James Edzwald - Dissolved Air Flotation For Water Clarification

DISSOLVED AIR
FLOTATION
FOR WATER
CLARIFICATION

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DISSOLVED AIR
FLOTATION
FOR WATER
CLARIFICATION

James K. Edzwald, Ph.D.

Johannes Haarhoff, Ph.D.

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ISBN 978-0-07-174563-5
MHID 0-07-174563-7

The material in this eBook also appears in the print version of this title: ISBN 978-0-07-174562-8, MHID 0-07-174562-9.

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Dissolved Air Flotation for Water Clarification

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ABOUT THE AUTHORS

James K. Edzwald is Professor Emeritus in the Department of Civil and Environmental Engineering at the University of Massachusetts, Amherst. He earned his B.S. and M.S. degrees in Civil Engineering and Environmental Health Engineering at the University of Maryland, and a Ph.D. in Water Resources Engineering at the University of North Carolina, Chapel Hill. He also held faculty positions at the University of Missouri, Clarkson University, and Rensselaer Polytechnic Institute. His research interests include water supply, drinking water treatment, and aquatic chemistry. Dr. Edzwald has authored or coauthored over 150 publications on water quality and treatment. He is the editor of the sixth edition of Water Quality & Treatment: A Handbook on Drinking Water, published by AWWA and McGraw-Hill. He received the 2004 A.P. Black Award from AWWA for his contributions in water supply research and the 2009 Founders Award from the Association of Environmental Engineering and Science Professors for his contributions to environmental engineering education and practice. He is a registered professional engineer in New York.

Johannes Haarhoff is Professor in the Department of Civil Engineering Science at the University of Johannesburg (UJ), South Africa. He earned an Honors B.Eng. in Civil Engineering at the University of Stellenbosch, South Africa, followed by an M.Eng. in Water Engineering at the same university. He spent eight years working in municipal engineering and civil construction before enrolling at Iowa State University, where he earned a Ph.D. in Sanitary Engineering. After a few years as a water treatment specialist at a prominent South African consultancy, Dr. Haarhoff was appointed a Professor at the Rand Afrikaans University (since 2005 the University of Johannesburg). He established the UJ Water Research Group, which focuses on practical aspects of water supply and drinking water treatment. He is a registered professional engineer in South Africa, a Fellow of the South African Institution of Civil Engineering, and a Senior Fellow of the Water Institute of Southern Africa.

Cover photo: Segaliud Water Treatment Plant (Sandakan, Sabah, East Malaysia). Photo courtesy of Purac, Sweden.

CONTENTS

PREFACE

The dissolved air flotation (DAF) process has now been in use for more than 40 years as an important process for the clarification of drinking water. During the past 20 years it became a widely adopted alternative for sedimentation in all parts of the world, for plants large and small. A rich body of experience and fundamental understanding has steadily accumulated among researchers, designers, and manufacturers and yet there is no professional book on this subject. The authors over the last 25 years have published scholarly journal papers, conducted research, have participated as keynote speakers at international conferences on DAF, and consulted worldwide to engineering companies and water utilities. We know from our own experience and from numerous discussions with professionals in the water field that there is a great need for this book. Our primary purpose with this book is to consolidate and to interpret this knowledge, for the first time, in a single volume entirely devoted to DAF for water clarification.