Water Treatment Plant Operation

666 Pages·2007·13.77 MB·English

DOCUMENT RESUME

ED 296 867
SE 049 158

TITLE
Water Treatment Plant Operation Volume 2. A Field
Study Training Program. Revised.
INSTITUTION
California State Univ., Sacramento. School of
Engineering.; National Environmental Training
Association, Valparaiso, IN.
SPONS AGENCY
California State Dept. of Health Services,
Sacramento. Sanitary Engineering Branch.;
Environmental Protection Agency, Washington, DC.
Office of Drinking Water.
PUB DATE
88
GRANT
T-901361-01-0
NOTE
690p.: Some charts and drawings may not reproduce
well. Pages containing final examination and answers
are printed on dark grey paper and maybe
illegible.
AVAILABLE FROM
Mr. Ken Kerri, California State
University-Sacramento, 6000 J Street, Sacramento, CA
95819-2654.
PUB TYPE
Guides
Classroom Use
Guides (For Teachers) (052)
Guides
Classroom Use
Materials (For Learner)
(051) -- Tests/Eveluation Instruments (160)

EDRS PRICE
DESCRIPTORS

ABSTRACT

MF04/PC28 Plus Postage.
Chemical Analysis; *Course Content; *Drinking Water;
*Environmental Education; Fluoridation; *Home Study;
Laboratory Procedures; Postsecondary Education;
Safety; Training Methods; *Water Quality; *Water
Treatment

The purpose of this water treatment field study
training program is to: (1) develop new qualified water treatment
plant operators; (2) expand the abilities of existing operators,
permitting better service both to employers and public; and (3)
prcpare operators for civil service and certification examinations
(examinations administered by state/professional associations which
operators take to indicate a level of professional competence).
Volume 2 is a continuation of volume 1,
in which the emphasis was on
the knowledge and skills needed by operators of conventional surface
water treatment plants. This 12-chapter volume contains information
on: iron and manganese control; fluoridation; softening;
trihalomethanes; demineralization; handling and disposal of processed
wastes; maintenance; instrumentation; safety; advanced laboratory
procedures; drinking water regulations; and administration.
Objectives, glossary, lessons, questions (with suggested answers),
and a test are provided for each chapter. A final examination (with
answers), how to solve water treatment plant arithmetic problems,
water abbreviations, complete glossary, and subject index are
provided in an appendix. Information on objectives, scope, and uses
of this manual and instructions to participants in home-study courses
are found in volume 1.
(TW)

Environmental Protection Agency Review Notice

This training manual has been reviewed by the Office of Drinking Water,
U.S. Environmental r ,*^^tion Agency and the California Department of
Health Services. Both agencies have approved this manual for publication.
Approval does not signify that the contents necessarily reflect the views
and policies of the Environmental Protection Agency nor the California
Department of Health Services. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use by
the Environmental Protection Agency; California Department of Health
Services; California State University, Sacramento; National Environmental
Training Association; authors of the chapters or project reviewers, consul-
tants. and directors.

3

WATER TREATMENT PLANT OPERATION

Volume II

A Field Study Training Program

prepared by

California State University, Sacramento
School of Engineering
Applied Research and Design Center

in cooperation with the
National Environmental Training Association

***************************************

Kenneth D. Kern, Project Director
***************************************

for the

Caiffornia Department of Health Services
Sanitary Enc:neering Branch
Standard Agreement #80-64652
and
U.S. Environmental Protection Agency
Office of Drinking Water
Grant No. T-901361-01-0

1988

4't

OPERATOR TRAINING MANUALS

OPERATOR TRAINING MANUALS IN THIS SERIES are available from Ken
Kern, California State University, Sacramento, 6000 J Street, Sacramento, CA
95819-2654, phone [phone].

