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20519999 ENVIRONMENTALSCIENCEVol.20,No.5Sep.,1999赵庆良(, 150090) 李湘中() NH+4-N,MgCl2·6H2ONa2HPO4·12H2OMgOH3PO4NH+4-N.,MgCl2·6H2ONa2HPO4·12H2OMg2+∶NH+4∶PO3-41∶1∶1,pH8.5～9.0NH+4-N5618mg/L65mg/L;2MgO85%H3PO4,NH+4-N5404mg/L1688mg/L. ,,,.:,35,,:1998-10-17Ammonia-nitrogenRemovalfromLandfillLeachatebyChemicalPrecipitationZhaoQingliang(SchoolofMunicipal&Environ.Eng.,HarbinUniversityofCivilEngineering&Architecture,Harbin 150090,China)LiXiangzhong(DepartmentofCivil&StructuralEngineering,TheHongKongPolytechnicUniversity,HongKong,China)Abstract Toremoveefficientlyhighstrengthofammonia-nitrogenfromlandfillleachateandtoavoidcarbonatescalingproblemsinaconventionalair-strippingtower,alab-scalestudywasconductedtoprecipitatetheammoni-aintheformofmagnesiumammomumphosphatebyapplyingsuchchemicalsasMgCl2·6H2OandNa2HPO4·12H2OorMgOand85%H3PO4withdifferentstoichiometricratios.TheexperimentalresultsdemonstratedthatNH+4-Nwaseffectivelyremovedfrominitial5618mg/Ldowntofinal65mg/LwhentheratioofMg2+∶NH+4∶PO3-4wascontrolledat1∶1∶1byusinganalyticalgradechemicalsofMgCl2·6H2OandNa2HPO4·12H2O,withtheoptimalpHfortheprecipitationabout8.5～9.0.TheothertwochemicalsofMgOand85%H3PO4werealsotestedandfoundtobenotasefficientasMgCl2·6H2OandNa2HPO4·12H2Otopre-cipitateNH+4-N,whichremovedNH+4-Nfrominitial5404mg/Lonlydowntofinal1688mg/Latthesameexperi-mentalconditions.Keywords landfillleachate,ammonia-nitrogen,precipitation,magnesiumammoniumphosphate. [1～4].,NH+4-N[5～9],lt[9],20%[6].NH+4-N.1 (WENT),.500mlpH.MgCl2·6H2ONa2HPO4·l2H2OMgO85%H3PO4NH+4-N,15min,pH.,15minNH+4-N.10mol/LNaOHpHpHNH+4-N.pHNH+4-N(OrionEA940),COD、BOD5、(VFA)、DOI:10.13227/j.hjkx.1999.05.023(TSS)、(VSS)、(TDS)(FDS)[10].2 2.1 1993-11,[11],40m3/d,COD6000～7000mg/L,BOD5/COD0.22,NH+4-N5000mg/L,(1).,,NH+4-N[12].1 /mg·L-1/Hazen7800Cl-3032VFA420pH8.22K3920/μmbo·cm-137000Na2505/NTU4100Ca13.7COD7511Mg93COD6508Fe3.811BOD51436Mn0.182TSS784Ni0.365VSS654Cu0.120TDS12352Zn1.155FDS9420Cr0.553NH+4-N5000Cd0.103PO3-4-P16.3Pd(CaCO3)13195(0.01)2.2 NH+4-NMgNH4PO4·6H2O0℃0.023g/100ml,:Mg2+∶NH+4∶PO3-4←→MgNH4PO46H2OpKs=12.6 (25℃) MgNH4PO4·6H2O245,1gNH+4-N17.5gMgNH4PO4·6H2O.N、PMg,、[7],[13].MgNH4PO4·6H2O,Mg2+∶NH+4∶PO3-41∶1∶1,,Mg2+∶NH+41∶1PO3-4(Na2HPO4·12H2O),NH+4∶PO3-41∶1Mg2+(MgCl2·6H2O),12.,Mg2+∶NH+4∶PO3-41∶1∶1,NH+4-N5618mg/L172mg/L,10%Mg2+PO3-4NH+4-N112mg/L158mg/L,Mg2+PO3-4NH+4-N,Mg2+∶NH+4∶PO3-41∶1∶1.1 PO3-4NH+4-NpH(Mg2+∶NH+41∶1,MgCl2·6H2ONa2HPO4·12H2O)2 Mg2+NH+4-NpH(NH+4∶PO3-41∶1,MgCl2·6H2ONa2HPO4·12H2O)Mg2+∶NH+4∶PO3-41∶1∶1915 ,pH,pHNH+4-NpH10mol/LNaOH3.3,MgCl2·6H2ONaHPO4·12H2O,pH8.866.74,NH+4-N210mg/L,pH8.64,NH+4-N65mg/L.,NH+4-NMgNH4PO4·6H2OpH8.5～9.0.3 pHNH+4-N(MgCl2·6H2ONa2HPO4·12H2O)Mg2+∶NH+4∶PO3-41∶1∶1,2MgO85%H3PO4pH,4.,MgOH3PO4,pH8.105.32,NH+4-N2150mg/L,pH8.50,NH+4-N1688mg/L,NH+4-N69%,MgO.4 pHNH+4-N(MgO85%H3PO4)3 BOD5/COD(0.22),NH+4-N5000mg/L,、.NH+4-NMgNH4PO4·6H2O,、,.MgCl2·6H2ONa2HPO4·12H2OMg2+∶NH+4∶PO3-41∶1∶1,pH8.5～9.0NH+4-N5618mg/L65mg/L,98%.1 ShultzBandKjeldsenP.Screeningoforganicmatterinleachatesfromsanitarylandfillsusinggaschromatogra-phycombinedwithmassspectrometry.Wat.Res.,1986,20(8):965～9702 Halling-SrensenBandJrgensenSE.Theremovalofni-trogencompoundsfromwastewater.LondonandNewYork:ElsevierSciencePublishersB.V.,1993.123 ChristensenTHetal.LandfillingofWaste:Leachate.LondonandNewYork:ElsevierSciencePublishers,1992.417～4284 ChristensenTHetal.LandfillingofWaste:Leachate.LondonandNewYork:ElsevierSciencePublishers,1992.313～3215 TǜnayOetal.Ammoniaremovalbymagnesiumammoni-umphosphateinindustrialwastewaters.Wat.Sci.Tech-nol.,1997,36(2～3):225～2286 KluteRetal.ChemicalWaterandWastewaterTreatmentⅡ.Berlin:SpringVerlag,1994.457～4657 SiegristH.Nitrogenremovalfromdigestersupernatant-comparisonofchemicalandbiologicalmethods.Wat.Sci.Technol.,1996,34(1～2):399～4068 ZdybiewskaMWandKulaB.RemovalofammoniaNi-trogenbytheprecipitationmethod,ontheexampleofsomeselectedwastewaters.Wat.Sci.Technol.,1991,24(7):229～234.9 Schulze-RettmerR.Thesimultaneouschemicalprecipita-tionofammoniumandphosphateintheformofmagne-sium-ammonium-phosphate.WatSci.Technol.,1991,23:659～66710 APHA.StandardMethodsfortheExaminationofWaterandWastewater(16thed.),WashingtonDC:AmericanPublicHealthAssociation,198511 HenryJGetal.Removaloforganicsfromleachatesbyanaerobicfilter.Wat.Res.,1987,21(11):1395～139912 LiXZandZhaoQL.Inhibitionofmicrobialactivityofactivatedsludgebyhighstrengthofammonia-nitrogeninleachate.Paperpresentedin19thIAWQBiennialInterna-tionalConference&Inhibition,21～26June,1998,Van-couver,Canada13 PerryDLandPhilipsSL.HandbookofInorganicCom-pounds.USA:CRCPressInc.,1995.23592 20