EPA/600/R-1 5/045 | February 2015 | www2.epa.gov/water-research
United States
Environmental Protection
Agency
Water Treatment Pilot Plant Design Manual:
Low Flow Conventional/Direct Filtration Water Treatment
Plant for Drinking Water Treatment Studies
I
Office of Research and Development
Water Supply and Water Resources Division
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EPA/600/R-15/045
February 2015
Water Treatment Pilot Plant Design Manual:
Low Flow Conventional/Direct Filtration Water
Treatment Plant for Drinking Water Treatment Studies
Prepared by:
Darren A. Lytle, Kim Fox, Richard Miltner, Thomas F. Speth, Michael R. Schock,
Michelle L. Latham, Hiba Ernst, Nicholas Dugan, Christy Muhlen, and Dan Williams
U.S. Environmental Protection Agency
Office of Research and Development
National Risk Management Research Laboratory
Water Supply and Water Resources Division
Cincinnati, Ohio 45268
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Disclaimer
The information in this document was funded by the United States Environmental Protection Agency
(EPA). It has been subject to the Agency's peer and administration review, and it has been approved
for publication as an EPA document. Mention of trade names or commercial products are for
informational purposes only and does not constitute endorsement or recommendation for use.
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
Nation's land, air, and water resources. Under a mandate of national environmental laws, EPA is
tasked with formulating and implementing actions leading to a compatible balance between human
activities and the ability of natural systems to support and nurture life. To meet this mandate, EPA's
research program is providing data and technical support for solving environmental problems today
and building a science knowledge base necessary to manage our ecological resources wisely,
understand how pollutants affect our health, and prevent or reduce environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center for
investigation of technological and management approaches for preventing and reducing risks from
pollution that threaten human health and the environment. The focus of NRMRL's research program
is on methods and their cost-effectiveness for prevention and control of pollution to air, land, water,
and subsurface resources; protection of water quality in public water systems; remediation of
contaminated sites, sediments, and ground water; prevention and control of indoor air pollution; and
restoration of ecosystems. NRMRL collaborates with both public and private sector partners to foster
technologies that reduce the cost of compliance and to anticipate emerging problems. NRMRL's
research provides solutions to environmental problems by: developing and promoting technologies
that protect and improve the environment; advancing scientific and engineering information to
support regulatory and policy decisions; and providing the technical support and information transfer
to ensure implementation of environmental regulations and strategies at the national, state, and
community levels.
Cynthia Sonich-Mullin, Director
National Risk Management Research Laboratory
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Abstract
Pilot plant systems are generally designed to reflect conditions of a particular full-scale system for the
purpose of studying the impact of drinking water treatment changes, effectiveness for the removal of
contaminants and the addition of new unit processes and practices. Pilot testing potential mitigation
strategies is a recommended procedure to research optimal water quality treatment variables and
avoid implementing a strategy that may not work for unforeseen reasons. This document is a
comprehensive design manual that summarizes the activities and experiences of an EPA research
team which was assembled to address Cryptosporidium contamination of drinking water, as well as
other research needs. All of the team members had significant experience with filtration studies or in
designing, fabricating, or operating pilot plant systems. The team concluded that the best, most
meaningful way to conduct the needed research was to design, build, and operate a 'mini pilot plant.'
The team designed and constructed a prototype 450 milliliter per minute conventional flocculation,
sedimentation, and filtration facility. Final design specifications of individual processes were
summarized and compared to other pilot- and full-scale systems. While originally designed for
Cryptosporidium research, the system was built to allow relatively simple, fast, and inexpensive
modifications for other studies.
in
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Acronyms and Abbreviations
p density
[j, dynamic viscosity
v kinematic viscosity
alum aluminum sulfate
As(III) arsenite
AWBERC Andrew W. Breidenbach Environmental Research Center
BSC biohazard safety cabinet
CSTR continuous-flow stirred tank reactor
CT contact time
d diameter
DOC dissolved organic carbon
EBCT empty bed contact time
EFL
EPA Environmental Protection Agency
ESWTR Enhanced Surface Water Treatment Rule
Fe(II) ferrous iron
G velocity gradient
H height
KCL potassium chloride
LR loading rate
NRMRL National Risk Management Research Laboratory
ORD Office of Research and Development
P power
PMAA polymethyl methacrylate
PTFE polytetrafluoroethylene
Q flow rate
r
SLR surface loading rate
t retention time
TTEB Treatment Technology Evaluation Branch
TOC total organic carbon
V volume
v inlet velocity
W width
WSWRD Water Supply and Water Resources Division
IV
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Units of Measure
yo
cm
ft
ft2
gal
gpm
gpm/ft2
H
hp
in
L
L/min
Ib
m/hr
min
mL
mL/min
mm
oocysts/mL
oocysts/min
rpm
sec
um
degree
percent
centimeter
foot/feet
square feet
gallons/gallons
gallons per day
gallon per minute
gallons per minute per square foot
height
horsepower
inch/inches
liter
liters/minute
pound
meters per hour
minutes
milliliter
milliliters per minute
millimeter
oocysts per milliliter
oocysts per minute
revolutions per minute
seconds
micrometer
v
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DISCLAIMER i
FOREWORD ii
ABSTRACT iii
ACRONYMS AND ABBREVIATIONS iv
UNITS OF MEASURE v
TABLE OF CONTENTS vi
LIST OF TABLES vii
LIST OF FIGURES viii
CHAPTER 1 - INTRODUCTION 1-1
1.1 BACKGROUND 1-1
1.2 HIGHLIGHTS 1-1
1.3 INITIAL PATHOGEN STUDIES 1-2
CHAPTER 2 - SAFETY CONSIDERATIONS 2-1
CHAPTER 3 - MATERIALS 3-1
CHAPTER 4 - PILOT PLANT DESIGN PRINCIPLES 4-1
4.1 DESIGN CONSIDERATIONS 4-1
4.1.1 System Specifications 4-2
4.1.2 Raw Water Storage 4-2
4.1.3 Flow Rate Calculations 4-3
4.1.4 Mixing 4-4
4.1.5 Flocculation 4-7
4.1.6 Sedimentation 4-8
4.1.7 Filtration 4-11
4.1.8 Clearwell (Backwash Water Storage Reservoirs) 4-14
4.2 PROCESS CONSIDERATIONS 4-15
4.2.1 Flow Control 4-15
4.2.2 Sludge Removal 4-15
4.3.3 Coagulant and Feed Systems 4-15
CHAPTER 5 - OPERATION 5-1
CHAPTER 6 - DATA COLLECTION 6-1
vi
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CHAPTER 7 - PROTOTYPE PILOT PLANT SYSTEM 7-1
7.1 PURPOSE 7-1
7.2 PRELIMINARY TESTS 7-1
7.3 TRACER STUDIES 7-2
7.4 BEAD STUDIES 7-4
CHAPTER 8 - SYSTEM MODIFICATIONS 8-1
8.1 EASE AND FLEXIBILITY 8-1
8.2 ARSENIC AND IRON REMOVAL STUDIES 8-1
8.3 OZONATION STUDIES 8-3
CHAPTER 9-REFERENCES 9-1
APPENDIX A: TABLES A-l
APPENDIX B: FIGURES B-l
APPENDIX C: CALCULATIONS & WORKSHEETS C-l
APPENDIX D: ANALYSIS RESULTS D-l
Table 1. Results of polymethyl methacrylate (PMMA) leaching study 3-1
Table 2. Theoretical oocyst concentrations at maximum design flow 4-4
Table 3. Performance comparison data between 1.5-inch (in) and 6-in filters' ability to remove
organic contaminants 4-12
Table 4. Filter media properties 4-12
Table 5. Proposed sample types and sites 6-1
