光催化降解甲胺磷影响因素的研究徐悦华

　收稿日期:2000-09-25　作者简介:(1964-),,,,.文章编号:1000-565X(2001)05-0068-04光催化降解甲胺磷影响因素的研究徐悦华　古国榜　李新军(,510640)摘　要:进行了纳米TiO2悬浮体系光催化降解甲胺磷的研究.结果表明,只有在光照、催化剂和氧同时存在的条件下才能有效地进行光催化降解甲胺磷.在甲胺磷浓度为1×10-4mol·L-1,反应液起始pH=6.82,通空气量为2L·min-1,催化剂用量为0.4g·L-1,光照时间为2h时,甲胺磷的降解率为77.5%.同时还探讨了起始pH值、甲胺磷起始浓度、光强、通气量,以及电子接受体H2O2、Fe3+等对光催化降解甲胺磷的影响.实验结果表明光催化降解甲胺磷是可行的.关键词:光催化降解;甲胺磷;纳米二氧化钛中图分类号:O643.32+2;TQ453.2+2　　　　文献标识码:A　　,[1].1969,、,.199633.05,37.8%,2001,30.5,34.7%[2].77%,6[3].[4][5].,(20～40)、、.(TiO2),·OH,·OHH2O、CO2、PO43-,,[6,7].TiO2.TiO2,.1　实验部分1.1　主要仪器和试剂756M,7230G,pHS_25.,TiO2(,189nm,61m2·g-1),.1.2　实验方法及分析方法,(70mm×210mm)500mL,,125W,,40℃.,.,,15min.,,PO43-,.2　实验结果和讨论2.1　催化剂用量的影响:1×10-4mol·L-1,(自然科学版)295JournalofSouthChinaUniversityofTechnologyVol.29　No.520015(NaturalScienceEdition)May　2001pH=6.82,2L·min-1,2h.,.TiO21.1　TiO2Fig.1　TheeffectoftheamountofTiO2onthephotoca_talysticdegradationofmethamidophos1,,,0.4g·L-1,77.5%.,,.,TiO2.,0.4g·L-1.,.,2h4.7%;,2hPO43-;10min,,2L·min-1,20min,2hPO43-.、.,,h+,·OH.2.2　起始pH值的影响1,pH,pH.1.1　pHTable1　TheeffectofpHvalueonthephotocatalyticdegradationofmethamidophospH　2.2　3.2　6.8　8.9/%92.884.677.582.3　　1,,.TiO26.87,pH,,pH,.,,OH-(h++OH-※·OH),.,,,H+,:H++O-2·※HO2·(1)HO2·+HO2·※H2O2+O2(2)HO2·+O-2·※HO-2+O2(3)HO2-+H+※H2O2(4)O2+2e-+2H+※H2O2(5)H2O2·OH:　　H2O2+e-※·OH+OH-(6)H2O2+O-·2※·OH+OH-+O2(7)H2O2+hv※2·OH(8)2.3　甲胺磷起始浓度的影响2.,.,TiO210-9s,,.,,.[8],,,(),,.2　Fig.2　Theeffectoforiginalconcentrationofmethami_dophosontheefficiencyofdegradation1—5×10-5mol·L-1;2—1×10-4mol·L-1;3—5×10-4mol·L-1.2.4　光源的影响:(1)25W,365nm;(2)125W,　5:69　　　365nm.3.3　Fig.3　Theeffectoflightsourceonthephotocatalyticdegradationofmethamidophos,25W,,2h,21%,125W77.5%.[9],,kI,,kI.2.5　空气通入量的影响,,2.2　Table2　Theeffectofair_flowonthephotocatalyticdegradationofmethamidophos/(L·min-1)　1.0　1.5　2.02.0(O2)/%48.464.677.599.3　　,,.,2.0L·min-1,2h,77.5%,99.3%.GorischerH[10],,O2.O2,—,O2-·,O2-·,·OH.O-·2+H2O※·OOH+OH-(9)2·OOH※H2O2+O2(10)·OOH+H2O+e-※H2O2+OH-(11)H2O2+e-※·OH+OH-(12)2.6　H2O2浓度的影响1h,H2O2.4.4　H2O2Fig.4　TheeffectofconcentrationofH2O2onthephoto_catalyticdegradationofmethamidophos　　4,H2O2.H2O210mmol·L-1,,H2O2,.H2O2,—,·OHH2O2.H2O2,H2O2,,;H2O2·OH,,H2O2.