超声波对活性炭吸附_脱附Cr_的影响_荆国华

第60卷第11期化工学报Vol.60No.112009年11月CIESCJournalNovember2009研究论文超声波对活性炭吸附/脱附Cr(Ⅵ)的影响荆国华,董梅霞,周作明,许庆清(华侨大学化工学院,福建厦门361021)摘要:研究了超声波对活性炭吸附/脱附Cr(Ⅵ)的影响,结果表明:有无超声波作用下,活性炭对Cr(Ⅵ)的吸附率均随pH值的升高而减小,相对于无超声作用体系,超声作用下的相平衡向吸附量减小的方向移动,且pH值越大,其减小的幅度越大;当Cr(Ⅵ)初始浓度由20mg·L-1增至110mg·L-1时,超声波作用下的Cr(Ⅵ)去除率由99.9%降至79.8%,平衡吸附量则由3.3mg·g-1增至15.0mg·g-1,与无超声波作用下的效果接近,但无超声波作用时的吸附率持续上升至平衡,而超声波作用下的吸附率先快速增加至近平衡,再出现小幅下降后又缓慢增至平衡。脱附实验发现,无论有无超声作用,活性炭表面Cr(Ⅵ)在蒸馏水中的脱附率均很小;添加NaOH可显著改善脱附效果,脱附率随NaOH用量的增加而增加,且超声场中NaOH对脱附的促进作用显著高于非超声场中的效果。关键词:活性炭;六价铬;超声波;吸附;脱附中图分类号:O647.3文献标识码:A文章编号:0438-1157(2009)11-2805-08Effectsofultrasoundonadsorptionanddesorptionofchromium(Ⅵ)onactivatedcarbonJINGGuohua,DONGMeixia,ZHOUZuoming,XUQingqing(CollegeofChemicalEngineering,HuaqiaoUniversity,Xiamen361021,Fujian,China)Abstract:Effectsofultrasoundontheadsorptionanddesorptionofchromium(Ⅵ)onactivatedcarbonwerestudied.Resultsshowedthatwithintherangeofexperimentconcerned,theadsorptionratioofchromium(Ⅵ)decreaseswithpHincreasingregardlessultrasoundapplication.However,withultrasound,theequilibriumofthesystemmovestothedirectioninthedecreaseofadsorption,whichbecomesseverewiththeincreaseinpH.Withultrasound,astheinitialCr(Ⅵ)concentrationincreasesfrom20mg·L-1to110mg·L-1,theremovalefficiencyofCr(Ⅵ)dropsfrom99.9%to79.8%,whiletheequilibriumadsorptioncapacityincreasesfrom3.3mg·g-1to15.0mg·g-1,whichissimilartothatwithoutultrasound.Theadsorptionratiocontinuouslyincreasesuntiltoanequilibriumwithoutultrasound,while,itappearsaslightdecreaseafterbeingquicklytotheequilibrium,andthengraduallyincreasestotheequilibriumagainincasewithultrasound.ThedesorptionratioofCr(Ⅵ)isverysmallindistilledwaterregardlessultrasoundapplication.While,thedesorptioncanbegreatlyimprovedbytheadditionofNaOH,andthispromotioneffectisremarkablefortheultrasonicsystem.Keywords:activatedcarbon;chromium(Ⅵ);ultrasound;adsorption;desorption2009-02-08收到初稿,2009-07-17收到修改稿。联系人及第一作者:荆国华(1975—),女,博士,副教授。基金项目:福建省自然科学基金项目(D0710019);华侨大学科研基金项目(07HZR22)。Receiveddate:2009-02-08.Correspondingauthor:JINGGuohua,