Table Al. Pilot plant coagulation design summary and comparisons A-l
Table A2. Pilot plant flocculation design summary and comparisons A-2
Table A3. Summary of sedimentation basin design A-3
Table A4. Pilot plants filter design summary and comparisons A-4
Table A5. Jar test and pilot plant operating variables A-5
Table A6. Average raw Ohio River water quality during pilot plant evaluation runs A-5
Table A7. Monitoring log and checklist used during Test Run 3 A-6
Table A8. Average percent and log reductions for Test Run 3 A-7
Table A9. Water quality parameters for mini pilot plant 83-hour test run A-7
Table A10. Water quality parameters for mini pilot plant 59-hour test run A-8
Table All. Average log reductions during 83-hour test run A-9
Table A12. Average log reductions during 59-hour test run A-10
vii
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Table Cl. Rapid mix chamber calculations for paddle radius of 1.2-inches (in) and depth of 0.9-in. It
is assumed that each base is square with a flow rate of 450 mL/min C-l
Table C2. Rapid mix chamber calculations for paddle radius of 1.1-inches (in) and depth of 1.3-in. It
is assumed that each base is square with a flow rate of 450 mL/min C-2
Table C3. Rapid mix chamber calculations for paddle radius of 1.0-inch (in) and depth of 1.9-in. It is
assumed that each base is square with a flow rate of 450 mL/min C-3
Table C4. Flocculation calculations for paddle radius of 2-inches (in) and depth of 3-in. Assumptions:
(1) four flow basins, (2) each base is square, and (3) the flow rate = 450 mL/min C-4
Table C5. Flocculation calculations for paddle radius of 2.5-inches (in) and depth of 1.5 in.
Assumptions: (1) four flow basins, (2) each base is square, and (3) the flow rate = 450 mL/min.... C-5
Table C6. Flocculation calculations for paddle radius of 3-inches (in) and depth of 0.75-in.
Assumptions: (1) four flow basins, (2) each base is square, and (3) the flow rate = 450 mL/min.... C-6
Table C7. Sedimentation calculation worksheet C-7
Table C8. Sedimentation basin design worksheet C-8
Table C9. Filter design parameters C-8
Table CIO. Combined overflow for various filter configurations C-9
Table Cll. Clearwell design worksheet C-10
Figure 1. The effect of changing the point of oxidant application on removal efficiency 8-2
Figure 2. The effect of changing the point of oxidant application on removal efficiency 8-4
Figure Bl. Rapid mix chamber dimensions constructed of H-inch polymethyl methacrylate (PMMA).
B-l
Figure B2. Mixing paddle options/alternatives constructed of stainless steel B-2
Figure B3. Rapid mixing chamber with influent and alum feed lines B-3
Figure B4a. Flocculation basin dimensions constructed of H-inch polymethyl methacrylate (PMMA).
B-4
Figure B4b. Flocculation baffle dimensions (constructed of Vi—in polymethyl methacrylate) B-5
Figure B4c. Flocculation chambers (side view) B-6
Figure B4d. Flocculation chambers (top view) B-6
Figure B5c. Sedimentation basin showing sludge accumulation after a 72-hr run B-9
Figure B6a. Filter base design details (not drawn to scale) B-10
Figure B6b. Filter design and media configuration B-ll
Figure B6c. Detail of filter top including filter splitter tube (not to scale) B-l2
Figure B6d. Full view of filter setup B-13
Figure B6e. Filter distribution network showing sample ports for settled water and filtrate B-14
Figure B6f Filter pump system and backwash pumps B-l5
Figure B7a. Water flow direction and filter configuration when in normal operation B-l6
viii
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Figure B7b. Water flow direction and filter configuration when in backwash mode B-17
Figure B8a. Filtrate clearwells showing lines leading to waste and to backwash B-18
Figure B8b. Schematic of future clearwell (not to scale) B-19
Figure B9. Raw water and alum feed systems for Cryptosporidiumparvum oocyst B-20
Figure BIO. Pilot plant Test Run 1 with Ohio River water treated by alum coagulation. Raw water
temperature was 18.1-18.9°C, and settled water temperature was 18.8-19.2°C B-21
Figure Bl 1. Pilot plant test run 2 with Ohio River water treated by alum coagulation. Raw water
temperature was 19.4-20.0°C, and settled water temperature was 18.8-21.3°C B-22
Figure B12. Temperature variation during pilot plant Test Run 3 with Ohio River water treated by
alum coagulation B-23
Figure B13. pH variation during pilot plant Test Run 3 with Ohio River water treated by alum
coagulation 24
Figure B14. Turbidity variations during pilot plant Test Run 3 with Ohio River water treated by alum
coagulation B-25
Figure B15. Three to six-micrometer (um) particle variation during pilot plant Test Run 3 with Ohio
River water treated by alum coagulation B-26
Figure B16. Total particle variation during pilot plant Test Run 3 with Ohio River water treated by
alum coagulation B-27
Figure B17. Impact of potassium chloride (KCL) on total dissolved solids (TDS) concentration of
Ohio River water B-28
Figure B18. Prototype mini pilot plant rising step tracer test results B-29
Figure B19. Prototype mini pilot plant rising step tracer results for rapid mix and flocculation
processes (CS/CS,0 = normalized tracer concentration) B-30
Figure B20. Prototype mini pilot plant rising step tracer results for rapid mix, flocculation, and
sedimentation processes (CS/CS,0 = normalized tracer concentration) B-31
Figure B21. Normalized time vs. normalized concentration of Filter #2 B-32
Figure B22. Normalized time vs. normalized concentration of Filter #3 B-33
Figure B23. Pulse input tracer study results and theoretical CSTRs B-34
Figure B24. Pulse input tracer study results following flocculation unit modifications B-35
Figure B25. Log removal comparisons (83-hour run) B-36
Figure B26. Log removal comparisons (59-hour run) B-37
Figure B27. Turbidity values at locations in the pilot plant during 83-hour test run B-38
Figure B28. Turbidity values at locations in the pilot plant during 59-hour test run B-39
Figure Cl. Calculated velocity gradient for four rapid mix paddles having all three radii and depth
sizes as identified in Tables Cl through C3 C-ll
Figure C2. Calculated velocity gradient for four flocculation mix paddles having all three radii and
depth sizes identified in Table C4 through C6 C-12
Figure Dl. Particle size distribution of anthracite filter media D-l
Figure D2. Particle size distribution of fine sand filter media D-2
Figure D3. Particle size distribution of coarse sand filter media D-3
ix
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Water Treatment Pilot Plant Design Manual Chapter 1 - Introduction
Chapter 1 - Introduction
• ' .;„,:•••.„-.-•.:id
Pilot plant systems are generally designed to reflect conditions of a particular full-scale system for the
purpose of studying the impact of drinking water treatment changes, effectiveness for the removal of
contaminants and the addition of new unit processes and practices. Pilot testing potential mitigation
strategies is a recommended procedure to research optimal water quality treatment variables and avoid
implementing a strategy that may not work for unforeseen reasons. This document is a comprehensive
design manual that summarizes the activities and experiences of a research team, consisting of
engineers, scientists, and technicians from the U.S. Environmental Protection Agency's (EPA) Office
of Research and Development, which was assembled to address Cryptosporidium contamination of
drinking water, as well as other research needs in the mid-1990s. All of the team members had
significant experience with filtration studies or in designing, fabricating, or operating pilot plant
systems. The team concluded that the best, most meaningful way to conduct the needed research was
to design, build, and operate a 'mini pilot plant.'
