MAP沉淀法目标产物最优形成条件及分析方法92453110a8114431b90dd851

MAP1,1,1,vanLoosdrechtMCM2(11,100044;21Kluyver,Delft2628BC,):(MAP:MgNH4PO4#6H2O),,;NH+4-N().,pH(),pHCa2+.,MAP,XRD.,90%pH715~910,,pH710~715.Ca2+,(pH810)MAP.,,MAPpH(810).:;pH;Ca2+;XRD;;:X703:A:0250-3301(2009)04-1120-06:2008-05-21;:2008-07-14:(863)(2006AA06Z320);(BJE10016200611);(KM200910016009):(1960~),,,,,E-mail:[e-mail]ionsandAnalyticalMethodsoftheTargetProductbyMAPPrecipitationHAOXiao-di1,LANLi1,WANGChong-chen1,vanLoosdrechtMCM2(11Research&DevelopmentCentreofSustainableEnvironmentalBiotechnology,BeijingUniversityofCivilEngineeringandArchitecture,Beijing100044,China;21DepartmentofBiochemicalEngineering,DelftUniversityofTechnology,Delft2628BC,Netherlands)Abstract:Inordertoestablishoptimalconditionsofthestruvite(MAP:MgNH4PO4#6H2O)formation,aciddissolutionwasappliedanddevelopedtoperformelementanalysesontheprecipitatesobtainedfromMAPprecipitation,andanovelanalyzingandcalculatingmethodwasdevelopedtoquantitativelydeterminethestruvitecontent(purity)intheharvestedprecipitatesaccordingtotheNH+4-Ncontent.Withthismethod,thepuritiesofstruvitewererespectivelydeterminedforbothultrapurewaterandtapwaterusedassolutes.Atthesametime,theeffectofpHandCa2+ontheformationandcrystallizationofstruvitewasevaluated.Thenewlydevelopedmethodwaseffectiveenoughtodeterminethepuritiesofstruvite,whichcouldbeabettermethodthanqualitativeX-raydiffraction(XRD).Basedonthedevelopedmethod,itwasfoundthattheoptimalpHrangesforhavingahighstruvitecontent(90%)wererespectivelyat715-910withultrapurewaterassoluteandat710-715withtapwaterassolute.Inrealwastewater,Ca2+atpH810mightresultinimpuritiesratherthanstruvite.Therefore,aneutralpHrange(810)isproposedtoperformstruviteprecipitationinwastewater.Keywords:struvite;pH;Ca2+;XRD;dissolutionmethod;elementanalyses,,(MAP:MgNH4PO4#6H2O).,[1~3]..,[1~7].pH;LeCorre[8,9],Ca2+.X(XRD)[1,8~12](SEM-EDS)[8].,,XRD,XRD[1,8,10~12],().,XRD.,,,30420094ENVIRONMENTALSCIENCEVol.30,No.4Apr.,2009XRD.,,.,,.,,,(MgNP)(1B1B1).,(90%)MAP.,Ca2+,Ca2+.1111NaH2PO4#2H2OMgSO4#7H2ONH4ClNaOH.(9910%,Alfa-Aesar).112,I015L510mmolNaH2PO4#2H2O;Ò015L610mmolMgSO4#7H2O1510mmolNH4Cl.Ò115L,Ñ,.MgBNBP112B3B1[13]..pH=615,NaOH(NaOH,1molPLNaOH)015pH,pH,615~1115.(25e)30min,.,.1h,.,,,(,).,(25e).,.:c(Ca2+)=2117mmolPL,c(Mg2+)=1134mmolPL.113X(RigakuDPmaxIIIA),Zeiss(AxioCamMRc5).114,,[14],.:40100mg,(pH1),250mL.ICP-AES(IRISAdvantage)[15],(DX-120)Mg2+Ca2+NH+4-N[16].2211XRD,Mg2+NH+4-NPO3-4.,,pH,Boistelle[17]Schuiling[18].,HPO2-4PO3-4,:Mg2++NH+4+HPO2-4+6H2OMgNH4PO4#6H2O+H+(1),pHCa2+.,pH()[1,6,9].,(25e),,pH.2,XRD,(9910%,Alfa-Aesar),1.1(),,pH715~910,XRD();,XRDpH710~815.XRD,pH,.1,pH,,.,pH910,XRD,,.11214:MAP1pHXRDFig.1XRDandmicroscopicimagesoftheprecipitatesformedinultrapurewaterandtapwaterwithdifferentpH112230,,Mg(OH)2(Ksp=511@10-12)Mg3(PO4)2(Ksp=110@10-24)[19].pH,,,.,Ca2+,pHMg(OH)2Mg3(PO4)2,,Ca3(PO4)2(Ksp=211@10-33),CaHPO4(Ksp=118@10-7)[19]Ca10(PO4)6(OH)2[20].1,,pH715~910,pH710~815.2,pH().,pH.212()(),..,:N(016456mmolPL)P(016464mmolPL)Mg(016532mmolPL),(NPMg)(016520mmolPL).,().,2,23.2Fig.2Elementanalysesofthedissolvedprecipitatesfromultrapurewater2,,pH[1015,pH,NH+4-N;pH1015,NH+4-N.pH=1110,pH.3Fig.3ElementanalysesofthedissolvedprecipitatesfromtapwaterNH+4-NNH3,(2).,NH+4-N,NH3,NH+4-NNH3[21].,pH.,pH,NH+4-N,Mg3(PO4)2Mg(OH)2,Lee[22].NH+4+OH-NH3+H2O(2)3.pH,NH+4-N.pH\1015,NH+4-N,.pH[815,Ca2+.,pH815,Ca2+,,Ca2+[Ca3(PO4)2CaHPO4Ca10(PO4)6(OH)2],,[8,20].,pH815,[Mg3(PO4)2Mg(OH)2].pH\1010,Ca2+PO3-4,.213(1),NPMg1B1B1.,pHCa2+,PMg.,N.,1molN1mol.,(3):=n@Mm@100%(3),n;M;m.11234:MAP(3),9819%,(9910%).,(3).(3)2,4.,pH7151015,,,90%pH715~910,pH1015,.4,pH,Ca2+.pH710715,9618%9517%.pH715,,pH=1010,1515%.pH1010,.,Ca2+CaNH4PO4#7H2O[23].,NH+4-N.(3),,pH815Ca2+,CaNH4PO4#7H2O,.pH[815Ca2+,(3).4pHFig.4ImpactofpHonthestruvitepurityintheprecipitates3(1),,,XRD,.(2),NH+4-N.(3)pHCa2+,,90%pH715~910,,pH710~715.pH,Ca2+Ca2+,.(4)Ca2+,,pH810.(5)pH,,.,.:[1]PastorL,ManginD,BaratR,etal.Apilo-tscalestudyofstruviteprecipitationinastirredtankreactor:conditionsinfluencingtheprocess[J].BioresourTechnol,2008,99(14):6285-6291.[2]RonteltapM,MaurerM,GujerW.Struviteprecipitationthermodynamicsinsource-separatedurine[J].WaterRes,2007,41:977-984.[3]WilsenachJ,SchuurbiersC,vanLoosdrechtM.Phosphateandpotassiumrecoveryfromsourceseparatedurinethroughstruviteprecipitation[J].WaterRes,2007,41:458-466.[4],,vanLoosdrechtMCM.[J].,2006,53(3):191-198.[5]OhlingerK,YoungT,SchroederE.Predictingstruviteformationindigestion[J].WaterRes,1998,26:2229-2232.[6]AbbonaF,BoistelleR,LundagerH.Crystallizationoftwomagnesiumphosphates,struviteandnewberyite:effectofpHandconcentration[J].JCrystGrowth,1982,57:6-14.[7]TaylorA,FrazierA,GurneyE.Solubilityproductsofmagnesiumammoniumphosphate[J].TransFaradaySoc,1963,59:1580-1584.[8]LeCorreK,ValsamiJE,HobbsP,etal.Impactofcalciumonstruvitecrystalsize,shapeandpurity[J].JCrystGrowth,2005,283(3-4):514-522.[9]StratfulI,ScrimshawM,LesterJ.Conditionsinfluencingtheprecipitationofmagnesiumammoniumphosphate[J].WaterRes,2001,35(17):4191-4199.[10]DoyleJ,OldringK,ChurchleyJ,etal.Chemical