Wastewater operator certification study guide : a guide to preparing for wastewater treatment

287 Pages·2009·6.74 MB·English

The Wastewater Operator Certifcation Study Guide provides practice questions to thoroughly prepare for
certifcation exams. It includes a range of sample questions and answers for Class I, II, III, and IV wastewater-
operator certifcation exams on all relevant topics, including multiple levels of wastewater treatment, equipment,
sampling, reporting, safety, solids handling, and more. Wastewater
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Wastewater
operator
CertifiCation Study Guide
A Guide to Preparing for Wastewater
Treatment Certifcation Exams
First Edition
John Giorgi
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Wastewater Operator Certifcation Study Guide: A Guide to Preparing for Wastewater
Treatment Certifcation Exams
Copyright © 2009 American Water Works Association
AWWA Publications Manager: Gay Porter De Nileon
Project Manager: Martha Ripley Gray
Copy Editor: Deborah J. Lynes
Production: Carrie Mattox
Cover Art: Cheryl Armstrong
All rights reserved. No part of this publication may be reproduced or transmitted in any form or by
any means, electronic or mechanical, including photocopy, recording, or any information or retrieval
system, except in the form of brief excerpts or quotations for review purposes, without the written
permission of the publisher.
Disclaimer
Although this study guide has been extensively reviewed for accuracy, there may be an occasion to
dispute an answer, either factually or in the interpretation of the question. AWWA has made every
effort to correct or eliminate any questions that may be confusing or ambiguous. If you do fnd a
question that you feel is confusing or incorrect, please contact the AWWA Publishing Group.
Additionally, it is important to understand the purpose of this study guide. It does not guarantee cer-
tifcation. It is intended to provide the operator with an understanding of the types of questions he
or she will be presented with on a certifcation exam and the areas of knowledge that will be covered.
AWWA highly recommends that you make use of the additional resources listed at the end of this
study guide in preparing for your exam.
Library of Congress Cataloging-in-Publication Data
Giorgi, John.
Wastewater operator certifcation study guide : a guide to preparing for wastewater treatment certi-
fcation exams / by John Giorgi. -- 1st ed.
p. cm.
Includes bibliographical references.
ISBN 978-1-58321-728-3
1. Sewage--Purifcation--Examinations--Study guides. 2. Sewage disposal plants--Examinations
--Study guides. 3. Sanitary engineers--Certifcation--United States--Examinations--Study guides.
I. Title.
TD745.G565 2009
628.3076--dc22
2009011271
6666 West Quincy Avenue
Denver, CO 80235-3098
303.794.7711
www.awwa.org
iii
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Contents
List of Figures, vii
Preface, ix
Acknowledgments, xi
Grade 1 Questions, 1
Wastewater Sources and Characteristics, 1
Basic Wastewater Treatment, 2
Wastewater Treatment Facilities, 3
Preliminary Treatment, 3
Racks, Screens, Comminutors, and Grit Removal, 4
Primary Sedimentation, 4
Sedimentation and Flotation, 4
Secondary Treatment Processes, 5
Activated Sludge, 5
Waste Treatment Ponds, 6
Odor Control, 6
Phosphorus Removal, 7
Disinfection, 7
Wastewater Solids Processing, 7
Sampling, Testing, and Reporting, 8
Maintenance, 10
Safety, 10
Basic Chemistry, 12
Grade 1 Answers and References, 15
Grade 2 Questions, 25
General Wastewater Treatment Principles, 25
Wastewater Treatment Facilities, 25
Wastewater Sources and Characteristics, 27
Racks, Screens, Comminutors, and Grit Removal, 28
Sedimentation and Flotation, 28
Secondary Treatment Processes, 29
Activated Sludge, 30
iii
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Trickling Filters, 33
Rotating Biological Contactors, 34
Waste Treatment Ponds, 35
Sludge Digestion and Solids Handling, 36
Odor Control, 40
Enhanced Biological (Nutrient) Control, 41
Disinfection, 41
Solids Removal from Secondary Effuents, 42
Effuent Disposal, 43
Wastewater Solids Processing, 43
Residual Solids Management, 46
Water and Wastewater Microbiology, 47
Maintenance, 47
Safety, 48
Basic Chemistry, 49
Grade 2 Answers and References, 51
Grade 3 Questions, 67
General Wastewater Treatment Principles, 67
Wastewater Treatment Facilities, 68
Wastewater Sources and Characteristics, 69
Racks, Screens, Comminutors, and Grit Removal, 69
Sedimentation and Flotation, 70
Activated Sludge, 71
Trickling Filters, 74
Rotating Biological Contactors, 76
Waste Treatment Ponds, 77
Sludge Digestion and Solids Handling, 79
Odor Control, 81
Phosphorus Removal, 82
Enhanced Biological (Nutrient) Control, 83
Disinfection, 84
Solids Removal from Secondary Effuents, 85
Effuent Disposal, 86
Residual Solids Management, 86
