AWWA 20683-2009 Wastewater Operator Certification Study Guide A Guide to Preparing for Wastewater Treatment Certification Exams (First Editioon).pdf

1、 #MBOL1BHFA Guide to Preparing for Wastewater Treatment Certification ExamsFirst EditionJohn GiorgiCERTIFICATION STUDY GUIDEWastewater Operator Wastewater Operator Certification Study Guide: A Guide to Preparing for Wastewater Treatment Certification ExamsCopyright 2009 American Water Works Associat

2、ionAWWA Publications Manager: Gay Porter De NileonProject Manager: Martha Ripley GrayCopy Editor: Deborah J. LynesProduction: Carrie MattoxCover Art: Cheryl ArmstrongAll rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanica

3、l, 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.DisclaimerAlthough this study guide has been extensively reviewed for accuracy, there may be an occasion

4、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 find a question that you feel is confusing or incorrect, please contact the AWWA Publishing Group.Additional

5、ly, it is important to understand the purpose of this study guide. It does not guarantee cer-tification. It is intended to provide the operator with an understanding of the types of questions he or she will be presented with on a certification exam and the areas of knowledge that will be covered. AW

6、WA 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 DataGiorgi, John.Wastewater operator certification study guide : a guide to preparing for wastewater treatment certi-ficat

7、ion exams / by John Giorgi. - 1st ed.p. cm.Includes bibliographical references.ISBN 978-1-58321-728-31. Sewage-Purification-Examinations-Study guides. 2. Sewage disposal plants-Examinations -Study guides. 3. Sanitary engineers-Certification-United States-Examinations-Study guides. I. Title.TD745.G56

8、5 2009628.3076-dc2220090112716666 West Quincy AvenueDenver, CO 80235-3098303.794.7711www.awwa.orgiiiContentsList of Figures, viiPreface, ixAcknowledgments, xiGrade 1 Questions, 1Wastewater Sources and Characteristics, 1Basic Wastewater Treatment, 2Wastewater Treatment Facilities, 3Preliminary Treatm

9、ent, 3Racks, Screens, Comminutors, and Grit Removal, 4Primary Sedimentation, 4Sedimentation and Flotation, 4Secondary Treatment Processes, 5Activated Sludge, 5Waste Treatment Ponds, 6Odor Control, 6Phosphorus Removal, 7Disinfection, 7Wastewater Solids Processing, 7Sampling, Testing, and Reporting, 8

10、Maintenance, 10Safety, 10Basic Chemistry, 12Grade 1 Answers and References, 15Grade 2 Questions, 25General Wastewater Treatment Principles, 25Wastewater Treatment Facilities, 25Wastewater Sources and Characteristics, 27Racks, Screens, Comminutors, and Grit Removal, 28Sedimentation and Flotation, 28S

11、econdary Treatment Processes, 29Activated Sludge, 30ivTrickling Filters, 33Rotating Biological Contactors, 34Waste Treatment Ponds, 35Sludge Digestion and Solids Handling, 36Odor Control, 40Enhanced Biological (Nutrient) Control, 41Disinfection, 41Solids Removal from Secondary Effluents, 42Effluent

12、Disposal, 43Wastewater Solids Processing, 43Residual Solids Management, 46Water and Wastewater Microbiology, 47Maintenance, 47Safety, 48Basic Chemistry, 49Grade 2 Answers and References, 51Grade 3 Questions, 67General Wastewater Treatment Principles, 67Wastewater Treatment Facilities, 68Wastewater S

13、ources and Characteristics, 69Racks, Screens, Comminutors, and Grit Removal, 69Sedimentation and Flotation, 70Activated Sludge, 71Trickling Filters, 74Rotating Biological Contactors, 76Waste Treatment Ponds, 77Sludge Digestion and Solids Handling, 79Odor Control, 81Phosphorus Removal, 82Enhanced Bio

14、logical (Nutrient) Control, 83Disinfection, 84Solids Removal from Secondary Effluents, 85Effluent Disposal, 86Residual Solids Management, 86Wastewater Reclamation and Reuse, 88Water and Wastewater Microbiology, 90Basic Chemistry, 91Grade 3 Answers and References, 95vGrade 4 Questions, 111General Was

15、tewater Treatment Principles, 111Sedimentation and Flotation, 112Activated Sludge, 112Trickling Filters, 120Rotating Biological Contactors, 121Waste Treatment Ponds, 122Sludge Digestion and Solids Handling, 123Odor Control, 124Phosphorus Removal, 124Enhanced Biological (Nutrient) Control, 125Disinfe

16、ction, 126Solids Removal from Secondary Effluents, 127Residual Solids Management, 129Water and Wastewater Microbiology, 133Basic Chemistry, 134Grade 4 Answers and References, 139Grades 14 Pumping Questions, 155Grade 1 Pumping Questions, 155Basic Water Hydraulics, 155Introduction to Centrifugal Pumps

