An Introduction to Water Quality Modelling

In past two decades the application of modelling techniques to water quality problems has increased dramatically and many useful techniques have emerged. Unfortunately, teaching of these techniques has not received the same attention and has consequently lagged behind. The hiatus is apparent in the large number of papers and books published for the advanced practitioner compared with the dearth of simple texts for the beginner. This text is aimed at the beginner. It is based upon a number of courses which have been held in the Civil Engineering Department of the University of Newcastle upon Tyne to introduce quality modelling to scientists and engineers who were working, or intending to work, in water pollution control. It is a simple guide, suitable for biologists, chemists, engineers and others without any previous knowledge of modelling or computing. The level of mathematical complexity has been deliberately restricted. An introductory chapter explains the concepts and terminology used in simulation, optimization and computer-aided design. This is followed by two other introductory chapters dealing with computing and numerical methods. The chapter on computing includes a guide to BASIC which is the simplest programming language in common use and the language used throughout the remainder of the book. The final introductory chapter explains the hydraulic, chemical and biological ideas which are used in formulating models of water quality. The remainder of the book is divided into two sections dealing with the application of modelling techniques to water pollution and wastewater treatment plants. Each chapter presents the modelling concepts and shows how these may be built into models suitable for examining frequently occurring problems. A complete listing of an example programme is included as an appendix to each chapter. In the 8 years since the publication of the first edition, there has been a tremendous increase in the use of mathematical models in environmental engineering, especially for the control of pollution in rivers and estuaries. Modelling has also addressed a much wider range of pollutants and there has been an increase in the range of conceptual approaches to the formulation of models. The text of this book has therefore been modified to reflect these changes. The chapters dealing with techniques have been expanded to cover a greater range of kinetics and intorduce a background of understanding for statistical and techniques and time series analysis. Similarly the chapters dealing with the applications of models to rivers, estuaries, lakes, groundwater and the marine environment have been expanded and updated.