Treatmentof246trinitrotolueneTNTredwaterbyvacuumdi

TechnicalNoteTreatmentof2,4,6-trinitrotoluene(TNT)redwaterbyvacuumdistillationQuanlinZhao,ZhengfangYe*,MoheZhangDepartmentofEnvironmentalEngineering,PekingUniversity,TheKeyLaboratoryofWaterandSedimentSciences,MinistryofEducation,Beijing100871,ChinaarticleinfoArticlehistory:Received22March2010Receivedinrevisedform30April2010Accepted3May2010Availableonline26May2010Keywords:TNTredwaterVacuumdistillationUV–visspectroscopyGC/MSAcutetoxicitytestabstract2,4,6-Trinitrotoluene(TNT)redwaterfromChineseexplosiveindustrywastreatedbyvacuumdistilla-tion.Thewaterqualitybeforeandafterdistillationwasevaluatedusinghighperformanceliquidchro-matograph,UV–visspectroscopy,GasChromatography/MassSpectroscopy(GC/MS)andotherphysicalandchemicalanalyses.TheacutetoxicityofTNTredwateranditsdistillatewasevaluatedbydetermin-ingtheluminescenceinhibitionofVibrioqinghaiensissp.Nov.TheresultsshowedthattheparametersexceptpHofthedistillatemetthecriterionspecifiedbytheChinesedischargestandardforwaterpollu-tantsfromordnanceindustry.Distillationremovedchemicaloxygendemandalmostcompletelyandthechrominancewasreducedfrom100000to17.Theconcentrationsof2,4-dinitrotoluene-3-sulfonateand2,4-dinitrotoluene-5-sulfonatedecreasedfrom20103and31103mgL1to1.3and1.8mgL1,respectively.GC/MSresultsshowedthatmostoftheorganiccomponentsofTNTredwatercanberemovedbydistillation.Theacutetoxicityofwatersampleafterdistillationreduced96%,comparedwiththatofunprocessedTNTredwater.2010ElsevierLtd.Allrightsreserved.1.Introduction2,4,6-Trinitrotoluene(TNT)isanimportanthighexplosivewidelyusedinmanyfields(ClarkandBoopathy,2007;Boparaietal.,2008;Kalderisetal.,2008;LeeandJeong,2009;Nyanhongoetal.,2009).Duringitsproduction,load,assembleandpackoper-ations,largeamountofTNTwasterwaterisproduced,whichcancauseenvironmentalpollutionanddoharmtopublichealthifitisdischargedwithouteffectivetreatment.Accordingtoitscharacteristiccolor,TNTwastewatercanbeclassifiedasyellowwater,redwaterandpinkwater.Barreto-Rodriguesetal.(2009a,b)evaluatedacontinualsystemtreatmentreactor(CSTR)consistingofcolumnzero-valentironandasystemtopromoteaFentonreactionfortreatingTNTyellowwater.TheyoptimizedthetreatmentprocessandfoundthatthemostefficientconditionforreducingtheconcentrationofTNTgeneratedsuffi-cientamountsofFe(II)forthesubsequentoxidativetreatmentthroughtheFentonreaction.Itcanremove100%ofTNT,100%oftheorganicnitrogenand95%oftheCOD,whichwassuggestedthatthetreatmentwashighlyefficientintermsofmeetingthemainassociatedenvironmentalparameters.Haoetal.(1993a)studiedtreatmentofTNTredwaterbywetairoxidation(WAO).Theyeval-uatedtheeffectoftemperature,partialoxygenpressure,initialredwaterconcentration,saltconcentrationandcatalyst/initiatoraddi-tiononWAOperformance.Theyalsodeterminedthecompositionoftheoff-gasafterwetoxidationofTNTredwaterandmonitoredbacterialtoxicityoftreatedwaste.Theresultsshowedthattheamountofsulfateconcentrationinthetreatedsamplewasmuchhigherthanthatofthemeasuredinorganicsulfateandtheorganicsulfurassociatedwiththedinitrotoluenesulfonatesinitiallypres-entintherawredwater,whichsuggestedthepresenceofotherunidentifiedS-containingorganiccompoundsinredwater.Vacuumdistillationisakindoftechnologybywhichwastewatercanbeconcentratedunderlowertemperatures.Inourprevi-ousstudy(Wangetal.,2008),weinvestigatedthepossibilityofTNTredwatertreatmentthroughvacuumdistillationfollowedbyimmobilizedmicroorganismprocess.Theobjectiveofthepres-entworkwastocharacterizephysicalandchemicalpropertiesofTNTredwaterbeforeandafterdistillationbyusingHighPerfor-manceLiquidChromatograph(HPLC),UV–Visspectroscopy,GasChromatography/MassSpectroscopy(GC/MS)andotherphysicalandchemicalanalyses.Inaddition,theacutetoxicityofTNTredwateranditsdistillatewasinvestigatedbybacteriumbiolumines-cenceassays.2.Materialsandmethods2.1.MaterialsTNTredwaterwasobtainedfromDongfangChemicalCorpora-tion,HubeiProvince,China.Ithasanintenseredcolorwiththedensityof1.101gmL1.TheinitialpHvalueis5.28.Thelumines-centbacteriumVibrioqinghaiensissp.Nov.wasprovidedbyBeijingHAMAMATSUPhotonTechniquesInc.,China.Sodiumchlorideand0045-6535/$-seefrontmatter2010ElsevierLtd.Allrightsreserved.doi:10.1016/j.chemosphere.2010.05.004*Correspondingauthor.Tel.:[phone];fax:[phone].E-mailaddress:[e-mail](Z.Ye).Chemosphere80(2010)947–950ContentslistsavailableatScienceDirectChemospherejournalhomepage:fluidizedat80C.Thedistilla-tionprocesswasstoppedwhentherewasnoliquiddroppedfromthecondensertube.2.3.WaterqualitydetectionThewaterqualitywasdetectedbydeterminingchemicaloxy-gendemand(COD)accordingtoChinesestandardGB11914-89.Thechrominancewasdeterminedbydilutionmethoduntilthewatersamplebecamecolorless.Theconcentrationsof2,4-dinitro-toluene-3-sulfonate(2,4-DNT-3-SO3)and2,4-dinitrotoluene-5-sulfonate(2,4-DNT-5-SO3)inTNTredwateranditsdistillate