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大小:2.24 MB
页数:10页
时间:2020-05-20
《炭化米糠经臭氧活化制备活性炭及其去除Cr(Ⅵ)离子(英文).pdf》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、第30卷第3期新型炭材料VO1.30NO.32015年6月NEWCARB0NMAT邑RIALSJun.2015文章编号:1007—8827(2015)03—0252—10炭化米糠经臭氧活化制备活性炭及其去除Cr(VI)离子SivarajuSugashini,KadharMohamedMeeraSheriffaBegum(DepartmentofChemicalEngineering,NationalInstituteofTechnology,Tiruchirappalli620015,Tamilnadu,In
2、dia)摘要:以臭氧为活化剂,炭化的米糠为原料制备出活性炭。采用氮吸附、SEM—EDAX和FT一瓜对样品进行表征。活性炭的比表面积由活化前的20m/g增加到380m/g。在臭氧活化过程中,吸附在炭材料上的二氧化硅变疏松,从而导致碳逸出。臭氧同时以氧分子和原子形式存在于炭表面。氧原子,作为强氧化剂,将炭表面氧化成酸性官能团如羧基、酮基和酚基。采用该活性炭吸附Cr(VI)离子,cr(VI)离子的最大去除率(94%)的条件为:pH值2.0、浓度100mg/L、吸附量0.2g,时间2.5h及转速300r/min。采用
3、吸附平衡和动力学模型探讨吸附机理,结果表明,吸附等温线符合Freundfich方程,吸附速率符合准二级动力学方程。吸附是自发的放热反应,可能与NaOH脱落而恢复Cr和碳有关。关键词:米糠;活性炭;臭氧处理;Cr(vi)离子;动力学;传质中图分类号:TQ127.11文献标识码:A通讯作者:KadharMohamedMeeraSherifaBegum.E—mail:meerasheriffa@gmail.com作者简介:SivarajuSugashini.E—mail:suga.chemical@gmail.co
4、m;meera@nitt.eduPreparationofactivatedcarbonfromcarbonizedricehuskbyozoneactivationf0rCr(VI、)removalSivarajuSugashini,KadharMohamedMeeraSheriffaBegum(DepartmentofChemicalEngineering,NationalInstituteofTechnology,TiruchirappaUi620015,Tamilnadu,India)Abstract
5、:Activatedcarbon(AC)waspreparedfromcarbonizedricehusksusingozoneasanactivatingagent.111eACwaschar-acterizedbynigogenadsorption.SEM.EDAXandFT—IR.TheBrunauer.Emmett.Tellersurfaceareaofthecarbonswasincreasedfrom20to380m/gbytheactivation.Itwasobservedthatthesil
6、icaa~achedtothecarbonaceousmateriaiisloosened.1eadingtoareleaseofcarbonduringtheozoneactivation.Ozoneexistsasbothmolecularandatomicoxygenonthesurfaceofcarbon.Atomicoxygen,asapowerfuloxidizingagent,oxidizesthecarbonsurfaceintoacidicfunctionalgroupssuchascarb
7、oxylic,ketonicandphenolic.ThericehuskACwasusedfortheadsorptionofCr(VI)ions.Amaximumremovalpercentage(94%)ofCr(VI)ionswasobtainedfora10omr./LaqueoussolutionattheoptimizedconditionsofpHvalueof2.0.adsorbentdosageof0.2g.timeof2.5handstirringspeedof300r/min.Adso
8、rptionequilibriumandkineticmodelswereusedtoinvestigatetheadsorptionmecha—nism.ItwasfoundthattheadsorptionisotllerrnswerewellfittedbytheFreundlichequation.Theadsorptionratefollowspseudosec—ondorderkinet
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