplytoanyformsofthermaltreatmentsystems.

Thisreportprovidesanoverviewofthefurnacesthatcanbeusedforwasteincinerationandmethodstheirdesignersusetoensuregoodcombustionandlowemissions.AirpollutioncontrolequipmentisemployedatlargerfacilitiestofurthercontrolthereleaseofPCDD/Fandthereportsummarizesthetypesofairpollutioncontrolsystemsthatcanbeused.MonitoringtheperformanceofsystemsrequiresthatsamplesbecollectedandanalysedtodeterminethequantityofPCDD/Fbeingreleasedatanytime.Areviewoftheacceptedmonitoringproceduresandtheirlimitationsisincluded.HowtheseresultsarereportedandtheregulationsthatthedefinethelimitsonemissionsinvariousjurisdictionsarereviewedtoprovideacomparisonfortheCWSstandard.TheoriginalCWSstandardwasdevelopedbaseduponareviewofemissionsfromtheincineratorsoperatinginthelate1990s.Comparingestimatedemissionsin2005withthosedevelopedfortheoriginalinventoryprovidesanimportantmeasureofprogressmadeinreducingemissions.AsthescientificcommunitysunderstandingofhowPCDD/Freactintheenvironmenthasgrownthemeasureofthetoxicityofthesecompoundshaschanged.AreviewofsomeoftheemissiondatafromCanadianincineratorswasconductedtoconfirmtheanticipatedeffectofchangingthetoxicequivalencyfactorsusedtoquantifyPCDD/Femissions.Duringthereviewtherewereanumberoffindingsandtheauthordevelopedsomeconclusionsfromthestudy.TheseconclusionswereusedtodevelopaseriesofrecommendationsthatshouldallowtheindustrytomovetowardstheultimateobjectiveofthevirtualeliminationofPCDD/Femissionsfromthesector.

PCDD/FFormation

PCDD/Freleasesfromcombustionprocessesaregenerallyconsideredtobeunintentional.Thatis,theprocessisnotdesignedtocreatethesecompoundsandtheirpresenceisindicativeofeithertheirlackofdestructioninthecombustionprocess,ortheirformationbysomemechanismsoperatinginthefurnace.

TheformationofPCDD/Fastracebyproductsofcombustionprocesseshasbeenstudied

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extensivelybecauseitisahighlycomplexphenomenainvolvingmultiplegasandsolidphasereactions.TwomaintheoriesregardingthemechanismofformationofPCDD/Fduringcombustionprocesseshavebeendeveloped.

Thedenovosynthesistheoryisconsideredthemajormechanism.ThistheorysuggeststhatPCDD/Fisformedinthepresenceofflyashcontainingchemicallyunrelatedunburntaromaticsandmetalcatalysts.Thereactionsoccurinthepresenceofoxygenandcatalystsattemperaturesintherangebetween250OCand450OC.Formanyincinerators,thistemperaturerangeisonlyfoundinthepostfurnaceregion,typicallythewasteheatboilerorinelectrostaticprecipitators(ESP).Denovosynthesisexperimentssuggestthatmorefuranthandioxincongenersareformed.

ThePrecursorTheorysuggestssimplythatthevariouschemicallyrelatedchlorinatedaromaticsundergocondensationreactionsonflyashsurfacesinthepresenceofmetalcatalysts.Thus,twoprecursormoleculesarecoupledtoformadioxinorfuranstructure.Theoptimaltemperaturerangeforsuchformationisthesameasthatobservedfordenovosynthesis(i.e.,250to450EC).Therefore,formationofPCDD/Ffromprecursorsmustalsooccurinthepostcombustionzonesofthermalprocesses.ThistemperaturerangeisoftenconsideredthewindowofopportunityforcatalyticformationofPCDD/Fonsurfacesofflyashparticles.Thetwotheoriesarenotnecessarilymutuallyexclusive.TheformationofPCDD/Finthermalprocessesisundoubtedlytheresultofacomplexsetofcompetingchemicalreactions.

RegardlessofwhichtheoryortheoriesbestexplainshowPCDD/Fareformed,certainoperatingconditionsincreasethepotentialforPCDD/Fformationincluding:

1. incompletecombustionofafuel2. anoxidizingatmosphere3. presenceofachlorinesource4. flyashsurfaces(carbonsource)5. flyashwithdegeneratedgraphiticstructures6. presenceofcatalyticmetals(especiallycopper,butiron,manganeseand

zincarealsoindicatedaspotentialcatalystsforPCDD/Fformation)7. temperature/timehistoryofatleast1secondatlessthan600OC(optimal

temperaturerangeliesbetween250and450OC)Thus,goodcombustion,whichreducestheconcentrationofproductsofincompletecombustion,boththegaseousandsolidforms,mustbethefoundationofanymeasurestoreducePCDD/Femissionsfromincinerators.Secondly,limitingthetimethegasesareinthegenerationtemperaturewindowwillfurtherhelpreduceemissions.

SomesuggestthatcontrollingtheamountofchlorineinthesystemmightinfluencethegenerationofPCDD/F,howeverconsistentanalysisoftheavailabledataindicatesthatchanging

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theamountofchlorinehasnodiscernibleimpactonPCDD/Femissions.

CombustionControl

Combustioncontrolmustcompensatefor:

thenaturalvariabilityinfuelquality;and, thecontrollingfactorsthatgoverntherateofchemicalreactions.

HomogeneityofthewastestreamismuchbetterinsewagesludgeandliquidhazardouswastesystemsthanMSW,medicalwasteorevensolidhazardouswastes.Eachcomponentofawastestreamhasitsinherentenergycontentandthismustbematchedwithsufficientoxygentoensurepropercombustion.Incineratoroperatorsunderstandtheneedtokeeptheoperationatasteadyleveltoachievethebestperformanceandtypicallymixthecomponentsasthefirststep.Fromthere,combustioncontrolsystemscompensatefortheremainingfuelvariability.

Intwostagestarvedairandkilnsystemsalargequantityoffuelinthefurnacewillreducethevariability.InconventionalmassburnMSWincineratorstherateofheatreleaseissensedandthesupplyofcombustionairisadjustedtocompensateforhighorlowheatreleaserates.Alternatively,thefuelfeedratecanbeadjustedtocompensateforthevariability.Throughthesestepsitispossibletoestablishanappropriaterangefortheconcentrationofoxygeninanysystem.OperationinthiszoneminimizesthereleaseofCOandthusalsominimizestraceorganicreleases.

Goodcombustionconditionsleadingtoreducedorganicemissionsarethosethat:

ensurecompletemixingofthefuelandtheair; maintainhightemperaturesinthepresenceofsufficientoxygen;and, preventtheformationofquenchzonesorlowtemperaturepathwaysthatwould

allowpartiallyreactedsolidsorgasestoexitfromthecombustionchamber.

Thesedesignconditionsmustbecombinedwithgoodoperatingconditionstoensurethattheperformanceismaintainedandorganicconstituentsarereducedtothebasicelements.

WhilemuchoftheresearchemphasishasbeenfocussedondefiningtheconditionsconducivetominimisingemissionsofPCDD/Fthroughthestack,theseconditionsalsohaveimplicationsforsolidresiduestreamsgeneratedbycombustionequipment.Obviously,ashfromthegrateofsolidfuelcombustiondevicewillbeexposedtotemperaturesinexcessofthatconducivetoformation,indeedtemperaturesintherangewhereanyPCDD/Fwillbedestroyed.RapidquenchingofashdischargedfromthegratesshouldminimisethepotentialforanyPCDD/Finthatwastestream.Ontheotherhand,residuesfromheatrecoverysystems,whichoperateinthecriticaltemperaturezonemaybeexpectedtohavesomePCDD/Fpresent,buttheamountwilllikelyvarywiththetemperatureregimewheretheashwascollected,andthetimetheash

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wasinthegasstreamatthesetemperatures.ThissuggeststhatthePCDD/Fformationprocessesrelatedtodenovosynthesisorprecursorsmaybeinhibitedifthegassesleavingthesystemarerapidlyquenchedtobelowtheoptimaltemperatureranges.

IncineratorSystemsandAirPollutionControlEquipment

WastestreamsbeingincineratedinCanadainclude:municipalsolidwaste[MSW];medicalwastes;hazardouswastes;andsewagesludge.Thewastestreamsdifferincharacterandparticularlyintheirenergyvalue.Designershavedevelopeddifferenttypesoffurnacestohandlethedifferentwastestreamsbutsincetherearealsosimilaritiessomefurnacescanbeusedforsimilarstreams,providedthedesigntakesintoconsiderationthecalorificvaluesofthewastestreamandprovidessufficientairtothefurnacetoensuregoodcombustion.ThusMSWandmedicalwastecanbeburnedinthesameincinerator,albeitatdifferentratessotheenergyinputtothefurnaceismaintained.ThegeneralclassesofincineratorsusedinCanadaare:

twostagemassburnincineratorsthathandleupto100Mg/dofMSWandcanhandlemedicalwasteatafeedrateapproximately50%thatofMSW;

Europeanmassburnincineratorsthatgenerallyarelargerthanthe2stagesystemsandoperatewithairorfuelfeedcontrolstominimisecombustionupsets;

liquidinjectionfurnacesthatstandaloneforthedisposalofhazardouswasteorareusedafterrotarykilnshandlingsolidhazardouswastesasaafterburner;

multihearthfurnacesforsewagesludgedisposalwhicharebeingreplacedbymoreeffectivefluidisedbedsystemsthatarecapableofhandlingvariationsinthemoisturecontentofthesludge;

newerbatchfedtwostagecombustionsystemsthatcanhavecapacitiesassmallat23kg/hrandrangeupto1Mg/day;and,

olderdesignssuchasmultiplechamberincineratorsusedinresearchfacilitiesandhospitals.

Allincineratorshaveazonewherethewasteisignitedandmixedwithairtopromotecombustion.Mostincineratorsprovideadditionalairtocompletethecombustionprocess.Afterthewastehasbeenoxidizedinthefurnace,residues,generallyreferredtoasbottomash,mustberemovedfromthefurnace.Theenergyavailableinthehotgasstreamgeneratedbycombustionmayberecoveredinaheatrecoverysteamgenerator[HRSG]orboilertherebycreatingsteamthatcanbeusedtoproduceelectricityorhotwaterforprocessorspaceheating.

WhileanHRSGinstalledinthesystemwillreducethegastemperatures,ifthereisnoheatrecoveryequipment,butthereisanairpollutioncontrolsystem,arapidquenchsystemwillbeusedtoreducegastemperaturestotherangethatisappropriatefortheAPCsystemtotreat.Suchquenchinglimitsthepotentialfordenovosynthesisbecausethegastemperaturemovesrapidlythroughthecriticaltemperaturerange.FurnacesequippedwithneitheranHRSGoranAPCsystemtypicallyreleasehightemperaturegasesdirectlytotheatmosphere.

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Ifanairpollutioncontrolsystemisinstalledtotreatthegasesleavingtheincineratoritisgenerallysizedforthevolumeofgasesproducedatthelowertemperature.Airpollutioncontrolequipmenttypicallyinvolvesinjectingreagentstocontrolacidgasreleases,sorbentstotrapmercuryandPCDD/Fandhighefficiencyparticulatemattercontroldevicestominimisethereleaseofdusttotheatmosphere.Solidresidues,flyash,depositedinHRSGunits,orcollectedinairpollutioncontrolsystemsareremovedfordisposal,generallyathazardouswastedisposalfacilities.ThequantityofPCDD/Fpresentintheflyashstreamscanvarydependinguponthetemperaturehistoryandwheretheflyashisremovedfromthesystem.

TypicalAPCsystemsusedinCanadainclude:

wetsprayhumidifiers/dryscrubbers/fabricfilterswithorwithoutpowderedactivatedcarbonadditiontothegasstreamusedinlargeMSWandcommercialmedicalwasteincineratorsaswellassomehazardouswasteincinerators;

wetscrubbersusedaloneinsewagesludgeincineratorinstallations,orincombinationwithpowderedactivatedcarbonandfabricfiltersinonehazardouswastefacility;

onehazardouswasteincineratoremploysanelectrostaticprecipitatorratherthanafabricfilterforparticulatecontrol;

onefacilityhasanactivatedcharbedfilterinstalledafteraquenchsystemandanotheronewillbeinstalledin2006;and,

onefacilityhasinstalledaselectivecatalyticreactorthatincludesprovisionstodestroyPCDD/Freachingthecatalystdownstreamofawetsprayhumifier/dryscrubber/PACinjection/fabricfiltersystem.

Detailsofthevarioustypesofincineratorsandairpollutioncontrolsystemsandtheirperformancecharacteristicsarepresentedinthereport.

PCDD/FSamplingMethods

MeasurementsofPCDD/FconcentrationsintheexhaustgasstreamsofcombustionsytemswererequiredtodeveloptheunderstandingoftheformationmechanismsandproveAirPollutionControlsystemperformance.SomeoftheearlyCanadiansamplingstudiesusedtechniquesthathavenowevolvedtoberecognizedasoneofthestandardmethodsforsamplingandanalysisofPCDD/Finstacks.TheEnvironmentCanadaproceduresareverysimilartothoseusedbytheUSEPA.SimilardevelopmentshavetakenplaceinEuropewherethreedifferentsamplingsystemshavebeendevelopedandapplied.Sincethemid1990smuchoftheemphasisinthisfieldhasbeenonimprovingmethodstoensurethatthequalityofthereportedresults,andtomeettheincreasingdemandsposedbylowerandloweremissionconcentrations.

ThemethodscurrentlyincorporatedinNorthAmericanandEuropeanregulationsandpermits

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aresimilar.Gasbeingexhaustedissampledbyextractingaportionoftheflowstreamisokinetically;filteringtheextracttoconcentratethespeciesofinterest;and,recoveringtheconcentratedsamplefromthesamplingsystemsothelaboratoryanalysiscanbecompletedusingHRGC/HRMStechniquesarethebasicstepsinallmethods.Beingsimilar,theyshouldproducesimilarresultsifthemethodsareemployedbytrainedsamplersandchemistswhotakecarewiththeirtasks.

Eveniftestersprovidereliablemeasurementresults,themethodshavelimitations.ItisdifficulttoquantifythemassofPCDD/Fpresentinsamplescollectedfromsystemsoperatingasverylowemissionrates,unlesslongsamplingtimesareemployed.Convertingthatquantitytoanemissionconcentrationmeasuringthesamplevolumeandthestackgasflow.Whenallthemeasurementsarecombinedsomeuncertaintyisinherentinthereportedresults.Thus,duetolimitsinthelevelofPCDD/Fthatcanbequantifiedandthevariationsinthesemeasurements,theEuropeanstandardincorporatesaproceduretodefinethelevelofquantificationforeachPCDD/Fcongenerandliststheuncertaintythatwasdeterminedforresultsfromalargecomparativetestingprograms.

InCanadatheapproachtodealingwithsampleswithlowconcentrationshasbeentoreferdirectlytothelaboratoryreports.Whenthelaboratoryliststheresultsasbeingbelowthedetectionlimit,thedetectionlimitvalueissubstitutedintothecalculationprocedurewhendeterminetheTEQvalueforthetest.TheresultingTEQvalueisthencomparedtoavalueof32pgITEQ/m3@11%O2,thevaluestatedbyEnvironmentCanadaasbeingthelevelofquantification,orthestackconcentrationlevelthatEnvironmentCanadasuggestscanbereliablymeasured.IftheresultinglevelislessthanthisEnvironmentCanadaLOQ,PCDD/Fareinterpretedashavingbeenvirtuallyeliminated.WhenreportingtoNPRI,sourceswithresultsbelow32pgITEQ/m3@11%O2canreportzeroemissions.

TheEuropeanapproachrequiresthattheconcentrationofeachcongenerbedeterminedandthesedatabeincorporatedintothecalculationoftheITEQvalueofthesample.IftheconcentrationofanycongenerislessthantheLOQderivedfromapplyingtheequationLOQi=0.5[pg/m3]/ITEFi,theITEQvaluefortheemissionconcentrationmustbereportedintwowaysusingthequantificationleveltosubstituteforvaluesbelowthatlevelandusingzerotosubstitutefortheconcentrationoftheparticularcongener.

Theimplicationsofthisapproacharethat,laboratoriesmightbeabletoreportlowervaluesandsomedo.Conversely,theLOQcalculatedfromthedatacanalsobeabovethepermissibleLOQ.Ifthisisthecase,andtheoverallITEQexceedstheapplicablestandard,thelaboratorymightberequiredtodomorecleanupofthesample,oranalysethesampleonanothercolumntoconfirmtheresults.Iftheproblemstillexists,theotheralternativeistoextendthesamplingtimetherebyincreasingthevolumeandthecongenerquantity.

Thevariabilityinsamplingresultswasexaminedintwostudies.InEuropetheresultsreflectthosefromcomparisonsamplingwithdifferentmethodsandusingdifferenttestingteams.The

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resultssuggestthattheexternalvariability,andhencetheuncertaintyofthemeasurementsofPCDD/F,was50pgITEQ/m3atameanmeasuredconcentrationof35pgITEQ/m3.Theresultssuggestthatnoconclusionsondifferencesinemissionscouldbemadeiftheresultsarelessthan85pgITEQ/m3becausethedataiswithintherangeoftheuncertainty.NorthAmericandatawasexaminedinastudyconductedfortheAmericanSocietyofMechanicalEngineers.Thisstudycomparedtheresultsofdualtraintestingatvariousvenues.Baseduponthedataavailableandanupper95%confidenceintervalthestudyfoundthat,at32pgITEQ/m3

theuncertaintyis18.6pgITEQ/m3.Theuncertaintyrisesto49.5pgITEQ/m3atanaverageconcentrationof80pgITEQ/m3.Theauthorofthestudyrecommendsthatmoredataattheextremesoftherangeisrequiredtoimprovethemodelused.TheNorthAmericanstudysuggestthatatthecurrentCWSlimitforincinerators,80pgITEQ/Rm3,theuncertaintyinthemeasuredvaluewouldextendfromlessthantheLOQtoapproximately130pgITEQ/Rm3.

WhilethereisconsiderablediscussionontheapplicationofthestandardPCDD/Fsamplingmethods,costsandtimelinessofdataavailabilityhavepromptedthedevelopmentofalternativeapproachesfordeterminingPCDD/Fconcentrations.TherearetwosimilarlongtermsamplingmethodsemployedinEurope.Theseessentiallycollectsamplesover30dayperiodsandthesamplesareanalysedbythesamemethodsusedforstacksamplingtrains.Theseapproachesofferalongersamplingperiodaveragewhichiscomfortingtopeoplewhoareconcernedthatnotallstacksamplingisconductedundertypicaloperatingconditions.Theyarealsolessexpensiveduetothereductioninmanpowerneededtocollectthesample.Havingnotbeenincorporatedintolegislationatpresent,thesemethodshaveseenonlylimitedapplication.

