Modeling tools for environmental engineers and scientists

325 Pages·2002·3.259 MB·English

by  N Nirmalakhandan

Modeling Tools
for
Environmental
Engineers
and
Scientists

Modeling Tools
for
Environmental
Engineers
and
Scientists
N. Nirmalakhandan
CRC PR ESS
Boca Raton London New York Washington, D.C.
disclaimer Page 1 Monday, November 12, 2001 11:51 AM
Library of Congress Cataloging-in-Publication Data
Nirmalakhandan, N.
Modeling tools for environmental engineers and scientists / N. Nirmalakhandan.
p. cm.
Includes bibliographical references and index.
ISBN 1-56676-995-7
1. Environmental sciences—Mathematical models. 2. Environmental
engineering—Mathematical models. I. Title.
GE45.M37 K43 2001
628¢.01¢1—dc21 2001052467

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Library of Congress Card Number 2001052467
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Frontmatter 11/9/01 9:30 AM Page v
Contents
Preface ix
Acknowledgments xi
FUNDAMENTALS
1. INTRODUCTION TO MODELING . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 What is Modeling? 3
1.2 Mathematical Modeling 6
1.3 Environmental Modeling 10
1.4 Objectives of This Book 13
Appendix 1.1 16
Appendix 1.2 17
2. FUNDAMENTALS OF MATHEMATICAL MODELING . . . . . . . 19
2.1 Definitions and Terminology in Mathematical Modeling 19
2.2 Steps in Developing Mathematical Models 21
2.3 Application of the Steps in Mathematical Modeling 29
3. PRIMER ON MATHEMATICS . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.1 Mathematical Formulations 39
3.2 Mathematical Analysis 41
3.3 Examples of Analytical and Computational Methods 42
3.4 Closure 63
v
Frontmatter 11/9/01 9:30 AM Page vi
vi Contents
4. FUNDAMENTALS OF ENVIRONMENTAL PROCESSES. . . . . 67
4.1 Introduction 67
4.2 Material Content 68
4.3 Phase Equilibrium 72
4.4 Environmental Transport Processes 80
4.5 Interphase Mass Transport 83
4.6 Environmental Nonreactive Processes 85
4.7 Environmental Reactive Processes 91
4.8 Material Balance 98
Appendix 4.1 104
5. FUNDAMENTALS OF ENGINEERED ENVIRONMENTAL
SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
5.1 Introduction 105
5.2 Classifications of Reactors 106
5.3 Modeling of Homogeneous Reactors 108
5.4 Modeling of Heterogeneous Reactors 116
6. FUNDAMENTALS OF NATURAL ENVIRONMENTAL
SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
6.1 Introduction 129
6.2 Fundamentals of Modeling Soil Systems 130
6.3 Fundamentals of Modeling Aquatic Systems 149
Appendix 6.1 161
7. SOFTWARE FOR DEVELOPING MATHEMATICAL
MODELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
7.1 Introduction 163
7.2 Spreadsheet-Based Software 165
7.3 Equation Solver-Based Software 166
7.4 Dynamic Simulation-Based Software 171
7.5 Common Example Problem:Water Quality Modeling
in Lakes 174
7.6 Closure 189
Appendix 7.1 193
Appendix 7.2 194
Frontmatter 11/9/01 9:30 AM Page vii
Contents vii
APPLICATIONS
8. MODELING OF ENGINEERED ENVIRONMENTAL
SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
8.1 Introduction 197
8.2 Modeling Example:Transients in Sequencing Batch
Reactors 197
8.3 Modeling Example:CMFRs in Series for Toxicity
Management 204
8.4 Modeling Example:Municipal Wastewater Treatment 213
8.5 Modeling Example:Chemical Oxidation 217
8.6 Modeling Example:Analysis of Catalytic Bed Reactor 224
8.7 Modeling Example:Waste Management 228
8.8 Modeling Example:Activated Carbon Treatment 228
8.9 Modeling Example:Bioregeneration of Activated Carbon 231
8.10 Modeling Example:Pipe Flow Analysis 236
8.11 Modeling Example:Oxygen/Nitrogen Transfer in Packed
Columns 240
8.12 Modeling Example:Groundwater Flow Management 243
8.13 Modeling Example:Diffusion through Porous Media 247
9. MODELING OF NATURAL ENVIRONMENTAL SYSTEMS . . . 253
9.1 Introduction 253
9.2 Modeling Example:Lakes in Series 253
9.3 Modeling Example:Radionuclides in Lake Sediments 259
9.4 Modeling Example:Algal Growth in Lakes 263
9.5 Modeling Example:Contaminant Transport Visualization 270
9.6 Modeling Example:Methane Emissions from Rice Fields 273
9.7 Modeling Example:Chemical Equilibrium 275
9.8 Modeling Example:Toxicological Exposure Evaluation 279
9.9 Modeling Example:Visualization of Groundwater Flow 282
9.10 Modeling Example:Air Pollution—Puff Model 286
9.11 Modeling Example:Air Pollution—Plume Model 289
9.12 Modeling Example:Fugacity-Based Modeling 293
9.13 Modeling Example:Well Placement and Water Quality
Management 297
BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
Frontmatter 11/9/01 9:30 AM Page viii
Frontmatter 11/9/01 9:30 AM Page ix
Preface
THIS book is not a treatise on environmental modeling. Several excellent
books are currently available that do more than justice to the science of
environmental modeling. The goal of this book is to bridge the gap between
the science of environmental modeling and working models of environmen-
tal systems. More specifically, the intent of this book is to bring computer-
based modeling within easy reach of subject matter experts and professionals
who have shied away from modeling,daunted by the intricacies of computer
programming and programming languages.
In the past two decades, interest in computer modeling in general and in
environmental modeling in particular,have grown significantly. The number
of papers and reports published on modeling, the number of specialty con-
ferences on modeling held all over the world, and the number of journals
dedicated to modeling efforts are evidence of this growth. Several factors
such as better understanding of the underlying science, availability of high
performance computer facilities, and increased regulatory concerns and
pressures have fueled this growth. Scrutiny of those involved in environ-
mental modeling, however, reveals that only a small percentage of experts
are active in the modeling efforts; namely those who also happen to be
skilled in computer programming.
For the rest of us, computer modeling has remained a challenging task
until recently. A new breed of software authoring packages has now become
available that enables nonprogrammers to develop their own models without
having to learn programming languages. These packages feature English-like
syntax and easy-to-use yet extremely powerful mathematical, analytical,
computational, and graphical functions, and user-friendly interfaces. They
can drastically reduce the time, effort, and programming skills required to
develop professional quality user-friendly models. This book describes eight
such software packages, and, with over 50 modeling examples, illustrates
how they can be adapted for almost any type of modeling project.
ix