Ozone Reaction Kinetics for Water and Wastewater Systems - Chapter 1 pptx

Students who want to getinvolve in the world of ozone application in water need to know the many aspects teach-of the subject covered here, including absorption or solubility teach-of oz

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To my wife, Rosa Maria, and to my son Fernando

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Preface

Today, ozone is considered as an alternative oxidant-disinfectant agent with multiplepossibilities of application in water, air pollution, medicine, etc Particularly, in watertreatment it has many abilities to disinfect, oxidize, or to be combined with othertechnologies and reagents Much of the information about these general aspects ofozone has been reported in excellent works like that of Langlais et al (1991) There

is another aspect, however, that the literature has not dealt with sufficiently — theozonation kinetics of compounds in water, especially those organic compoundsusually considered water pollutants About this, on the contrary, there are manyworks published in scientific journals like Ozone Science and Engineering, Water Research, Industrial and Engineering Chemistry Research, etc., that present simpleexamples of the multiple possibilities of ozone in water and wastewater treatment

as far as the kinetics is concerned I thought that this wide array of ozone kineticinformation deserved to be published in a unique book in which the many aspects

of this subject can be grouped together for a better understanding of its fundamentalsthrough a general overview

For more than 20 years I have been working on the use of ozone to oxidizeorganic compounds, both in organic and, especially, aqueous media Results of thisresearch work has generated different doctoral theses on the ozonation of dyes,phenols, herbicides, polynuclear aromatic hydrocarbons, wastewater, etc, and havealso resulted in more than 100 papers in different scientific journals such as thosecited above Also, for many years I have been lecturing on ozonation kinetics indoctoral courses at the University of Extremadura (Badajoz, Spain) As a result ofthis accumulated experience, I can affirm that the multiple possibilities of ozone forapplication in water and wastewater treatment make the study of the ozonationkinetics a challenging subject in which theory and practice can be simultaneouslyexamined The work presented here represents a compilation of study throughout

my years in this field

This book is intended for both undergraduate and postgraduate students, ers, and professionals of water and wastewater treatment Students who want to getinvolve in the world of ozone application in water need to know the many aspects

teach-of the subject covered here, including absorption or solubility teach-of ozone, stability ordecomposition, reactivity, kinetic regime of absorption, ozonation kinetics, andreactor modeling Those practicing ozone water treatment, that is, professionals inthe ozonation processes field, will be able to add to their fund of knowledge withthe advanced information it contains Finally, the book can also be a tool for teaching

in which the many fundamentals of chemistry, reaction mechanisms, and, larly, chemical engineering kinetics and heterogeneous kinetics can be verified fromexamining the results of the ozonation of organic compounds in water

particu-The various subjects that affect the ozone kinetics in water are presented in 11chapters Chapter 1 gives a short history of ozone in nature and tells us about theelectronic structure of the ozone molecule which is responsible for the ozone reactivity

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In Chapter 2 the chemistry of ozone reactions in water is reviewed by studying thetwo known reaction types through which ozone acts in water: the direct and indirect

or free radical reactions Chapter 3 focuses on the kinetics of the direct ozone reactions

It is explained that these studies can be developed through experimental homogeneousand heterogeneous ozone reactions Chapter 4 and Chapter 5 continue with studies ondirect ozone reaction kinetics, but they exclusively deal with heterogeneous gas–liquidreaction kinetics which represents the way ozone is applied in water and wastewatertreatment — that is, in gas form Chapter 4 presents the fundamentals of the kinetics

of these reactions It gives detailed explanations about the kinetic equations of uid reactions that are later applied to ozone direct reaction kinetic studies in Chapter

gas–liq-5 Chapter 5 covers examples of kinetic works on ozone gas–water reactions, startingwith the necessary tools to accomplish this task: the properties of ozone in water, such

as solubility and diffusivity Also in Chapter 5, the ozone kinetic studies are presentedaccording to the kinetic regimes of ozone absorption that, once established, allow therate constant and mass transfer coefficients to be determined Chapter 6 is dedicated

to wastewater ozonation reactions Thus, classification of wastewater with regard toits reactivity with ozone, characterizing parameters, the importance of pH, and theinfluence of ozonation on biological processes are treated in Chapter 6 The secondpart of Chapter 6 addresses to the kinetics of wastewater ozone reactions and someinsights are given to carry out these studies experimentally

Chapters 7 to 9 deal with the kinetics of indirect ozone reactions that can also

be named as ozone involving advanced oxidation reactions: ozone alone and ozonecombined with hydrogen peroxide and UV radiation Chapter 7 deals with theindirect reactions coming from the decomposition of ozone (without the addition ofhydrogen peroxide or UV radiation) The chapter begins with a study on the relativeimportance of ozone direct and the ozone decomposition reactions whose resultsare fundamental to establishing the overall kinetics of any ozone–compound Breaction Also in Chapter 7, methods to determine the rate constant of the reactionsbetween the hydroxyl free radical and a compound B, and characteristic relationships

of natural water to ozone reactivity are given Chapter 8 presents the kinetic study

of ozone–hydrogen peroxide processes Again, aspects related to the rate constantdetermination, kinetic regimes, and competition with direct ozone reactions aredeveloped Chapter 9 focuses on the UV radiation/ozone processes It first dealswith the direct photolytic and UV radiation/hydrogen peroxide processes, the latterbecause it is also present when ozone and UV radiation are simultaneously applied.Chapter 9 includes methods to determine quantum yields, rate constants of hydroxylradical reactions, and multiple aspects on the relative importance of different reac-tions; ozone direct reactions; ozone–peroxide reactions; and ozone direct photolysis,among other subjects

