Heterogeneous photocatalysis with titanium dioxide suspensions containing bromide and dissolved organic carbon [Elektronische Ressource] / Luis Alberto Tercero Espinoza

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• Publié par: karlsruher_institut_fur_technologie
• Publié le: 01 janvier 2010
• Nombre de lectures: 101
• Poids de l'ouvrage: 4 Mo

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Band 51
Schriftenreihe des Lehrstuhls für Wasserchemie und
der DVGW-Forschungsstelle am Engler-Bunte-Institut
des Karlsruher Instituts für Technologie (KIT)
Heterogeneous photocatalysis with
titanium dioxide suspensions containing
bromide and dissolved organic carbon
Luis Alberto Tercero Espinoza
Herausgeber
Fritz H. Frimmel
Karlsruhe 2010Luis Alberto Tercero Espinoza
Heterogeneous photocatalysis with titanium dioxide suspensions containing bromide
and dissolved organic carbon
Herausgeber: Fritz H. Frimmel
Band 51
Schriftenreihe des Lehrstuhls für Wasserchemie und der DVGW-Forschungsstelle
am Engler-Bunte-Institut des Karlsruher Instituts für Technologie (KIT)
Karlsruhe 2010
ISSN: 1612-118X
Lehrstuhl für Wasserchemie und DVGW-Forschungsstelle
am Engler-Bunte-Institut des Karlsruher Instituts für Technologie (KIT)
Engler-Bunte-Ring 1
D-76131 Karlsruhe
Tel.: [phone]
Fax: [phone]
E-mail: [e-mail]
http://wasserchemie.ebi.kit.edu
Dieses Werk wird duch das deutsche Urheberrechtsgesetz und internationale Verträge urheberrech-
tlich geschütz. © 2010 Prof. Dr. F. H. Frimmel. Alle Rechte vorbehalten. All rights reserved.Heterogeneous photocatalysis with
titanium dioxide suspensions containing
bromide and dissolved organic carbon
zur Erlangung des akademischen Grades eines
DOKTORS DER INGENIEURWISSENSCHAFTEN (Dr.-Ing.)
der Fakultät für Chemieingenieurwesen und Verfahrenstechnik des
Karlsruher Instituts für Technologie (KIT)
genehmigte
DISSERTATION
von
Luis Alberto Tercero Espinoza, M.Sc.
aus León, Nicaragua
Referent: Prof. Dr. rer. nat. habil. F. H. Frimmel
Korreferent: Prof. Dr.-Ing. habil. H. Nirschl
Tag der mündlichen Prüfung: 3. Mai 2010ivTomyfamilyintwocontinents
vviAcknowledgements
TheworkpresentedherewasdoneattheDivisionofWaterChemistryoftheEngler-
Bunte-InstitutattheUnviersitätKarlsruhe(TH)betweenApril2004andMarch2009.
Differentpeopleandorganizationscontributedtothesuccessofthisthesis:
Iwouldliketothankmyadvisor,Prof. FritzFrimmel,forgivingmetheopportunity
to work in his research group and for his trust and encouragement. Prof. Hermann
Nirschl,withwhomIalsohadthepleasureofworking,waskindenoughtoassume
theroleofsecondcorrector.
I am also grateful to Dr. Gudrun Abbt-Braun and Dr. Birgit Gordalla for their help
making things happen in spite of clever bureaucratic hurdles, and to Sylvia Heck
whowasalwayswillingtolendahelpinghand. IamgratefulalsotoDunjaHaakfor
keepingthedatasafeandthecomputersrunning.
To my colleagues in the Graduiertenkolleg, for their support and the friendly atmo-
sphere,Icanonlysaythankyou.
My colleagues at the EBI, past and present, also have my enduring gratitude for
their professional and personal support. I would like to mention Christian Zwiener
andThomasGlauner, whosesuggestionspointedmeinfruitfuldirections. Working
withMarianaNeam¸tu, FlorenciaSaravia, Eiketer Haseborg, MarkusDelay, Carsten
Jobelius,UlrichMetzgerMarkusZiegmann,andHeikoSchwegmannindiversetasks
related and unrelated to this thesis was a great experience. To my office mates (and
theyweremany!): thanksfortheniceatmosphere.
The results presented here would have costed a lot more pain and time were it not
forthesupportofthetechnicalstaff. MatthiasWeberwasbehindthemanymeasure-
ments with size exclusion chromatography. Axel Heidt invested numerous hours
not only with trihalomethane measurements but keeping a safe working environ-
ment. RafaelPeschkeandEllyKarlewereresponsiblefortheHPLCanalysesandthe
measurement of small organic acids by ion chromatography. Domnic Bandara was
perseverantintheoftencapriciousAOXmeasurements. Finally,ReinhardSembritzki
performedthemeasurementsofmetalionconcentrations.
viiAcknowledgements
IwouldliketothankMartaLópezFurelos,ClaraArribasMatesanz,EikeZiegler,Lei
Gao, MaríaJesúsRubio, RaquelMalerbaandMaximilianRemborfortrustingmeto
guidetheirstudentprojectsandforcontributingtothisthesis.