·OH+H2O2※H2O+HO2·(14)·OH+HO2·※H2O+O2(15)2.7　Fe3+浓度的影响1h,Fe3+.3.3　Fe3+Table3　TheeffectofconcentrationofFe3+onthephotocatalyticdegradationofmethamidophosc(Fe3+)/(mmol·L-1)0.00250.0052　0.011/%54.959.764.1c(Fe3+)/(mmol·L-1)0.0300.0520.10　0.20/%58.351.442.1　28.2　　3,Fe3+,.Fe3+0.011mol·L-1,.Fe3+0.011mol·L-1,.Fe3+,—,TiO2·OH,.Fe3+,Fe(OH)2+,Fe(OH)2+290～400nm[11],TiO2,.70　　　(自然科学版)29　3　结　论(1)TiO2,、.,,,TiO20.4g·L-1.(2)·OH,.pH=2.292.8%,pH=8.982.3%,77.5%.、、,.(3)H2O2,H2O210mmol·L-1,1h79.1%.Fe3+,Fe3+.Fe3+0.011mmol,1h64.1%,Fe3+.参考文献:[1]　.[M].:,1998.35.[2]　,　.[J].,1999,38(7):1-3.[3]　.[J].,1998,37(6):7-10.[4]　,.B_82[J].,1999,18(12):564-567.[5]　,.[J].,1999,19(2):172-175.[6]　DoongRuey_an,ChangWen_huei.Photoassistedironcom-poundcatalyticdegradationoforganophosphorouspesti-cideswithhydrogenperoxide[J].Chemosphere,1998,37(13):2563-2572.[7]　MalatoS,BlancoJ,Richterc,etal.Pre_industrialex-perienceinsolarphotocatalyticmineralizationofwastewater—Applicationtopesticidecontainerrecy-cling[J].WatSciTech,1999,40(4-5):123-130.[8]　,,.[J].,1999,15(2):14-17.[9]　GoswamiDY.Areviewofengineeringdevelopmentofaqueousphasesolarphotocatalyticdetoxificationanddisinfectionprocesses[J].JofSolarEnergyEngi-neering,1997,119:101-107.[10]　GorischerH,HellorA.Theroleofoxygeninpho-tooxidationoforganicmoleculesonsemiconductorparticles[J].JPhysChem,1991,95(13):5261-5267.[11]　SclafaniA,PalmisanoL,PaviE.Photocatalyticdegrada-tionofphenolinaqueouspolycrystallineTiO2disper-sions:TheinfluenceofFe3+,Fe2+andAg+onthereac-tionrate[J].JPhotochemPhotobiol(A):Chem,1991,56(1):113-123.AStudyofFactorsAffectingPhotocatalyticDegradationofMethamidophosXuYue_hua　GuGuo_bang　LiXin_jun(CollegeofChemicalEngineering,SouthChinaUniv.ofTech.,Guangzhou510640,China)Abstract:Thephotocatalyticdegradationofmethamidophosinsemiconductorsuspensionhasbeenstu_died.Itwasfoundthatthesimultaneouspresenceoflight,photocatalystandoxygenwasnecessary.Whentheconcentrationofmethamidophosis1×10-4mol·L-1,theoriginalpHvalueofthereactionso-lution6.82,theair_flow2L·min-1,theamountofcatalyst0.4g·L-1,theradiationtime2h,thedegradationefficiencyofmethamidophosis77.5%.Variousfactors,suchastheoriginalpHvalue,theoriginalconcentrationofmethamidophos,thelight,theair_flow,theacceptorofelectronH2O2、Fe3+thatinfluencethephotocatalyticdegradationofmethamidophos,havebeenstudied,thephotocatalyticdegradationofmethamidophosprovedtobefeasible.Keywards:photocatalyticdegradation;methamidophos;TiO2nanometrepowder　5:71