Anothermethodthatpromisesfastercheaperresultsisabioassayapproach.BioassayproceduresuseadioxinspecificantibodyfordioxinsanddioxinsimilarcompoundstodetectandquantifyasampledirectlyasanITEQsumvalue.Bioassaysareextremelysensitive(0.001pgrange),andcanbeusedforsampleswithaminorPCDD/Fcontent,typicallyfeedandfoodsamples.Indeed,inJapan,bioassaywasadoptedasoneofmeasurementmethodintheLawConcerningSpecialMeasuresagainstDioxins(DioxinsLaw).Onepresumesthatshouldthebioassaysuggestasamplehasfailedtomeetthelimits,therewouldbeaneedtoverifythisconclusionbycompletingthedetailedtesting.

PCDD/FRegulatoryStandards

Thereare210isomersofPCDD/Fand209isomersofPCBthatcouldbeidentifiedintheanalyticalprocedures.Trackingthesesubstancesforthepurposesof:settinglimits;identifyingcontroltechniques;or,evendeterminingthemechanismsbywhichtheyareformed,wouldbeextremelyonerous.WhenscientistsidentifiedthatparticularisomerswereresponsiblefortheeffectsnotedduringexposuretoPCDD/Ftheyreasonedthat,ifthedegreeofeffectcausedbydifferentisomerscouldbemeasured,itcouldbepossibletoexpresstheamountofPCDD/Fpresentbasedupontheanticipatedeffectofthemixture.Thus,theconceptofassessingPCDD/Femissionsonthebasisoftoxicitywasadopted.Thisapproachhasbecomeknownas

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theTEQortoxicequivalencemethod,baseduponapplyingtoxicequivalencyfactors[TEFs]thatrelatethetoxicityofeachisomertothatofthemosttoxicdioxincongener,namely2,3,7,8tetrachlorodibenzopdioxin(2,3,7,8TCDD).Twoschemeshavebeenusedoverthepast1520years.Thefirstschemewasbaseduponthe1989InternationalToxicEquivalencyFactors[ITEQ].ThesecondschemeevolvedfromincreasedknowledgeabouttheeffectsofthesechemicalsandincorporatesvaluesforthecoplanarPCBcompounds.Areviewoftheaffectoftheapplicationofthetwodifferentapproachessuggeststhatthelatestscheme,theWHO98TEFapproach,wouldaddabout15%tothetotalPCDD/Femissions.Todatenojurisdictionhasadoptedthisapproachtoexpressingemissionstandards.

Inreviewingemissionregulationsfromvariousjurisdictionsitisevidentthatnotallconcentrationsareexpressedinthesamemanner.Differentjurisdictionshaveattemptedtostandardizesuchreadingsbydefininghowtheresultsshouldbeexpressed.Whiletemperatureandpressureaffectgasvolumes,andarespecifiedinmoststandards,concentrationcanalsobeinfluencedbytheamountofairpresentinthegasstream.Ifmoreairisadded,theconcentrationisreduced,butthemassflowrateofthepollutantofinterestdoesnotchange.

Theregulatorystandardsfordifferentjurisdictionsareshowninthetableonthenextpage.TheEmissionLimitunitsareexpressedas[pgITEQ/Rm3@11%O2],wherethereferenceconditionsare25OCand101.3kPa.

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SummaryofInternationalEmissionRegulationsforPCDD/FfromIncinerators

COUNTRY Incinerator Type EmissionLimit

Comments

European Union All 92 diluent corrections note applied when < 11% O2Australian &New Zealand

All 92

Japan(based uponsize and age)

>4 Mg/hr 92 existing facilities have limit of 920

2 - 4 Mg/hr 920 existing facilities have limit of 4600

225 Mg/d c/w ESP = 25 w/o ESP = 21new all sizes = 9 ng total/Rm3 @ 11%O2small units 225existing Class I c/w ESP = 50 w/o ESP = 25existing Class II = 88 ng total/Rm3 @ 11%O2

Medical(existing)

1,61010,500

Existing urban total = 88 ng total/Rm3 @ 11%O2 Existing rural total = 560 ng total/Rm3 @ 11%O2

Medical(new)

182

1,610

725 kg/day batch (17.5 ng total/Rm3 @ 11%O2)

HazWaste 14278

without dry APCD system or waste heat boilerwith dry APCD or waste heat boiler

Commercial &Industrial Waste

287 >32 Mg/day capacity

Other SolidWaste

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TheCanadianIncineratorPCDD/FInventory

AspartoftheoriginalCanadaWideStandards[CWS]PCDD/Fcommitteesworkaninventoryofoperatingfacilitieswasassembledin2000.Theincineratorsoperatingatthattime,andtheestimatedemissionsfromthesefacilitiesaresummarizedinthetablebelow.

Baseduponthetotalnumberofincineratorsinthelist,54%wereusedformedicalwastedisposal.Themedicalwasteincineratorswereestimatedtoaccountfor72%oftheannualPCDD/Femissions.Theotherlargecategorywerethefacilitiesonfederallandswhichmadeupathirdofalltheincineratorslisted,howeverthesewereestimatedtoaccountofonly20%oftheannualemissions.Onlyafewofthemedicalwasteincineratorshadbeentestedatthetimetheinventorywaspreparedandnodatawasavailableforthefederalfacilities.Thus,emissionshadtobeestimatedbaseduponboththeestimatedtonnageprocessedbytheseincineratorsandemissionfactorsfromtheliterature.Theemissionfactorselectedforthesesourceswas4.67mgITEQ/Mgwasteburned.

Table1 SummaryofIncineratorsusedin2000EvaluationofPCDD/FEmissions

IncineratorClassification

Number of Incinerators by Province Totals

AB BC MB NB NF NT NS NU ON PE QC SK YK

Municipal 1 1 2 1 2 1 3 11

Medical 37 3 6 46 1 7 1 101

Hazardous 1 4 2 7

Sewage Sludge 5 2 7

Federal Entities 11 7 6 2 6 4 5 16 2 3 62

Remote

TOTALS 13 8 43 5 8 10 6 0 73 2 9 10 1 188


Estimated PCDD/F Emissions to Air [mg I-TEQ/yr] by Province Totals

AB BC MB NB NF NT NS NU ON PE QC SK YK

Municipal 1.4 6.6 117 13 2034 85 36 2293

Medical 9269 2.3 1501 9165 133 603 389 21,062

Hazardous 141 2.5 35 178.5

Sewage Sludge 82 29 111

Federal Entities 791 524 311 54 653 278 235 2709 124 87 5766

Remote

TOTALS 933 531 9580 56 770 1779 248 0 13,993 218 224 690 389 29,411

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ToupdatethePCDD/Femissioninventoryforincinerationfacilitiesforthisstudy,itwasnecessarytoestablishwhichfacilitieswereoperating,howmuchwastetheyburnannually,selectanappropriateemissionfactorforeachfacility,andprovideanestimateofthetotalemissionstocomparetothe2000numbers.The2005estimatesareshowninthetablebelow.

Table2 SummaryofIncineratorsandPCDD/FEmissions2005


NumberIdentified

WasteQuantity

Releases of PCDD/F[mg I-TEQ/year]

[Mg/year] Air Residues TotalLarge Municipal 7 762,793 60 4,139 4,198

Medical 42 8,082 3,142 81 3,222

Hazardous 9 204,418 257 610 867

Sewage Sludge 6 172,525 46 1,501 1,547

Federal Entities 30 1,087 159 9 168

Remote and Federal Lands 22 3,320 34 14 47

Totals 116 1,152,225 3,697 6,353 10,051

In2000,theonlyemissionsconsideredwerethosetotheatmosphere.Addedtotheinventoryfor2005isaestimateofthePCDD/Freleasedinresidues.Thenumberofoperatingincineratorsin2005,116,issignificantlyfewerthanthoselistedinthe2000inventory,188.Theactualnumberofincineratorslistedinthereportis119.Thelatternumberincludesthreehazardouswasteincineratorswhicheitherdidnotoperateasaseparatesystemin2005orforwhichnodefinitivedatacouldbegathered.TheBelledunefacilitywasnotoperatingin2005,butiscommissionedandcanoperate.ThecarbottomfurnaceatMRRcanonlybeoperatedinconjunctionwiththeotherfurnaceonsiteandemissionswereassumedtobecombined.Lastly,nothroughputdataisavailableontheSteacyfacility.The2006reviewidentifiedincineratorsthathavebeenaddedtotheinventorysince2000orweremissedfromthatinventory.Theseincludethreehazardouswasteincineratorsthatwerenotincludedin2000and22incineratorsatnewresourcedevelopmentsites.

Theclosureofolderfacilities,combinedwithadjustmentsintheestimatingprocedures,producesarevisedestimateforannualPCDD/Femissionstotheairthatisjust16%ofthe2000number,lessthan4gmITEQperyear.Thebiggestreductionsoccurredinthemedicalwastecategorywherethe2005estimateis15%oftheearliernumber.GiventhePCDD/Femissionfactorusedforearlierestimatesofthesewagesludgeincineratoremissions,theclosureoftheTorontofacilityreducedairemissionsforthiscategorybyover50%.SimilarreductionsareevidentinthelargeMSWincineratorcategory.Asignificantnumberofincineratorsoperatedbyfederalentitieshavebeenclosedleavingjust30incineratorsinthiscategoryandtheiremissionsareestimatedtohavebeenreducedtolessthan3%ofthepreviousnumber.Hazardouswasteincineratorsoperatinginthecountryhaveincreasedfrom7to12inthelisting,althoughmostoftheadditionalunitsarenotnew,justonesthatwereoverlookedinthepreviousinventory.Emissionstotheatmosphereforthiscategoryhaverisenbyover40%toanestimated0.26g/year.