17、, 155Centrifugal Pump Components, 156Centrifugal PumpsTheory, 157Pump Nomenclature, 157Mechanical Seals, 158Grades 24 Pumping Questions, 158Basic Water Hydraulics, 158Centrifugal PumpsTheory, 159Centrifugal PumpsTypes, 160Pump Nomenclature, 160Replacement of Pump Components on End Suction Centrifuga

18、l Pumps, 161Selection and Replacement of Packing, 162Pump Piping System, 163End Suction and Split-Case Centrifugal Pumps, 163Line Shaft Turbine Operating Conditions, 164Special Pumping Units, 164Introduction to Centrifugal Pumps, 165Centrifugal Pump Components, 166Centrifugal Pumps: Operational Proc

19、edures, 168Centrifugal Pump: Maintenance Procedures, 168Centrifugal Pump: Lubrication, 168viCentrifugal Pump: Troubleshooting, 169Centrifugal Pump: Modifications, 170Positive-Displacement Pumps, 170Grades 14 Pumping Answers and References, 171Math Questions, 181Answers to Math Questions, 195Math Que

20、stions with Solutions, 197Appendix ACommon Conversion Factors, 229Appendix BSummary of Wastewater Treatment Equations (All Grades), 233Appendix CWastewater Flowchart Diagrams, 255Appendix DAbbreviations, 269References, 273viiFiguresFigure 1 Flowchart of Typical Wastewater Treatment Processes, 256Fig

21、ure 2 Flowchart of Conventional Activated Sludge Process, 257Figure 3 Flowchart of Contact Stabilization Process, 258Figure 4 Flowchart of Activated Sequencing Batch Reactor, 259Figure 5 Flowchart of Typical Wastewater Treatment Using Ponds after Secondary Treatment, 260Figure 6 Flowchart of Typical

22、 Wastewater Treatment Using Polishing Ponds in Series Treatment, 261Figure 7 Flowchart of Wastewater Treatment Using Rotating Biological Contactor Process, 262Figure 8 Flowchart of Typical Wastewater Treatment Using an Oxidation Ditch, 263Figure 9 Flowchart of Typical Wastewater Treatment Using Elec

23、trodialysis or Nanofiltration, 264Figure 10 Flowchart of Typical Wastewater Treatment Using a Membrane Bioreactor, 265Figure 11 Flowchart of Wastewater Treatment Nitrification Process, 266Figure 12 Flowchart of Wastewater Treatment Plant Processing Sludge, 267viiiThis work is dedicated to my wife, F

24、lora Zhou Giorgi; my children, Sara, Stephanie, and Steve; my mother, Thelma Giorgi; and my father, Albert Peter Giorgi.ixPrefaceThis guide is intended to give operators practice answering questions that are similar in format and content to the questions that appear on certification exams. The quest

25、ions in this study guide are not the same questions that will appear on the certification exam. However, the questions allow operators to experience the types of questions that may be on a certifi-cation exam. If you have difficulty answering any of the questions in this study guide, you should cons

26、ult the reference source provided following the answer to the question.American Water Works AssociationAWWA is an international nonprofit 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 t

27、he 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

28、 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

29、 health, safety, and welfare by uniting the efforts of the full spectrum of the water community.xiAcknowledgmentsJohn Giorgi would like to thank the staff and editors of the American Water Works Associa-tion; Gay Porter De Nileon, Publications Manager; and Dean Bugher for his assistance and recommen

30、dations.The following people served as reviewers for this edition of the Wastewater Operator Certifi-cation Study Guide. Their assistance is greatly appreciated.E.E. Arasmith, ACR, Albany, Ore. (AWWA)K.D. Kerri, California State University, Sacramento, Calif. (AWWA)S.M. Passarelli, AWWA, Denver, Col

31、o. (AWWA)D.S. Sarai, Asheville, N.C. (AWWA)1Grade 1 QuestionsWastewater Sources and Characteristics1. What is the most common reason for a wastewater to contain intermittent large amounts of sand, gravel, and grit?a. groundwater infiltrationb. storm eventsc. cement company dischargesd. refinery disc

32、harges2. Combined wastewater is defined asa. domestic wastewater and industrial wastewaterb. sanitary wastewaterc. domestic wastewater and stormwater runoffd. sanitary wastewater and stormwater runoff3. In general, the solids content in wastewater is abouta. 0.1%b. 0.6%c. 1%d. 2.5%4. In general, wha

33、t is the percentage of suspended solids in the total amount of solids?a. 30%b. 35%c. 45%d. 55%5. Generally, the percentage of dissolved solids in the amount of total solids is abouta. 45%b. 55%c. 65%d. 70%6. Which type of organisms would most probably be associated with poor treatment or young bioma

34、ss?a. amoebasb. free-swimming ciliatesc. rotifersd. stalked ciliates7. Which type of organisms would most probably be associated with very clear plant effluent, low biochemical oxygen demand (BOD), and low amounts of suspended solids?a. free-swimming ciliatesb. stalked ciliatesc. amoebasd. rotifers2

