改性活性氧化镁的除氟效能及机制

95Vol．9No．520155ChineseJournalofEnvironmentalEngineeringMay20151111212*1.2300362.230036、、。Langmuir88.50mg/g0.3681L/mgCl－、NO－3、SO2－4HCO－3HPO2－4100mg/L。pH。30℃pH6～9．5。。X703A1673-9108201505-2125-06FluorineremovingperformanceandmechanismofmodifiedactivatedmagnesiumoxideWangHuiling1ZhangYanyan1XuWei1HuaRimao12LiXuede121.SchoolofResourceandEnvironmentAnhuiAgriculturalUniversityHefei230036China2.ScientificObservingandExperimentalStationofAgri-EnvironmentMinistryofAgricultureHefei230036ChinaAbstractFluorideremovalefficiencyoftheactivatedmagnesiumoxidewasstudiedbyusingadsorptionex-perimentandthemodifiedmechanismoftheactivatedmagnesiumoxidewasdiscussedbydeterminationofspe-cificsurfaceareaporevolumeporediametertheelementsandcompoundscontentsonthesurfaceofactivemagnesiumoxide．TheresultsindicatedthattheadsorptionisothermsofmodifiedmagnesiumoxidewerefittedwiththeLangmuiradsorptionmodelthatwasadsorptionofmonolayeradsorption．Thesaturatedadsorptionca-pacitywas88.50mg/gtheadsorptionequilibriumconstantwas0.3681L/mgTheadsorptionoffluoridewasfollowedpseudo-second-orderkinetics．Fluorideremovalefficiencyofmodifiedmagnesiumoxidewasnotinflu-encedbyCl－NO－3SO2－4andHCO－3andwasinfluencedbyHPO2－4theadsorptioncapacityofthemodifiedactivatedmagnesiumoxidewasreducedsignificantlywhentheconcentrationofHPO2－4washigherthan100mg/L．Theadsorptioncapacityofmodifiedactivatedmagnesiumoxideincreasedwiththeincreasingofsolutiontem-perature．ThepHofdrinkingwaterhadlesseffectonthefluorideremoval．Theexperimentsuggestedthattheop-timumtemperatureandpHwere30℃and6～9.5respectively．Theincreasingofspecificsurfaceareaandporevolumemaybeoneofthemainreasonsfortheimprovementoftheadsorptioncapacityofactivatedmagnesiumox-ide．Keywordsmodifiedactivatedmagnesiumoxidefluorideremovalefficiencyinfluencingfactorsmecha-nismanalysis“863”2012AA0626052014－03－282014－04－171987—。[e-mail]*[e-mail]。130.077%1。80～4700mg/kg7070mg/kg200～300mg/kg、、pH2。92。1mg/L、、3-5。。、、、6-9。、、、10、、、。11。。。、14mg/g。。11．1G1G2。1．2、、、、、、。1．3DHG-9140ApHFE2078-1ZWY-2102CAL104SX2TristarⅡ3020MMicromeriticsXXRF-1800。1．41．4．10.1g100mL25℃200r/min。1．4．20.1g100mL2、5、10、20、50、80、100、120、150200mg/L25℃200r/min5h。1．4．30．1g100mL20mg/L200r/min5h。pH100mLpH20mg/L0.1g25℃200r/min5h。20mg/L0.1g25℃200r/min5h。1．4．41．4．5、、BETTristarⅡ3020M-。XRF-1800X。22．1、1。621251Fig.1Adsorptionkineticsprocessofactivatedmagnesiumoxide1。。5h10h。10～50mg/L。、1。1R20．99MgO、MgO。12。MgO、MgOF－、13。。2．2LangmuirFreundlich2。21/n0.40841/nl/n=0.1～0.51/n214Langmuir15。Langmuir88.50mg/g1Table1FittingresultsofactivemagnesiumoxideadsorptionkineticsmodelC0mg/Lqecalmg/gk1min－1R2qecalmg/gk2g/mg·minR2109．890．17430．952310．350．06770．99842019．690．19280．974520．920．02560．99915046．130．11010．520948．780．00710．9977109．930．15100．777910．030．29670．99992019．900．20800．879019．960．48271．00005047．100．26650．893450．760．00960．9945721292LangmuirFreundlichTable2FittingparametersofFreudlichandLangmuirmodelsLangmuirqmaxmg/gbL/mgR2FreundlichKFL/g1/nR259．520．65880．998715．44540．36740．848788．500．36810．992818．28520．40840．881559.52mg/g32.7%20mg/L6.3950.587mg/L。。2．3。。210～20℃20～40℃。10～40℃。30℃。2Fig.2Effectoftemperatureonadsorptioncapacity2．4pH、pH。3pH=4．518.8mg/gMgOH2+2F－→MgF2↓+2OH－pH=10．517.0mg/gpHF－OH－F－。3pH6.5～9.518.3～18.5mg/g。《》GB5749-2006pH6.5～8.56.5～9.5pH。3pHFig.3EffectofpHonadsorptioncapacity2．5Cl－、NO－2、NO－3、SO2－4、HCO－3HPO2－4F－。5。5HCO－3pH。Cl－、SO2－4HPO2－4HPO2－4100mg/L。16HPO2－4pH。Cl－SO2－4Cl－38．3982125～106.62mg/LSO2－438.25～73.95mg/L。。。4Fig.4Effectofcoexistingnegativeionsonadsorptioncapacity2．6MgOBET3。3MgOBETTable3BETspecificsurfaceareasandporestructureparametersofmagnesiumoxideBETm2/g×10－6cm3/gnm14．6951．2517．84434．0063．2516．0513BET14．695m2/g34．006m2/g1．3。1．25×10－6cm3/g3.25×10－6cm3/g1．6。17.844nm16.051nm10．05%。。4。43.54%8.53%2.41。。MgO4Table4Elementsandcompoundscontentonthesurfaceofactivemagnesiumoxidebeforeandaftermodificationwt．%MgO91．2287．8689．9383．08SiO25．475．877．576．20CaO1．661．630．930．94Fe2O30．490．510．520．56Al2O30．370．340．420．41F0．183．540．238．53P2O50．100．070．080．083K2O0．0800．0240．0280．03Na2O0．03540．0450．0260．085MnO0．030．0310．0320．0373.36%6.85%。31Langmuir。0.3681L/mg88.50mg/g。2pHpH6～1018.3～18．5mg/g。pH。10～1000mg/LCl－、NO3－、SO2－4HCO－3HPO2－4100mg/L。30℃pH6～10。3BET14.695m2/g34.006m2/g1．25×10－6cm3/g3．25×10－6cm3/g。921291．．200030-402HichourM．PersinF．SandeauxJ．etal．Fluoridere-movalfromwatersbyDonnanDialysis．SeparationandPur-ificationTechnology2000l811-113MahramanliogluM．KizilcikliL．BicerI．O．AdsorptionoffluoridefromaqueoussolutionbyacidtreatedSpentbleachingearth．JournalofFluorineChemistry2002115141-474MohapotraD．MishraD．MishraS．P．etal．Useofoxidemineralstoabatefluoridefromwater．JournalofColloidandInterfaceScience20042752355-3595LouniciH．AddourL．BelhocineD．etal．Studyofanewtechniqueforfluorideremovalfromwater．Desalina-tion19971143241-2516IslamM．PatelR．K．Evaluationofremovalefficiencyoffluoridefromaqueoussolutionusingquicklime．JournalofHazardousMaterials20071431-2303-3107NigussieW．ZewgeF．ChandravanshiB．S．Removalofexcessfluoridefromwaterusingwasteresiduefromalummanufacturingprocess．JournalofHazard