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TheadditionofanestimateforthePCDD/Finresiduestreamsaddsapproximately6.4g/yeartothetotalPCDD/FreleasesfromincineratorsinCanada.Thisnumberdoesnotincludethecontributionofresiduesstreamsfromthehazardouswastesectorbecausedisposalvolumesfortheseunitswerenotavailable,notwasthereanyinformationontheamountofresiduetheyproduced.Alltheresidueemissionsareestimatedonthebasisofdefaultfactorsandwouldbenefitfromconfirmationbysitespecifictesting.

Thetotalemissionsfromincineratorsin2005,includingtheportionassignedtotheresiduestreams,isestimatedtobeapproximatelyonethirdofthatidentifiedfortheairemissionsonlyinthe2000inventory.

FindingsandConclusions

Duringthecourseofthestudy,22incineratorswereidentifiedashavingbeeninstalledatremoteminingandexplorationcampstoaddresstheneedforsafewastedisposalinareaswherelandfillingisnotapracticalwastemanagementoption.Theseunits,someservicingrelativelylargecamps,disposeofconsiderableamountsofwasteonadailybasis.AnothergroupofnewincineratorsinstallationswereidentifiedatvariousindustrialandcommercialinterestsinAlberta,butitwasnotascertainedwhetherthistrendhasoccurredinotherprovinces.Mostofthesenewunitsarebatchtypeincineratorsdesignedwithaprimaryandsecondarychamberthelatterbeingequippedwithatemperaturecontrolledsecondaryburner.NoneareequippedwithHRSGsandfewhavebeeninstalledwithAPCequipment.RegardlessofthelackofAPCequipmentontheseunits,limitedtestdatasuggeststhattheiremissionscouldmeettheCWSstandard.Goodcombustioncontrolintheseunitscoupledwithanafterburnerthatensuresthatminimalquantitiesofproductsofincompletecombustionarereleased,andstacktemperatureswellinexcessofthedenovosynthesiswindowexplainthisperformance.

Commercialwasteincinerators,thoseburningMSWandmedicalwaste,havebeenupgradedtomeettheCWS.MostofthisoccurredshortlyaftertheStandardwasadopted,andconsistentmonitoringdatashowsmostofthesefacilitiestoberecordingemissionconcentrationsthatarebelowthe32pgITEQ/Rm3@11%O2levelofquantificationstandarddefinedbyEnvironmentCanadaassatisfactorilyprovingvirtualeliminationforthatsource.LargecommercialhazardouswasteincineratorsdidnotmeettheCWSstandardasearlyastheMSWincinerators.Threeofthe6majorhazardouswasteincineratorslistedinaSeptember2004reporthadtestdatabelowtheCWStarget.ThisreviewhasshownthatthereisuncertaintyinthereportedPCDD/Fvaluesbutevenassumingtheworstcase,thecommercialMSWandmedicalwasteincineratorsarestillbelowtheCWSstandard.Ifthereporteddatawereassumedtobesubjecttoapositivebias,thehazardouswasteincineratorperformancemightbesatisfactorytomeettheCWS.

ThesamplingandanalysismethodsusedinCanadaarecomparabletothoseusedinEurope.ThelattermethodswererecentlyupdatedbytheEuropeanNormalisationCommissionandcanbeassumedtoreflectthebestavailabletechniquesforensuringrepresentativeemission

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concentrationsarereported.TheEuropeansamplingmethodsprovideanalternativewayofdeterminingthelevelofquantificationinasamplebaseduponreviewingthecongenerdataprovidedbytheanalyticallaboratory.WiththisapproachthecontributionofspecificcongenersisincludedoromitteddependinguponthequantitydeterminedintheanalysisandthecalculationoftheITEQvaluesisdeterminedontwodifferentdistributions.Thisclearlyshowsthepotentialimpactofusingdetectionlimit/quantificationlimitvaluesintheequivalencycalculationandovercomessomeoftheinconsistencieswiththewaytheresultsarepresented.

Similarregulatorystandardsareappliedtoincineratorsinmostjurisdictions.Thesestandardsareappliedregardlessofthewastetheincineratorisburning,orthesizeoftheincinerator,withtheexceptionofsomelowlevelcutoffs.FurtherexceptionstothisfindingwerefoundintheUnitedStatesofAmericawheredifferenttypesofincineratorsaresubjecttodifferentstandard,andinJapanwhereaslidingscaleofallowableemissionsbaseduponsizeisapplied.IntheUnitedStates,thestandardsweresetonthebasisoftheMACTprotocolwherethebest12%oftheexistingpopulationwereusedtosetthestandard.InJapan,thereappearstobearecognitionofthecosteffectivenessofaddingmoresophisticatedcontrolstolargerfacilities.

CanadasCWSPCDD/Fstandardsarethemoststringentinanynationallegislation.

ItdoesnotappearthatanycountryhasmovedtowardsadoptionoftheWHO98TEFfactorsintheirnationallegislation;however,giventheuncertaintyinPCDD/Fmeasurements,andthelimitedimpactthattherevisedTEFswouldhaveonthetotalWHO98TEQvalueformostoperatingfacilities,itsimplementationshouldhavelittlerepercussiononoperatingfacilities.

LargefacilitiesinCanadaarerequiredtoroutinelymonitorthestackemissionsofPCDD/FaccordingtotheCWS.Suchmonitoringappearstoberequiredannually,apracticethatisinlinewiththerequirementsoftheUSEPA,butlessfrequentthanthetwiceyearlytestingrequiredintheEuropeanUnion.Provinceshavetheoptiontoallowtestingfrequencytobechangedafteraconsiderableperiodofreportedconcentrationsbelowthe32pgITEQ/Rm3LOQleveldefinedbyEnvironmentCanada.TheCWSrequiresthatthisvaluebedeterminedusingdetectionlevelvaluesforcongenersthatarenotquantifiedduringtheanalyticalprocedure.TheCWSwouldappeartoimplythatsmallfacilitiesarethoseburninglessthan26Mgperyear.TheseunitsarerequiredtomakedeterminedeffortstoachievetheCWStargets,and,ifpossible,theyaretoprovethattheyindeedtomeetthesestandardsbyasingleroundoftesting.

Thisstudyhasidentifiedthatamajorlimitationinthedataavailablefrommanyofthenoncommercialfacilitiesisthelackofconsistencyindefininghowmuchwasteischargedtothefurnace.Thisleadsmanyfacilitiestofallintoasituationwheretheytrytorationalizetheirstatusasasmallfacilityonthebasisofthatthefacilitiesareusedinfrequently,eventhoughtheincineratorsratedcapacitywouldsuggestthatthefacilitycouldburnconsiderablymorethan26Mg/yror500kg/weekor70kg/day.

Typically,smallbatchincinerators,designatedbytheirhourlyburncapacity,willaccept

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between70and210kgofwasteperbatch,operatefor23hoursoneachbatch,andcanbecycledanywherefrom3to6timesperday.Thissuggeststhatthesesystemscouldprocess26Mg/yrifthesmallestunitwasrunoncedailythroughouttheyearbutthesameunitcouldprocessupto156Mg/yrifrunatthemaximumfrequency.Consideringthesmallestunitisratedat50lbor22kg/hrburnrate,itisclearthatmanyoftheseincineratorshavethepotentialtoexceedthesmallincineratordesignationintheCWS.

Ifthisrationaleisaccepted,mostincineratorsinthecountrythushavethecapacitytoexceedthesmallincineratordesignation.ThatmeansthattheCWSsuggeststhattheymustallbetestedannually.Giventhecapacityofthetestingindustry,theremotelocationsofmanyofthesefacilities,andthecostofcompletingsuchtesting,itisunlikelythatsuchtestingwillbecompleted.Thus,thereisaneedtoreconsidertherequirementsunderCWSwithrespecttothesizeoftheincinerators.

Recommendations

TheimplementationoftheCanadawideStandardsforPCDD/Ffromincineratorshasbeeneffectiveinreducingemissionsfromlargefacilities,andhasforcedtheclosureofmanysmallerfacilitiesthatcouldnotbeviablyupgradedtomeetthestandards.Furthermore,thisstudyhasshownthattheCWSPCDD/Femissionstandardsetstheworldsmoststringentemissiontargettherefore:

ItisrecommendedthatnofurtheradjustmenttotheCWSPCDD/Fnumericalemissionstandardsisnecessary.

Toclearlyenunciatetherequirementsdefinedbythestandard,giventhedefinitionofwasteincineration:

ItisrecommendedthatanysystemthatthermallytreatswastesforthepurposeofdisposalbesubjecttotheCanadawideStandardsforPCDD/F.

Whilenewthermaldestructiontechnologiesarebeingdevelopedandemployedinvariouscountries,theirapplicationinCanadawillrequirethattheymeettheCWSforPCDD/F.Toavoidanydebatesabouttheapplicabilityofnewtechnologiestomeetthesestandards:

Itisrecommendedthatanynewthermaldestructiontechnologyonlybeapprovediftheproponentcandemonstratethatthesystemwillmeettheemissionstandard,eitherthroughtheapplicationofasuitableairpollutioncontrolsystem,orbysubmittingvalidatedtestdatafromafullscalefacilityoperatinginanotherjurisdiction.Fullscalefacilitiesaretypicallydeemedtobeincommercialoperation,thatistheyarenotlargescalepilotfacilities,orevenproofofconceptdemonstrationunits.

