Sediment-associated constituent release at the mud-water interface due to monochromatic waves

346 Pages·1996·11.7 MB·English

by  Li, Yigong

SEDIMENT-ASSOCIATEDCONSTITUENTRELEASEAT
THEMUD-WATERINTERFACEDUETOMONOCHROMATICWAVES
By
YIGONGLI
ADISSERTATIONPRESENTEDTOTHEGRADUATESCHOOL
OFTHEUNIVERSITYOFFLORIDAINPARTIALFULFILLMENT
OFTHEREQUIREMENTSFORTHEDEGREEOF
DOCTOROFPHILOSOPHY
UNrVERSITYOFFLORIDA
1996
ACKNOWLEDGMENT
Firstofall,Iwouldliketoexpressmydeepestgratitudetomyadvisorandthe
chairmanofmysupervisorycommitteeProfessorAshishJ.Mehta,forhisconstructive
direction,enthusiasm,adviceandunflaggingsupportthroughoutthisfouryearstudy,which
hasbeenachallenging,joyfulandunforgettableexperienceinmylife.
IwishtothankProfessorsKirkHatfieldandRobertG.Deanfortheircontinuously
valuableadvice,suggestionsanddiscussions. Thanksarealsoduetotheothercommittee
members,includingProfessorPeterY.ShengandProfessorBrijM.Moudgilfortheiradvice,
commentsandpatienceinreviewingthisdissertation.
Appreciationisextendedtoallotherfacultymembersinthedepartment,aswellas
thoseintheDepartmentofAerospaceEngineeringMechanicsandEngineeringScience,
CivilEngineering,AgriculturalEngineering,SoilScienceandChemicalEngineeringfor
supplyingvariouscomponentsofknowledgeessentialforthepursuitofthisstudythrough
theircreativeteachingefforts.
Gratitudeisduetodepartmentalstaff,especially,Mr.SydneySchofield,Mr.Jim
JoinerandMr.GeorgeChappellattheCoastalEngineeringLaboratoryfortheircoorperation
andhelpduringtheexperimentalphaseofthisresearch. Supportalsocamefrommany
friendsandfellowresearchassistants.
ii
SpecialthanksgotoSandraBivins,BeckyHudson,LucyHamm,CynthiaVey,John
DavisandHelenTwedellfortheirkindness,whichhelpeddirectlyorindirectlyinthe
completionofthisstudy. DeepappreciationgoestoDr.FengJiang,Dr.XinjianChenand
Dr.Say-ChongLee,withwhosehelpIgotthroughthehardinitialperiodofmystayin
Gainesville. AppreciationalsogoestoMr.PaulDevine,Mr.AhmadTarigan,Mr.Hogo
Rodriguez,Ms.XuWang,Ms.JieZheng,Dr.TaerimKim,Mr.EduardoYassuda,Mr.Mike
KrecicandMr.AlbertBrowderfortheirassistanceandusefuldiscussions.
FundingforthisworkcamefromU.S.ArmyEngineerWaterwaysExperiment
StationatVicksburg,Mississippi. Thecontaminantportionoftheworkwasfundedby
contractDACW39-95-K-0023throughtheEnvironmentalLaboratory,andthesedimentpart
bycontractDACW39-95-K-0022throughtheHydraulicsLaboratory. Assistanceprovided
especiallybyDr.MarkDortchandDr.T.M.Parchureinprocessingthecontracts,managing
themandprovidingvaluabletechnicalguidanceissincerelyacknowledged.
MyfinalacknowledgementisreservedforthosewhomIprobablyowethemost,my
wife,WendyS.Tan,forherlove,support,encouragementandpatiencethroughout these
fouryears,andmyparents,whoinstilledinmetheworkethicandvaluesthathaveallowed
metomakeitthisfar,andhavesupportedmeallmylife.
