简介:Inthisstudy,titaniumdioxidesupportedbymulti-walledcarbonnanotubes(MWCNTs/TiO2)andCr-dopedTiO2supportedbyMWCNTs(MWNTs/Cr-TiO2)weresynthesizedbythesol-gelmethod.Thepreparedsampleswerecharacterizedbytransmissionelectronmicroscopy,X-rayphotoelectronspectroscopy,X-raydiffraction,theBrunauerEmmett-Telleranalysis,andtheRamanspectroscopy.TheoxidationandefficiencyforremovalofSO2inasimulatedfluegaswereinvestigatedexperimentallyinafixed-bedreactor.The15%MWCNTs/Cr-Ti02sampledisplayedexcellentadsorptionproperties,andaSO2removalrateequatingto30.4151mg/gfromthesimulatedfluegascontaining2300μg/gofSO2,8%of02,and5%ofH20wasachievedunderoptimalconditionscoveringatemperatureof333.15K,andaspacevelocityof1275h^-1.TheadsorptionprocesswasenhancedbecauseCrdopingmodifiedtheporestructureandinhibitedthegraingrowthofTiO2.Inaddition,theFreundlichandLangmuirmodelsrevealedthatSO2wasmainlyadsorbedthroughchemicaladsorptiononthesamplesurfaces,andthethermodynamicmodelanalysisindicatedthattheadsorptionwasaspontaneous,exothermic,andentropy-reducingprocess.TheadsorptionkineticsofSO2canbedescribedbythepseudosecond-orderkineticandtheBanghamdynamicsmodels.Thepossiblereactionmechanisminvolvedindesulfurizationprocesswasalsoproposed.
简介:随着污染物排放标准的日益提高,为降低硫磺回收装置排放尾气中的SO2浓度,从实际出发,分析和探讨了相应的减排措施:升高反应炉炉膛温度、控制好CLAUSE反应炉配风比例和降低硫冷凝器出口温度等,提高硫磺装置系统的硫收率;将部分自产净化尾气作为液硫鼓泡脱气的汽提气,并把含硫废气进行加氢处理,高效净化硫磺尾气;硫池气和脱硫醇氧化尾气改送至CLAUSE反应炉进行制硫;在硫磺回收装置废热锅炉至尾气焚烧炉间的跨线上增加蝶阀,设置氮封,降低或避免高浓度气体泄漏;提高贫胺液品质,降低吸收塔顶温度,提高吸收塔脱硫效果;碱洗处理吸收塔后尾气或将吸收塔后尾气送至脱硫脱硝系统处理。
简介:Anovelhighgravitymulti-concentriccylinderelectrodes-rotatingbed(MCCE-RB)wasdevelopedfortheelectrocatalyticdegradationofphenolwastewaterinordertoenhancethemasstransferwiththeself-madeRuO2-IrO2-SnO2/Tianodes.Theinfluencesofelectriccurrentdensity,inletliquidcirculationflowrate,highgravityfactor,sodiumchlorideconcentration,andinitialpHvalueonphenoldegradationefficiencywereinvestigated,withtheoptimaloperatingconditionsdetermined.Theresultsshowedthatundertheoptimaloperatingconditionscoveringacurrentdensityof35mA/cm^2,aninletliquidcirculationflowrateof48L/h,ahighgravityfactorof20,asodiumchlorideconcentrationof8.5g/L,aninitialpHvalueof6.5,areactiontimeof100min,andaninitialphenolconcentrationof500mg/L,theefficiencyforremovalofphenolreached99.7%,whichwasimprovedby10.4%ascomparedtothatachievedinthenormalgravityfield.Thetendencyregardingthechangeinefficiencyforremovalofphenol,totalorganiccarbon(TOC),andchemicaloxygendemand(COD)overtimewasstudied.Theintermediatesanddegradationpathwayofphenolwerededucedbyhighperformanceliquidchromatography(HPLC).
简介:介绍了橡胶促进剂2,2′-二硫代二苯并噻唑主要生产方法,包括采用亚硝酸钠、氯气、次氯酸钠作氧化剂的传统生产方法和氧气作氧化剂的新工艺,并分别对其优缺点进行了对比。传统的生产方法原料成本高,废水、废气对环境污染严重,不符合绿色化工发展的要求;氧气作氧化剂生产橡胶促进剂DM不仅原料易得,成本低,无污染,而且母液可循环使用,基本无废水排放。中试已成功生产出合格产品,符合大规模工业化生产要求,有广阔的工业应用前景。
简介:Nitrobenzene-containingindustrialwastewaterwasdegradedinthepresenceofozonecoupledwithH2O2byhighgravitytechnology.Theeffectofhighgravityfactor,H2O2concentration,pHvalue,liquidflow-rate,andreactiontimeontheefficiencyforremovalofnitrobenzenewasinvestigated.TheexperimentalresultsshowthatthehighgravitytechnologyenhancestheozoneutilizationefficiencywithO3/H2O2showingsynergisticeffect.ThedegradationefficiencyintermsoftheCODremovalrateandnitrobenzeneremovalratereached45.8%and50.4%,respectively,underthefollowingreactionconditions,viz.:ahighgravityfactorof66.54,apHvalueof9,aH2O2/O3molarratioof1:1,aliquidflowrateof140L/h,anozoneconcentrationof40mg/L,aH2O2multipledosingmodeof6mL/h,andareactiontimeof4h.Comparedwiththeperformanceofconventionalstirredaerationmixers,thehighgravitytechnologycouldincreasetheCODandnitrobenzeneremovalraterelatedwiththenitrobenzene-containingwastewaterby22.9%and23.3%,respectively.