The team designed and constructed a prototype 450 milliliter per minute (mL/min) conventional
flocculation, sedimentation, and filtration pilot plant at EPA's Andrew W. Breidenbach Environmental
Research Center (AWBERC) in Cincinnati, Ohio. A series of shakedown tests, tracer studies, and
preliminary experimental runs were conducted to hydraulically characterize the system, identify
operational problems, and evaluate treatment performance. Several modifications to the prototype
plant's design were made to remedy problems identified during the shakedown period. Final design
specifications of individual processes were summarized and compared to other pilot plants and full-
scale systems (Tables Al to A4, Appendix A).
This manual highlights the project constraints and concerns, and includes detailed design calculations
and system schematics. The plant is based on engineering design principles and practices, previous
pilot plant design experiences, and professional experiences and may serve as design guide for similar
scale systems.
While originally designed for Cryptosporidium research, the system was built to allow relatively
simple, fast, and inexpensive modifications for other studies. The initial system design was guided by
1-1
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Water Treatment Pilot Plant Design Manual Chapter 1 - Introduction
the flow rate, an important design restriction to achieve the desired concentration of micro-organisms
for a given period of time. The plant was designed for ease of use and to minimize number of staff
required for operation, reduce water needs, and to create a flexible, modular design that can be
modified to meet the system requirements for various future experimental needs, including arsenic
removal studies, iron removal studies, etc.
1-3
Although this pilot plant was initially designed to conduct pathogen studies, specifically the removal of
Cryptosporidium oocysts from drinking water, the design principles established for pathogen studies
can be modified to perform other water quality studies. The need to study the removal of
Cryptosporidium oocysts from drinking water is driven by a number of waterborne cryptosporidiosis
outbreaks(1"5), including the United States' largest outbreak in the City of Milwaukee during the spring
of 1993^6' 7\ Due to the widespread publicity and concern over these events, the water industry and
water utilities reexamined their treatment practices. In response, research was being conducted to study
the removal of Cryptosporidium oocysts from drinking water under various conditions and to explore
the use of surrogate parameters (i.e., particle counts, aerobic bacterial endospores, etc.) for monitoring
the effectiveness of treatment processes and fine-tuning treatment conditions.
When this project began, EPA was developing the Enhanced Surface Water Treatment Rule (ESWTR),
which established a regulatory limit for Cryptosporidium oocysts in drinking water. The information
gained from the research studies involved in this project may have, in part, supported the development
of the regulation. Specifically, the experimental studies that provided useful information for
developing log removal credit guidance for various filtration scenarios (e.g., coagulant type, filter
media, etc.) under the ESWTR and establishing achievable Cryptosporidium oocyst removal
boundaries. Filtration studies were also useful in identifying surrogate parameters for evaluating
overall treatment performance, and identifying correlations between turbidity, surrogate parameters,
and Cryptosporidium oocyst removal. The impact of plant operational practices (e.g., filter loading
rate, filter backwashing protocol, etc.) on oocyst levels and water quality were also evaluated. Finally,
the studies were useful in determining whether the physical rigors of a water treatment plant damages
the outer walls of oocysts, consequently rendering them more susceptible to disinfection.
Every pilot-scale research study that has evaluated the removal of Cryptosporidium oocysts from
drinking water, including those conducted at AWBERC, has been conducted by spiking
Cryptosporidium oocysts into the source water over a relatively brief time frame (minutes to hours).
"Slug-spiking" is practiced because of constraints imposed by the amount of Cryptosporidium oocysts
available and by flow conditions of the plant. This method, however, is not representative of the true
environmental conditions under which a water treatment plant operates. In addition, experimental
sampling through the treatment process to precisely catch the spike peak is difficult to accomplish.
1-2
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Water Treatment Pilot Plant Design Manual Chapter 1 - Introduction
This difficulty is exacerbated because a ceiling is usually placed on the number of samples that can be
taken during a test run. Another problem is the frequent inability to calculate statistically significant
log removals of oocysts due to filtered water oocyst levels below the detection limit. As a result, log
removal data is frequently reported as a "greater-than" value based on some detection limit threshold.
To avoid such problems, high concentrations of oocysts must reach the filter to increase the chance
that measurable amounts will be present in the filter effluent.
A number of jar tests and pilot plant runs were conducted by the research team using Cryptosporidium
parvum oocysts. The effects of a number of initial water quality conditions and coagulant types and
dosages on the removal of the protozoan were examined. The general conclusion that can be drawn
from all of the data collected, thus far, is that Cryptosporidium oocyst removal paralleled the removal
of particles, turbidity, and aerobic bacterial endospores. Typically, when optimum removal of these
parameters was achieved, optimal removal of Cryptosporidium oocysts was coincidently observed.
1-3
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Water Treatment Pilot Plant Design Manual Chapter 2 - Safety Considerations
Chapter 2 - Safety Considerations
Safety issues should be incorporated into the planning process of any pilot plant study/experiment.
These plans should include a description of procedures and equipment required to handle the
equipment, chemicals, pathogens, etc. used for experiments. Safety and precision in a laboratory
setting is critical not only for the health and wellness of the researchers, technicians, and operators, but
it is also critical to the accuracy and validity of the study and data results. The biosafety practices
outlined here are by no means exhaustive or all encompassing; they are meant to indicate standard best
practices and necessary considerations when dealing with potentially harmful or toxic materials. The
excerpts below come from the Center for Disease Control's Biosafety Level 2 resource, Biosafety in
Microbiological and Biomedical Laboratories, 5th Edition ^:
Biosafety Level 2 practices, equipment, and facility design and construction are applicable to clinical,
diagnostic, teaching, and other laboratories in which work is done with the broad spectrum of
indigenous moderate-risk agents that are present in the community and associated with human disease
of varying severity. With good microbiological techniques, these agents can be used safely in activities
conducted on the open bench, provided that the potential for producing splashes and aerosols is low.
Primary hazards to personnel working with these agents relate to accidental percutaneous or mucous
membrane exposures, or ingestion of infectious materials. Extreme caution should be taken with
contaminated needles or sharp instruments. Even though organisms routinely manipulated at BSL-2
are not known to be transmissible by the aerosol route, procedures with aerosol or high splash potential
that may increase the risk of such personnel exposure must be conducted in primary containment
equipment, or in devices such as biological safety cabinets or safety centrifuge cups.
Personal protective equipment should be used as appropriate, such as splash shields, face protection,
gowns, and gloves. Secondary barriers, such as hand washing sinks and waste decontamination
facilities, must be available to reduce potential environmental contamination.
Standard Microbiological Practices
• Access to the laboratory is limited or restricted by the laboratory director when work with
infectious agents is in progress.
• Work surfaces are decontaminated at least once a day and after any spill of viable material.
• All infectious liquid or solid wastes are decontaminated before disposal.
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Water Treatment Pilot Plant Design Manual Chapter 2 - Safety Considerations
• Mechanical pipetting devices are used; mouth pipetting is prohibited.
• Eating, drinking, smoking, and applying cosmetics are not permitted in the work area. Food
may be stored in cabinets or refrigerators designated and used for this purpose.
• Persons wash their hands after handling infectious materials and animals when they leave
the laboratory.
• All procedures are performed carefully to minimize the creation of aerosols.
Special Practices
• Contaminated materials that are to be decontaminated at a site away from the laboratory are
placed in a durable leak-proof container which is closed before removal from the laboratory.
• The laboratory director/operator limits access to the laboratory in general. Persons who are
at increased risk of acquiring infection or for whom infection may be unusually hazardous
are not allowed in the laboratory or animal rooms. The director/operator has the final
responsibility for assessing each circumstance and determining who may enter or work in
the laboratory.
• The laboratory director establishes policies and procedures whereby only persons who have
been advised of the potential hazard and meet specific entry requirements (e.g.,
immunization) enter the laboratory or animal rooms.
• When the infectious agent in use in the laboratory requires special provisions for entry (e.g.,
vaccination), a hazard warning sign, incorporating the universal biohazard symbol is posted
on the access door to the laboratory work area. The hazard warning sign identifies the
infectious agent, lists the name and telephone number of the laboratory director or other
responsible person(s), and indicates the special requirement(s) for entering the laboratory.
• An insect and rodent control program is in effect.
• Laboratory coats, gowns, smocks, or uniforms are worn while in the laboratory. Before
leaving the laboratory for non-laboratory areas (e.g., cafeteria, library, administrative
offices), this protective clothing is removed and left in the laboratory or covered with a clean
coat not used in the laboratory.
• Animals not involved in the work being performed are not permitted in the laboratory.
• Special care is taken to avoid skin contamination with infectious materials; gloves should be
worn when handling infected animals and when skin contact with infectious materials is
unavoidable.
• All wastes from laboratories and animal rooms are appropriately decontaminated before
disposal.
2-2
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Water Treatment Pilot Plant Design Manual
Chapter 3 -Materials
Chapter 3 - Materials
When considering the property of the material used to build the rapid mix, flocculation, and
sedimentation chambers, the most important was the material's inertness, especially with respect to
organic leaching. Although it was not a necessary component, a clear material was used to obtain a
visual observation and description of what occurs in the chambers. Glass is difficult to work with in
terms of construction and breakability; thus, polymethyl methacrylate (PMMA)1 is recommended. The
major concern associated with the use of PMMA is the potential release of organics from the joint
cement or binding material.
PMMA, H-inch (in) thickness, was constructed into a square container with 1-foot (ft) long sides. A
bonding agent consisting of methylene chloride, methyl methacrylate monomer, and trichloroethylene
was used. A leaching study was done to determine the extent to which the binding agent contributes
contaminants to the water, and if continuous water flow would rinse away any residue. The container
was filled with deionized water2 (before being rinsed or cleaned in any manner) and allowed to sit
stagnant for seven days. After seven days, the water was analyzed for methylene chloride and
trichloroethane; the container was allowed to air dry for nearly two days, after which the container was
again filled with deionized water3 and allowed to sit for six days before analysis began. And, finally,
the water was allowed to continually flow into the container at a rate of approximately 100 ml/min
periodically over a two-week time frame, and was sampled twice during that time (Table 1).
Table 1. Results of polymethyl methacrylate (PMMA) leaching study.
10-3-1996
10-9-1996
10-18-1996
10-21-1996
Description
batch
batch
flow
flow
Duration Methylene chloride
(days) (ug/L)
7 standing 2524
6 standing 138
16 flowing <0.1
18 flowing <0.1
Trichloroethene
27
2.7
<0.1
<0.1
Hg/L = micrograms/liter
1 PMMA is also known as acrylic glass or by the name brand Plexiglas8
2 NANOpure® deionized water was used.
NANOpure® deionized water was used.
5-1
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Water Treatment Pilot Plant Design Manual Chapter 3 - Materials
The results of the leaching study clearly demonstrated that with little effort and time, any materials left
from the binding procedure can easily be removed. Therefore, these materials will not likely become a
source for contamination.
5-2
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
Chapter 4 - Pilot Plant Design Principles
Jo:;;,.-,,, " '•
Using accepted engineering practice, the processes in the following sections have been designed to
reflect hydraulic conditions and treatment effectiveness of the 1.6-gallons per minute (gpm), or 6056-
mL/min, organics control pilot plant (-9~11-). Two identical parallel mini pilot plants were built and each
treatment train consisted of coagulation, flocculation, and sedimentation processes followed by
filtration. The sections to follow outline the governing design considerations and the final design of
each system component. While the design considerations were specific to the initial needs of the
pathogen study, system modifications can be easily made to support other water quality studies (See
Chapter 8 - System Modifications).
The design of the pilot plant for studies to evaluate Cryptosporidium oocyst removal was primarily
governed by two restrictions: Cryptosporidium oocyst availability and flow rate. First, the number of
oocysts available for the studies had to be identified by the microbiological support staff. Second, a
desirable flow rate had to be calculated to produce necessary raw water oocyst concentrations that
would meet the project objectives.
The quantity of Cryptosporidium parvum oocysts available for pilot studies was limited by staff
availability. The oocysts were harvested in mice within AWBERC by EPA microbiologists and were
available for use by the research team. The oocyst production rate for this project was identified as
approximately 1 x 109 oocysts/week.
Accurately observing large reductions of Cryptosporidium oocysts in any setting (i.e., full-scale, pilot
plant, etc.) requires that large numbers of oocysts be measured in the influent water while maintaining
measurable levels in the effluent stream. Filtration studies using the existing 1.5-gpm (5678 mL/min)
conventional/direct filtration pilot plant would have required enormous numbers of oocysts illustrated
by the following example:
If a 3-log (99.9%) oocyst reduction through the pilot plant is expected, and measurable amounts
of oocysts are seen in the effluent stream, then the raw water must be spiked with at least 1,000
oocysts/milliliter (oocysts/mL) and the filter effluent must contain at least one measured
oocyst/mL. Therefore, oocysts must be spiked into the raw water at a rate of 5.68 x 106
oocysts/minute (oocysts/min). In only three hours, the entire weekly limit of 1.0 x 109 oocysts
would be used.
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
This example is an ideal case scenario. In reality, analytical limitations and unexplained losses of
oocysts throughout the treatment plant must be considered, after requiring an increase in the number of
oocysts needed. Research was conducted by the EPA team to define any losses.
Nearly all studies involving Cryptosporidium oocyst research based on short-term spiking or
'slugging' were primarily due to the resource constraints described above. In natural systems, however,
a treatment facility would be more likely challenged with oocysts over an extended period of time.
Therefore, a long spike period in a pilot setting would be more representative of field conditions with
respect to exposure duration. The number of oocysts available, the need to spike continuously over an
extended period, and the oocyst concentration required in the raw water made the current pilot plant
too large to meet the research needs. The only solution to the identified problems was to design a
smaller scale, low-flow, conventional filtration pilot plant.
4.1.1 System Specifications
The following limitations served as the primary pilot plant design parameters:
• Supply of 1 x 109 oocysts/week
• Raw water oocyst concentration 1,000 to 10,000 oocysts/mL
• Minimum 1.5-in filter diameter (As) to minimize wall effects
• Filter surface loading rate of 2 gpm per square foot (gpm/ft2)
• Design flow rate (Q) through the rapid mix chamber of 450 mL/min
• Retention time (t) in rapid mix chamber of 1.5 minutes (min)
4.1.2 Raw Water Storage
EPA has the ability to truck water in using its 5,300-gallon (gal), or 20,000-liter (L) tanker trailer. The
tanker trailer can be gravity drained using a series of 3-in diameter hoses to an existing 5,500-gal
(20,800 L) 304 stainless steel rectangular water storage tank. Water is continuously recirculated
through the tank by a 3/4 horsepower (hp) pump to reduce particle settling. In addition, a submersible
pump has been lowered into the tank to provide additional mixing.
Water from the storage reservoir is pumped up to a covered 100-gal, 304 stainless steel cylindrical
constant head tank. A series of 3/4-in diameter, 304 stainless steel pipes and valves and a 1/5 hp pump is
used to feed the tank. The tank is not intended to be used for pre-sedimentation or chemical feed. The
tank provides a constant volume of water with a constant head, from which raw water is pumped at a
regulated rate to downstream processes. The tank is continuously filled, and its level is maintained 16
inches above the pilot plant feed pump by a 1-in diameter, 304 stainless steel overflow line that
recirculates the water back to the 5,500-gal tank. A Vi-in diameter polytetrafluoroethylene (PTFE)4
line from a tee in the overflow line leads to a micro pump that feeds the pilot plant at a constant rate.
1 PTFE is commonly known by the name brand Teflon®.
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
To avoid a build-up of algae and sludge at the bottom of the tank, it is drained when the pilot plant is
not in operation.
4.1.3 Flow Rate Calculations
The flow rate (Q) through the system had to be adjusted so that the supply of Cryptosporidium parvum
oocysts (or other pathogens) could be continuously spiked into a raw water supply ahead of the plant
inlet for extended time periods (at least 24 hours). The concentration of oocysts in the influent water
needed to be high, and measurable numbers of oocysts needed to pass the filters in order to reliably
calculate 3 to 4-log removals. The following calculations are approximations for the prototype pilot
plant. Detailed calculations will be presented in the following sections. The surface area (As) of a 1.5-
in diameter (d) filter is
A =^£='[<'-5m/12'n/lft> =00122 fr
Q per each As based on an initial filter loading rate (LR) of 2 gpm/ft2, 4.9 meters per hour (m/hr), is
Q= LR = AS
= 2.0 gpm/ft2 = 0.0122 ft2 = 0.0244 gpm = 0.2642 liters/min. (L/min)/gpm = 0.092 L/min
= 92 mL/min
Rounding Q and adding a filter overflow (50 mL/min for design) to bring the design Q per filter of 150
mL/min. The pilot plant is designed to operate with up to three parallel filters, which result in a total
design Q of 450 mL/min.
The theoretical raw water oocyst concentration based on design flow must be determined to indicate
whether the primary design criteria can realistically be met:
. . T. total oocysts available
Concentration (oocysts/mL) =
450 mL/ min • spike duration (min)
This equation can be used to calculate the theoretical oocyst concentrations for a number of spiking
conditions as shown in Table 2.
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Water Treatment Pilot Plant Design Manual
Chapter 4 - Pilot Plant Design Principles
Table 2. Theoretical oocyst concentrations at maximum design flow.
Spike duration
(available oocysts/wk)
Raw water concentration
(oocysts/mL)
24 hr spike, 1 x 109oocysts
48 hr spike, 1 x 109oocysts
24 hr spike, 2 x 109 oocysts
48 hr spike, 2 x 109 oocysts
1543
772
3086
1544
Table 2 suggests that it may be possible to fall within the desirable raw water oocyst concentration
range under the maximum design flow rate. However, it must also be pointed out that Cryptosporidium
oocysts are known to be highly adhesive to many surfaces. Consequently, actual concentrations may be
significantly lower in practice than calculated estimates.
4.1.4 Mixing
The design Q through the rapid mix chamber and retention time (t) were predetermined to be 450
mL/min and 1.5 min, respectively, based upon recommended guidelines and reported design practice
(see section 4. 1). The retention time was based upon recommended guidelines (12> 13) and reported
design practice. Also, adequate retention time was needed to size a mixing chamber that could
accommodate a reasonably-sized mixer paddle. The mix chamber was square in shape and does not
contain baffles. These design parameters were used to size the rapid mix chamber:
V = Q. t = (450 mL/min) (1. 5 min) = 675 mL = 0.675
L
= Q.Q238 ft3 =41. 13 in3
Where,
V = volume of chamber
The dimensions of the chamber, assuming that the water height (H) is equal to 1.25 times the width
(W)13, are
V = (W) (W) (H) = 40.96 in3,
So,W = 3.2"andH = 4.0"
A 3.5-in freeboard was added to the design height for a total height of 7.5 inches. Figure Bl (Appendix
B) is a schematic of the rapid mix chamber. The water level was controlled by a Va-in, 304 stainless
steel overflow line connecting the rapid mix chamber to the flocculation chamber at the 4-inch water
height. This was accomplished by a %-inch PTFE bulkhead fitting and hose nozzle located as shown in
Figure Bl (Appendix B). The water travels through (1) a %-inch stainless steel tubing to a 90° elbow,
8-inch drop through %-inch tubing, (2) then through another 90° elbow to a short 3-inch run of %-inch
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
stainless steel tubing, (3) and then into the flocculation basin through a 3/4-in PTFE bulkhead fitting
(Figures B4a to B4d, Appendix B).
Paddle design was based on previous pilot plant design experiences and targeted to meet acceptable
values for the mean velocity gradient (G). The dimensions of the final paddle design allow for
reasonable clearance between paddle tip and chamber walls/water surface.
