Water and Wastewater Laboratory Techniques

By Roy-Keith Smith and Water Environment Federation

A teaching and reference tool for educating analysts in water and wastewater laboratories in the skills and techniques of the bench chemist. This book provides the vital background information needed to operate in a laboratory and engage with Standard Methods and other collections employed in a lab setting.A teaching and reference tool for educating analysts in water and wastewater laboratories in the skills and techniques of the bench chemist. This book provides the vital background information needed to operate in a laboratory and engage with Standard Methods and other collections employed in a lab setting.

• Language: English
• Publisher: Water Environment Federation
• Release date: Mar 1, 2019
• ISBN: 9781572783560

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Copyright © 2018 by the Water Environment Federation. All Rights Reserved. Permission to copy must be obtained from WEF.

Water Environment Research, WEF, and WEFTEC are registered trademarks of the Water Environment Federation.

ISBN 978-1-57278-356-0

IMPORTANT NOTICE

The material presented in this publication has been prepared in accordance with generally recognized engineering principles and practices and is for general information only. This information should not be used without first securing competent advice with respect to its suitability for any general or specific application.

The contents of this publication are not intended to be a standard of the Water Environment Federation® (WEF) and are not intended for use as a reference in purchase specifications, contracts, regulations, statutes, or any other legal document.

No reference made in this publication to any specific method, product, process, or service constitutes or implies an endorsement, recommendation, or warranty thereof by WEF.

WEF makes no representation or warranty of any kind, whether expressed or implied, concerning the accuracy, product, or process discussed in this publication and assumes no liability.

Anyone using this information assumes all liability arising from such use, including but not limited to infringement of any patent or patents.

The Publisher works hard to ensure that the information in this publication is accurate and complete. However, it is possible that the information may change after publication, and/or that errors or omissions may occur. We welcome your suggestions on how to improve this publication and correct errors. The Publisher disclaims all liability for, damages of any kind arising out of use, reference to, or reliance on information included in this publication to the full extent provided by state and federal law.

About WEF

The Water Environment Federation (WEF) is a not-for-profit technical and educational organization of 35,000 individual members and 75 affiliated Member Associations representing water quality professionals around the world. Since 1928, WEF and its members have protected public health and the environment. As a global water sector leader, our mission is to connect water professionals; enrich the expertise of water professionals; increase the awareness of the impact and value of water; and provide a platform for water sector innovation. To learn more, visit www.wef.org.

Foreword 2019 Edition

Over 20 years have passed since I wrote the original Foreword for this publication. In looking back over the years, most things have not changed. Indeed, if you are a new want-to-be analyst or an experienced analyst in another testing position, there are still things you need to know about environmental testing and the responsibilities (sometimes personal) that go along with it.

The trend toward replacing wet chemical methods with multi-analyte instrumental techniques continues unabated. Many of the wet methods in the 18th edition of Standard Methods have been removed from the 23rd edition in favor of instrumental methods. Although the U.S. Environmental Protection Agency (U.S. EPA) still approves most of the older wet methods for use, there is an increasing trend toward multi-analyte methods such as ion chromatography, capillary ion electrophoresis, ICP/AES, ICP/MS, flow injection, and others. Although computers may seem to run the instrument and the laboratory, it is still humans that provide the chemical knowledge and expertise.

The legal scrutiny never stops. In addition to state environmental agency and U.S. EPA oversight, various organizations such as the American Canoe Association have discovered that there is money to be made in bringing civil lawsuits against water resource recovery facilities for non-compliance with permits and regulations. In particular, they have found that the laboratory is a prime target for non-compliance. Non-compliance may take the form of an inability to meet legislated detection/reporting limits or the use of non-approved methods.

You may think you are a simple laboratory analyst but, in actuality, you are a prime target for a lawsuit. Moreover, in the event of a lawsuit, you may be named personally as a defendant. Thus, you need to protect yourself. Know the regulations and follow them to the letter. These include 40 CFR Part 136 for wastewater and 40 CFR Part 141 for water analysis. Know the requirements of your facility’s permits. Make sure you document everything, no matter how minor it seems.