Chapter 10 presents the state of the art of another type of ozone action:heterogeneous catalytic ozonation Although dating from the 1970s, this fieldhas advanced significantly in the last decade which has witnessed considerableincrease in work on heterogeneous catalytic ozonation In Chapter 10, the fun-damentals of the kinetics of these gas–liquid–solid catalytic reactions are firstgiven and then applications to the catalytic ozonation of compounds in water.Also, a commented and extensive list (through tables) of studies already pub-lished on this ozone action is offered Finally, Chapter 11 presents the kineticmodeling of ozone reactions Chapter 11 starts with a detailed classification onpossible ways of ozone kinetic modeling according to the different kinetic

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regimes of ozone absorption Mathematical models are presented together withthe way in which they can be solved, with ozone literature examples The studyfocuses on studies of ozone reactions on model compounds, which are morerelated to drinking water treatment and wastewater ozonation The book’s appen-dix gives mathematical tools, concepts on ideal reactors and actinometry, andnonideal flow studies needed to solve and understand the ozonation kineticexamples previously developed

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About the Author

Fernando Juan Beltran Novillo received his doctorate in chemistry in 1982 fromthe University of Extremadura in Badajoz, Spain, and in 1986 he became ProfesorTitular in Chemical Engineering at the University of Extremadura

In 1985 and 1986 he did postdoctoral studies at the Laboratoire de Chimie del’eau et de Nuisances at the University of Poitiers (France) where he worked withProfessors Doré, Legube, and Croué on the ozonation of natural fulvic substancesand the effect on trihalomethane formation In 1988 and 1989, he worked at theSchool of Chemical Engineering, Bath University (England) on catalytic combustion

of PCBs and catalytic wet air oxidation with Professors Kolaczkowski andCrittenden He spent another research stay in the Environmental Science and Engi-neering Department at the University of North Carolina in 1991, working withProfessor Glaze on the UV radiation/hydrogen peroxide oxidation system

He became Catedratico (Professor) in Chemical Engineering in 1992 at theUniversity of Extremadura

In 1993, he was Visiting Professor at the University of Bath (England).Doctor Beltran has codirected 13 doctoral theses mainly dealing with the ozo-nation kinetics of model compounds and wastewaters, and has published more than

100 papers on ozonation studies, most of them on kinetics

He is a member of the International Ozone Association, a member of the editorialboard of Ozone Science and Engineering and International Water Quality He hascollaborated in the peer reviewing process of many scientific and engineering jour-nals such as Ozone Science and Engineering, Industrial Engineering Chemistry Research, Environmental Science and Technology, Water Research, and Applied Catalysis B

At present, he teaches chemical reaction engineering for undergraduate studentsand ozone reaction kinetics in water for postgraduate students at the University ofExtremadura, where he is also director of a research group on water treatment

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2.5 Indirect Reactions of Ozone

2.5.1 The Ozone Decomposition Reaction

References

Chapter 3 Kinetics of the Direct Ozone Reactions

3.1 Homogeneous Ozonation Kinetics

3.1.1 Batch Reactor Kinetics

3.1.2 Flow Reactor Kinetics

3.1.3 Influence of pH on Direct Ozone Rate Constants

3.1.4 Determination of the Stoichiometry

4.1.1 The Film Theory

4.1.2 Surface Renewal Theories

4.2.2 Danckwerts Surface Renewal Theory

4.2.2.1 First-Order or Pseudo First-Order Reactions

4.2.2.2 Irreversible Second-Order Reactions

4.2.2.3 Series-Parallel Reactions

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4.2.3 Influence of Gas Phase Resistance

4.2.3.1 Slow Kinetic Regime

4.2.3.2 Fast Kinetic Regime

4.2.4 Diffusion and Reaction Times

References

Chapter 5 Kinetic Regimes in Direct Ozonation Reactions

5.1 Determination of Ozone Properties in Water

5.1.1 Diffusivity

5.1.2 Ozone Solubility: The Ozone–Water Equilibrium System

5.2 Kinetic Regimes of the Ozone Decomposition Reaction

5.3 Kinetic Regimes of Direct Ozonation Reactions

5.3.1 Checking Secondary Reactions

5.3.2 Some Common Features of The Kinetic Studies

5.3.2.1 The Ozone Solubility

5.3.2.2 The Individual Liquid Phase Mass-Transfer Coefficient,

kL

5.3.3 Instantaneous Kinetic Regime

5.3.4 Fast Kinetic Regime

5.3.5 Moderate Kinetic Regime

5.3.5.1 Case of No Dissolved Ozone

5.3.5.2 Case of Pseudo First-Order Reaction with Moderate

Kinetic Regime5.3.6 Slow Kinetic Regime

5.3.6.1 The Slow Diffusional Kinetic Regime

5.3.6.2 Very Slow Ozone Kinetic Regime

5.4 Changes of the Kinetic Regimes during Direct Ozonation Reactions5.5 Comparison Between Absorption Theories in Ozonation ReactionsReferences

