沉淀池污泥层高度的模拟与控制

2008,28(3)274~278ChinaEnvironmentalScience1,1*,1,2(1.,,2000922.,200092)(SBH),,SBH.COST624/682,2.,,SBHSS,.X703A10006923(2008)03027405Simulationandcontrolofsludgeblanketheightinsettlingtanks.ZHOUZhen1,WUZhi-chao1*,GUGuo-wei1,HUAHong2(1.StateKeyLaboratoryofPollutionControlandResourceReuse,CollegeofEnvironmentalScienceandEngineering,TongjiUniversity,Shanghai200092,China2.DepartmentofMathematics,TongjiUniversity,Shanghai200092,China).ChinaEnvironmentalScience,2008,28(3)274~278AbstractInordertoachieveaccuratepredictionandeffectivecontrolofthesludgeblanketheight(SBH)inrealoperation,astableandreliableSBHalgorithmwasselectedbasedonmeasuredsuspendedsolids(SS)profiles,andthenincorporatedintoalayeredanddispersivesettlingtankmodelderivedfrommassbalanceanalysis.ThesecondarysettlingtankinCOST624/682benchmarkwastewatertreatmentplantunderstormweatherwasusedforsteady-stateanddynamicsimulationsofsettlingtankoperationundertwodifferentcontrolstrategies,constantreturnrateandconstantreturnratio.ThelaterperformsweremoreeffectivelyandsteadilyincontrollingtheSBHandunderflowSSconcentrationwhenlargefluctuationofinfluenthydraulicloadoccured,thusreducingtheriskofeffluentsludgeescape.Keywordsactivatedsludgesettlingtanksludgeblanketheightmathematicalmodelcontrol,.(SBH)[12].SBH,(SS).[36],SBH,SS.SBH[1].,SBH,(RAS)SS[78].,SBH[910],,,.,,SBH[24].,SBH,[1112],.SBH,SSSSSBH,SBH.11.1,,20070621(50138010)*,,[e-mail]3275,()suvvXXXDtzzz∂+⎡⎤∂∂∂⎛⎞⎣⎦=−⎜⎟∂∂∂∂⎝⎠(1):XSS,mg/L;z,m;D,m2/d;vsvuSS,m/d.(1),(1).QfXfQeXeQuXu1Fig.1AlayeredanddispersivesettlingtankmodelQfQeQu;XfXeXuSS;XfXeXuSS1.2Takács[13],(i),:()()pnsfhnsfs,00's,0ee0iiXfXXfXiivvvvvγγ−−−−⎧=−⎪⎨⎪⎩(2):γpγh,L/g;v0v′0,m/d;fnsSS(Xf).1.3SBHSBH.[10,1416],SBHSSSS.,Hamilton[14]Watts[15](Pi)(Ri)SBH,PiRi(3)(4).1iiiXXPzδ−−=(3)11δ−−−=iiiiiXXzRXX(4)[17]204(12131517)SS,SS(2).2,2SS().,RiSBH,,.,RiSBH.(a)02000400060008000100000.00.51.01.52.02.53.03.5Pi(b)00.40.81.21.622.40.00.51.01.52.02.53.03.5(m)Ri2SSPiRiFig.2AbsoluteandrelativeconcentrationslopeofSSprofilesversussettlingtankheightinpilot-scaletest12131517,Ri27628hi.hi1hihi+1Ri1RiRi+1(i,2SBH;i,SBH).3(5):2()Rhahbhc=++(5)(5)SS.dR(h)/dh=0,/2hba=−,SBH.