The mean velocity gradient, G (sec"1), was calculated as follows (^15-):
G =
where,
P = power, ft = pound/second (Ib/sec)
V = volume of water in rapid mix chamber, ft3
[i = dynamic (absolute) viscosity of water, Ib = seconds (sec)/ft2
p_Cd-A'P-^
2
where,
Cd= drag coefficient (unitless)
A = total cross sectional area of paddles, ft2
P = density of water, Ib = sec2/ft4
vp= velocity of paddles relative to water, ft/sec, = 0.75 = TC • r • n / 60, where
r = length of paddle blade (in ft)
n = revolutions per minute (rpm)
Therefore, based on design calculations, G can be calculated as a function of revolutions of the paddle
by substituting the following:
V = 0.0238 ft3
H = 1.90 x ID'5 lbf = sec/ft2 @ 75°F
Cd=1.2
p = 62.4 lbm/ft3 / 32.2 lbm= ft/sec2 = 1.938 Ib = sec2/ft4
vp= (0.75 • 2;i • r • [1712"] • n) / 60 = 0.006545 • r • n ft/sec
where,
lbf = pound-force
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
lbm = pound-mass
and, substituting into the equation of P,
P = 1.2 • A • (1.938 Ib = sec2/ft4) (0.006545 • r • n ft/sec)3 / 2
P = 2.264 x ID'9-A-^-n3
and, substituting in for G,
G = [2.264 x ID'9 • A • r3 • n3 / (0.0238 ft3) (1.90 x lO'5 lbf= sec/ft2)]'72
which simplifies to
G = 7.08 x 10-2 = (A)0-5 = (r3)0-5 = (n3)0-5
where,
A = total area of all paddles (in2)
r = paddle radius (in)
n = paddle speed (rpm).
The final equation is based on a temperature of 25°C, and conversions from feet to inches have been
incorporated.
The mixer paddles consist of two pairs of flat, rectangular blades located above one another and
rotated at right angles (Figure B2, Appendix B). The design was chosen because of previous design
experiences, ease of fabrication, and simplicity. Spreadsheet calculations of G for several potential
paddle blade sizes (1.0-in radius and 1.9-in depth, 1.1-in radius and 1.3-in depth, and 1.2-in radius and
0.9-in depth) and mixing speeds are included in Tables Cl to C3 (Appendix C). One option for the mix
paddle dimensions and blade positioning is shown in Figure B2 (Appendix B). The paddles are
fabricated from approximately 1.5 mm thick 316 stainless steel and welded to 1-foot long, H-inch
diameter, 304 stainless steel rods using 316 stainless steel welding. The ease of paddle fabrication and
low cost will easily permit all paddle sizes to be interchanged if necessary.
Figure Cl (Appendix C) shows the calculated G for the paddle designs and various mixing speeds at
25°C. Since all mixer blade dimensions produce nearly identical G values for a given mixer speed, the
1.1 x 1.3-in blades were initially incorporated into the construction of the pilot plant based upon their
ease of fabrication and ability to fit within the mixing chamber. The initial mixer speed was 100 rpm,
which translates to a G of 195 sec"1. This G value is below recommended values (-13'16\ as illustrated in
Table Al (Appendix A). However, the relatively long retention time should provide sufficient mixing.
Mixing speed should be adjusted if the proposed conditions are demonstrated to be insufficient.
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
A dual-shaft mixer with a remote speed controller (0 to 333 rpm) that resembles a blender was used.
The mixer motor was suspended above the chamber by a metal frame5 so the bottom blade was
suspended approximately one and one-half inches above the bottom of the chamber. The frame was
adjustable so that the blade depth may be raised or lowered.
Raw water and coagulant entered the mix chamber through V/t-in PTFE and Vg-in plastic tubing6,
respectively. The lines are held in place by channels (!/2-inch diameter tube cut vertically) fastened to
the corners of the mix chamber. The inlet levels are adjustable and the final water level was
experimentally determined. The coagulant feed line extends beyond the channel to allow the coagulant
to freely disperse into the chamber at the mixer blade. Figure B3 (Appendix B) is a picture of the rapid
mix chamber.
4.1.5 Flocculation
The system has a cross-flow or horizontal flow flocculation unit with four rectangular chambers or
cells. The flocculation unit was separated from the clarifier, or sedimentation, unit. The t through the
entire flocculation unit was 60 min (15 min per chamber) based upon recommended guidelines (12>13'16)
and previous experience. Evenly spaced baffles separated each chamber and forced water flow to take
an under-over route. The volume of the total chamber, V, was calculated as follows:
V =Q-t = (450mL/min)(60min) = 27000mL= 27.0L- °-0353ft = 0.95ft3 = 1647in3
_L/
Dividing the volume by four chambers gives a resulting size per chamber of 0.238 ft3 (6.75 L). The
internal tank design dimensions used were 7.5-in x 7.0-in x 28.75-in (Height x Width x Length). A 4-in
freeboard was added to the water height to bring the chamber height to 11.5 inches. A sampling port
was located on a side wall of the last chamber. Figures B4a and B4b show the flocculation unit design.
Mixing motors are mounted above each chamber on the same or similar frame as that used to support
the rapid mixer. This design permits easy access to motors, shafts and paddles, and eliminates the need
to drain the system in the case of motor repairs. G values tapered through successive chambers.
Velocity gradients of 30, 20, 15, and 10 sec"1, for the respective chambers, were initially evaluated
based on recommended guidelines (12>16) and previous experience, but were subject to change following
experimentation. Similar to the derivation of G for rapid mixing, the following equation can be used to
calculate G (sec"1) for individual flocculation chambers:
G = 2.238 x 10"2 = (A)0-5 = (r3)0-5 = (n3)0-5
where,
A = Total area of all paddles (in2)
r = Paddle radius (in)
n = Paddle speed (rpm)
5 Unistrut® metal frame was used.
6 Nalgene® brand tubing was used.
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
The final equation was based on a temperature of 25°C, and conversions from feet to inches were
incorporated.
As with the rapid mix design, the mixer paddles consisted of two pairs of flat, rectangular mixer blades
located above one another at right angles. The bottom blades were supported approximately 1.5 inches
from the basin bottoms. Spreadsheet calculations of G for several potential paddle blade sizes (2.5-in
radius and 1.5-in depth; 2.0-in radius and 3.0-in depth, and 3.0-in radius and 0.75-in depth) and mixing
speeds are included in Tables C4 to C6 (Appendix C). The paddle dimensions and positioning are
shown in Figure B2 (Appendix B). The paddles were fabricated from 304 stainless steel and rotated on
a Vi-in 304 stainless steel shaft. The ease of fabrication and low cost allowed all previously mentioned
paddle sizes to be evaluated if necessary. Figure C2 (Appendix C) shows the calculated velocity
gradient, G, for the paddle designs and various mixing speeds at 25°C.
Since all mixer blade dimensions produce nearly identical G values for a given mixer speed (Figure
Cl, Appendix C), the 2.5 x 1.5-in blades were initially incorporated into the construction of the pilot
plant based upon their ease of fabrication and geometry within the mixing chamber. The mixer speeds
were adjusted to the appropriate settings to achieve the desired G values (Table C5, Appendix C).
Mixing speed was adjusted if the proposed conditions were demonstrated to be insufficient.
The flocculation basin was connected to the sedimentation basin by a Vi-in PTFE bulkhead. This
connection will limit the distance floe particles travel and minimize shearing forces. Photographs of
the flocculation chambers are shown in Figures B4c and B4d (Appendix B).