The German Research Foundation (DFG) and the German Technical and Scientific
Association for Gas and Water (DVGW) provided financial support for this work.
Especially, the DFG Graduate Training Program on Surface Phenomena in Aquatic
Systems and Aqueous Phases (Graduiertenkolleg 366) was what originally attracted
metothisinstituteandultimatelytothiswork.
A Travel Bursary and the Malcolm Award of the International Humic Substances
Society(IHSS)allowedtometraveltoRussiaandpresentapartoftheresultsinthis
thesisatthe14thMeetingoftheIHSS,heldinSeptemberof2008. Atravelstipendof
the GermanResearch Foundationallowedmeto present a widerselection of results
immediately after at the 13th International Conference on TiO Photocatalysis held2
inSanDiego,USA.
Karlsruhe,May2010
LATE
viiiContents
Acknowledgements vii
Zusammenfassung xiii
1 Introduction 1
2 Background 9
2.1 Electronicpropertiesofsemiconductors . . . . . . . . . . . . . . . . . . 9
2.1.1 Bandgapstructureofsemiconductors . . . . . . . . . . . . . . . 9
2.2 Semiconductorphotocatalysis . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.1 Titaniumdioxide . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.2 Photogenerationandreactionsofelectron/holepairs . . . . . . 12
2.3 Photocatalyticdegradationofhumicmaterial . . . . . . . . . . . . . . . 13
2.3.1 Reductionofthetrihalomethaneformationpotential . . . . . . 14
2.3.2 Decolorizationofhumic-richwaters . . . . . . . . . . . . . . . . 15
2.3.3 Openquestions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.4 Harmfulbyproductsindisinfectionandoxidationprocesses . . . . . . 17
2.4.1 Sourcesofbromideinnaturalwaters . . . . . . . . . . . . . . . 17
2.4.2 Brominatedtrihalomethanes . . . . . . . . . . . . . . . . . . . . 17
2.4.3 Bromate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.4.4 Semiconductorphotocatalysisanddisinfectionbyproducts . . . 20
2.5 Designofexperiments(DoE) . . . . . . . . . . . . . . . . . . . . . . . . 20
2.5.1 Factorialdesigns . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.5.2 Box-Behnkendesigns. . . . . . . . . . . . . . . . . . . . . . . . . 23
2.5.3 Screeningdesign . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.5.4 Identificationofimportantfactors . . . . . . . . . . . . . . . . . 24
3 Materials and Methods 29
3.1 Chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.2 Analyticalmethods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.2.1 Wetchemicaloxidationwithcarbondioxidedetection . . . . . 30
ixContents
3.2.2 Size exclusion chromatography with dissolved organic carbon
andultravioletdetection(SEC-DOCandSEC-UV) . . . . . . . . 30
3.2.3 Inductively coupled plasma-optical emission spectroscopy
(ICP-OES) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.2.4 Coulometrictitration . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.2.5 Ionexchangechromatography(IC) . . . . . . . . . . . . . . . . . 33
3.2.6 Highperformanceliquidchromatography(HPLC) . . . . . . . 35
3.2.7 Photometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.2.8 Gaschromatography . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.3 Experimentalequipmentandprocedures . . . . . . . . . . . . . . . . . 36
3.3.1 ForChapter4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.3.2 ForChapter6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.3.3 ForChapter7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.3.4 ForChapter8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3.3.5 ForChapter9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4 Photocatalytic degradation of natural organic matter (NOM) 43
4.1 ResultsfromSEC-DOC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.1.1 ApparentselectivityofthedegradationofNOM . . . . . . . . . 46
4.1.2 AdsorptionofNOMontothesurfaceofthephotocatalyst . . . 47
4.1.3 Comparisonwithdirectphotolysis . . . . . . . . . . . . . . . . . 49
4.1.4 Formationofhydrophobiccompounds . . . . . . . . . . . . . . 50
4.2 Results from size exclusion chromatography with UV absorption de-
tection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
4.2.1 Comparisonwithhomogeneousadvancedoxidationprocesses 54
4.3 Formationandlowmolecularweightorganicacids(LMWOA) . . . . . 55
4.4 Bioavailabilityofthedissolvedorganiccarbon(DOC) . . . . . . . . . . 56
4.5 Interimsummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
5 Simulation of the photocatalytic degradation of natural organic matter 59
5.1 Underlyingphysicalmodel . . . . . . . . . . . . . . . . . . . . . . . . . 60
5.2 Simulationalgorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5.2.1 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5.2.2 Reactionstepinahomogeneoussystem . . . . . . . . . . . . . . 62
5.2.3 Reactionstepinaheterogeneoussystem . . . . . . . . . . . . . 64
5.2.4 Iteration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.3 Simulationoftheheterogeneoussystem . . . . . . . . . . . . . . . . . . 64
5.3.1 Comparisonofexperimentalandsimulatedchromatograms .