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ThisstudyhasidentifiedagroupofexistingandnewincineratorsforwhichthemonitoringrequirementsoftheexistingCWSstandardarenotviable.Assuchthereareanumberofstepsthatcouldbetakentoaddressthesesystems.

Thereisevidencethatmostsmallincineratoroperatorsdonotroutinelyrecordwasteloadstotheirfurnacesandthusthetotalwasteprocessedinayearispoorlydefined.Sincesomestepsshouldbetakentoestimatetheannualemissionsfromsuchfacilities:

Itisrecommendedthatwastethroughputusedforannualemissioncalculationsforanysmallbatchincineratorshouldbebaseduponthedesignratedcapacityofthespecificincinerator.

Furthermore,itisrecommendedthatthenumberofbatchesassumedtobechargedtotheunitbebasedupon24dividedbytwicethemanufacturerscycletimefortheunitinhours.

Inanyoftheaboverecommendationsthedocumentidentifiedthatwhendefiningcapacityforanyinstallationisshouldbeinthebasisofallincineratorsinstalledonasite:

Itisrecommendedthat,forthepurposesofdefiningthestepsthatanoperatormusttaketoensurethatthefacilitymeetsalltherequirementsoftheCWSforPCDD/F,thetotalinstalledincinerationcapacityonagivenpropertybeused.

ThiswillresultinnewinstallationscomprisedofnumeroussmallincineratorsnotbeingabletoavoidtheprovisionsoftheCWSbyclaimingtheunitswerebelowthe26Mg/yearthreshold.

Largeincinerators,whoprovideaservicebaseduponatippingfee,shouldbeusingtheirannualtestdataandtheannualwastethroughputtocalculateannualPCDD/Femissions.However,thereiscurrentlylimitedinformationavailablefrommostfacilitieswithrespecttoPCDD/Finsolidresiduesthataretransferredfordisposalso:

ItisrecommendedthatPCDD/Finsolidresiduesshouldbeincludedintheannualemissionestimatesfromallincinerators.Proceduresandsuitabledefaultfactorsshouldbedevelopedtoaidinthesesubmissions.

Whilelargefacilitiesareroutinelytestedinmostjurisdictions,thesameisnotthecaseforsmallerincinerators.Indeed,eventhoughthedeterminedeffortsclauseoftheCWSsuggeststhataonetimeproofofeffectivenessshouldbecompletedforthesmallerfacilities,thishasnotbeenaccomplished.Suchtestingwouldimposealargefinancialburdenonsmallfacilities.However,thelimitedtestdatapresentedfornewequipmentshowsthatmoderntwostagesystemsarecapableofmeetingtheCWS.Toencouragetheuseofgoodincinerationpracticesthatwillassisttheoperatorinmeetingthestandards:

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ItisrecommendedthatjurisdictionsexploreopportunitiestoemployuptodateincinerationequipmenttoreplaceexistingsystemsthatwouldotherwiseneedtobeupgradedwithcomplexairpollutioncontrolsystemstomeettheCWS.

Furthermore,itisrecommendedthatjurisdictionsallowsuchequipmenttobeoperatedwithouttheannualtestingrequirementsprovidedtheoperatortakesappropriatemeasurestoensuregoodoperationandprovidesadequaterecordsofsuchoperation.

Coupledwiththeserecommendationsareaseriesofimplementationrecommendations.

CurrentlyavailabledatasuggeststhatnewincineratorsarecapabletomeetingtheCWSstandardswhenoperatedaccordingtothemanufacturersinstructions.

ItisrecommendedthatanymanufacturersellingabatchincineratorinCanadaobtainthirdpartycertificationthattheunitmeetstheCWSforPCDD/Fwhenburningthetypeofwasteintendedforaspecificinstallation.

Tofacilitatesuchcertification

Itisrecommendedthatamultistakeholdercommitteeconsistingofregulators,manufacturers,andtestingcompaniesbeconvenedtocommencethedevelopmentofacertificationprocedureforbatchincinerationequipment.

Suchsystemsshouldbeequippedwithcertainmonitoringequipmenttoensureproperoperationismaintained.Asawayofimplementingsuchmeasures:

Itisrecommendedthatequipmentthatachievescertificationcanonlybesoldwithamonitoringpackagecapableofrecordingpertinentoperatingparametersthatensurethesystemisbeingusedinthemanneritwasintendedtobeused.

Furthermore,itisrecommendedthatallinstallationsusingacertifiedincineratorshallinstallweighscalestorecordthechargeweightofeachloadchargedtotheincinerator.

Themonitoringpackageshouldbeconnectedtoacomputerwhichwillcontinuouslylogdatafromtemperatureprobes,differentialpressuremetersandauxiliaryfuelflow.Thedatafromthissystemwillbemadeavailabletoenvironmentalinspectorswhowillbeabletochecktheperformanceofthesystem.Thus:

Itisrecommendedthatthecomputermonitoringequipmentbeintegratedwithalltheoperatingcontrolsofthefacilityinamannerthatwouldfacilitateremoteaccesstothedatatoenablethemanufacturertoassisttheoperatorwithtroubleshootingtheoperationoftheunit.

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Furthermore,itisrecommendedthatarrangementsbemadesotheappropriateregulatoryorjurisdictionalauthoritycanaccessthedataremotelyforthepurposesofmonitoringtheoperation.

Theoperatorsofsuchequipmentmustunderstandtheirrolesinensuringappropriateperformanceandthusitisrecommendedthat:

Operatorsbetrained,eitherthroughanappropriatesitespecifictrainingprogramsorthroughacertificationprogramprovidedbyaqualifiedbody,ontheoperationoftheunit.

Operatorsbeinstructedtodistinguishbetweenbroadcategoriesofwaste,saypackagingversusfoodwaste,andbegivenclearinstructionsonhowmuchofeachcomponentitissuitabletochargethefurnacewithoneachload.

Theprovisionsforequipmentcertificationthatavoidtheneedforannualtesting,andthesuggestionthatcertainsystemsdonotneedAPCsystemstomeettheCWSonlyappliestosystemsthatventdirectlytotheatmosphereattemperaturesinexcessof600OC.Systemsequippedwithheatrecoveryboilershavethepotentialtohavehigheremissionsduetothegasesspendingtimeinthedenovosynthesistemperaturewindow.

ItisrecommendedthatanyownercontemplatingtheinstallationofaboileronawasteincineratorberequiredtoinstallanAPCsystemtoremovePCDD/Ffromtheexhaustgasstream.

Newer,simplersystemshavebecomeavailableandcanbeusedtolimitemissionswhilenotundulyincreasingthecomplexityofthesystem.

ExistingincineratorsshouldberequiredtoprovethattheyaremeetingtheCWSforPCDD/F.Tothatendseveralrecommendationsaddressthesmallsystemstilloperatinginthecountry.Manyoftheseincineratorshaveproducedlittledatatoenabletheiremissionstobeestimated.Indeed,annualwastethroughputdatawasnotavailableformostofthesesystems.Therefore:

Itisrecommendedthatallfacilitiesinstallscalesandstartrecordingtheamountofwastechargedtotheirincineratoralongwiththedateandtimeofthestartandcompletionofeachoperatingcycle.

Electronicrecordsshouldbecollectedtofacilitateanalysisofannualthroughput.

Sincemostofthesesystemsaresmall,batchincinerators,forwhichthecostofannualtestingmaybeprohibitive,ifitisdeemedappropriatetoallownewbatchinstallationswithoutPCDD/Ftestingrequirements,existingsmallbatchincineratorsshouldmeetsimilarrequirements.Thus:

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Itisrecommendedthatthesefacilitiesberequiredtoinstalltemperature,pressureandauxiliaryfuelflowmonitoringequipmenttoconfirmtheincineratorisoperatedappropriately.

Furthermore,itisrecommendedthatallrecords,monitoringdataandreportsrequiredshallbemaintainedatthesiteforaminimumperiodofatleasttwo(2)yearsfromthedateoftheircreationinahardcopyformatandasanelectronicrecordandshallbemadeavailableforinspectionbyregulatorystaff.

WhilethePCDD/Finventorywasupdatedforthisstudy,keepingituptodaterequiressomeinformationfromtheoperatingfacilities.Toimprovetheinventory:

Itisrecommendedthatallfacilitiesberequiredtofile,withtheappropriateregulatoryauthority,theirannualwastethroughputdata,bytheendofMarchinthefollowingyearstartinginMarch2008.Thisfilingshouldincludedetailsonthequantityanddispositionofresiduesdischargedfromthefacility.

Asnotedearlier,arecommendationwasincludedtoencouragethedevelopmentofmoredataonresiduequalityandvolumessotheinventorycanbeupdatedtoincludethecontributionoftheresidues.Lastly,whenthethroughputandresiduedatabecomeavailable:

ItisrecommendedthatthePCDD/Finventorydevelopedaspartofthisstudybeupdatedin2008bytheincorporationofwastethroughputandresiduegenerationdataalongwiththeresultsoftheresiduetestingprograms.

Basedupontheresultsofthisupdate:

ItisrecommendedthatsuitabledefaultfactorsforairemissionsandPCDD/Finresiduesbedevelopedtoaidinpreparingtheannualemissionestimatesfromallincinerators.

1 CEPA,1999.CanadianEnvironmentalProtectionAct,1999.1999,c.33[AssentedtoSeptember14,1999]Availableathttp://laws.justice.gc.ca/en/C15.31/

A.J.Chandler&AssociatesLtd.

