Adsorption

    56IMP&HIRFIAnnualReport2006

    2--20AdsorptionBehaviorofAmandEuonSilicon

    DioxideinNitricAcidSolution

    MaJian,DingHuajieandQinZhi

    Theadsorptionbehaviorof.Amand52,Euonsilicondioxideinnitricacidsolutionwasstudiedby

    usingthebatchexperiment.

    The.Amand152.Euadsorptionbatchexperimentswerecarriedoutinsealedpolypropylenetest

    tubes.6mlde—

    ionizedwater,1mlKNO3(1M),1.0gsilicondioxide,1mlAm(NO3)3andEu(NO3)3SO—

    lution.ThepHofthesolutionwasadiustedbyaddingKOHandHNO3stocksolutions.Foralladsorption

    reactions,theionstrengthofthesolutionwaskeptat0.0125MKNO3andthesolid—

    liquidratioat125

    g/1.Whentheadsorptionequilibriumwasachieved,thefinalpHofthesolutionwasthenmeasured.After

    centrifugation,partsofthesupernatantsolutionwasremovedandmeasured.Theadsorptionrates(Kd)

    werecalculatedbasedontheradioactivityofAmandEuinthesolutionbeforeandafteradsorptionreac—

    t1Ons

    K一×

    where10andItdenotetheradioactivityofAmandEuinthesolutionbeforeandafteradsorptionreactions

    respectively.

    Fig.1showsthattheadsorptionequilibriumwasachievedwithin10h. Ol0l52O25

    Time(h)

    Fig.1Adsorptionratioversusequilibriumtime.Fig.2AdsorptionratioversuspHofthesolution.

    Theadsorptionratioof241Amand'..EuonSiO,asafunctionofpHareshowninFig.2.Thead—

    sorptionratioof.Amand..'EuwerelOWatpH<4,andincreasedsharplyatpH?

    6.Wethinkthat

    theadsorptionofAmandEuonsilicondioxideinnitricacidsolutionbelongstOcationexchangepro—

    gressL.Am.andEu'.exchangewithHwhichdissociatefromOH—

    onthesurfaceofsilicondioxide.

    WhenpH<6,littleH—

    iSdissociatedandtheadsorptionratioiSlOW.CorrespondinglywhenpH>6,the adsorptionratioincreases.AfterpH>8,theconcentrationofHisverylOWandthereactionequilibrium

    Wasachieved.

    Reference

    _】jCuiYuguo,LinCansheng,YeGuoan,JournalofNuclearandRadiochemistry.0253—

    9950(2003)0l一?l4一O4

    一一0一_II10一dJ0??

    一一0焉_Ic0dJ0??