This is a wonderful industry to work in. Aside from the vital public health function that we perform, it is also personally rewarding with excellent growth potential. In June of 2000, I resigned from a commercial analytical laboratory (Analytical Services, Inc.). Rather than stop working, however, my situation has allowed more time to explore many new challenges in the industry. In addition to continuing to write books and give seminars to laboratory groups, I have been involved as an expert witness in court, giving depositions and testimony about laboratory procedures, analysis, quality control, and results. It seems that every day brings a new opportunity.

ACKNOWLEDGMENTS

A work of this type, in a science as complicated as laboratory chemistry, is impossible to produce in a vacuum. I owe an unpayable debt of gratitude to the many persons who assisted in the donation of information, pictures, and their time for technical creation of the manuscript. First and foremost, I acknowledge the contributions and assistance of the company that paid for my daily bread and allowed me to pursue such desires as the writing of the first edition of this book, Analytical Services, Inc. Special thanks go to Robert G. Owens, Jr., Denise S. Geier, Billy P. Dyer, G. Wyn Jones, Jeff Newman, Lang Allen Reeves, and the rest of the technical staff at Analytical Services for their help, data, and pictures. Also providing enormous assistance in this work and (dare I forget it) restraint in putting up with my oftentimes abrupt and abrasive personality were Paul McMinn, Fisher Scientific, Norcross, Georgia; Susan Grable, Fisher Scientific, Pittsburgh, Pennsylvania; James B. Carl, Painted Post, New York; David Black and Jane Leisenring, Corning Inc., Corning New York; Lisa M. Lazzara, Nalge Company, Rochester, New York; Paul Stinson, Ever Ready Thermometer Co. Inc., West Patterson, New Jersey; Judy Poxon, Vee Gee Scientific, Kirkland, Washington; Andy Sendelback and Chris Clark, Varian Sample Preparation Products, Palo Alto, California; and Jennie Durant, Bill Smutney, Maryanne Reves, and David Fenili, Kimble Kontes, Vineland, New Jersey. Jon P. Henderson, Georgia Water and Wastewater Institute, Georgia Water and Pollution Control Association, Carrollton, Georgia, deserves mention for allowing me time with live classes of operators and laboratory analysts to work out the presentation problems of many of the concepts discussed in this book. The reviewers of the book—David Kimbrough, California Environmental Protection Agency, Los Angeles, California; Dr. Larry Keith, Radian Corp., Austin, Texas; Robert G. Owens, Jr., ASI, Norcross, Georgia; Dr. Mark Bruce, Quanterra, North Canton, Ohio; and Dr. David Carrick, Australian National Laboratories, Asquith New South Wales, Australia, are thanked for their time and many useful comments for improving the presentation and content. To steal a dedication used by a classmate of mine from the graduating class of 1968, East Greenwich High School, East Greenwich, Rhode Island, I dedicate this book to the memory of my parents, Mary Eda Keller Smith and Commander Roy Fowler Smith, USN, without whom I would not be here.

Finally, I owe a debt of gratitude to my editor, Lorna Ernst, and her staff at the Water Environment Federation for the original idea for a second edition of this work and the help they provided for its completion and delivery.

ABOUT THE AUTHOR

Roy-Keith Smith began his laboratory career with the U.S. Army in 1969 and is a Vietnam veteran. After his discharge, he obtained his BS in Chemistry from the Georgia Institute of Technology and graduated from Colorado State University with a Ph.D. in Chemistry. He then completed a one-year research faculty appointment at the California Institute of Technology. After several years working with the Georgia Department of Agriculture, he took a position as a laboratory manager in an environmental laboratory. Taking time out for a stint as a college professor of environmental chemistry, he returned to the environmental industry with, first, a six-month sabbatical replacement position in the Hewlett-Packard Analytical Education Center and then moved on to a position as Analytical Methods Manager with Analytical Services, Inc. He left ASI in June 2000.

Dr. Smith served the industry as an educational consultant to the Georgia Water and Wastewater Institute and was a member of the Georgia Water Pollution Control Association Laboratory Committee, the Water Environment Federation Laboratory Practices Committee, and as part coordinator for Part 4000 and Part 5000 of Standard Methods. Through his consulting firm Apichemical Consultants, he has published numerous books on environmental analytical chemistry and served as an expert witness in environmental analytical chemistry. He is the recipient of the 1994 WEF Laboratory Analyst Excellence Award from the GWPCA.

Dr. Roy-Keith Smith

Apichemical Consultants

PO Box 1243

St. Augustine FL 32085

Contents

Foreword

List of Figures

List of Tables

Chapter 1     Analytical Standards and Reagents

1.0     TYPES OF CHEMICALS

2.0     GRADES OF CHEMICALS

3.0     STORAGE OF CHEMICALS

4.0     MANUFACTURER-PREPARED STOCK SOLUTIONS AND CERTIFICATION

5.0     REAGENT WATER

Chapter 2     Analytical and Toploading Balances

1.0     TYPES OF BALANCES

2.0     SITING AND ENVIRONMENTAL CONCERNS

3.0     CALIBRATION OF BALANCES AND CERTIFIED WEIGHTS

4.0     ACCESSORIES

5.0     OPERATION AND DAILY MAINTENANCE

Chapter 3     Laboratory Ware

1.0     TYPES AND CHARACTERISTICS OF GLASS

2.0     LABORATORY GLASSWARE DESCRIPTION

3.0     CERAMICWARE DESCRIPTION AND CHARACTERISTICS

4.0     PLASTICWARE DESCRIPTION AND CHARACTERISTICS

5.0     METALWARE DESCRIPTION AND CHARACTERISTICS

Chapter 4     Volumetric Devices and Their Use in Measurement

1.0     VOLUMETRIC MEASURING TOOLS

2.0     PROPER USE OF VOLUMETRIC GLASSWARE

3.0     CALIBRATION OF NONSTANDARD MEASURING TOOLS

4.0     REFERENCES

Chapter 5     Temperature Measurement

1.0     INTRODUCTION

2.0     DESCRIPTION OF TEMPERATURE MEASURING DEVICES

3.0     CALIBRATION CHECKING AND MAINTENANCE OF LIQUID-IN-GLASS THERMOMETERS

Chapter 6     Preparation of Solutions and Dilutions

1.0     USE OF BALANCES AND VOLUMETRIC WARE

2.0     PREPARATION OF DILUTIONS

3.0     STORAGE OF PREPARED SOLUTIONS

Chapter 7     Calibrations

1.0     STANDARDIZATION OF SOLUTIONS

2.0     DIRECT STANDARDIZATION

3.0     INDIRECT STANDARDIZATION

4.0     SOLUTION LIFETIME

5.0     CALIBRATION

5.1     One-Point Calibrations

5.2     Multipoint Graphical Techniques

5.3     Multiple Standard Additions

6.0     FREQUENCY OF CALIBRATION AND CALIBRATION CHECKS

7.0     REFERENCE

Chapter 8     Test Procedures

1.0     DISTILLATION

2.0     FILTRATION

3.0     GRAVIMETRIC DETERMINATIONS

4.0     COLORIMETRIC DETERMINATIONS

5.0     TURBIDIMETRIC DETERMINATIONS

6.0     TITRATION

7.0     pH AND ION-SELECTIVE ELECTRODES

8.0     REFERENCE

Chapter 9     Calculation and Reporting Results

1.0     SIGNIFICANT FIGURES

2.0     CALCULATIONS

3.0     DRY WEIGHT CORRECTIONS

4.0     REPORTING RESULTS

Chapter 10     Controlling the Test Procedure

1.0     THE ABILITY OF THE TEST TO ACTUALLY MEASURE THE DESIRED PARAMETER IN THE SAMPLE

2.0     HOW CLOSE THE RESULT IS TO THE ACTUAL AMOUNT OF ANALYTE IN THE SAMPLE

3.0     CAN THE SAME RESULT BE OBTAINED REPEATEDLY?

4.0     WHAT IS THE LOWEST LEVEL OF ANALYTE THAT CAN BE DETECTED IN THE SAMPLE?

5.0     IS THE DETECTED PARAMETER ACTUALLY IN THE SAMPLE?

6.0     BATCH ANALYSIS

7.0     REFERENCES

8.0     RECOMMENDED READING

APPENDICES

Appendix A     Molecular and Formula Mass

Appendix B     Molarity and Normality

Appendix C     Types of Chemical Reactions

Appendix D     Stoichiometry of Chemical Reactions

Appendix E     Laboratory Analyst Training

1.0     INTRODUCTION

2.0     TRAINING GOALS

3.0     TRAINING PROGRAM

4.0     TRAINING DOCUMENTATION

5.0     CONCLUSION

6.0     REFERENCES

Index

List of Figures

1.1     Acid storage cabinet

1.2     A deionizing unit for laboratory water purification

2.1     Triple beam balance

2.2     Top loading balance

2.3     Analytical balance

2.4     Aluminum weighing boats

2.5     Disposable plastic weighing boats

2.6     Reagent (weighing) funnel

2.7     Weighing scoop

3.1     (a) Tapered and (b) spherical joints

3.2     Diagrams of the size designation for a 24/40 male standard taper joint (left) and a 35/25 male spherical joint (right). Units are millimeters

3.3     O-ring joint

3.4     Stopcock plug

3.5     Buret with rotaflow valve

3.6     (a) Berzelius and (b) Griffin beakers

3.7     Erlenmeyer flasks with screw caps

3.8     Ribbed watch glass used with a beaker

3.9     Narrow mouth reagent bottle

3.10   Vacuum flask with side arm

3.11   Test tube

3.12   Kjeldahl flask and condenser

3.13   (a) West, (b) Graham, (c) Allihn, and (d) Liebig jacketed condensers

3.14   Jacketed condenser with ground glass fittings

3.15   Powder funnel

3.16   Plain long-stem filtering funnel

3.17   Perforated funnel with vacuum attachment

3.18   Porcelain Buchner funnel

3.19   Fritted Buchner funnel

3.20   Funnel and support assembly

3.21   Separatory funnel

3.22   Heavier-than-water continuous liquid-liquid extractor

3.23   Lighter-than-water continuous liquid-liquid extractor

3.24   Accelerated one-step continuous liquid-liquid extractor

3.25   (a) mortar and pestle, (b) spotplate, (c) crucibles, and (d) dishes

3.26   ASTM resin identification codes

3.27   Wash bottle without right-to-know label

3.28   Wash bottle with right-to-know labels

3.29   Variable-volume reagent dispenser

3.30   Petri dishes

3.31   Serological pipets

3.32   Disposable pipetter tips

3.33   Teflon beaker with metal bottom

3.34   Tubing connectors

3.35   Quick-disconnect tubing connector

3.36   Stainless steel adjustable hose clamp

3.37   Presterilized sample containers with dechlorination tablets for coliform testing

3.38   Long-handle sampling spoons

3.39   Disposable filtration units

3.40   Reusable filtration units

3.41   Hand-operated vacuum pump

3.42   Single ferrule compression fitting

3.43   Variety of support clamps: (Top) Fixed position, medium 3 prong dual adjust clamp. (Bottom) Fixed position, medium 2 prong single adjust clamp

4.1     Class A volumetric flasks

4.2     (a) Class A volumetric pipet, (b) Class A measuring pipet (Mohr), (c) a serological pipet

4.3     Class A graduated cylinder

4.4     Class AS micro buret with attached reservoir

4.5     Correct position of calibration mark and meniscus (left). Meniscus positioned higher than calibration mark (right)

