臭氧法降解水中氟苯的动力学研究何志桥

212No.2Vol.2120074JournalofChemicalEngineeringofChineseUniversitiesApr.20071003-9015(2007)02-0298-061,1,2,2,1(1.,310032;2.,310027)pH0.52mmol⋅L−1pH91.25×10−6mol⋅s−160min95C=C0exp(−0.324exp(−7437/RT)QO30.41C0−0.372[OH−]0.0942t)GC-MSX592X703.1X787AKineticsofFluorobenzeneDegradationbyOzoneinAqueousSolutionHEZhi-qiao1,SONGShuang1,YANGYue-ping2,XUXin-hua2,CHENJian-meng1(1.CollegeofBiologicalandEnvironmentalEngineering,ZhejiangUniversityofTechnology,Hangzhou310032,China;2.DepartmentofEnvironmentalEngineering,ZhejiangUniversity,Hangzhou310027,China)Abstract:Thedegradationoffluorobenzene(FB)byusingozonationprocesswasstudied,andtheinfluencesofpHvalue,initialconcentrationoffluorobenzene,ozonefluxandreactiontemperatureonthereactionkineticswereinvestigated.Experimentalresultsshowthattheozonationprocessiseffectivefordegradationoffluorobenzene,andFBcanberemovedupto95%after60minutestreatingwithozonefluxof1.25×10−6mol⋅s−1atpHvalueof9.0andtemperatureof25.Inallcases,thereactionoffluorobenzenedegradationbyozonefollowspseudofirst-orderkinetics.BasedontheconsiderationofthecontributionofpHvalue,initialconcentrationoffluorobenzene,ozonefluxandreactiontemperaturetotheozonationprocess,asimplifiedmechanisticmodelforfluorobenzenedegradationbyozonewasderived,andthekineticreactionequationwasfittedasanexponentialfunction:C=C0exp(−0.324exp(−7437/RT)QO30.41C0−0.372[OH−]0.0942t).Duringthedegradationoffluorobenzenebyozonationprocess,variousintermediateproductsweredetectedandidentifiedasphenol,benzonquinone,furandioneandbiiphenylenebyusingthehighperformanceliquidchromatography(HPLC)andgaschromatography-massspectrometry(GC-MS).Keywords:fluorobenzene;ozoneoxidation;intermediates;kinetics1(FB)2,4-[1~3]2005-10-132006-03-07(20407015)(1973-)E-mail:[e-mail]202299C–F[4~8][9][10]•OH[11,12]22.1(CHYF-3A)(Φ50mmH400mm)12.2pH0.45µm2.3(Agilent1100SeriesAgilent)SBC-18V4.6×150mm210nm//(35/65/0.2)1.0mL⋅min−13020µLGC-MS(-)GC(Variancp3800system)30m×0.25mm×0.25µm(WCOTfusedsilicaseries)802min15⋅min−12501minHe0.8mL⋅min−120:1MSEI70eVm/z30~500280F−(792BasicICMetrohm)MetrosepASupp5-2504.0mm×250mmNaHCO3(1.0mmol⋅L−1)/Na2CO3(3.2mmol⋅L−1)0.6mL⋅min−120µL33.11.25×10−6mol⋅s−1(2×10−6m3⋅s−1)pH9(C0)(C)23.2pHpH3.05.07.09.01Fig.1SchemeofexperimentalinstallationBathWaterReactorOzonegeneratorO2OzonegeneratorReactorWaterBathO205001000150020002500300035000.00.10.20.30.40.50.6C/mmol·L−1t/sC0=0.520C0=0.416C0=0.312C0=0.208C0=0.1042Fig.2OzonationdegradationcurvesoffluorobenzeneinaqueoussolutionOperatingconditions:ozoneflux1