电位滴定法测定电镀废水中铜含量龙霞

266()Vol.26No.62009　12JournalofGuizhouUniversity(NaturalSciences)Dec.2009　1000-5269(2009)06-0048-03＊龙　霞,刘定富,岳敏杰(,550003)　:根据电镀废水中铜(Ⅱ)离子与其他组分化学性质的差异,控制溶液的酸度,以铜离子选择性电极作指示电极,双盐桥饱和甘汞电极作参比电极,以硫化钠标准溶液作滴定剂,采用选择沉淀电位滴定法测定电镀废水中的铜。结果表明:控制溶液pH值1.0～1.5,以氟化铵掩蔽废水中共存的铁(Ⅲ),可以直接用Na2S选择沉淀电位滴定法测定电镀废水中铜的含量。该法不需分离就可直接测定,操作简单,分析速度快,灵敏度高。将本法测定结果与原子吸收分光光度法进行比较,结果无显著性差异。:选择沉淀;电位滴定法;电镀废水;铜:O657.1　　:B　　,。,、、、,,。,,。,。。[1],,。,:,,,;,I-I2Cu2+,[2]。,,、,,,、、、、、、、,,,、、、[3]。,,,(Ⅱ),。,。1　,,、pH1.0,(Ⅲ),Na2S(Ⅱ),:Cu2++S2-=CuS↑:KNO3SCESCE。E:E=ESCE-ECu2+/CuECu2+/Cu(Cu2+)aCu2+,[4],298k:ECu2+/Cu=EθCu2+/Cu+2.303RTnFlg1aCu2+＊:2009-10-30:(:【2008】24-3):　(1984-),,,,:,Email:[e-mail].＊:,Email:[e-mail]:10.15958/j.cnki.gdxbzrb.2009.06.018aCu2+,,。ECu2+/Cu=EθCu2+/Cu+2.303RTnFlg1CCu2+EθCu2+/Cu。Na2S,CuS,Cu2+,,Cu2+,,。T,ECu2+/CuCcu2+,。2　2.1　(FA1004),PHS-3C(),(),217(),78-1,,,,,。。2.2　2.2.1　标准混合溶液的配制、、、,pH1,1000ml,:97.50mg/L,82.82mg/L,32.02mg/L,9.48mg/L.2.2.2　硫化钠标准溶液浓度的标定,,。。1×10-3mol/L。25ml100ml,,217,(),,,,。1.1,11.729ml,11.729ml,。C=V1×mMV2:C—,mol/L;V1—1,mL;V2—,mL;m—CuSO4·5H2O,g;M—CuSO4·5H2O,g/mol.,3.266×10-3mol/L.1　12.2.3　实际电镀废水浓度的测定1:410.00、15.00、20.00、25.00、30.00ml,,。1.1　12345V1/mL10.0015.0020.0025.0030.00V2/mL9.39014.13018.76523.6928.283mg/L194.89195.52194.74196.68195.68　　:Cm=C×V2V1×MCu:Cm—,mg/L;C—,mol/L;V1—,mL;V2—,mL;MCu—,g/mol.20ml,·49·6　:2.2　22,18.765mL,18.765mL.3　3.1　H2S,()。,,。3.2　,Cu2+,。3.3　[5],Cu2+,。,PH1.31,Cu2+pH≈1.5,Ni2+PH,Ni2+。3.4　Cr6+,Fe3+,Ni2+pHCu2+。,pH1,Cu2+,Ni2+pH2.6[5]。3.5　(),2.2　123456mg/L194.89195.52194.74196.68195.68195.00　　t-[6],95%,μ=195.00mg·L-1.X=∑5i=1Xin=195.50mg·L-1;s=∑5i=1(Xi-X)25-1=0.7705t=X-μsn=1.4510.t,f=5-1=4,95%,t=2.78,tt,,,。:[1],,,.()[M].:,2007:280.[2],,.()[M].:,2006:280.[3],,.[J].,2001,30(3):17-20.[4],.[M].:,2006:18-19.[5],.[J].,2008,33(3):1-3.[6],.[M].:,2004:15-16.(59)·50·()26PonderonProtectionandUseofMineralResourceintheCambrianSystemNiutitangGroupBlackRockinGuizhouTANYue,ZHANGMei-jiang(CollegeofResourcesandEnvironmentEngineering,GuizhouUniversity,Guiyang550003,China)Abstract:ThecambriansystemNiutitanggroupblackrockareaccumulationrockseriesthathavemineralre-sourcessuchasvanadium,molybdenum,phosphorus,rareearth,gold,silver,platinum,andsoon.Thataboveelementsassumetheparagenesisrelationsintheblackrockseries.Whenitisdeveloped,itshouldbecompre-hensivelyutilized.Butnow,thetenenterprisesonlyminethesoleoreinGuizhou,whichcausesnotonlyde-structionandbutalsoresourceswastage,moreoveritcausesseriousenvironmentpollution.Thescientificdevel-opmentconceptshouldbeadoptedtoprotecttheimportantmineralresourcesinNiutitanggroup,utilizethere-sourcesduringtheprocessofprotection.Keywords:Guizhou;blackrock;Niutitanggroup;polymetallicandpreciousmetalaccumulationrock;protec-tionresources(50)PotentiometricTitrationUsedintheDeterminationofCopperinElectroplatingWastewaterLONGXia,LIUDing-fu,YUEMin-jie(CollegeofChemistryandChemicalEngineering,GuizhouUniversity,Guiyang550003,China)Abstract:AccordingtothedifferenceofthechemicalpropertiesbetweenCopper(Ⅱ)ionandothercomponentsintheelectroplatingwastewater,thecoppervaluecontainedintheselectedsamplecanbemeasuredbymeansofprecipitationPotentiometricTitrationbycontrollingtheacidityandtemperatureofthesolutionwhenusingCopperion-selectiveelectrodeanddoublesaltbridgesaturatedcalomelelectrodeasinstructiveelectrodeandreferencee-lectroderespectivelywiththetitrantofappropriatestandardsolution.Thestudyshowsthat:whenthePHiscon-trolledintherangefrom1.0to1.5,theinterferenceofcoexistenceironions(Ⅲ)havebeenavoidedbyusingNH4F,thecontentsofcoppervaluecanbedirectlymeasuredbyabovementionedmethodwhichismuchmoresimple、fasterandsupersensitive,alsoitisunnecessarytoseparatethecoexistencecontentsinthesolution,meanwhiletheresultshavenosignificantdifferencewhenitiscomparedwithAAS.Keywords:selectedprecipitation;Potentiometrictitrationelectroplatingwastewater;copper·59·6　: