1、 Blank PageGrade 2 Water TreatmentCopyright 1979, 1995, 2003, 2010, 2016 American Water Works Association. All rights reserved. Printed in the United States of America. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photo
2、copy, 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 Many of the photographs and illustrative drawings that appear in this book have been furnished through the cour
3、tesy of various product distributors and manufacturers. Any mention of trade names, commercial products, or services does not constitute endorsement or recommendation for use by the American Water Works Association or the US Environmental Protection Agency. In no event will AWWA be liable for direct
4、, indirect, special, incidental, or consequential damages arising out of the use of information presented in this book. In particular, AWWA will not be responsible for any costs, including, but not limited to, those incurred as a result of lost revenue. In no event shall AWWAs liability exceed the a
5、mount paid for the purchase of this book. Library of Congress Cataloging-in-Publication Data CIP data has been applied for. ISBN: 9781625761248 000200010272023365 6666 West Quincy Avenue Denver, CO 80235-3098 303.794.7711 iii Contents Foreword vii Acknowledgments viii How to Use This Book ix Chapter
6、 1 Basic Microbiology and Chemistry 1 Chemical Formulas and Equations 1 Moles and Molarity 6 Equivalent Weights and Normality 7 Dilution Calculations 8 Standard Solutions 12 Chapter 2 Operator Math 15 Volume Measurements 15 Conversions 22 Average Daily Flow 30 Surface Overflow Rate 33 Weir Overflow
7、Rate 36 Filter Loading Rate 38 Filter Backwash Rate 41 Mudball Calculation 43 Detention Time 44 Pressure 47 Flow Rate Problems 52 Chemical Dosage Problems 55 Chapter 3 USEPA Water Regulations 71 Types of Water Systems 71 Disinfection By- product and Microbial Regulations 72 Chapter 4 Coagulation and
8、 Flocculation Process Operation 89 Operation of the Processes 89 Dosage Control 93 Safety Precautions 93 Record Keeping 94 Chapter 5 Sedimentation and Clarifiers 97 Process Description 97 Sedimentation Facilities 98iv WSO Water Treatment, Grade 2 Other Clarification Processes 104 Regulations 107 Ope
9、ration of the Process 107 Chapter 6 Filtration 115 Equipment Associated With Gravity Filters 115 Operation of Gravity Filters 123 Pressure Filtration 135 Regulations 138 Safety Precautions 138 Record Keeping 139 Chapter 7 Chlorine Disinfection 143 Gas Chlorination Facilities 143 Hypochlorination Fac
10、ilities 155 Operation of the Chlorination Process 157 Chlorination Operating Problems 162 Safety Precautions 165 Record Keeping 170 Chapter 8 Iron and Manganese Treatment 173 Excessive Iron and Manganese 173 Control Processes 175 Control Facilities 178 Regulations 182 Manganese Greensand Filter Oper
11、ation 182 Process Monitoring 188 Operating Problems 188 Record Keeping 188 Chapter 9 Fluoridation Process Operation 191 Operation of the Fluoridation Process 191 Fluoridation Operating Problems 193 Control Tests 194 Safety Precautions 195 Record Keeping 196 Chapter 10 Water Quality Testing 199 Testi
12、ng and Laboratory Procedures 199 Physical and Aggregate Properties of Water 209 Chapter 11 Corrosion Control 221 Purposes of Corrosion and Scaling Control 221 Water System Corrosion 222 Scale Formation 226 Corrosion and Scaling Control Methods 227 Corrosion and Scaling Control Facilities 230 Chemica
13、l Feed Equipment 233Contents v Chapter 12 Lime Softening 237 Lime Softening Chemical Reactions 237 Lime Softening Facilities 239 Regulations 244 Chapter 13 Ion Exchange 247 Ion Exchange Softening 247 Facilities 247 Operation of Ion Exchange Processes 252 Operating Problems 254 Ion Exchange for Remov
14、al of Arsenic, Barium, Radium, Nitrate, TOC, and Uranium 255 Activated Alumina Fluoride Removal Process 257 Adsorptive Media 257 Chapter 14 Activated Carbon Adsorption 261 The Principle of Adsorption 261 Adsorption Facilities 262 Powdered Activated Carbon 263 Granular Activated Carbon 265 Regulation
