1

Oxidative Processes in WaterTechnology:

Intro

Faculty of ChemistryChair of Instrumental Analytical Chemistry

Prof. Dr. Torsten C. Schmidt

• Diploma, Chemistry, 1994PhD, Analytical Chemistry, 1997(+ law studies 1994-1997)

• Postdoc Environmental Chemistry1998-2002

• Group Leader Environmental Chemistry and Analysis2002-2006

• Chair of Instrumental Analytical Chemistry since 2006 Director of the Center for Water and Environmental Research since 2009

• Scientific Director for WaterChemistry, IWW Water Centre since 2006

• President of the Water Chemical Society since 2013

http://www.uni-duisburg-essen.de/iac

3

Dr. Jochen Türk• Diploma, Chemistry,

Technical University Dortmund, 2001

• PhD, Analytical ChemistryUniversity Duisburg – Essen, 2007

• Institute of Energy and Environmental Technology (IUTA), Duisburg since 2001 (Affiliated Institute of the University Duisburg-Essen) Head of Laboratory, Department of Environmental

Hygiene & Analysis, 2003 – 2008 Head of Department Research Analysis, since 2009

Analytical Technologies Waste water technologies Pharmaceuticals and micro pollutants

in the environmentContact: tuerk@iuta.de

http://www.iuta.de

4Dr. Holger Lutze

Contact: Holger.Lutze@uni-due.de

• B.Sc. Water ScienceUniversity Duisburg-EssenThesis: Ozonation of benzotriazoles

Eawag aquatic research (Switzerland)(2005)

• M.Sc. Water ScienceUniversity Duisburg-Essen

Thesis: Degradation of taste and odor compounds in ozone based oxidationEawag aquatic research (Switzerland)(2007)

• Scientific assistant and advisorIWW Water Centre Feasibility studies on oxidants in water treatment Co-supervisior in different water treatment pilot studies(since 2008)

• Ph.D. on sulfate radical based oxidationUniversity Duisburg-Essen (funded by the Water Chemistry Society) Cooperation with IWW water center in several drinking water projects(since 2009/2010)

5Your Assistants: Sarah Willach

Since 2013 Ph.D. Instrumental Analytical Chemistry University Duisburg-Essen

Ph.D. Thesis Development of a liquid chromatography-15N-isotope ratio mass spectrometer interface

2010 – 2012 M.Sc. in Water ScienceUniversity Duisburg-Essen

Master Thesis(2012)

Optimisation and application of an analytical method for the determination of adsorbable organofluorinecompounds (AOF) in the water cycleTechnologiezentrum Wasser, Karlsruhe, Germany

2007 – 2010 B.Sc. in Water ScienceUniversity Duisburg-Essen

Bachelor Thesis(2010)

Effect of the pH on formation of disinfection by-products in swimming pool watersDanmarks Tekniske Universitet, Lyngby, Denmark

Ph.D. Student - University Duisburg-Essen - Germany

Contact: sarah.willach@uni-due.de

6Your Assistants: Alaa Salma

Since 2011 Ph.D. Instrumental Analytical Chemistry University Duisburg-Essen

Ph.D. Thesis Pharmaceuticals wastewater treatment by advanced oxidation processesInstitute of Energy and Environmental Technololgy, Duisburg

2004 – 2006 M.Sc. in Industrial Systems Safety and Environment ManagementDamascus University, Syria & Poitier University, France

Master Thesis(2006)

Analyses and Assessment of Hazard in York Unit for the Production of Ammonia Nitrogen Fertilizer plant & Damascus University, Syria

1999 – 2004 B.Sc. in Chemical SciencesDamascus University, Faculty of Science, Syria

Bachelor Thesis(2004)

Separation and Determination of Aromatic Hydrocarbons in KeroseneDamascus university, Faculty of science, Syria

Ph.D. Student - University Duisburg-Essen - Germany

Contact: Salma@iuta.de

Fields of Research: (Advanced) Oxidation Processes

0

5

10

15

20

25

30

35

40

45

50

0 50 100 150 200 250

[Ozone] / µM

[Dic

lofe

nac]

and

[Pro

duct

s] /

µM

N

O

Cl

Cl

CH2

COOH

CH2N

CO2HH Cl

Cl

Current Research Projects: Development, Set-Up and Characterization of Nonthermal Plasmas by Corona

Discharge in Water Treatment (Svetlana Gasanova MC-ITN, Klaus Kerpen) Reactive Species in the Fenton Process (Alexandra Fischbacher, Alexandra Beermann) Sulfate Radicals in Oxidative Water Treatment (Holger Lutze) Behaviour of Complexing Agents in Oxidative Water Treatment with Focus on Gd

Complexes used in MRI (Maike Cyris) UV assisted Oxidation for Removal of Micropollutants in Wastewater (Alaa Salma) Mechanistic Aspects of the Reaction of Primary and Secondary Amines with

Ozone in Aqueous Systems (Agnes Tekle-Röttering external at Westfälische Hochschule)

Recent Funding

8

Why do We Offer a Dedicated Courseon Oxidative Processes?