4.6     Finger (left) and thumb (right) pipetting techniques

4.7     Position of meniscus in a graduated cylinder estimated as 52.8 mL

4.8     Pipette bulb

5.1     Liquid-in-glass thermometer

5.2     Enclosed-chamber thermometers

5.3     Digi-Sense® Armored Liquid-In-Glass Thermometer

5.4     Digi-Sense® 7 Point Reversible Temp Label

6.1     Flask with ground glass stopper

6.2     Ultrasonic cleaning baths

6.3     Reagent dispenser bottle

7.1     Example of a three-cycle semilog graph

7.2     Example of a rectangular graph

7.3     Computer generated calibration plot of phosphate data

7.4     Line graph of phosphate data

7.5     Locating an absorbance value intersection with the calibration curve

7.6     Locating a concentration value from an absorbance result

7.7     Added phosphate calibration points demonstrating saturation

7.8     Regression line of all phosphate data

7.9     Regression line for phosphate data with top two points eliminated

7.10   Fluoride calibration data plotted on rectangular paper

7.11   Log of fluoride calibration data plotted on rectangular paper

7.12   Fluoride calibration data plotted on semilog paper

7.13   Multiple standard addition calibration for reactive phosphorous

8.1     Cyanide distillation system

8.2     Ammonia nitrogen distillation apparatus

8.3     Total Kjeldahl nitrogen (TKN) automated still

8.4     Kuderna-Danish concentrator

8.5     TurboVap II® Automated Solvent Evaporation System

8.6     Vacuum rotary evaporator

8.7     Distillation trap

8.8     Heating mantle and temperature controller

8.9     Water bath

8.10   (a) Cone, (b) Filter support with gasket, (c) Stopper

8.11   Vacuum trap

8.12   Dewar flasks

8.13   Solid-phase extraction apparatus for oil and grease

8.14   Solid-phase extraction disk

8.15   Glass desiccator

8.16   Plot of absorbance versus wavelength for a colorimeter test

9.1     Uncertainty of reading the position of a meniscus in a burette

9.2     Meniscus at 4.41-mL volume in a burette

9.3     Meniscus at 5.00-mL volume in a burette

10.1   Theoretical distribution of results controlled only by random error around a mean

10.2   Frequency distribution for total suspended solids recovery

10.3   Accuracy and precision illustrated by target shooting

10.4   Benchsheet used for batch analysis

List of Tables

1.1     Abbreviations frequently found in material data safety sheets

1.2     Comparison of price and quality of the common solvent acetone from one supplier

1.3     Similar reagent-grade terms for some of the major suppliers

1.4     Primary standards and uses

1.5     Quality parameters for ASTM class waters

2.1     Tolerances (mg) of various ASTM and NIST classes of standard weights

3.1     Rubber stopper sizes

3.2     Pores sizes of fritted glass filters

3.3     Chemical composition (percent) of elements other than iron in stainless steel alloys

4.1     Comparison of Class A and Class B tolerances for volumetric flasks

4.2     Comparison of Class A and Class B tolerances for pipettes

4.3     Comparison of Class A and Class B tolerances for graduated cylinders

4.4     Comparison of Class A and Class B tolerances for burettes

4.5     Comparison of relative percent accuracy of the calibration marks on 25-mL measuring devices for Class A and Class B tolerances

4.6     Comparison of percent accuracy for determination of dispensing 1.00 mL from a variety of Class A measuring devices

4.7     Flow times for TD transfer pipettes

4.8     Density variation of reagent water with temperature

5.l     Comparison of Kelvin, Celsius, and Fahrenheit temperature scales

5.2     Thermocouple types, constructions, and temperature ranges

5.3     Infrared emissivity of various materials

7.1     Absorbance data for phosphate calibration

7.2     Fluoride calibration data

7.3     Multiple standard addition for a phosphorus test

8.1     Particle retention ratings for a variety of qualitative filter papers

8.2     Residue fractions determined in the laboratory

8.3     Characteristics of drying agents for potential use in a desiccator

8.4     Absorbance data obtained from varying the wavelength around a method maximum

8.5     Some pH indicators for use in checking wavelength adjustment on spectrophotometers

8.6     Methods that result in wavelength standards for checking colorimeter

8.7     Exact wavelength setting variation depending on the direction of approach

9.1     Implied uncertainties for different ways of writing a number on a benchsheet

9.2     SI prefixes for metric units

10.1   Examples of relative percent difference calculated from matrix spike and matrix spike duplicate recoveries

B.1    Serial dilutions performed on glucose solution

C.1    Common names of some laboratory chemicals

E.1    Introduction to quality assurance lesson plan

E.2    Analyst class schedule

1

Analytical Standards and Reagents

1.0    TYPES OF CHEMICALS

2.0    GRADES OF CHEMICALS

3.0    STORAGE OF CHEMICALS

4.0    MANUFACTURER-PREPARED STOCK SOLUTIONS AND CERTIFICATION

5.0    REAGENT WATER

Chemical testing can be divided into two types. The first type of testing measures a bulk physical property of the sample, such as volume, temperature, melting point, moisture content, or mass. These measurements are characteristically nondestructive to the sample. Moreover, these measurements are typically performed with an instrument, and one simply has to calibrate the instrument to perform the test. Most analyses, however, are of the second type of testing, in which a chemical property of the sample is determined that generates information about how much of what is in the sample. Measurements of this type are destructive to the sample.