.25×10−6mol⋅s−1pH9.0;25C0=0.520mmol⋅L−1C0=0.416mmol⋅L−1C0=0.312mmol⋅L−1C0=0.208mmol⋅L−1C0=0.104mmol⋅L−1C/mmol⋅L−13002007405001000150020002500300035000.00.20.40.60.81.0C/C0t/spH=3.12pH=4.96pH=7.11pH=9.073pHFig.3EffectofpHonfluorobenzenedegradationOperatingconditions:C0=0.52mmol⋅L−1;ozoneflux1.25×10−6mol⋅s−1;2505001000150020002500300035000.00.20.40.60.81.0C/C0t/sO3=0O3=0.625O3=1.25O3=2.504Fig.4EffectofozonefluxonfluorobenzenedegradationOperatingconditions:C0=0.52mmol⋅L−1;pH9.0;25mmol⋅L−1mmol⋅L−1mmol⋅L−1mmol⋅L−1C/C0C/C0pH33pHpH3.124.967.119.0760min55708195pHHO2−·OH·OH[12,13]pH·OHpH3.33442.5×10−6mol⋅s−13.4pH9.00.52mmol⋅L−11.25×10−6mol⋅s−155015254060min899295974GC-MSIC(IonChromatograph)05001000150020002500300035000.00.20.40.60.81.0C/C0t/s0°C15°C25°C40°C5Fig.5EffectoftemperatureonfluorobenzenedegradationOperatingconditions:C0=0.52mmol⋅L−1;ozoneflux1.25×10−6mol⋅s−1;pH9.0C/C001525402023010.00320.00330.00340.00350.00360.0037-7.5-7.4-7.3-7.2-7.1-7.0-6.9-6.8-6.7-6.6-6.5lnkobs(1/T)/K−17lnkobs−1/TFig.7lnkob−1/Tfittedcurve-14.4-14.2-14.0-13.8-13.6-13.4-13.2-13.0-12.8-12.6-7.5-7.4-7.3-7.2-7.1-7.0-6.9-6.8-6.7-6.6-6.5lnkobslnQO38lnkobs−lnQO3Fig.8lnkobs−lnQO3fittedcurve,pH9665[14]−dC/dt=kCm3OnC(1)−dC/dt=kobsCm(2)0.98m1−dC/dt=kobsC(3)·OHkobskobs(·OH)·OHkobsC0(QO3)pHkobsAexp(−Ea,obs/RT)QO3αC0β[OH−]γ(4)(4)lnkobslnA−Ea,obs/RT+αlnQO3+βlnC0+γln[OH−](5)TC0(QO3)pH[16](1)lnkobs—1/Tlnkobs1/T7−Ea,obs/R=−894.6r0.987Ea,obs894.6R894.68.314=7437J⋅mol−10600120018002400300036000.00.10.20.30.40.50.6t/minF−FB6Fig.6VariationoftheconcentrationofFBandfluorionwithozonationtimeOperatingconditions:C0=0.52mmol⋅L−1;ozoneflux1.25×10−6mol⋅s−1;pH9.0;25C/mmol⋅L−130220074-9.5-9.0-8.5-8.0-7.5-7.0-7.5-7.0-6.5-6.0lnkobslnC09lnkobs−lnC0Fig.9lnkobS−lnC0fittedcurve-24-20-16-12-8.5-8.0-7.5-7.0-6.5lnkobsln[OH−]10lnkobs−ln[OH-]Fig.10lnkobs−ln[OH-]fittedcurve(2)lnkobs—lnQO3lnkobslnQO38α=0.41r=0.972(3)lnkobs—lnC0lnkobslnC09β=−0.372r=0.982(4)lnkobs—ln[OH−]lnkobsln[OH−]10γ=0.0942r=0.989kobsAexp(−7437/RT)QO30.41C0−0.372[OH−]0.0942(6)AlnA1.383A0.324A(6)(3)kobs0.324exp(−7437/RT)QO30.41C0−0.372[OH−]0.0942(7)C=C0exp(−0.324exp(−7437/RT)QO30.41C0−0.372[OH−]0.0942t)(8)2~5kobs1(8)0.104~0.520mmol⋅L−1pH3~90~1.25×10−6mol⋅s−10~6025%6(1)0.52mmol⋅L−1pH91.25×10−6mol⋅s−160min95(2)(3)C=C0exp(−0.324exp(−7437/RT)QO30.41C0−0.372[OH−]0.0942t)1Table1FittedrateconstantsbasedontheexperimentalresultsNopHT/KC0103/mol⋅L−13OQ106/mol⋅s−1kobs103/s−1r19298.150.1041.251.70340.98329298.150.2081.251.33810.98939298.150.3121.251.21010.99149298.150.4161.251.0768