The-investigation-of-kinetic-and-isotherm-of-fluoride-adsorption-onto-functionalize-pumice-stone-(1)

JournalofHazardousMaterials217–218(2012)123–132ContentslistsavailableatSciVerseScienceDirectJournalofHazardousMaterialsjournalhomepage:www.elsevier.com/locate/jhazmatTheinvestigationofkineticandisothermoffluorideadsorptionontofunctionalizepumicestoneGhorbanAsgaria,BabakRoshanib,∗,GhaderGhanizadehcaDepartmentofEnvironmentalHealthEngineering,SchoolofHealth,HamadanUniversityofMedicalSciences,Hamadan,IranbDepartmentofChemicalandBiologicalEngineering,UniversityofSaskatchewan,57CampusDrive,Saskatoon,SK,S7N5A9,CanadacHealthResearchCenterandHealthSchool,BaqiyatallahUniversityofMedicalSciences,Tehran,IranarticleinfoArticlehistory:Received7October2011Receivedinrevisedform25January2012Accepted2March2012Availableonline23March2012Keywords:PumiceAdsorptionFluorideDrinkingwaterHexadecyltrimethylammoniumabstractInthisresearchwork,pumicethatisfunctionalizedbythecationicsurfactant,hexadecyltrimethylammo-nium(HDTMA),isusedasanadsorbentfortheremovaloffluoridefromdrinkingwater.Thisworkwascarriedoutintwoparts.TheeffectsofHDTMAloading,pH(3–10),reactiontime(5–60min)andtheadsorbentdosage(0.15–2.5gL−1)wereinvestigatedontheremovaloffluorideasatargetcontaminatefromwaterthroughthedesignofdifferentexperimentalsetsinthefirstpart.Theresultsfromthisfirstpartrevealedthatsurfactant-modifiedpumice(SMP)exhibitedthebestperformanceatdose0.5gL−1,pH6,anditadsorbsover96%offluoridefromasolutioncontaining10mgL−1fluorideafter30minofmixingtime.ThefourlinearformsoftheLangmuir,Freundlich,TemkinandDubinin–Radushkevichisothermsmodelwereappliedtodeterminethebestfitofequilibriumexpressions.Apartfromtheregressioncoefficient(R2),fourerrorfunctionswereusedtovalidatetheisothermandkineticsdata.Theexperi-mentaladsorptionisothermcomplieswithLangmuirequationmodeltype1.Themaximumamountofadsorption(Qmax)was41mgg−1.Thekineticstudiesindicatedthattheadsorptionoffluoridebestfittedwiththepseudo-second-orderkinetictype1.Thermodynamicparametersevaluationoffluorideadsorp-tiononSMPshowedthattheadsorptionprocessundertheselectedcondition