1. The use of oxidative processes is a common and important tool in watertreatment

2. Current political pressure for furtherremoval of micropollutants will increasedemand for advanced treatment optionsincluding AOPs

3. Oxidative processes play a major role in natural transformation processes

9The Mülheim Process for Treating

Ruhr River Water

Slow sandfiltration

Activated Carbon Filters

UV disinfection

Chlorine dosage

Chloro-dioxide dosage

NaOH dosage

Pre-Ozonation

If needed

10

Ozonation in Wastewater Treatment

Conventional WWTP Ozone contactor Posttreatment River

Example: WWTP Bad Sassendorf (Lippeverband)

11

Aims of the Lecture

• Overview of routine and state-of-the-art oxidative processes used in water and wastewater treatmentSmall overlap with the optional courses on water and wastewater treatment but hardly focus on technical implementation

• Advanced understanding of fundamental transformation processes involved in technical processes

• Evaluation of advantages and drawbacks of oxidative processes for exemplary applications

• Development of criteria for the selection of appropriate technological solutions

12

Required Background

• Physical Chemistry: Thermodynamics, chemical equilibrium, mass balance equations, kinetics

• Organic Chemistry: Functional groups, Reaction mechanisms (including radical-based mechanisms)

• Water Chemistry: – Ions in aqueous solution (Acid/base, Dissolution, Complexation)– Redox chemistry – Homogenous transformation reactions– Photochemistry

13

Organisation• Lecture and Tutorial

Wednesday 1415-1600, T03 R03 D89, Wednesday 1615-1700, T03 R03 D89

• Formation of groups for problem discussion and presentation • During the four tutorials up to May 21 each group presents their

solution to a specified problem in a problem set distributed in the course. Their approach will be discussed. It is NOT the primary goal to show the correct result but to learn how to tackle such problems. Group formation will be done by the PhD students after collecting contact data to ensure a good mixture of external/internal and German/international students.

14

Organisation II2nd half of term:

Review Preparation and PresentationSubmission of a review on a distributed paper with emphasis on weaknesses, missing data etc. Short presentations of major findings during last two-three tutorials

15

Course ContentsSubject Who? Date Date

TutorialIntroduction to oxidative processes and course organization

TS/All 09.04.14

Kinetic constants and oxidant exposure HL 16.04.14Ozone-based reactions HL 23.04.14 30.04.14Hydroxyl radical-based reactions HL 30.04.14 07.05.14Further oxidants HL 07.05.14 14.05.14Applications in water treatment (including disinfection) I

TS 14.05.14 21.05.14

Applications in water treatment (including disinfection) II

TS 21.05.14

Applications in wastewater treatment I JT 04.06.14Applications in wastewater treatment II JT 11.06.14 (11.06.14)Disinfection/transformation by-products: (Eco)toxicological evaluation

JT 18.06.14 18.06.14

Economical considerations JT 25.06.14 25.06.14Wrap-Up all 02.07.14Exam 23.07.14

or14.10.14

16

Literature• Urs von Gunten, Clemens von Sonntag:

Chemistry of Ozone in Water and Wastewater Treatment: From Basic Principles to Applications.IWA Publishing, 2012

• Christiane Gottschalk, Judy Ann Libra, Adrian Saupe:Ozonation of Water and Waste Water: A Practical Guide toUnderstanding Ozone and its Applications. Wiley-VCH, 2009

• Thomas Oppenländer: Photochemical Purification of Water and Air: Advanced Oxidation Processes (AOPs): Principles, Reaction Mechanisms, ReactorConcepts. Wiley-VCH, 2002

17

Are Oxidative Processes New Treatment Technologies?

