Biogas The Microbiology Of Anaerobic Dogesters

The Microbiology of
Anaerobic Digesters

WASTEWATER MICROBIOLOGY SERIES

Editor
Michael H. Gerardi

Nitrification and Denitrification in the Activated Sludge Process
Michael H. Gerardi
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Process
Michael H. Gerardi
The Microbiology of Anaerobic Digesters
Michael H. Gerardi

The Microbiology of
Anaerobic DigestersMichael H. Gerardi

A John Wiley & Sons, Inc., Publication

Copyright © 2003 by John Wiley & Sons, Inc. All rights reserved.
Published by John Wiley & Sons, Inc., Hoboken, New Jersey.
Published simultaneously in Canada.
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Library of Congress Cataloging-in-Publication Data:
Gerardi, Michael H.
The microbiology of anaerobic digesters / Michael H. Gerardi.
p. cm.
Includes bibliographical references and index.
ISBN 0-471-20693-8 (cloth)
1. Sewage sludge digestion. 2. Anaerobicbacteria. I. Title.
TD769 .G47 2003
628.3¢5—dc21
2003007454
Printed in United States of America
10 9 8 7 6 5 4 3 2 1

To
Mom and Dad

The author extends his sincere appreciation to
joVanna Gerardi for computer support
and
Cristopher Noviello for artwork used in this text.

Contents

Preface
PART I

ix
OVERVIEW

1 Introduction

1
3

2 Bacteria

11

3 Methane-formingBacteria

17

4 Respiration

31

5 Anaerobic Food Chain

39

6 Fermentation

43

7 Anaerobic Digestion Stages

51

PART II

SUBSTRATES, PRODUCTS, AND BIOGAS

59

8 Substrates and Products

61

9 Biogas

73

PART III

OPERATIONAL CONDITIONS

77

10 Introduction to Operational Conditions

79
vii

viii

CONTENTS

11 Start-up

81

12 Sludge Feed

8513 Retention Times

87

14 Temperature

89

15 Nutrients

93

16 Alkalinity and pH

99

17 Toxicity

105

18 Mixing

117

PART IV PROCESS CONTROL AND TROUBLESHOOTING

121

19 Upsets and Unstable Digesters

123

20 Foam and Scum Production and Accumulation

127

21 Supernatant

133

22 Monitoring

135

PART V DIGESTERS

141

23 Types of Anaerobic...