Chapter 6 Kinetics of the Ozonation of Wastewaters

6.1 Reactivity of Ozone in Wastewater

6.2 Critical Concentration of Wastewater

6.3 Characterization of Wastewater

6.3.1 The Chemical Oxygen Demand

6.3.2 The Biological Oxygen Demand

6.3.3 Total Organic Carbon

6.3.4 Absorptivity at 254 NM (A254)

6.3.5 Mean Oxidation Number of Carbon

6.4 Importance of pH In Wastewater Ozonation

6.5 Chemical Biological Processes

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6.6.3.1 Fast Kinetic Regime (High COD)

6.6.3.2 Slow Kinetic Regime (Low COD)

References

Chapter 7 Kinetics of Indirect Reactions of Ozone in Water

7.1 Relative Importance of the Direct Ozone–B Reaction and the Ozone Decomposition Reaction

7.1.1 Application of Diffusion and Reaction Time Concepts

7.2 Relative Rates of the Oxidation of a Given Compound

7.3.2.2 The Competitive Method

7.4 Characterization of Natural Waters Regarding Ozone Reactivity7.4.1 Dissolved Organic Carbon, pH, and Alkalinity

7.4.2 The Oxidation–Competition Value

7.4.3 The RCTConcept

References

Chapter 8 Kinetics of the Ozone/Hydrogen Peroxide System

8.1 The Kinetic Regime of the O3/H2O2Process

8.1.1 Slow Kinetic Regime

8.1.2 Fast-Moderate Kinetic Regime

8.1.3 Critical Hydrogen Peroxide Concentration

8.2 Determination of Kinetic Parameters

8.2.1 The Absolute Method

8.2.2 The Competitive Method

8.2.3 The Effect of Natural Substances on the Inhibition of Free Radical Ozone Decomposition

8.3 The Ozone/Hydrogen Peroxide Oxidation of Volatile Compounds8.4 The Competition of the Direct Reaction

8.4.1 Comparison Between the Kinetic Regimes of the Ozone–B and Ozone–Hydrogen Peroxide Reactions

8.4.2 Comparison between the Rates of the Ozone–B and Hydroxyl Radical–B Reactions

8.4.3 Relative Rates of the Oxidation of a Given Compound

References

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Chapter 9 Kinetics of the Ozone–UV Radiation System

9.1 Kinetics of the UV Radiation for the Removal of Contaminants from Water

9.1.1 The Molar Absorptivity

9.1.2 The Quantum Yield

9.1.3 Kinetic Equations for the Direct Photolysis Process

9.1.4 Determination of Photolytic Kinetic Parameters: The Quantum Yield

9.1.4.1 The Absolute Method

9.1.5 Quantum Yield for Ozone Photolysis

9.1.5.1 The Ozone Quantum Yield in the Gas Phase

9.1.5.2 The Ozone Quantum Yield in Water

9.2 Kinetics of the UV/H2O2System

9.2.1 Determination of Kinetic Parameters

9.2.1.1 The Absolute Method

9.2.2 Contribution of the Direct Photolysis and Free Radical

Oxidation in the UV/H2O2Oxidation System

9.3 Comparison between the Kinetic Regimes of the Ozone-B and

Ozone-UV Photolysis Reactions

9.3.1 Comparison Between the Ozone Direct Photolysis and the Ozone Direct Reaction With a Compound B through Reaction and Diffusion Times

9.3.2 Contributions of Direct Photolysis and Direct Ozone Reaction

to the Ozone Absorption Rate

9.3.2.1 Strong UV Absorption Exclusively Due to Dissolved

Ozone9.3.2.2 Strong UV Absorption due to the Dissolved Ozone

and a Compound B9.3.2.3 Weak UV Absorption

9.3.3 Contributions of the Direct Ozone and Free Radical Reactions

to the Oxidation of a Given Compound B

9.3.3.1 Strong UV Absorption Exclusively due to Dissolved

Ozone9.3.3.2 Strong UV Absorption due to Dissolved Ozone and a

Compound B9.3.3.2 Weak UV Absorption

9.3.4 Estimation of the Relative Importance of the Rates of the Direct Photolysis/Direct Ozonation and Free Radical Oxidation of a Compound B

9.3.4.1 Relative Importance of Free Radical Initiation

Reactions in the UV/O3Oxidation System9.3.4.2 Relative Importance of the Direct Reactions and Free

Radical Oxidation Rates of Compound BReferences

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