()()2112223111112131SBH2iiiiiimRmRmRmRmRmR−+−+−++=++(6):mijMij:12112211111iiiiiihhhhhh−−−++⎡⎤⎢⎥=⎢⎥⎢⎥⎣⎦M(7)22.1COST624/682[18].,23,18446m3/d.,6000m3,1500m2,4m,2.2m.,385m3/d,18446m3/d.2.2COST[18]Takács:v0=474m/d;v′0=250m/d;γp=2.86L/g;γh=0.576L/g;fns=0.00228.EFOR()WEST(),10,(D=0)SS,3.3,EFORWEST.4:[17].,;,SBH.,SBH.D=2.5m2/d,EFOR,D=2.5m2/d.COSTSBH=2.27m.010002000300040005000600070000.01.02.03.04.0(m)SS(mg/L)EFORWESTD=0D=2.5m2/dEFORWESTD=0D=2.5m2/d3SSFig.3SSprofilesintheCOSTsettlingtank2.3SBH,4.,,SS,..0123456702468101214(d)(×104m3/d)4Fig.4InfluentflowunderstormweatherCOST3277,5.SS13.2,6637.8mg/L,,SS,27,13560mg/L.,SBH1.87~1.88m,,SBH3.20m.400080001200016000SS(mg/L)1.52.02.53.03.502468101214(d)SBH(m)51015202530SS(mg/L)(b)(a)(c)0246810121402468101214SS(103mg/L)1612845Fig.5DynamicsimulationofsettlingtankoperationwithconstantRASflowrateunderstormweather,,1.6.,SS,,28.1mg/L;,SS,,6403.8mg/L.,SBH(1.87~1.88m),,SBH.51015202530SS(mg/L)62006300640065006600SS(mg/L)1.861.871.881.8902468101214(d)SBH(m)(a)(b)(c)0246810121402468101214SBH(M)SS(103mg/L)6.66.56.46.36.26Fig.6DynamicsimulationofsettlingtankoperationwithconstantRASratiounderstormweather,SSSBH,.SSSBH,SS.,[1],SBH.3,SBH,COST624/682278282.,,,SSSBH;,SSSBH,SS,SBH.[1]EkamaGA,BarnardJL,GunthertFW,etal.Secondarysettlingtanks:Theory,modeling,designandoperation[R].London:IAWQ,1997.[2]CouillardD,ZhuSC.Controlstrategyfortheactivatedsludgeundershockloading[J].WaterRes.,1992,26(5):649655.[3]MüllerJR,KrauthK.Wastewaterflowmanagementtomaximisethecapacityofsewagetreatmentplants[J].WaterSci.Technol.,1998,37(9):4956.[4]VanderhasseltA,AspegrenH,VanrolleghemPA,etal.Settlingcharacterisationusingon-linesensorsatafull-scalewastewatertreatmentplant[J].WaterSA,1999,25(4):16.[5]EkamaGA,MaraisP.Assessingtheapplicabilityofthe1Dfluxtheorytofull-scalesecondarysettlingtankdesignwitha2Dhydrodynamicmodel[J].WaterRes.,2004,38(3):495506.[6]BouzasA,RibesJ,FerrerJ,etal.Fermentationandelutriationofprimarysludge:EffectofSRTonprocessperformance[J].WaterRes.,2007,41(4):747756.[7]GrijspeerdtK,BogaertH,VerstraeteW.Designandverificationofamodelsecondaryclarifierforactivatedsludge[J].J.Chem.Technol.Biotechnol.,1996,67(4):404412.[8]MaY,PengYZ,WangSY.Newautomaticcontrolstrategiesforsludgerecyclingandwastagefortheoptimumoperationofpredenitrificationprocesses[J].J.Chem.Technol.Biotechnol.,2006,81(1):4147.[9]KochG,PiantaR,KrebsP,etal.Potentialofdenitrificationandsolidsremovalintherectangularclarifier[J].WaterRes.,1999,33(2):309318.[10]ChavanPV.TheinfluenceofdenitrificationinclarifiersonbiologicalphosphorusremovalatCCSTplant[D].LasVegas,theUSA:UniversityofNevada,2003.[11],,.[J].,2007,1(3):2124.[12],,,.[J].,2007,27(2):155159.[13]TakácsI,PatryGG,NolascoD.Adynamicmodeloftheclarification-thickeningprocess[J].WaterRes.,1991,25(10):12631271.[14]HamiltonJ,JainR,AntoniouP,etal.Modelingandpilot-scaleexperimentalverificationforpred