1.0 INTRODUCTION

UndertheCanadianEnvironmentalProtectionAct1,thefederalToxicSubstancesManagementPolicy(TSMP)andtheCCMEPolicyfortheManagementofToxicSubstances,dioxinsandfurans[PCDD/F]weredesignatedasTract1substancesandscheduledforvirtualeliminationfromtheCanadianenvironment.ToachievethisgoaltheincidentalreleaseofPCDD/Finemissionsfromvariouscombustionsystemswastargettedforaction.DuringthedevelopmentoftheCanadaWideStandardforPCDD/F,thatculminatedintheadoptionbytheMinistersin2001,anumberofsourcecategorieswereconsideredforspecificrecommendations.Amongthesourceswasincinerationforwhichspecificairemissionstandardswereadopted.

UndertheadoptedCWSstandard,allneworexpandedincinerationfacilitieswererequiredtomeetanumerictargetandconfirmthatthishadbeenachievedthroughonetimetestingfollowingstartup.Existinglargeincinerationfacilitieswererequiredtomeetnumericstandardsby2006,andtoprovetheymetthestandardbyundertakinganannualtestingprogram.Existingsmallincinerators,definedasthoseincineratinglessthan

22 JacquesWhitford,2005.DioxinsandFuransCanadaWideStandardsEmissionInventoryUpdateandReviewofTechnicalPollutionPreventionOptions.AreporttotheCanadianCouncilofMinistersoftheEnvironment.

3 USEPA,2005.TheInventoryofSourcesandEnvironmentalReleasesofDioxinLikeCompoundsintheUnitedStates:TheYear2000Update(ExternalReviewDraft,March2005;EPA/600/p03/002A)http://www.epa.gov/ncea/pdfs/dioxin/2kupdate/


ApreliminaryreviewoftheprogressmadeontheCanadaWideStandardforPCDD/FwasconductedforCCMEin20052.Thatreportmadeanumberofrecommendationsthatwereincorporatedintothescopeofthisstudy.Thestudyteamnotedthattheyhadnotbeenabletocorrelatethe2000PCDD/Finventoryestimateswithdataavailableinthe2004NPRIlistings.Theysuggestedthattherewasaneedtomakethelinkbetweenthetwolistsmoretransparentandatthesametimeevaluatethequalityoftheinventorydata.Furthermore,thestudyteamsuggestedthattheirexaminationoftheliteratureindicatedthatemissionswerenotreportedinaconsistentmannersoitwasdifficulttocompareliteraturedatatoavailableemissioninformation.

Toprovidethebackgroundfortheemissionestimatesderivedinthisreport,incineratortechnologiesandairpollutioncontrolequipmentcapabilitiesarereviewed.Asanextensionofthetechnologydescriptions,typicaltestdatafromvariousfacilitiesarereviewedanddiscussedwithrespecttothecurrentunderstandingoftheformationofPCDD/Fincombustionprocesses.Suchdatacanbeinterpolatedtoprovidebetterestimatesofemissionsfromincineratorsinstalledinthelastfiveyears.Moreover,toimprovethetransparencyoftheemissionestimatesderivedinthereport,adiscussionofallaspectsofemissioninventorydevelopmentisprovidedandtheinventoryisbaseduponrecommendationsforcalculatingtheappropriatefactors.

1.2 Nomenclature

Aspointedoutinthe2005review,partoftheproblemmanypeoplehavewhenreviewingdataonPCDD/Femissionsisthatthedataarenotexpressedinaconventionalconcentrationmanner.ThisisbecausethetermPCDD/Freferstomanyorganicspecies.

Thepolychlorinateddibenzopdioxins[PCDD],thepolychlorinateddibenzofurans[PCDF]andthepolychlorinatedbiphenyls[PCB],thethreeorganicspeciesofparticularinterestinthisreport,aresimilarinnature.Theirgeneralmolecularstructureconsistsoftworingsofsixcarbonatoms(benzenerings,asshowninFigure11)boundbyoxygenatom(s)(shownasOinthefigure)withchlorineorhydrogenatomsattachedinthenumberedpositions.Thereare75differentconfigurationsforthechlorineatomsassociatedwithPCDDs,eachofwhichisknownasanisomerorcongener.Theyarefoundin8groups,definedashomologuesorcongenergroupsintheUSEPA3.Homologuesaredividedbaseduponthenumberofchlorineatomspresentontherings(1,2,3,4,5,6,7or8).Similarly,thereare135PCDFcongenersalsodividedinto8homologues.

3A.J.Chandler&AssociatesLtd.

Figure1.1 SchematicDiagramsofPCDD,PCDFandPCBs

44 Ahlborg,VG;Becking,GC;Birnbaum,LS;etal.(1994)ToxicequivalencyfactorsfordioxinlikePCBs.Chemosphere28(6):10491067.

5 USEPA,(1989a)Interimproceduresforestimatingrisksassociatedwithexposurestomixturesofchlorinateddibenzopdioxinsanddibenzofurans(CDDsandCDFs)and1989update.Washington,DC:RiskAssessmentForum.EPA/625/389/016.

6 Kutz,FW,Barnes,DG,Bottimore,DP,Greim,H,Bretthauser,EW.1990.Theinternationaltoxicityequivalencyfactor(ITEF)methodofriskassessmentforcomplexmixturesofdioxinsandrelatedcompounds.Chemosphere,20,751757.


Polychlorinatedbiphenyls[PCBs]aremorecomplicatedthanPCDD/Fs.Thereare209PCBcongeners,ofwhichonly13werethoughttobesimilartodioxins:thosewithfourormorelateralchlorineatomswithoneornosubstitutionintheorthoposition4.Thesecompoundsaresometimesreferredtoascoplanar,meaningthatthetwobenzeneringsareonthesameplanegivingthemoleculeaflatstructure.

Forallthesechemicals,thephysical/chemicalpropertiesofeachisomervariesaccordingtothedegreeandpositionofchlorinesubstitution.

Ascanbeappreciatedtryingtodocument,letalonetrackandsetlimitsfor210PCDD/Fisomersand13specificPCBcongenerswouldbeexceedinglydifficult.Indeed,duringtheNITEPPEIstudiesconductedforEnvironmentCanada,theresultsforthePCDD/Fsweremerelyreportedasthehomologuevalues,withthesumofthehomologuesbeingthedatathatwaspublishedforPCDD/Femissions.PCBswerereportedasthesumofallPCBhomologuesmeasuredduringthattesting.Itwasnotuntilafterthatstudy,conductedin1984,thattheconceptofassessingPCDD/Femissionsonthebasisoftoxicitywasadopted5.ThisapproachhasbecomeknownastheTEQortoxicequivalencemethod,baseduponapplyingtoxicequivalencyfactors[TEFs]thatrelatethetoxicityofeachisomertothatofthemosttoxicdioxincongener,namely2,3,7,8tetrachlorodibenzopdioxin(2,3,7,8TCDD).ThisconceptwasinitiallyappliedforPCDD/Fcongeners,andonlymorerecentlyhasitbeenextendedtoincludePCBs.ThemostcommonTEFvaluesusedthroughoutthe1990sweretheInternationalfactors(ITEF)6.ThesumofthePCDD/FemissionsexpressedinthismanneraredesignatedintheliteratureasITEQvalues.Forthemostpart,allconcentrationsreferredtointhisreportareexpressedinthismanner,asdesignatedbytheinclusionofITEQinthedefinitionofmass,ie.pgITEQ/g.

Otherconventionsrelatedtodescribingemissions,namelytheinclusionofdiluentfactorsanddifferenttemperaturesstandards,ortheusealternativetoxicequivalencyschemesareintroducedintheappropriatesectionsofthisreport.


1.3 ReportStructure

Thisreportisorganizedintothefollowingchapters:

Chapter2PCDD/FFormationprovidesabriefoutlineofthecurrentunderstandingoftheformationofPCDD/Fasameansofexplainingwhythemainwayofcontrollingtheirreleaseisgenerallytoapplygoodcombustionpractices.

Chapter3IncinerationProcessessummarizesthetypesofincineratorsystemsusedinCanadaandhoweachattemptstoaddresstherequirementforprovidinggoodcombustioncontrol.

Chapter4AirEmissionControlStrategiesprovidesadiscussionofairpollutioncontrol(APC)systemswithanemphasisonthemethodsusedtocontrolthereleaseofPCDD/Fpresentinthegasesleavingthecombustionportionofthefacility.

Chapter5PCDD/FSamplingMethodsreviewsthesamplingmethodsusedbydifferentjurisdictionstodeterminetheamountofPCDD/Fbeingemittedintheexhaustgasstream.

Chapter6ReportingMeasurementResultsdiscusseshowdifferentjurisdictionsexpressPCDD/Fmeasurementresultsandidentifiesconversionprocedurestoallowcomparisonofresults.

Chapter7PCDD/FEmissionRegulationsprovidesasummaryofthePCDD/FemissionslimitsthatareinplaceinAustralia,EuropeanUnion,Japan,NewZealand,andtheUnitedStates.

Chapter8EmissionDataprovidesasummaryoftheavailableemissiondataforincineratorsoperatinginCanadainfourmaincategories(largeMSWincinerators,medicalwasteincinerators,hazardouswasteincinerators,andsewagesludgecategories)andalsoprovideslimiteddataonsmallbatchincinerators.

Chapter9AlternativeEquivalencyFactorsprovidesadiscussionofalternativestotheITEQequivalencyfactorsandexaminestheeffectofusinganalternativeequivalencyfactoronCanadianincineratoremissionmeasurementresults.

Chapter10FindingsandConclusionsprovidesasummaryofthemainfindingsandconclusionsofthisreport.

Chapter11Recommendationsprovidesrecommendationsbasedonthefindingsandconclusionsofthisreport.

7 Chandler,A.J.,2002.TechnicalPollutionPreventionOptionsforIncineratorsAReportPreparedforTheCanadianCouncilofMinistersoftheEnvironmentInc.byA.J.Chandler&AssociatesLtd.WillowdaleON.September2002


2.0 PCDD/FFORMATIONPCDD/Freleasesfromcombustionprocessesisgenerallyconsideredtobeunintentional.Thatis,theprocessisnotdesignedtocreatethesecompoundsandtheirpresenceisindicativeofeithertheirlackofdestructioninthecombustionprocess,ortheirformationbysomemechanismsoperatinginthefurnace.Thischapterprovidesabriefoutlineofthecurrentunderstandingoftheirformationasameansofexplainingwhythemainwayofcontrollingtheirreleaseisgenerallytoapplygoodcombustionpractices.AdetaileddiscussionofPCDD/FformationisincludedinaCCMEcommissionedreportonwastemanagementpollutionpreventionalternatives7.Thatdocumentprovidesthefollowingsummaryoftheissuessurroundingformationandcontrol:

TheformationofPCDD/Fastracebyproductsofcombustionprocesseshasbeenstudiedextensivelysincethemid1980swithmuchoftheresearchbeingconductedonmunicipalsolidwasteincinerators.Thisstudyhasdeterminedthatformationisahighlycomplexphenomenainvolvingmultiplegasandsolidphasereactionsbetweenminutequantitiesofreactants.TwomaintheoriesregardingthemechanismofformationofPCDD/Fduringcombustionprocesseshavebeendeveloped.Thesetheoriesshouldnotberegardedasbeingmutuallyexclusivefromoneanothersincetheymayactincombinationduringthecombustionofanycarbonaceousmaterial.

ThedenovosynthesistheoryisconsideredthemajormechanismbywhichPCDD/Fareformedinthermalindustrialprocesses.ThistheorysuggeststhatPCDD/Fisformedinthepresenceofflyashcontainingchemicallyunrelatedunburntaromaticsandmetalcatalysts.Gasphasechlorineisbelievedtoformmetalchloridesonthesurfaceoftheflyash.Themetalchloridessubsequentlyreactwiththecarbonstructuresontheflyash.Thisisfollowedbymetalcatalyzedoxidation/gasificationoftheflyashsurface,whichreleasesvariouschlorinatedorganiccompoundsincludingPCDD/F,chlorophenols,chlorobenzenes,andaliphatics.Thesereactionsmustoccurinthepresenceofoxygenandcatalystsformedfromtransitionorheavymetals.Moreover,researchersfoundthattemperaturesintherangebetween250OCand450OCweremostlikelytoresultinhigherPCDD/Fgeneration.Formanyincinerators,thistemperaturerangeisonlyfoundinthepostfurnaceregion,typicallythewasteheatboilerorinelectrostaticprecipitators(ESP).Denovosynthesisexperimentssuggestthatmorefuranthandioxincongenersareformed(ie.,PCDF:PCDD>1.0)alongwithotherchlorinatedorganiccompounds(eg.,PCBs,chlorobenzenes,chlorophenols,chlorinatedpolycyclicaromatics).

ResearchershaveconcludedthatthebasicsetofconditionsrequiredfordenovosynthesisofPCDD/Fareasolidmatrixcontainingcarbonstructures,organicorinorganicchlorine,copperorironions,anoxidizingatmosphere,andanoptimaltemperaturerangeof250to


450OC.

ThePrecursorTheorysuggestssimplythatthevariouschemicallyrelatedchlorinatedaromaticsundergocondensationreactionsonflyashsurfacesinthepresenceofmetalcatalysts.Thus,twoprecursormoleculesarecoupledtoformadioxinorfuranstructure.Inthistheory,theprecursorcompoundsmusthaveastructuralresemblancetodioxinandfuranmolecules.Theoptimaltemperaturerangefordioxinandfuranformationoverwhichtheprecursortheoryoperatesisthesameasthatobservedfordenovosynthesis(i.e.,250to450EC).Therefore,formationofPCDD/Ffromprecursorsmustalsooccurinthepostcombustionzonesofthermalprocesses.ThistemperaturerangeisoftenconsideredthewindowofopportunityforcatalyticformationofPCDD/Fonsurfacesofflyashparticles.

Boththedenovoandprecursortheorieshavebeenvalidatedinlaboratorystudies;however,therelevanceofeachtheorytoactualcombustionscenariosinthefieldhasnotbeenwellestablished.Themaindifferencebetweenthesetwotheoriesrelatestothecarbonsource.Itislikelythatfurtherresearchmayblurthedistinctionbetweenthesetwotheories,suchthatthecarbonsourceinPCDD/Fformationisderivedbothfromcondensationofgasphaseorganicsandvolatilizationofflyashderivedorganics,withtherelativeattributiondependentonfacilityandprocessspecificvariables.Thus,thetwotheoriesarenotnecessarilymutuallyexclusive.TheformationofPCDD/Finthermalprocessesisundoubtedlytheresultofacomplexsetofcompetingchemicalreactions.

RegardlessofwhichtheoryortheoriesbestexplainshowPCDD/Fareformedduringthermalprocesses,certainconditionsthatactincombinationtoincreasethepotentialforPCDD/Fformationhavebeenwellcharacterizedinthescientificliterature,particularlythosestudiesconductedwithmunicipalsolidwasteincinerators.Theseconditionsinclude:

incompletecombustionofafuel anoxidizingatmosphere presenceofachlorinesource flyashsurfaces(carbonsource) flyashwithdegeneratedgraphiticstructures(moreorderedcarbonatom

arrangementsarelesspronetodecompositionreactions) presenceofcatalyticmetals(especiallycopper,butiron,manganeseand

zincarealsoindicatedaspotentialcatalystsforPCDD/Fformation) temperature/timehistoryofatleast1secondatlessthan600OC(optimal

temperaturerangeliesbetween250and450OC)

Fromthisitfollowsthatgoodcombustion,whichreducestheconcentrationofproductsofincompletecombustion,boththegaseousandsolidforms,mustbethefoundationofanymeasurestoreducePCDD/Femissionsfromincinerators.Theotherattributesrelate


totheconditionsandsubstancesfoundintheincineratorand,aftergoodcombustioncontrolhasbeenemployed,littlecanbedonetochangethesesituations.

Onthebasisofthislist,somehavesuggestedthatcontrollingtheamountofchlorineinthesystemmightinfluencethegenerationofPCDD/F.ConsistentanalysisoftheavailabledataindicatesthatchangingtheamountofchlorineinwastestreamsdoesnothaveadiscernibleimpactonPCDD/Femissionsfromwasteincinerators.Therefore,itisunlikelythatinterventionstoreducetheamountofchlorineinwastewillproduceanyappreciableeffectonPCDD/Femissions.

FromtheforegoingitcanbeseenthatgoodcombustionisnecessarytoensurelowPCDD/Femissions.Forengineersandscientiststhephrasegoodcombustionhassomemeaning,butwhataretheimplicationsforregulatorsormembersofthepublictryingtograpplewiththepotentialperformanceofnewincinerators?Moreover,withmanyinfrastructureprojectsbecomingapublic/privatepartnership,howdopoliticiansandfinanciersjudgethesuitabilityofaparticulardesignfortheirspecificrequirements?

2.1 CombustionControlPrinciples

Combustioncontrolmustcompensatefor:

thenaturalvariabilityinfuelquality;and, thecontrollingfactorsthatgoverntherateofchemicalreactions.

SewagesludgeandliquidhazardouswastesaremorehomogeneousthanMSWandmedicalwastestream,therebyiteasiertocontrolcombustioninincineratorsusedfortheirdisposal.However,variabilityinthefuelstillmustbeaddressed.Incineratoroperatorsunderstandtheneedtokeeptheoperationatasteadyleveltoachievethebestperformance.Eachcomponentofawastestreamhasitsinherentenergycontentandthismustbematchedwithsufficientoxygentoensurepropercombustion.Becausethemixofcomponentscanchange,somemeansmustbeprovidedtoallowthesystemtohandlethisvariability.Ensuringthatthewasteiswellmixedbeforeitischargedtothefurnaceisthefirststep.Theremainingvariabilityinthefuelmustthenbehandledbyawelldesignedfurnace.

Typicallycombustioncontrolsystemscompensateforthefuelvariability.TwostagestarvedairsystemsandkilnsystemsgenerallyrelyuponmaintainingalargequantityoffuelinthekilntodampoutthevariabilityinthewastequalitywhereasconventionalmassburnMSWincineratorsmustrespondtotheheatreleasebyadjustingtheairflow.Bysensingtherateofheatreleaseinthefurnaceandadjustingthesupplyofcombustionairthecontrolscompensateforespeciallyhighorlowheatreleaserates.Alternatively,somedesignersadjustthefuelfeedratestocompensateforthecalorificvaluevariability.