iii
TABLEOFCONTENTS
ACKNOWLEDGMENT ii
LISTOFFIGURES viii
LISTOFTABLES xiii
LISTOFSYMBOLS xv
ABSTRACT xxx
1 INTRODUCTION 1
1.1ProblemStatement 1
1.2Objective,TasksandScope 5
1.3OutlineofPresentation 7
2 BACKGROUNDINFORMATION 9
2.1Introduction 9
2.2 MudRheologyandWave-MudInteractionModeling 9
2.2.1MudRheology 10
2.2.2 Wave-MudInteractionModeling 19
2.3 MudFluidizationandFluidMud 23
2.4 ProcessesGoverningtheVerticalStructureofSuspension 28
2.4.1Settling 28
2.4.2Diffusion 31
2.4.3DepositionRate 35
2.4.4Entrainment 36
2.5SorptionModels 40
2.5.1EquilibriumSorptionIsotherm 40
2.5.2KineticSorptionModels 43
2.5.3AdvancedSorptionModels 46
2.6Sediment-AssociatedContaminantTransport 49
2.6.1ContaminantTransportinWater 49
2.6.2 ContaminantTransportinBottomSediment 52
2.6.3FluxesAcrosstheSediment-WaterInterface 58
iv
2.6.4FluxesAcrosstheFluidMud-BedInterface 62
3 MUDFLUIDIZATIONBYWAVES 64
3.1Introduction 64
3.2 MechanicsofFluidization 65
3.2.1 VerticalandHorizontalMotionsofBedunderWaves 65
3.2.2 BedFailurebyHorizontalForces 66
3.2.3 BedFluidizationbyVerticalForces 68
3.2.4AHeuristicCriterionforBedFluidizationUnderWaves 70
3.3 VoigtandExtensional-VoigtModels 72
3.4 BedasaSpring-Dashpot-MassSystem 74
3.4.1 Case1:G„,andunIndependentofDepth 75
3.4.2 Case2:G„,andunIncreasewithDepth 77
3.5 DynamicResponseofBed 79
3.5.1 WaveoverBed:One-DegreeofFreedom 79
3.5.2 WaveoverFluidMudaboveBed:Two-DegreesofFreedom 80
3.6 FluidizationDepth 83
3.6.1 ModelResults 83
3.6.2 ComparisonwithData 90
3.7 ApplicationtoFieldData 93
3.7.1FieldConditions 93
3.7.2 ModelApplication 96
3.8 Conclusions 99
4 SEDIMENTTRANSPORTMODELING 102
4.1Introduction 102
4.2 Three-LayeredSystem 102
4.3Wave-AveragedTransportEquationforConstituentTransport 103
4.4 SedimentTransportModel 107
4.4.1 VerticalFine-grainedSedimentTransportEquation 107
4.4.2 BoundaryConditions 110
4.5FluidMudEntrainmentRate 112
4.5.1 EntrainmentRateFormulation 112
4.5.2 LaboratoryExperiment 115
4.5.3 CriticalGlobalRichardsonNumberforEntrainment 118
4.5.4 ComparisonwithExperimentalData 124
4.6 LaboratorySimulations 128
4.7 ModelApplicationtoFieldData 132
4.7.1 CoastofLouisiana 133
4.7.2 SouthwestCoastofIndia 142
5 SORPTIONKINETICS 152
5.1Introduction 152
v
5.2Dyes,SedimentsandFluidCharacteristics 153
5.3 SorptionTestProcedure 155
5.3.1SamplingofSediment-Dye-WaterMixture 155
5.3.2PhotographicMethodforDyeConcentrationDetermination
inWater 156
5.3.3 CalibrationExperiments 158
5.4 ResultsandDiscussion 160
5.4.1SorptionIsotherms 160
5.4.2SorptionKinetics 164
5.4.3Discussion 169
6 CONSTITUENTTRANSPORTMODELING 174
6.1Introduction 174
6.2ConstituentTransportModel 174
6.2.1Formulation 174
6.2.2GoverningEquations 176
6.2.3 BoundaryandInterfacialConnectiveConditions 178
6.3Wave-InducedDiffusivityinFluidMud, 184
6.4MassTransferCoefficient,K12c 190
6.5 SolutionTechnique 196
7 FLUMEEXPERIMENTS 198
7.1Introduction 198
7.2ExperimentalEquipment 198
7.2.1WaveFlume 198
7.2.2Colorimeter 199
7.3TestConditionsandProcedure 204
7.3.1TestConditions 204
7.3.2Procedure 204
7.4 DataAnalysis 206
7.4.1 SuspendedSediment 206
7.4.2 DyeReleaseinWater 215
8 RESULTS,DISCUSSIONANDCONCLUSIONS 225
8.1Introduction 225
8.2ResultsofModelSimulationsandCalibrations 225
8.2.1ModelConditions 225
8.2.2SuspendedSedimentConcentrations 230
8.2.3DyeConcentrations 233
8.3AnalysisandDiscussion 238
8.3.1ReleaseFluxandSub-fluxes 238
8.3.2EffectsonReleaseSub-fluxes 243
8.4SummaryandConclusions 250
vi
8.5RecommendationsforFutureStudies 254