4.1.6 Sedimentation
A cross or horizontal clarifier was not employed for this study and plate or tube settlers were not
incorporated. Based upon the design Q of 450 mL/min, clarifier design specifications were developed
for a number of conditions. A 3-hour detention time was selected as being typical. Design calculations
are given for one condition as follows:
V = (3 x 450 x 60) mL = 81,000 mL = 81L
V „, V mL min hr
t =— =3hrs =
Q 450 mL 60 min
V = = 2.86ft'
7.48 gal
y = 2' 4galft3 =
7.48 gal
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
Based on this volume, if depth (D) of the clarifier is 1.0 ft, then the cross sectional area (As) is 2.86 ft2,
and if the length (£) is 2.86 ft, then the width (W) will be 1.0 ft.
Like flocculation, sedimentation was difficult to scale down because the geometry of the basin can be
reduced, but the size of the discrete and flocculated particles cannot. While surface loading rates
(SLRs) for full-scale sedimentation basins are typically greater than 500 gallons per day (gpd)/ft2 (-12-),
they are much smaller in small systems and in pilot systems in order to avoid extremely deep basins.
L :W ratios are typically in the 2:1 to 5:1 range. Using a 1-ft depth and a L :W = 2.86:1, then
1440mm
gpd 450 mL day gal 60gpd
— — —
ft2 min 2ft 3785 mL ft
The settling velocity, vs, is proportional to the SLR:
™ j/r-2 4.74xlO'5 cm/sec
vs =60gpd/ft • =0.002 cm/sec
s or i /PI 2
gpd/ft
The horizontal velocity, v0, is defined by the flow rate, Q, = 450 mL/min and the W x D:
Q 450 mL gal ft3
_m_
vn = - = - - • — - - • - =0.016fpm
WxD min (1x1) ft2 3785 mL 7.48 gal
In full-scale basins, v0 ranges from approximately 0.5 to 3-ft/min; the v0 range is appreciably smaller in
pilot systems.
The Reynolds number, Re, is a function of the horizontal velocity, the viscosity and the hydraulic
radius, R. The hydraulic radius is the cross sectional area (W x D) divided by the wetted perimeter
(W+2D). At 10°C, the viscosity, vi = 1.41xlO"5 ft2/sec. for the 1-ft x 1-ft cross section is as follows:
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Water Treatment Pilot Plant Design Manual
Chapter 4 - Pilot Plant Design Principles
R=A= (ixl)ft'
P (l + l + l)ft
vn =
0.016ft min _ 0.000265ft
min 60 sec sec
R = L=
v
0.000265 ft
sec
sec
1.41 xlO"
The suggested Reynolds numbers for full-scale basins are below 2,000 ^2\ A Re = 6.2 is very laminar,
but consistent with attempts to settle full-sized flocculated particles in very small and very shallow
basins. Using temperatures of either 20°C or 5°C (unlikely to occur with an indoor pilot plant) has an
insignificant impact on Re.
The previous calculations were repeated for a number of scenarios and are shown in Tables C7 and C8
(Appendix C). The final design size was 1-ft x 1-ft x 34.25-in (H x W x L). A 3-in freeboard was
added to the depth for a total of fifteen inches. The final design is shown in Figure B5a (Appendix B).
A deflector shield and adjustable perforated baffle (Figure B5b) will be inserted in the settling basin as
shown in Figures B5a and B5b (Appendix B). L = 2.85 ft and is approximately 34 inches, as shown in
Figure B5a (Appendix B). Two baffle walls are utilized; their location was determined by trial and
error. The closest baffle wall separator, SB1, was intended as a deflector to prevent floe from short
circuiting across the basin, although the bulkhead fitting at the entry to the basin was large enough that
the velocity should minimize short circuiting and not shear the floe. It is recommended that the G value
through the bulkhead should not be greater than the velocity gradient within the last flocculation(12).
Because no reference on how to calculate G values for such fittings could be found, the issue of floe
shearing was indirectly examined by calculating the inlet velocity (v) through the bulkhead:
Q 450 mL/min ft3
v = — = ( - - — ; - ) •
A (0.75/12)2ft2(;r/4)
gal
-
mn
7.48gal 3785mL 60sec
= 0.09 ft/sec
In full-scale basins, inlet velocities are typically 0.5 to 5 ft/sec (12> 17' 18) to maintain floe in suspension.
Since the calculated velocity was well below recommended values, the velocity was also presumed to
be too low to create shearing of the floe.
The other baffle wall was intended to distribute the 450 mL/min over the cross section of the basin.
Similarly, 15 holes of 3/g-inch diameter will not produce velocities that will shear the floe (v = 0.023
ft/sec).
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
The sedimentation basin weir design was subject to experimental testing, because the weir design was
complicated by the low flow conditions. The simplest design consisted of a standpipe situated at the
end of the sedimentation basin at the desired water level. A Va-in diameter, stainless steel tube will set
the water depth to 12 inches. The tube was located approximately Va-in from the exit wall of the basin.
Based on the pipe perimeter, the weir loading rate may be calculated as
450 mL/min-1440 min/day • gal/3785 mL = 1300gpd/ft
(0.5/12 ft) 7i
Full-scale plant weir loading rates range from 11,000 to 22,000-gpd/ft weir length ^12l A photograph of
the sedimentation basin is shown in Figure B5c.
Water flowed directly downward to the filter distribution manifold. The number of elbows and length
of tubing was minimized to reduce particle shearing. An air brake was introduced in the line to reduce
air bubbles that can block the standpipe opening or interfere with water flow to the filters. The water
was then distributed amongst the three filters.
4.1.7 Filtration
The sedimentation basin was followed by a set of three parallel cylindrical glass filter columns.
Column design and operation was based on previous experiences. Dual-media, anthracite over silica
sand was initially used.
Filter diameter was minimized to match flow restrictions, but not so much that it introduced
complications associated with wall effects. Numerous studies have examined the DC/DP ratio (column-
to-particle diameter ratio) needed to avoid wall effects. Generally, ratios greater than 20:30 have been
considered acceptable (19~21). For original pathogen studies, anthracite filter media was used with an
effective size of approximately 1.0-millimeters (mm) - an effective size is one that exceeds the
representative sample weight by 90 percent (%) - and silica sand with an effective size of 0.4 to 0.55-
mm (actual sizes may vary depending upon supplier). Based upon ratio criteria (for sand), a column
would have to be greater than 8 to 16.5-mm (0.31 to 0.65-in) to minimize wall effects. Previous EPA
pilot plant studies have incorporated 1.5-in (38-mm) diameter columns without experiencing wall
effects.
The data shown in Table 3 compares 6-in diameter and 1.5-in diameter dual media filters by their
ability to remove organic contaminants from the test water; the removal efficiencies are calculated as
percentages. The data was collected during a 220-day pilot study with the filters operating with a
loading rate (LR) of 2-gpm/ft2. Each filter received identical ozonated, aluminum sulfate (alum)
coagulated, and settled Ohio River water. Paired t-tests showed no statistically significant difference in
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Water Treatment Pilot Plant Design Manual
Chapter 4 - Pilot Plant Design Principles
any of the parameters at 95% confidence. Based upon these data and design limitations, 1.5-inch
diameter columns were used.
Each filter consisted of a 6-ft high glass column and a 9-in high glass tee (all 1.5-in in diameter). The
bottom three media layers (4-in of #3 gravel, 4-in of #4 gravel, and 4-in coarse sand) were used for
structural support and retained by a PTFE plate as shown in Figure B6a (Appendix B). A 30-in media
layer sits on top of the structural support layers. Initially, a dual media filter was assembled that
consisted of a 15-in layer of anthracite over a 15-in layer of fine sand. A summary of the filter media
properties is given in Table 4, and sieve analysis results are shown in Figures Dl to D3 (Appendix D).