Theimportanceofthecontrolstepscannotbeoveremphasizedbecausethethermaldestruction

98 Miller,J.A.andG.A.Fisk,1987.CombustionChemistry.C&ENAug.31,1987;pp2248.


oforganicsisnotasimpleprocess.Manyintermediatestepsareinvolvedintheoxidationoflongchainhydrocarbonmaterialstotheproductsofcompletecombustionnamelycarbondioxide(CO2)andwater.Generally,itisagreedthatthereactionoccurringinthefuelbedisoneofgasification,withthewastebeingexposedtoairwhilebeingheated.Theamountofairaddedunderthebedofmaterialandthedegreeofagitationofthebedcontrolstherateofgasgeneration.Thegasesthatleavethebedarerichincarbonmonoxideandhydrogenandcontainmanyunburnedhydrocarbons.Whenprovidedwithadditionalairthesegaseswillburnreadily.Thisadditionalairisnormallyreferredtoasoverfireairandissuppliedabovethebed.Thedegreetowhichthecombustionprocessiscompletedisafunctionofhowwelltheairandthegasesaremixed.Theamountofcarbondioxidegenerateddefinestheextentofcombustioncompletionandisgenerallyreferredtoasthelevelofcombustionefficiency.CompletecombustionwillresultinthegenerationofCO2andwatervapouronlybutthisisrarelythecaseassometracesoforganicmaterialscanusuallybefoundinincineratorexhauststreams.

Carbonmonoxide(CO)isthemostrefractory,ordifficulttooxidize,speciesintheoxidativechainfromhydrocarbontocarbondioxideandwater.TheoxidationofCOtoCO2isaccomplishedmuchfasterinthepresenceofhydrogen.MillerandFisk8suggestthedominantreactioninthechainis:

CO+OH>CO2+H

Theconcentrationofhydroxylradicalsisthusveryimportantinthereaction.However,thereactionbetweenhydroxylradicalsandhydrocarbonsisfasterthanthatbetweenCOandOHanditisnecessarytoconsumeallthehydrocarbonsinthesystembeforethesystemcanmaximizetheconversionofCOtoCO2.ThushighlevelsofCOaregenerallycorrelatedwithhigherlevelsofresidualhydrocarbonsillustratingtheratelimitingstepsinthereaction.

Ifexcessiveairispresentinthefurnace,thecombustiontemperatureandtheconcentrationofhydroxylradicalsarereduced.Inturn,theorganicsreactwiththeOHradicalsandtheCOoxidationdoesnotoccur.Conversely,insufficientaircanleadtopocketsoffuelrichgasthatlacksufficientoxygentooxidizetheCO.Itispossibletoestablishanappropriaterangefortheconcentrationofoxygeninanysystem.OperationinthiszoneminimizesthereleaseofCOandthusalsominimizestraceorganicreleases.Theestablishmentofthisrangeismostimportantbecause,oncedeterminedforasystem,itcanbeusedtoensurethatthesystemisoperatingatitsmostefficientlevel.

Goodcombustionconditionsleadingtoreducedorganicemissionsarethosethat:

ensurecompletemixingofthefuelandtheair; maintainhightemperaturesinthepresenceofsufficientoxygen;and,

10

9 McKay,Gordon,2002.Dioxincharacterisation,formationandminimisationduringmunicipalsolidwaste(MSW)incineration:review.ChemicalEngineeringJournal86(2002)343368.Availableat:http://www.seas.columbia.edu/earth/wtert/sofos/mckay_dioxinformation_2002.pdf.

10 NITEP,1986.TheNationalIncineratorTesting&EvaluationProgram,(NITEP),AirPollutionControlTechnology.EnvironmentCanada,ReportEPS3/UP/2,September.

11 Chandler,A.J.,2003.BackgroundStudyontheIncinerationofHazardousWaste.FinalDraftofAReporttoENVIRONMENTCANADAtocompleteContractNumberK223720006.PreparedbyA.J.Chandler&AssociatesLtd.Toronto.March


preventtheformationofquenchzonesorlowtemperaturepathwaysthatwouldallowpartiallyreactedsolidsorgasestoexitfromthecombustionchamber.

Thesedesignconditionsmustbecombinedwithgoodoperatingconditionstoensurethattheperformanceismaintainedandorganicconstituentsarereducedtothebasicelements.AsnotedbyMcKay9itisparticularlyimportanttopreventthegenerationofsootinthesystem,becausesootconsistsofcarbon,andasdiscussedintheprevioussection,carbonintheflyashoftheincineratorwillleadtoPCDD/Fformation.

Whilecombustioncontrolisgenerallydesignedtoaddressthedestructionoforganiccompounds,adjustingcombustionconditionscanalsoinfluencethedownstreampartitioningofinorganicmaterialsintheincinerator.Highertemperaturesinthefurnaceinfluencethenatureofthecompoundsformedinthefurnaceandwhetherthesecompoundsarevolatilizedortransportedinsolidphasewiththeexhaustgases.Highertemperaturesandmorecompletecombustionresultintracemetalsbeingfoundfurtherdownthesystem,particularlyintheAPCresiduestream.SuchconditionswerenotedduringtheNITEPMSWsystemtestingatPEIinthemid80s10.Ofcourse,sincetracemetalemissionsmustbealsobecontrolled,theairpollutioncontrolsystems,discussedlaterinthisreport,mustfulfillvariousroles.Whilenofurtherdiscussionoftherelationshipsbetweencombustionandtracemetalsemissionsiscontainedinthisreport,thereaderisreferredtootherdocumentsforadetaileddiscussiononthosecontaminants11.

TheconditionsthatleadtoareductioninorganicemissionsalsocancauseanincreaseinthegenerationofNOx.TheformationofNOxisattributedtotwomechanisms:theoxidationofthefuelnitrogentoNOx;andthecombinationofnitrogenandoxygenincombustionairathightemperatures,thethermalNOxportion.TheconversionoffuelnitrogentoNOxisdependentuponthelocaloxygenavailabilitytovolatilespecies,theamountoffuelboundnitrogenandthechemicalstructure.ThethermalNOxreactionisstronglytemperaturedependentbecauseitisformedbythecombinationofradicalsofthetwospecies.Ithasbeenshownthattheconversionoffuelnitrogencanrangefrom5%to50%controlledlargelybytheextentofmixingandthecontentofoxygen.

Partofthepreviousdiscussionindicatedthatifdenovosynthesisistooccurseveralconditionsmustbesatisfied,nottheleastofwhichishavingthegasandparticulateparticipatinginthe

11

12 Hagenmaier,H.,M.Kraft,H.Brunner,andR.Haag,CatalyticEffectsofFlyAshfromWasteIncineratorFacilitiesontheFormationandDecompositionofPolychlorinatedDibenzopdioxinsandPolychlorinatedDibenzofurans,EnvironmentalScienceandTechnology21,pp.10801084,1987


reactionspendsufficienttimeinthetemperaturerangeconducivetosuchsynthesis.Typicallyheatrecoverysteamgenerators[HRSG],orboilers,areusedatMSWincineratorfacilitiestoconverttheenergyinthewastetousefulformsofenergyfordistrictheatingorelectricityproduction.Temperaturesinsuchdevicesareintheappropriaterangetoencouragethesynthesisreactions.Thusonewouldexpectthat,giventhesamecombustionefficiencyinanMSWincineratorsandasewagesludgeincinerator,thePCDD/FemissionsfromtheMSWincineratormightbehighergiventhatHRSGdevicesaremorelikelytobeusedinMSWfacilitiesthanonsewagesludgeincinerators.Similarly,boilersarenottypicallyinstalledinhazardouswasteincineratorsorbiomedicalwasteincinerators.

WhilemuchoftheresearchemphasishasbeenfocussedondefiningtheconditionsconducivetominimisingemissionsofPCDD/Fthroughthestack,themechanismsdiscussedabovealsohaveimplicationsforsolidresiduestreamsgeneratedbycombustionequipment.Obviously,ashfromthegrateofsolidfuelcombustiondevicewillbeexposedtotemperaturesinexcessofthatconducivetoformation,indeedtemperaturesintherangewhereanyPCDD/Fwillbedestroyed.RapidquenchingofashdischargedfromthegratesshouldminimisethepotentialforanyPCDD/Finthatwastestream.Ontheotherhand,residuesfromheatrecoverysystems,whichoperateinthecriticaltemperaturezonemaybeexpectedtohavesomePCDD/Fpresent,buttheamountwilllikelyvarywiththetemperatureregimewheretheashwascollected,andthetimetheashwasinthegasstreamatthesetemperatures.ThissuggeststhatthePCDD/Fformationprocessesrelatedtodenovosynthesisorprecursorsmaybeinhibitedifthegassesleavingthesystemarerapidlyquenchedtobelowtheoptimaltemperatureranges.Ofcourse,thecorollaryisalsotrue.IfPCDD/FmaterialsareexposedtoelevatedtemperaturesintheabsenceofoxygenthePCDD/Fwillbedestroyed.BaseduponhisresearchHagenmaier12

developedtheheatsoaktechnologyinGermany.ByheatingtheflyashinanatmospherewithlittleornooxygenPCDD/Faredestroyed.ThisapproachisnowbeingsuccessfullyusedforPCDD/PCDFdecontaminationofflyashandotherresiduesmainlyinEuropeandJapan.


3.0 INCINERATIONPROCESSES

3.1 Introduction

ThepreviouschapteridentifiesincineratoroperatingcharacteristicsthatareanticipatedtogiverisetoinadvertentproductionofPCDD/F.TounderstandhowthesefactorsmightrelatetoPCDDD/FemissionsthischaptersummarizesthetypesofincineratorsystemsusedinCanadaandhoweachattemptstoaddresstherequirementofprovidinggoodcombustioncontrol.WiththelikelihoodthatsomePCDD/Fmaybereleasedevenfromthebestoperatingincinerators,airpollutioncontrolsystemscanbeemployedasthelastoptiontominimizethereleaseofPCDD/Ftotheatmosphere.Theavailableairpollutioncontrolsystemsarediscussedinthenextchapter.

Figure3.1isageneralizedschematicofanincinerationsystem.Notallcomponentsshowninthediagramareinstal

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Review of Dioxins and Furan From Incineration CSR

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