Ozone Treatment Waterworks Hermannstadt1915

UV-Treatment 1915

Modified after M. Exner, U Bonn

Use of Oxidation Processes in Water Treatment

Advantages: • Constant process performance• Combined disinfection and pollutant control• No disposal of concentrates or solids

(compared with AC sorption or membrane filtration)

Areas of Use:• Drinking water

– Disinfection, Decolorization, Fe(II) andMn(II) Removal, Micropollutant Elimination, Taste and odor elimination

• Municipal wastewater– Disinfection, Further elimination of micropollutants

• Industrial wastewater• High purity industrial process waters

Common Oxidants in Water TreatmentOxidant Purpose

Direct addition to water

Oxygen/air Fe(II) oxidation

Chlorine (HOCl) Disinfection only (German DWG)

Chlorine dioxide Disinfection only (German DWG)

Ozone Disinfection/oxidation (also •OH)

Hydrogen Peroxide Oxidation (mainly •OH)

Permanganate Oxidation

Persulfate Oxidation (•OH and SO4•- )

In situ formation

OH radicals Oxidation/AOPs

19

20

Important Considerations in Oxidative Treatment Processes

Pollutants Oxidation CO2, H2O LifetimeMechanismsKinetics

Transformation products

Biodegradability Toxicologicaleffects

Scavenging by matrix components

Possible lossof efficiency, Oxidation byproducts

Structuredeterminesreactivity, lesspronounced forOH

Oxidation

Modified after U. von Gunten, eawag

Energy Demand/Carbon Footprint?

Formation ofsecondaryoxidants

21

Estrogen Receptor

Effect?Effect

Oxidation

Estrogenically active compound

Effect of Oxidative Transformation I:Reduction of Estrogenicity

Transformation product

binds?binds

Modified after U. von Gunten, eawag

17-Estradiole (E2)

22

Reduction of estrogenicity is proportional to concentration decline of EE2

Lee et al. 2008

Reduction of Estrogenic Effects (EEEQ) of 17-Ethinylestradiole by Oxidative Processes

d o s e , M0 5 1 0 1 5 20 2 5 3 0

Rel

ativ

e EE

2 or

EEE

Q

0 .0

0 .2

0 .4

0 .6

0 .8

1 .0

R e la tiv e E E 20.0 0 .2 0 .4 0 .6 0 .8 1 .0

Rel

ativ

e EE

EQ

0 .0

0 .2

0 .4

0 .6

0 .8

1 .0C h lo rin e

d o s e , M0 5 1 0 1 5 20 2 5 3 0

B ro m in e

R e la tiv e E E 20.0 0 .2 0 .4 0 .6 0 .8 1 .0

Rel

ativ

e EE

EQ

0 .0

0 .2

0 .4

0 .6

0 .8

1 .0

d o s e , M0 5 1 0 1 5 2 0 2 5 3 0

O zo n e

R e la tive E E 20 .0 0 .2 0 .4 0 .6 0 .8 1 .0

Rel

ativ

e EE

EQ

0 .0

0 .2

0 .4

0 .6

0 .8

1 .0

U V flu e n c e , m J /c m 20 1 00 2 0 0 3 00 4 0 0

0 .0

0 .2

0 .4

0 .6

0 .8

1 .0

O H ra d ic a l

R e la tiv e E E 20 .0 0 .2 0 .4 0 .6 0 .8 1 .0

Rel

ativ

e EE

EQ

0 .0

0 .2

0 .4

0 .6

0 .8

1 .0

d o s e , M0 5 10 1 5 2 0 25 30

C h lo rin e d io x id e

R e la tive E E 20.0 0 .2 0 .4 0 .6 0 .8 1 .0

Rel

ativ

e EE

EQ

0 .0

0 .2

0 .4

0 .6

0 .8

1 .0

d o s e , M0 10 2 0 3 0 40

F e rra te

R e la tive E E 20.0 0 .2 0 .4 0 .6 0 .8 1 .0

Rel

ativ

e EE

EQ

0 .0

0 .2

0 .4

0 .6

0 .8

1 .0

1

r2 = 0 .9 6 r2 = 0 .9 9

1 1

r2 = 0 .9 9

1

r2 = 0 .99

1

r2 = 0 .9 9

1

r2 = 0 .99

Rel

ativ

e EE

2 or

EEE

Q

EE2EEEQ

Modified after U. von Gunten, eawag17-Ethinylestradiole (EE2)

23

Effect of Oxidative Transformation II:Reduction of Toxic Effects in Bulk Samples

• Data from WWTP Regensdorf, CH:

Adapted from S. Zimmermann, EPFL

Elimination by ozonation and slow sand filtration in %

Bioluminescence suppression

Acetylcholinesterase suppression

Algae test (photosynthesis)

Algae test (growth)

YES Assay

Describing Pollutant Removal

Oxidant nNo. of publ. kinetic const. kn (ca. 2008)

Ozone ~ 500OH Radicals ~ 2000Chlorine ~ 300

Chlorodioxide ~ 100

Ferrate(VI) ~ 50

1

n

n n

d Pk ox P

dt

10

lnn

n n

Pk ox dt

P

pH, T!