35、 WASTEWATER OPERATOR CERTIFICATION STUDY GUIDEBasic Wastewater Treatment8. Aerobic bacteria will reproduce and live in an environment that contains onlya. hydrogen sulfideb. oxygenc. waterd. methane9. Anaerobic bacteria will reproduce and live only in an environment that completely lacksa. free or d

36、issolved nitratesb. dissolved methanec. dissolved hydrogen sulfided. free or dissolved oxygen (DO)10. The biochemical oxygen demand (BOD) test usually has a specific time ofa. 2 daysb. 3 daysc. 5 daysd. 10 days11. An Imhoff cone measuresa. volume of settleable solidsb. how fast sludge water will fil

37、ter through a membranec. depth of transparency in a digesterd. sludge carry-over from a digester12. Septic conditions are caused bya. fungib. moldsc. anaerobic bacteriad. hydrogen sulfide accumulation13. Scum is usually removed in the _ treatment stage.a. primaryb. secondaryc. biologicald. chemical1

38、4. When domestic wastewater enters natural waters, what species deplete most of the oxygen?a. anaerobic bacteriab. aerobic bacteriac. protozoansd. rotifers15. Once the oxygen is depleted in a natural body of water, which organisms take over?a. flagellatesb. sporozoansc. anaerobic bacteriad. coliform

39、 bacteriaGRADE 1 QUESTIONS 316. The major gas produced by anaerobic decomposition isa. methaneb. carbon dioxidec. nitrogend. hydrogen sulfideWastewater Treatment Facilities17. Another name for primary treatment isa. chemical treatmentb. sedimentationc. grit removald. biological treatment18. Digester

40、 gas is _ when mixed with air in the proper proportions.a. extremely toxic and moderately explosiveb. extremely explosivec. slightly toxic and explosived. slightly explosive when there is an ignition source and19. A pond that is used to treat raw wastewater is calleda. an oxidation pondb. a facultat

41、ive pondc. a waste stabilization pondd. a decomposition pond20. A pond that has an aerobic top layer and an anaerobic bottom layer is calleda. an oxidation pondb. a facultative pondc. a waste stabilization pondd. a decomposition pondPreliminary Treatment21. What is the angle of the bars on a manuall

42、y cleaned bar screen?a. 25b. 30c. 33d. 4522. What is the angle of the bars on a mechanically cleaned bar screen?a. 30 to 45b. 40 to 45c. 45 to 60d. 50 to 6023. What is the ideal wastewater velocity in feet per second (ft/s) through a screen channel?a. 0.5 ft/sb. 1.0 ft/sc. 1.5 ft/sd. 2.0 ft/s4 WASTE

43、WATER OPERATOR CERTIFICATION STUDY GUIDE24. What is the ideal wastewater velocity in feet per second (ft/s) for grit removal in a grit chamber?a. 0.7 ft/sb. 1.0 ft/sc. 1.2 ft/sd. 1.4 ft/s25. In general, what is the water content of screened material?a. 50%b. 65%c. 80%d. 89%26. What is the wastewater

44、 velocity range in feet per second (ft/s) for grit removal in a grit chamber?a. 0.5 to 1.0 ft/sb. 0.7 to 1.4 ft/sc. 0.8 to 1.5 ft/sd. 1.0 to 1.5 ft/sRacks, Screens, Comminutors, and Grit Removal27. Which one of the following chemicals gives water its greatest capacity to neutralize acids?a. hydroxid

45、eb. silicatec. borated. phosphate28. The bar rack is useda. when the bar screen is out of serviceb. before the bar screenc. after the bar screend. either before or after the bar screenPrimary Sedimentation29. Typically, what is the average detention time for wastewater in a primary clarifier?a. 2 hr

46、b. 3 hrc. 3.5 hrd. 4.5 hrSedimentation and Flotation30. Which one of the following gases is irritating to the eyes?a. carbon monoxideb. chlorinec. methaned. hydrogen sulfideGRADE 1 QUESTIONS 531. Activated sludge clarifiers accept material to be settled froma. an aeration tankb. a primary clarifierc

47、. a trickling filterd. a primary digester tankSecondary Treatment Processes32. According to the Clean Water Act, secondary treatment is defined as a wastewater plant producing an effluent that has no more than _ total suspended solids and no more than _ BOD5.a. 20 mg/L, 40 mg/Lb. 30 mg/L, 30 mg/Lc.

48、40 mg/L, 40 mg/Ld. 40 mg/L, 20 mg/L33. The color of the biofilm on a rotating biological contactor would appear _ under normal operating conditions.a. dark greenb. greenish grayc. grayd. brownActivated Sludge34. A primary effluent and returned activated sludge mixture is calleda. mixed liquorb. mixe

49、d liquor suspended solidsc. activated sludge liquord. waste activated sludge35. The mixture of organisms and solids in water that is removed from the settling tank is calleda. mixed liquorb. mixed liquor suspended solidsc. activated sludge liquord. mixed activated sludge36. Under normal operating conditions, what color is the activated sludge?a. dark chocolate brownb. light to medium brownc. greenish brownd. dark gree