Wastewater Reclamation and Reuse, 88
Water and Wastewater Microbiology, 90
Basic Chemistry, 91
Grade 3 Answers and References, 95
iv v
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Grade 4 Questions, 111
General Wastewater Treatment Principles, 111
Sedimentation and Flotation, 112
Activated Sludge, 112
Trickling Filters, 120
Rotating Biological Contactors, 121
Waste Treatment Ponds, 122
Sludge Digestion and Solids Handling, 123
Odor Control, 124
Phosphorus Removal, 124
Enhanced Biological (Nutrient) Control, 125
Disinfection, 126
Solids Removal from Secondary Effuents, 127
Residual Solids Management, 129
Water and Wastewater Microbiology, 133
Basic Chemistry, 134
Grade 4 Answers and References, 139
Grades 1–4 Pumping Questions, 155
Grade 1 Pumping Questions, 155
Basic Water Hydraulics, 155
Introduction to Centrifugal Pumps, 155
Centrifugal Pump Components, 156
Centrifugal Pumps—Theory, 157
Pump Nomenclature, 157
Mechanical Seals, 158
Grades 2–4 Pumping Questions, 158
Basic Water Hydraulics, 158
Centrifugal Pumps—Theory, 159
Centrifugal Pumps—Types, 160
Pump Nomenclature, 160
Replacement of Pump Components on End Suction Centrifugal Pumps, 161
Selection and Replacement of Packing, 162
Pump Piping System, 163
End Suction and Split-Case Centrifugal Pumps, 163
Line Shaft Turbine Operating Conditions, 164
Special Pumping Units, 164
Introduction to Centrifugal Pumps, 165
Centrifugal Pump Components, 166
Centrifugal Pumps: Operational Procedures, 168
Centrifugal Pump: Maintenance Procedures, 168
Centrifugal Pump: Lubrication, 168
iv v
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Centrifugal Pump: Troubleshooting, 169
Centrifugal Pump: Modifcations, 170
Positive-Displacement Pumps, 170
Grades 1–4 Pumping Answers and References, 171
Math Questions, 181
Answers to Math Questions, 195
Math Questions with Solutions, 197
Appendix A—Common Conversion Factors, 229
Appendix B—Summary of Wastewater Treatment Equations (All Grades), 233
Appendix C—Wastewater Flowchart Diagrams, 255
Appendix D—Abbreviations, 269
References, 273
vi vii
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Figures
Figure 1 Flowchart of Typical Wastewater Treatment Processes, 256
Figure 2 Flowchart of Conventional Activated Sludge Process, 257
Figure 3 Flowchart of Contact Stabilization Process, 258
Figure 4 Flowchart of Activated Sequencing Batch Reactor, 259
Figure 5 Flowchart of Typical Wastewater Treatment Using Ponds after Secondary
Treatment, 260
Figure 6 Flowchart of Typical Wastewater Treatment Using Polishing Ponds in Series
Treatment, 261
Figure 7 Flowchart of Wastewater Treatment Using Rotating Biological Contactor
Process, 262
Figure 8 Flowchart of Typical Wastewater Treatment Using an Oxidation Ditch, 263
Figure 9 Flowchart of Typical Wastewater Treatment Using Electrodialysis
or Nanofltration, 264
Figure 10 Flowchart of Typical Wastewater Treatment Using a Membrane
Bioreactor, 265
Figure 11 Flowchart of Wastewater Treatment Nitrifcation Process, 266
Figure 12 Flowchart of Wastewater Treatment Plant Processing Sludge, 267
vi vii
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This work is dedicated to my wife, Flora Zhou Giorgi; my children, Sara, Stephanie, and
Steve; my mother, Thelma Giorgi; and my father, Albert Peter Giorgi.
viii ix
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Preface
This guide is intended to give operators practice answering questions that are similar in
format and content to the questions that appear on certifcation exams. The questions in this
study guide are not the same questions that will appear on the certifcation exam. However,
the questions allow operators to experience the types of questions that may be on a certif-
cation exam. If you have diffculty answering any of the questions in this study guide, you
should consult the reference source provided following the answer to the question.
American Water Works Association
AWWA is an international nonproft and educational society and the largest and oldest
organization of water professionals in the world. Its more than 55,000 members represent the
full spectrum of the water community: treatment plant operators and managers, scientists,
environmentalists, manufacturers, academicians, regulators, and others who hold genuine
interest in water supply and public health. Membership includes more than 4,600 utilities
that supply water to roughly 180 million people in North America. Through our collective
strength, we become better stewards of water for the greatest good of the people and the
environment.
Founded in 1881, AWWA provides knowledge, information, and advocacy to improve the
quality and supply of water in North America and beyond. AWWA advances public health,
safety, and welfare by uniting the efforts of the full spectrum of the water community.
viii ix
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