1. WATER TREATMENT PLANT OPERATION, 2 Volumes,

2. SMALL WATER SYSTEM OPERATION AND MAINTENANCE,

3. WATER DISTRIBUTION SYSTEM OPERATION AND MAINTENANCE,

4. OPERATION OF WASTEWATER TREATMENT PLANTS, 2 Volumes,

5. ADVANCED WASTE TREATMENT,

6. INDUSTRIAL WASTE TREATMENT,

7. TREATMENT OF METAL WASTESTREAMS,

8. PRETREATMENT FACILITY INSPECTION, AND

9. OPERATION AND MAINTENANCE OF WASTEWATER COLLECTION
SYSTEMS, 2 Volumes.

NOTICE

This manual is revised and updated before each printing based on comments
from persons using the manual.

First printing, 1983

Second printing, 1988

7,000

5,000

Copyright © 1988 by
Hornet Foundation, Inc
California State University, Sacramento

5

ii

PREFACE

VOLUME II

Volume II is a continuation of Volume I. In Volume I, the emphasis was on the knowledge and skills needed by
operators of cor rentional surface water treatment plants. Volume II stresses information needed by those
operators but also includes information on specialized water treatment processes for iron and manganese
control, fluoridation, softening, trihalomethanes, demineralization and the handling and disposal of process
wastes. Topics of importance to the operators of all water treatment plants include maintenance, instrumenta-
tion, safety, advanced laboratory procedures, water quality regulations, administration, and how to solve water
treatment plant arithmetic problems.

You may wish to concentrate your studies on those chapters that apply to your water treatment plant. Upon
successful completion of this entire volume, you will have gained a broad and comprehensive knowledge of the
entire water treatment field.

For information on:

1. Objectives of this manual,
2. Scope of this manual,
3. Uses of this manual,
4. Instructions to participants in the home-study course, and
5. Summary of procedure,

please refer to Volume I.

The Project Director is indebted to the many operators and other persons who contributed to this manual.
Every effort was made to acknowledge material from the many excellent references in the water treatment field.
Reviewers Leonard Ainsworth, Jack Rossum, and Joe Monscvitz deserve special recognition for their extremely
thorough review and helpful suggestions. John Trax, Chet Pauls, and Ken Hay, Office ofDrinking Water, U.S. En-
vironmental Protection Agency, and John Gaston, Bill MacPherson, Bert Ellsworth, Clarence Young, Ted Bakker,
and Beverlie Vandre, Sanitary Engineering Branch, California Department of Health Services, a:I performed
outstanding jobs as resource persons, consultants and advisors. Larry Hannah served as Education Consultant.
Illustrations were drawn by Martin Garrity. Charlene Arora helped type the field test and final manuscript for print-
ing. Special thanks are well deserved by the Program Administrator, Gay Kornweibel, who typed, administered
the field test, managed the office, administered the budget, and did everything else that had to be done to com-
plete this project successfully.

KENNETH D. KERRI
PROJECT DIRECTOR

1

iii

G

TECHNICAL CONSULTANTS

John Brady
Gerald Davidson
Larry Hannah

Jim Sequeira
Susuma Kawamura
Mike Young

NATIONAL ENVIRONMENTAL TRAINING ASSOCIATION REVIEWERS

George Kinias, Project Coordinator
E. E. "Skeet" Arasmith
Andrew Holtan
William Redman
Terry Engelhardt
Deborah Horton
Kenneth Walimaa
Dempsey Hall
Kirk Laflin
Anthony Zigment
Jerry Higgins
Rich Metcalf

Leonard Ainsworth
Ted Bakker
Jo Boyd
Dean Chausee
Walter Cockrell
Fred Fah len
David Fitch
Richard Haberman
Lee Harry
Jerry Hayes
Ed Henley
Charles Jeffs

PROJECT REVIEWERS

Chet Latif
Frank Lewis
Perry Libby
D. Mackay
William Maguire
Nancy McTigue
Joe Monscvitz
Angela Moore
Harold Mowry
Theron Palmer
Eugene Parham
Catherine Perman

7

iv

David Rexing
Jack Rossum
William Ruff
Gerald Samuel
Carl Schwing
David Sorenson
Russell Sutphen
Robert Wentzel
James Wright
Mike Yee
Clarence Young