The determination of chemical properties typically involves observation of the reaction between the sample and selected chemicals, called reagents. Without reagents, few chemical analyses could be performed.

An important class of reagents comprises analytical standards. These are the chemicals used to calibrate a procedure so that the data generated will correctly reflect the composition of the sample. Reagents allow the test to be done, whereas analytical standards are necessary to obtain reliable results from the test.

1.0   TYPES OF CHEMICALS

The three physical forms of matter encountered in the laboratory are solids, liquids, and gases. Different chemicals exist in one of the three phases at room temperature. When chemicals from commercial suppliers are purchased, solids and liquids come in plastic or glass bottles, whereas gases typically arrive compressed in steel cylinders. The chemical and physical properties of the chemicals serve to classify them into appropriate groups for handling and storage.

Many chemicals are not particularly corrosive or caustic, generating solution pHs of approximately 7 (neutral). Some chemicals are highly acidic, resulting in low pH solutions (1 to 4), whereas others are highly basic and give solutions of high pH (10 to 14).

Two terms that are widely misused in chemistry are strength (also, strong or weak) and concentration (also, concentrated or dilute). They are completely different concepts.

Strength is a chemical property. It relates to the degree that individual molecules of a substance remain intact in a water solution or break apart into ions. A strong acid, such as hydrochloric acid, has no intact molecules of HCl in the solution; instead, the molecules are all ionized (HCl → H+ + Cl−). Examples of strong acids include hydrochloric acid, nitric acid, sulfuric acid, hydrobromic acid, perchloric acid, and chromic acid. In a similar vein, there are strong bases such as sodium hydroxide. There are no intact molecules of NaOH in solution; instead, they are all ionized (NaOH → Na+ + OH−). Examples of strong bases include sodium hydroxide, potassium hydroxide, barium hydroxide, and calcium oxide (lime). There are also weak acids and bases. Weak means that the substance is largely intact as molecules in the solution, with very little ionization. Acetic acid (in vinegar) is a weak acid, and more than 95% of the molecules are intact in solution with very little ionization (HOAc ↔ H+ + OAc−). Examples of weak acids include acetic acid, phosphoric acid, hydrofluoric acid, lactic acid, and ascorbic acid. Weak bases are also largely intact as molecules in solution. An example of this is ammonia. A solution of ammonia represents mostly intact ammonia molecules in solution with very little ionization (NH3 + H2O ↔ NH4+ + OH−). Other weak bases include magnesium oxide, nicotine, and many others.

Concentration is a physical property. It relates to how much of the material is in the solution. If there is a lot of the substance in the solution, it is termed concentrated, whereas, if there is only a small amount in solution, it is called dilute. The strong acids are typically provided as concentrated solutions such as hydrochloric acid (37%), sulfuric acid (96%), and nitric acid (70%). The weak acid acetic acid is typically provided pure (100%, glacial). Although these acids are diluted before use (i.e., 1.0-M hydrochloric acid or 1.0-M sulfuric acid), they are still strong acids. A 1.0-M solution of acetic acid is a dilute weak acid. The strong-base sodium hydroxide is provided as a solid that must be diluted in water to provide a working solution of, say, 1.0-M NaOH; however, it is still a strong base. A concentrated or dilute solution of ammonia is always going to be weak regardless of how powerfully it affects your eyes or nose.

A number of salts, such as ammonium chloride, ferric chloride, aluminum sulfate (alum), and sodium acetate, form acidic or basic solutions when dissolved in water. Although these solutions are not as strong as those of the strong acids or bases, they can still be corrosive.

Acids and bases need to be stored separately in secure areas. Regardless of whether they are strong or weak, acids and bases will generate a lot of heat and can