APPENDICES
A FLUMEEXPERIMENTALDATA 257
B SIMULATEDANDMEASUREDSUSPENDEDSEDIMENT
ANDDYECONCENTRATIONPROFILES 269
B.1SuspendedSedimentProfiles 269
B.2DyeConcentrationProfilesinWater 280
BIBLIOGRAPHY 296
BIOGRAPHICALSKETCH 313
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LISTOFFIGURES
1.1 Totalcontaminantfluxandsub-fluxes 2
2.1 Commontwo-parameterviscoelasticmodels 13
2.2 Jeffreymodels 14
2.3 Atypicalwave-mudsystem(afterHwang,1989) 23
2.4 Schematicofinstantaneousstressprofileinawave-mudsystem
(afterMehtaetal.,1994) 24
2.5 Three-layeredwater-fluidmud-bedsystemand
verticalsedimenttransportprocessesunderwaves 25
2.6Aschematicdescriptionofsettlingvelocityandfluxvariation
withsuspensionconcentration(afterHwang,1989) 29
2.7 Sediment-associatedcontaminanttransportprocesses 49
3.1 Forcesonaparticleorfloe 68
3.2 BedsimulatedasaS-D-Msystemwithknownverticaldistributionsofbeddensity,
p,extensionalelasticmodulus,Gn,andextensionalviscouscoefficient,un. ...74
3.3 Bedlayerrepresentedbyaone-degreeoffreedomsystem 80
3.4 Fluidmudandbedlayersrepresentedbyatwo-degreesoffreedomsystem 81
3.5 Aschematicdescriptionofthecriterionforequilibriumfluidizationdepth,z'c. ...83
3.6 Fluidizationdepthvariationwithwavefrequencyandamplitude
withnegligiblecohesionandwithoutconsideringinitialfluidmudeffects 84
3.7 Fluidizationdepthvariationwithwavefrequencyandbedelasticmodulus
withnegligiblecohesionandwithoutconsidering initialfluidmudeffects. ...85
3.8 Fluidizationdepthvariationwithwavefrequencyandbedviscouscoefficient
withnegligiblecohesionandwithoutconsideringinitialfluidmudeffects 85
3.9 Fluidizationdepthvariationwithwavefrequencyandamplitude
withnegligiblecohesion,butincludinginitialfluidmudeffects 87
3.10 Fluidizationdepthvariationwithwavefrequencyandbedelasticmodulus
withnegligiblecohesion,butincludinginitialfluidmudeffects 87
3.11 Fluidizationdepthvariationwithwavefrequencyandbedviscouscoefficient
withnegligiblecohesion,butincludinginitialfluidmudeffects 88
3.12 Fluidizationdepthvariationwithwavefrequencyandcohesionparameter 89
3.13 Comparisonbetweencalculatedandflume-measuredfluidizationdepths 92
3.14 BathymetricmapofLakeOkeechobee. Deptharerelativetoadatum
whichis3.81mabovemsl(afterMehtaandJiang,1990) 94
3.15MudthicknesscontourmapofLakeOkeechobee(afterKirbyetal.,1989) 95
3.16ArepresentativebottommuddensityprofileinLakeOkeechobee 97
viii
3.17CalculatedfluidizationdepthasafunctionofwaterdepthinLakeOkeechobee
andbandofmeasuredvalues 98
3.18AnexampleoffluidizationdepthcalculationforLakeOkeechobeeatasite
wherewaterdepthwas1.43m 98
4.1 Three-layeredsystemandverticalsedimenttransportprocessesconsidered 102
4.2 Sideviewofwaveflumeusedinentrainmentexperiments 115
4.3 CriticalRichardsonNumberforentrainmentbywaves 121
4.4 CriticalRichardsonNumberestimatedfromtheexperimentsofMaa(1986) 121
4.5 DimensionlessentrainmentrateasafunctionofRichardsonNumber 125
4.6 Entrainmentfluxasafunctionofwaveheightandmudviscosity 127
4.7 ComparisonbetweensimulatedandmeasureddataforRun4ofMaa(1986). ...130
4.8 ComparisonbetweensimulatedandmeasureddataforRun5ofMaa(1986). ...130
4.9 ComparisonbetweensimulatedandmeasureddataforRun6ofMaa(1986). ...131
4.10 LocationmapofthestudyareaofKemp(1986) 135
4.11 Simulatedandmeasureddata(Kemp,1986)fortheLouisianacoast
duringfrontalpassage 139
4.12 Simulatedandmeasureddata(Kemp,1986)fortheLouisianacoast
duringthepost-frontalperiod 140
4.13 LocationmapofthestudyareaofMathew(1992)offAlleppey
intheStateofKerala,India 143