COURSE OUTLINE

WATER TREATMENT PLANT OPERATION, VOLUME I

Page

1
9. Taste and Odor Control
by Russ Bowen

15
10. Plant Operation
by Jim Beard

39
11. Laboratory Procedures
by Jim Sequeira

91
Appendix by Ken Kern

Final Examination

How to Solve Water Treatment
Plant Arithmetic Problems

Water Abbreviations

Water Words

Subject Index

1. The Water Treatment Plant Operator
by Ken Kern

2. Water Sources and Treatment
by Bcrt Ellsworth

3. Reservoir Management and Intake Structures
by Dick Barnett

4. Coagulation, and Flocculation
by Jim Beard

5. Sedimentation
by Jim Beard

6. Filtration
by Jim Beard

7. Disinfection
by Tom Ikesaki

8. Corrosion Control
by Jack Rossum

143

195

247

333

COURSE OUTLINE

WATER TREATMENT PLANT OPERATION, VOLUME II

Page

1
12. Iron and Manganese Control
by Jack Rossum

13. Fluoridation
by Harry Tracy

14. Softening
by Don Gibson and Marty Reynolds

15. Trihalomethanes
by Mike McGuire

16. Demineralization
by Dave Argo

17. Handling and Disposal of Process Wastes
by George Uyeno

18. Maintenance
by Parker Robinson

19. Instrumentation
by Leonard Ainsworth

20. Safety
by Joe Monscvitz

25
21. Advanced Laboratory Procedures
by Jim Sequeira

63
22. Drinking Water Regulations
by Tim Gannon

115
23. Administration
by Tim Gannon

135
Appendix by Ken Kern

Final Examination

How to Solve Water Treatment
Plant Arithmetic Problems

Water Abbreviations

Water Words

Subject Index

179

207

331

V

8

Page
373

413

455

527

528

541

586

587

633

Page
387

445

487

535

561

563

573

599

501

649

CHAPTER 12

IRON AND MANGANESE CONTROL

by

Jack Rossum

with a special section by

Gerald Davidson

!)

2 Plant Operation

TABLE OF CONTENTS

Chap`or 12.
Iron and Manganese Control

OBJECTIVES
3

GLOSSARY
4

12.0
Need to Control Iron and Manganese
6

12.1
Measurement of Iron and Manganese
6

12.10 Occurrence of Iron and Manganese
6

12.11
Collection of Iron and Manganese Samples
7

12.12 Analysis for Iron and Manganese
7

12.2
Remedial Action
9
1220 Alternate Source
9

12.21
Phosphate Treatment
9

12.22 Removal by Ion Exchange
11

12.23 Oxidation by Aeration
12

12.24
Oxidation with Chlorine
13

12.25 Oxide ion with Permanganate
13

12.26 Operation of Filters
14

12.27
Proprietary Processes by Bill Hoyer
14

12.28 Monitoring of Treated Water
15

12.29 Summary
15
12.3
Operation of an Iron and Manganese Removal Plant

by Gerald Davidson
16

12.30
Description of Process
16

12.31
Description of the Plant
17

12.32 Operation of the Greensand Process
19

12.4
Maintenance of a Chemical Feeder
20
12.5
Troubleshooting Red Water Problems
21

12.6
Arithmetic Assignment
21

12.7
Additional Reading
21

Suggested Answers
22

Objective Test
23

10

Iron and Many r.ese
3

OBJECTIVES

Chapter 12.
IRON AND MANGANESE CONTROL

Following completion of Chapter 12, you shoula be able
to:

1. Identify and describe the various processes used to
control iron and manganese,

2. Collect samples for analysis of iron and manganese,

3. Safely operate and maintain the fallowing iron and man-
ganese control processes:

a. Phosphate treatment,
b. Ion exchange,
c. Oxidation by aeration,
d. Oxidation with chlorine,
e. Oxidation with permanganate,
f.
Greensand,
g. Proprietary processes, and

4. Troubleshoot red water problems.

1 i

4
Plant Operation

GLOSSARY

Chopter 12.
IRON AND MANGANESE CONTROL

ACIDIFIED (uh-SID-uh-FIE-d)
ACIDIFIED
The addition of an acid (usually nitric or sulfuric) to a sample to lower the pH below 2.0. The purpose of acidification is to "fix" a
sample so it won't change until it ;s analyzed.