15、s 268 Operating Procedures for Adsorption 268 Operating Problems 272 Control Tests 273 Record Keeping 276 Chapter 15 Aeration 279 Water-Into-Air Aerators 279 Air-Into-Water Aerators 284 Combination Aerators 285 Chapter 16 Membrane Treatment 291 Microfiltration Facilities 291 Pleated Membrane Facilit
16、ies 294 Reverse Osmosis Facilities 297 Chapter 17 Plant Waste Treatment and Disposal 303 Removal of Sludge from Conventional Sedimentation Processes 303 Softening Sludge Handling, Dewatering, and Disposal 305 Solids Separation Technologies 306 Chapter 18 Instrumentation and Control Systems 313 Flow,
17、 Pressure, and Level Measurement 313 Other Operational Control Instruments 316 Automation 317 Computerization 318vi WSO Water Treatment, Grade 2 Chapter 19 Centrifugal Pumps 321 Operation of Centrifugal Pumps 321 Centrifugal Pump Maintenance 325 Record Keeping 336 Pump Safety 336 Chapter 20 Treatmen
18、t Plant Safety and Security Practices 339 Treatment Plant Safety Review 339 Plant Security 348 Chapter 21 Administration, Records, and Reporting Procedures 355 Process Records 355 Reporting 359 Plant Performance Reports 360 Public Relations 360 Chapter 22 Additional Study Questions 363 Study Questio
19、n Answers 369 References 378 Glossary 379 Index 387 vii Foreword This book is part of the Water System Operations (WSO) series. This water operator education series was designed by the American Water Works Association (AWWA) to address core test content on certification exams by operator certificati
20、on type (treatment or distribution) and certification grade level. The current books in the series are: WSO Water Treatment, Grade 1 WSO Water Treatment, Grade 2 WSO Water Treatment, Grades 3 for example, one oxygen atom and two hydrogen atoms form a molecule of the compound water (H 2 O). “H 2 O” i
21、s called the chemical formula of water. The formula is a shorthand way of writing what elements are present in a molecule of a com- pound, and how many atoms of each element are present in each molecule. Reading Chemical Formulas The following are examples of chemical formulas and what they indicate
22、. Example 1 The chemical formula for calcium carbonate is CaCO 3 According to the formula, what is the chemical makeup of the compound? First, the letter symbols given in the formula indicate the three elements that make up the calcium carbonate compound: Ca = calcium C = carbon O = oxygen Second, t
23、he subscripts (the small numbers at the lower right corners of the letter symbols) in the formula indicate how many atoms of each element are present in a single molecule of the compound. There is no number just to the right of the Ca or C symbols; this indicates that only one atom of each element i
24、s present in the molecule. The subscript 3 to the right of the O sym- bolizing oxygen indicates that there are three oxygen atoms in each molecule. chemical formula Using the chemical symbols for each element, a shorthand way of writing what elements are present in a molecule and how many atoms of e
25、ach element are present in each of the molecules. 2 WSO Water Treatment, Grade 2 Determining Percent by Weight of Elements in a Compound If 100 lb of sodium chloride (NaCl) were separated into the elements that make up the compound, there would be 39.3 lb of pure sodium (Na) and 60.7 lb of pure chlo
26、rine (Cl). We say that sodium chloride is 39.3 percent sodium by weight and that it is 60.7 percent chlorine by weight. The percent by weight of each element in a compound can be calculated using the compounds chemical formula and atomic weights from the periodic table. The first step in calculating
27、 percent by weight of an element in a compound is to determine the molecular weight (sometimes called formula weight) of the compound. The molecular weight of a compound is defined as the sum of the atomic weights of all the atoms in the compound. For example, to determine the molecular weight of so
28、dium chloride, first count how many atoms of each element a single molecule contains:Na Cl1 atom 1 atom Next, find the atomic weight of each atom, using the periodic table: atomic weight of Na = 22.99 atomic weight of Cl = 35.45 Finally, multiply each atomic weight by the number of atoms of that ele