4.14 Aconceptualmodelofmudbankevolution 143
4.15 Settlingvelocitydatausedformudbankturbiditysimulation 150
4.16 SimulatedsuspendedsedimentconcentrationprofilesanddataofMathew(1992)
inthevicinityofAlleppeyPier 151
5.1 Schematicdiagramofthesorptionprocedure 156
5.2 Schematicdiagramforphotographyinsorptiontests 157
5.3 Procedurefordeterminingdyeconcentration 157
5.4 CalibrationcurveforRhodamineBsolutions 159
5.5 CalibrationcurveforErioglaucineAsolutions 160
5.6 LinearisothermofRhodamineBsorbedontokaolinite 161
5.7 LinearisothermofRhodamineBsorbedontoAKmud 161
5.8 LinearisothermofErioglaucineAsorbedontokaolinite 162
5.9 LinearisothermofErioglaucineAsorbedontoAKmud 163
5.10 EffectoftemperatureonsorptionofRhodamineBonkaolinite 163
5.11 Comparisonbetweenkineticsorptionmodelandexperimentaldata 167
5.12 Comparisonbetweenkineticsorptionmodelandexperimental 167
5.13 Comparisonbetweenkineticsorptionmodelandexperimentaldata 168
5.14 Comparisonbetweenkineticmodelandexperimentalresults 168
5.15 Comparisonbetweenkineticsorptionmodelandexperimentaldata 169
5.16ChemicalstructuresofRhodamineBandErioglaucineA 169
5.17Idealizedclaygeometriesofkaoliniteandattapulgite 170
6.1 Sediment-associatedcontaminanttransportprocessesconsidered 175
6.2 Contaminantfluxesacrossthewater-fluidmudandfluidmud-bedinterfaces. ...179
ix
6.3 Schematicrepresentationofthemodeofindirectdissolvedand
particulatecontaminanttransportacrossthewater-mudinterface 183
6.4Schematicofenergytransportanddissipation,velocitydistributionand
momentumtransport,andconstituentconcentrationdistributionand
momentum-analogousconstituentmasstransport 188
6.5Schematicshownofbottomdiffusivesub-layerandwaveboundarylayerinwater,
anddirectconvectiveflux 191
7.1 Waveflumeusedinexperiments 199
7.2 RelationshipbetweenincidentwavelengthandtransmittanceforRhodamineB..201
7.3 RelationshipbetweenincidentwavelengthandtransmittanceforErioglaucineA.201
7.4 CalibrationofRhodamineBconcentrationwithselectedlightwavelength,
LrB=550nm 202
7.5 CalibrationofErioglaucineAconcentrationwithselectedlightwavelength,
=625nm 202
7.6 SuspendedsedimentconcentrationprofilevariationswithtimeatB,CandD
inthedurationrangeof240~480minutes 207
7.7 SuspendedsedimentconcentrationprofilevariationswithtimeatAandE
inthedurationrangeof240~480minutes 208
7.8 SuspendedsedimentconcentrationprofilevariationswithtimeatB,CandD
inthedurationrangeof480~720minutes 209
7.9 SuspendedsedimentconcentrationprofilevariationswithtimeatAandE
inthedurationrangeof480~720minutes 210
7.10 Comparisonbetweenthecalculatedsuspendedsedimentconcentration
usingthreemethods(Eqs.7.7,7.10and7.11) 214
7.11 DyeconcentrationprofilevariationswithtimeatB,CandD
inthedurationrangeof0~240minutes 215
7.12 DyeconcentrationprofilevariationswithtimeatAandE
inthedurationrangeof0~240minutes 217
7.13 DyeconcentrationprofilevariationswithtimeatB,CandD
inthedurationrangeof240~480minutes 218
7.14 DyeconcentrationprofilevariationwithtimeatAandE
inthedurationrangeof240~480minutes 219
7.15 DyeconcentrationprofilevariationswithtimeatB,CandD
inthedurationrangeof480~720minutes 220
7.16 DyeconcentrationprofilevariationswithtimeatB,CandD
inthedurationrangeof480~720minutes 221
7.17 Comparisonbetweencalculateddyeconcentrationusingthreemethods
(Eqs.7.12,7.15and7.16) 223
8.1 Comparisonbetweensimulatedandmeasureddepth-averaged
suspendedsedimentconcentrationsinTest2 230
8.2 Comparisonbetweensimulatedandmeasureddepth-averaged
suspendedsedimentconcentrationsinTest3 231
x