AQUIFER (ACK-wi-fer)
AQUIFER
A natural underground layer of porous, water-bearing materials (sand, grave;) usually napable of yielding a large amount or
supply of water.

BACKFLOW
BACKFLOW
A reverse flow condition, created by a difference in water pressures, which causes water to flow back into the distribution pipes
of a potable water supply from any source or sources other than an intended source. Also see BACKSIPHONAGE.

BACKSIPHONAGE
BACKSIPHONAGE
A form of backflow caused by a negative or below atmospheric pressure within a water system. Also see BACKFLOW.

BENCH SCALE TESTS
BENCH SCALE TESTS
A method of studying different ways or chemical doses for treating water on a small scale in a laboratory.

BREAKPOINT CHLORINATION
BREAKPOINT CHLORINATION
Addition of chiorine to water until the chlorine demand has been satisfied. At this point, further additions of chlorine will result in
a free residual chlorine that is directly proportional to the amount of chlorine added beyond the breakpoint.

CHELATION (key-LAY-shun)
CHELATION
A chemical complexing (forming or joining together) of metallic cations (such as copper) with certain organic compounds, such
as EDTA (ethylene diamine tetracetic acid). Chelation is used to prevent the precipitation of metals (copper). Also see
SEQUESTRATION.

COLLOIDS (CALL-bids)
COLLOIDS
Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small
size and electrical charge. When most of the particles in water have a negative electrical charge, they tend to repel each other.
This repulsion prevents the particles from clumping together, becoming heavier, and settling out.

DIVALENT (die-VAY-lent)
DIVALENT
Having a valence of two, such as the ferrous ion, Fe2+. Also called BIVALENT.

GREENSAND
GREENSAND
A sand which looks like ordinary filter sand except that it is green in color. The sand is a natural ion exchange material which is
capable of softening water and removing iron and manganese.

INSOLUBLE (in-SAWL-you-bull)
INSOLUBLE
Something that cannot be dissolved.

ION EXCHANGE
ION EXCHANGE
A water treatment process involving the reversible interchange (switching) of ions between the water being treated and the
solid resin. Undesirable ions in the water are switched with acceptable ions on the resin.

ION EXCHANGE RESINS
ION EXCHANGE RESINS
Insoluble polymers, used in water treatment, that are capable of exchanging (switching or giving) acceptable cations or anions
to the water being treated for less desirable ions.

.
12

RESINS

See ION EXCHANGE RESINS.

SEQUESTRATION (SEE-kwes-TRAY-shun)

Iron and Manganese 5

RESINS

SEQUESTRATION

A chemical complexing (forming or joining together) of metallic cations (such zs iron) with certain inorganic compounds, such
as phosphate Sequestration prevents the precipitation of the metals (iron). Also see CHELATION.

ZEOLITE
ZEOLITE

A type of ion exchange -naterial used to soften water. Natui at zeolites are siliceous compounds (made of silica) which remove
calcw
and m-.gnesiul.,
m hard water and replace them with sodium. Synthetic or organic zeolites are ion exchange materi-

als %
,
.-crnc.r.'s calc: JIT1 or magnesium and replace them with either sodium or hydrogen. Manganese zeolites are used to re-
move .cmganese.

6
Plant Operatior

CHAPTER 12.
IRON AND MANGANESE CONTROL

12.0 NEED TO CONTROL IRON AND MANGANESE

Like the cities of Minneapolis and St. Paul, iron and
manganese are referred to as a pair. They are, in fact, two
distinct elements and are often found in water separately
Neither of them has any direct adverse health effects.
Indeed, both are essential to the growth of many plants and
animals, including humans.

However, the iron and manganese found in drinking water
have no nutrient value for humans. Even if they were
available in beneficial amounts, the presence of iron and
manganese in drinking water would still be objectionable.

Clothes laundered in water containing iron and manga-
nese above certain levels come out stained. When bleach is
added to remove the stains, they are only intensified and
become fixed so that no amount of further washing with
iron-free water will remove the stains. They can be removed
by treatment with oxalic acid, but this is rather hard on
fabrics or by the use of commercial rust removers. Exces-
sive amounts of iron and manganese are also objectionable
because they impart stains on plumbing fixtures, bath tubs
and sinks.

Perhaps the most troublesome consequence of iron and
manganese in the water is that they promote the growth of a
group of microorganisms known as iron bacteria. These
organisms obtain energy for their growth from the chemical
reaction that spontaneously occurs between iron and man-
ganese and dissolved oxygen. These bacteria form thick
slimes on the walls of the distribution system mains. Such
slimes are rust colored from iron and black from manga-
nese. Variations in flow cause these slimes to come loose
which result in dirty water (a big source of consumer
complaints). Furthermore, these slimes will cause foul tastes
and odors in the water.

The growth of iron bacteria is controlled by chlorination
However, when water containir., ron is chlorinated, the iron
is converted into rust particles, and manganese is converted

'lel' Ola
'-.

14\°F.I.n9r

into a jet black compound called manganese dioxide These
materials form a loosely adherent coating on the pipe walls.
pieces of this coating will break loose from the pipe walls
when there are changes or reversals of flow in the distribu-
tion system.

'roil and manganese in water can be easily detected by
observing the color of the inside walls of filters and the filter
media If the raw water is prechlorinated, there will be black
stains on the walls below the water level and a black coating
over the top portion of the sand filter bed. This black colnr
will usually indicate a high level of manganese in the raw
water while a brownish-black stain indicates the presence of
both iron and manganese.

The generally acceptable limit for iron in drinking water is
0.3 mg/L and that for manganese is P n5 mg/L. However, if
the water contains more than 0.02 mg/ of manganese, the
operator should
. vitiate an effective flushing program to
avoid complaints. By regularly flushing the water mains, the
buildup of black manganese dioxide can be prevented.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 22.

12 OA What problems are caused by iron an
manganese in
drinking water9

12 OB How can the growth of iron bacteria be controlled'?

12.0C What are the generally acceptable limits for iron and
manganese in winking water9

12.1
MEASUREMENT OF IRON AND MANGANESE

12.10
Occurrence of Iron and Manganese

Because both .ron and manganese react with dissolved
oxygen to form INSOLUBLE COMPOUNDS,' they are not
found in high concentrations in waters containing dissolved
oxygen except as COLLOIDAL SUSPENSIONS2 of the
oxides. Accordingly, surface waters are generally free from
both iron and manganes6. One exception to this rule is that
manganese up to one mg/L or higher may be found in
shallow reservoirs and may come and go several times a
year.

1 Insoluble Compounds (in-SAWL-you-bull).
Compounds that cannot be dissolved.
2 Colloidal Suspensions (CALL-loid-al)
Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid
for a long time due to their small size and electrical charge. When most of the particles in water have a negative electrical charge, they
tend to repel each other This repulsion prevents the particles from clumping together, becoming heavier, and settling out.
14

Iron or manganese is most frequently found in water
systems supplied by wells and springs. Horizontal wells
under rivers are notoriously prone to produce water contain-
ing iron, Bacteria will reduce iron oxides in soil to the
soluble, DIVALENT3 form of Ton (Fe2+) which will produce
groundwater with a high iron content.

Iron bacteria can make use of the ferrous ion (Fe2'). These
bacteria will oxidize the iron and use the energy for reducing
carbon dioxide to organic forms (s:.mes). The manganous
ion (Mn2') is used in a similar fashion by certain bacteria.
Very small concentrations of iron and manganese in water
can cause problems, because bacteria obtain the nutrients
(iron and manganese) from water in order to grow even
when the concentrations are very low.