29、ment in the molecule, and total the weights: Number of Atoms Atomic Weight Total Weight sodium (Na) 1 22.99 = 22.99 chlorine (Cl) 1 35.45 = 35.45 molecular weight of NaCl = 58.44 Once the molecular weight of a compound is determined, the percent by weight of each element in the compound can be found
30、 with the following formula: Using the formula, first calculate the percent by weight of sodium in the compound: percent by weight The proportion, calculated as a percentage, of each element in a compound. molecular weight The sum of the atomic weights of all the atoms in the compound. Also called f
31、ormula weight.Basic Microbiology and Chemistry 3 Then, calculate percent by weight of chlorine in the compound: To check the calculations, add the percentages. The total should be 100: Chemical Equations A chemical equation is a shorthand way, through the use of chemical formulas, to write the react
32、ion that takes place when certain chemicals are brought together. As shown in the following example, the left side of the equation indicates the reactants, or chemicals that will be brought together; the arrow indicates which direction the reaction occurs; and the right side of the equation indicate
33、s the prod- ucts, or results, of the chemical reaction. The 2 in front of CaCO 3is called a coefficient. A coefficient indicates the relative number of molecules of the compound that are involved in the chemical reaction. If no coefficient is shown, then only one molecule of the compound is involved
34、. For example, in the preceding equation, one molecule of calcium bi- carbonate reacts with one molecule of calcium hydroxide to form two molecules of calcium carbonate and two molecules of water. Without the coefficients, the equation could be written If you count the atoms of calcium (Ca) on the l
35、eft side of the equation and then count the ones on the right side, you will find that the numbers are the same. In fact, for each element in the equation, as many atoms are shown on the left side as on the right. An equation for which this is true is said to be balanced. A balanced equation accurat
36、ely represents what really happens in a chemical re- action: because matter is neither created nor destroyed, the number of atoms of each element going into the reaction must be the same as the number coming out. Coefficients allow balanced equations to be written compactly. chemical equation A shor
37、thand way, using chemical formulas, of writing the reaction that takes place when chemicals are brought together. The left side of the equation indicates the chemicals brought together (the reactants); the arrow indicates in which direction the reaction occurs; and the right side of the equation ind
38、icates the results (the products) of the chemical reaction. coefficient An indication of the relative number of molecules of the compound that are involved in the chemical reaction.4 WSO Water Treatment, Grade 2 Coefficients and subscripts can be used to calculate the molecular weight of each term i
39、n an equation, as illustrated in the following example. Example 2 Calculate the molecular weights for each of the four terms in the following equation: First, calculate the molecular weight of Ca(HCO 3 ) 2 : Number of Atoms Atomic Weight Total Weight calcium (Ca) 1 40.08 = 40.08 hydrogen (H) 2 1.01
40、= 2.02 carbon (C) 2 12.01 = 24.02 oxygen (O) 6 16.00 = 96.00 molecular weight of Ca(HCO 3 ) 2 = 162.12 The molecular weight for Ca(OH) 2is determined as follows: Number of Atoms Atomic Weight Total Weight calcium (Ca) 1 40.08 = 40.08 oxygen (O) 2 16.00 = 32.00 hydrogen (H) 2 1.01 = 2.02 molecular we
41、ight of Ca(OH) 2 = 74.10 The coefficient 2 in front of the next term of the equation (2CaCO 3 ) indi- cates that two molecules of CaCO 3are involved in the reaction. First find the weight of one molecule, then double that weight to determine the weight of two molecules: Number of Atoms Atomic Weight Total Weight calcium (Ca) 1 40.08 = 40.08 carbon (C) 1 12.01 = 12.01 oxygen (O) 3 16.00 = 48.00 weight of one molecule of CaCO 3 = 100.09 weight of two molecules of CaCO 3 = (2)(100.09) = 200.18