Quantification oxidant exposure:• Matrix dependent

• Dosage dependent

• Consideration of secondary oxidants

Determination kinetic constants:• Direct measurements

• Indirect measurements (Competition kinetics)

• Quantitative structure activity relationships

(QSARs)

• Estimation from similar oxidants

Modified after U. von Gunten, eawag

Oxidation kinetics: Estimation of Rate ConstantsQSAR for the Reaction of Phenols and Phenolates with

Ozone

o,m,p+

-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5

log(

k O3)

2

4

6

8

10

Neutral speciesAnionic species

= -3.4(±0.3)y0 = 3.4(±0.1)r2 = 0.94

= -2.4(±0.2)y0 = 8.9(±0.1)r2 = 0.96

2-Cla

4-ClaPhOHa

triclosan

Penta-Cla

Penta-Brb

4-NO2a

2-OHb4-OHb

4-CH3a

3-CH3a

2-CH3a

2,6-CH3c

2,4-CH3c

3,4-CH3c

2,3-CH3c

4-Cla

triclosan2-Cla

PhOHa

O3O3O

Cl

ClCl

OH

O3

pKa = 8.1

Phenolates

Phenols

Triclosan

Modified after U. von Gunten, eawag

25

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 50 100 150 200 250

norm

aliz

ed o

xida

nt-c

once

ntra

tion

Stability of Oxidants in Lake Zurich Water

Permanganate

Chlorine

Ferrate

Chlorine dioxideOzone

Time - min

Stability of oxidants: .OH (s) << O3 < ClO2 < HFeO4

- < HOCl < MnO4-

Modified after U. von Gunten, eawag

26

Overview Advanced Oxidation ProcessesUV based Ozone based H2O2 based

UV/H2O2

UV/O3

O3/H2O2

No Chemicals

O3/AC

Ozonation

Fenton Ultrasound

UV/TiO2

H2O+Ultrasound OH +H

H2O + VUV(120-160nm) OH +H

2O3 + HO2- 2OH +3O2

O3 + AC OH + O2

O3 + (OH-, NOM) OH

H2O2 + UVC 2 OH (

O3+UVC H2O2 OH+O2

TiO2 + h h+ + e- OH + O2-

Vacuum UV (VUV)

OH- yield: 50%

[Fischbacher et al., ES&T 2013]

H2O2

Fe(II) Fe(III)

OH

H2O2HO2

[Fe(III)HO2]2+

Also directphotolysis

pH < 4

28Comparison of Advanced Oxidative Processes

UV based Ozone based H2O2 basedUV/H2O2(TiO2)

UV/O3

O3/H2O2

No Addition

Carbazon

Ozonation

FentonUltrasound

Energy demand

Vacuum UV

Loss of oxidation efficiency via matrix scavenging, assimilable organic carbon formation, unknown transformation products

Negative Effects

Modified after H. Lutze

BrO3-

NDMA

29Comparison of Advanced Oxidative Processes

UV based Ozone based H2O2 basedUV/H2O2(TiO2)

UV/O3

O3/H2O2

No Addition

Carbazon

Ozonation

FentonUltrasound

Energy demand

Vacuum UV

Loss of oxidation efficiency via matrix scavenging, assimilable organic carbon formation, unknown transformation products

Negative Effects

Modified after H. Lutze

Br- HOBr/OBr-

BrO3-

O3

O3/•OH

H2O2

Br-

30

Introductory Words on ReactionMechanisms

• Oxidation processes: Transformation processes initiated by oxidants

• Reaction mechanisms:– Seldomly Electron transfer– Much more common since oxidants are electrophilic

reagents:• Addition to electron rich positions in organic molecules

(activated aromatics, olefines, deprotonated amines, reduced sulphur moieties)

• H-Abstraction (in particular OH radicals)• Substitution (in particular chlorine/HOCl)

31

Efficiency of Oxidation Processes

• Decisive: Reaction rate of oxidant with target compound– Depending on electronic and structural properties of oxidant and

compound

• Lifetime of oxidant in water– Selectivity vs. unspecific reactivity– Matrix scavenging – Oxidant exposition (c x t)– Formation of oxidation byproducts

• Energy demand for specific removal rates

Modified after U. von Gunten, eawag