Iron bacteria are found nearly everywhere. They are
frequently found in iron water pipes and everywhere else
that a combination of dissolved oxygen and dissolved iron is
usually or frequently present. Only one cell of iron bacteria is
needed to start an infestation of iron bacteria in a well or a
distribution system. Unfortunately it is almost impossible to
drill a well and maintain sterile conditions to prevent the
introduction of iron bacteria.

12.11
Collection of Iron and Manoanese Samples

The best way to determine if there is an iron and manga-
nese problem in a water supply is to look at the plumbing
fixtures in a couple of houses. If the fixtures are stained,
then there is a problem. Determination of the concentrations
of iron and manganese in water is useful when evaluating
well waters for use and treated waters for effectiveness of
treatment processes.

The results of tests for iron and manganese are wrong
more often than they are right. This is because samples for
these substances are difficult to collect. Both iron and
manganese form loosely adherent (not firmly attached)
scales on pipe walls, including the sample lines. When the
sample tap is opened, particles of scale may be dislodged
and enter the sample bottle. If many of these particles enter
the sample bottle, the error can b "me very large. Further-
more, unless the sample is acidnied (enough nitric acid
added to drop the pH to less than 2), both iron and
manganese tend to form an adherent scale on the walls of
the sample bottle in the few days that sometimes elapse
before the analysis is started. When the sample is poured
from the bottle for testing, most of the iiron and manganese
will then remain inside the sample bottle.

To avoid this situation, samples should be taken from a
plastic sample line located as close to the well or other
source as possible. Open the sampling tap slowly so that the

iron and Manganese
7

flow rate is su:table for filling the sample bottle. Allow the
sample water to flew for at least one minute for each 10 feet
(3 m) of sample line before the sample is collected.

Samples for iron and manganese should be tested within
48 hours unless they have been acidified. If the sample
contains any clay or if any particles of rust .ire picked up
from a steel pipe or fitting, an acidified sampl will dissolve
the iron in these substances and the results will be too high
If clay or rust particles are observed in a sample, do not
acidify and request lab to analyze sample immediately
Furthermore, many laboratories fail to be sure that iron and
manganese are in the divalent form (Fe2+ or Mn2') by adding
enough nitric acid prior to the tests to lower the pH to less
than two, so laboratory errors may be even greater than
sampling errors.

12.12
Analysis for Iron and Manganese

The preferred method of testing for iron and manganese is
atomic absorption, but for the small plant the equipment is
too expensive. With careful attention to laboratory proce-

dures, colc metric methods (comparing colors of unknowns
with known standards) can provide sufficient accuracy in
most instances. These colorimetric methods use either a
spectrophotometer, a filter photometer, or the less satisfac-
tory set of matched Nesslei tubes with standards. Good
results have been obtained by the use of properly calibrated
colorimeters (Figure 12.1). For detailed procedures on how
to use a spectrophotometer to measure iron and manga-
nese, see Chapter 21, "Advanced Laboratory Procedures."

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 22.

12.1A How do iron and manganese form insoluble com-
pounds?

12.1B Why must iron and manganese samples be acidified
when they are collected?

12.1C Where sh^uld a sample for iron and manganese
testing Ix
ollected?

3 Divalent (die-VAV-lent).
Having a valence of two, such as the ferrous ion, Fe2+. Also called BIVALENT.

15

8
Plant Operation

,......
,-,11, St14.10,1r

L-
A

HI
LO

PANEL ALARM
(optional)

RECORDER
CONROLL ER
(oplional)
(optional)

POWER

ANALYZER

FLOW METER/
CONTROL VALVE
(rocommandod)

DRAIN

STRAINER
(optional)

RECOMMENDED
(furnished by customer)

SHUT.OFF
VALVE

ALTERNATE
WATER
SUPPLY

SSTAMEPAMLE
R

TYPICAL INSTALLATION

Fig. 12.1
Typical continuous on-line pump - colorimeter analyzer
for iron, manganese or permanganate

(Permission of Hach)

16