A schematic of the filter column is shown in Figure B6b (Appendix B).
Table 3. Performance comparison data between 1.5-inch (in) and 6-in filters' ability to remove organic
contaminants.
Percent Removal*
Organic Contaminants F3 (6-in diameter)
formaldehyde
AOC- NOX
TOXFP
HAA6FP
THMFP
TOC
UV254
88 ±5
48 ± 12
25 ±8
36 ±6
21 ±8
20 ±8
5±6
n = 25
n= 19
n= 15
n = 22
n= 13
n= 17
n = 78
F4 (1.5-in diameter)
89 ±5
54 ± 10
26 ±3
41 ±5
18±7
22 ±7
6±6
n = 25
n = 25
n = 25
n = 25
n = 25
n = 25
n = 25
HPC(R2A)/mL
(geometric mean)
turbidity, NTU
93,900
0.087 ±
0.024
n = 20
n = 254
76,300
0.090 ±
0.027
n = 20
n = 252
* Percent removal by mean percentage +/- the standard deviation.
Table 4. Filter media properties.
Layer
Anthracite
Fine sand
Coarse sand
#3 gravel
#4 gravel
1 Depth
(in)
15
15
4
4
4
Effective Size
0.97
0.45
0.79
—
—
Uniformity
Coefficient
1.309
1.544
1.481
—
—
Size Range
—
0.45-0.55
0.80- 1.20
3.17-6.35
6.35- 12.7
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
Using a 1.5-in diameter filter, the surface area, As, is
As = (1.5/12)2 • O/4) = 0.0123ft2
If Q is 2 gpm/ft2, then the flow rate, Q, is
Q = 2 gpm/ft2 • 0.0123ft2 • 3785mL/gal = 93mL/min(4.9m/hr)
Using a 30-in media depth (not considering structural support), the empty bed contact time (EBCT), or
t, is
_ V
t- Q
V= 0.0123ft2 • 2.5ft • 7.48 gal/ft3 • 3785mL/gal = 871 mL
871 mL
t = = 9.4mm
93 mL/min
Values of the Q and EBCT for different loading rates are calculated in Table C9 (Appendix C).
Water was transferred to the filters from a %-in horizontal stainless steel splitter tube through a series
of V/nn and %-in stainless steel valves, fittings and tubing as shown in Figure B6c (Appendix B). A
valve was installed at the end of the splitter tube as a filter by-pass or for periodically flushing-out
settled material in the tube. The height of standing water above the media was approximately 2.5 ft.
This depth was sufficient to allow for 50% bed expansion during backwashing (i.e., 15 in or 1.25 ft).
The overflow port was at the 9-in glass tee located 2.5 ft above the media. Water enters each filter
column at a location three inches below the overflow port. This feature prevents air bubbles from
blocking filter feed lines and stopping flow to individual filters. A settled water sampling port installed
in the !/2-in stainless steel line connecting the sedimentation standpipe to the splitter tube at four inches
above the splitter tube and seven inches below the filter overflow level (Figure B6c, Appendix B). An
appropriate flushing protocol was established before sampling from this port. Photographs of various
aspects of filter design are shown in Figures B6d to B6f (Appendix B).
The filters operate at a constant level mode. Pumps and valves were used to maintain a constant flow
of 93 mL/min through the filter, while the head increased over time. A flow rate of approximately 450
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
mL/min was delivered to up to three parallel filters at a time. Overflow conditions for various filter
configurations and flow rates are shown in Table CIO (Appendix C). Studies have been done to
evaluate the effects of filter loading rates on pathogen removal and other studies. Hydraulic conditions
may be evaluated in future pilot plant studies.
Filters operated in either normal mode or backwash mode by adjusting valve settings and operating
pumps. Figure B7a (Appendix B) is a schematic of the filter flow control system and shows the pump
and valve settings during normal filter operation. All tubing and fitting connections following the filter
were Vi-in diameter, 304 stainless steel. Filter effluent water flowed through the effluent tubing line,
past a rotameter, and would freefall from a port into a funnel and down a drain line at a height of 55
inches above the filter base. The drain lines fed individual clearwells. Filter effluent samples were
collected at the freefall port. The filter pump was sized for a flow of 93 mL/min plus at least 50% (140
ml/min) at a LR of 2 gpm/ft2. Gear pumps with digital flow controllers are used to meet desired flow.
A !/4-inch plastic tubing7 line was inserted at the base of the tube and runs along the filter height to
monitor headloss.
Figure B7b (Appendix B) shows the pump and valve settings during filter backwash mode. Filter
backwashing was based on one of the following: headloss, turbidity, flow rate, time, or a combination
of them. Bed expansion is 50% of the bed depth, while the backwash pump has the capacity to achieve
at least 100% expansion. The pump was capable of producing a flow of at least 1,400 mL/min plus
50% (2100 mL/min). Air scour is not used to break up surface accumulations due to filter size
constraints. Filters are backwashed for ten minutes after 50% bed expansion is achieved, although time
may be adjusted as needed. The backwash Q is 1.3 to 1.5 L/min to achieve bed expansion. Previous
experience has found that desired bed expansion without losing media typically takes approximately
two minutes. Adding ten minutes at 50% expansion (for a total of twelve minutes of backwashing) and
multiplying by an average backwash Q of 1.4 L/min gives the volume of water, 16.8 L (4.4 gal),
needed for backwashing. To accommodate this volume, clearwell volume should be at least ten gallons
(37.9 L). The filters could be backwashed at least every 24 to 48 hours depending on the requirements
of the study and the associated water quality parameters.
4.1.8 Clearwell (Backwash Water Storage Reservoirs)
Each filter effluent stream was initially plumbed to an independent 40-gal clearwell8 using V/nn
stainless steel; water entered the clearwells from the top. Two ports are located at the base of the tank,
one for draining the tank and the other for delivering backwash water. An overflow line controls the
water level in the tank. A photograph of the clearwells is shown in Figure B8a (Appendix B).
The clearwell design was later modified to accommodate disinfection research. Ten gallon clearwells,
constructed of either stainless steel or PMAA, were fabricated as shown in Figure B8b (Appendix B).
The clearwells operated in upflow mode to provide sufficient residence time. Disinfectant feed and
7 Nalgene® brand tubing was used.
8 Nalgene® brand plastic clearwell was used.
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
static mixers were incorporated into the feed line (from filter effluent). Additional feed lines for NFb,
pH adjustment, and others may be added as well. Static mixers were tested to assure complete
chemical mixing. A number of other sized units can be built. Table Cl 1 (Appendix C) gives
dimensions for a number of clearwell sizes. Consideration was given to make the clearwells
interchangeable.
' 7 • :-, '/.:'.: :
All pilot plant components are modular so that they can be configured in any sequence or easily
removed and replaced to satisfy the needs of various research studies (i.e., arsenic removal by iron
removal studies, filter media studies, pathogen studies, etc.). Minor design changes may be necessary
based upon research needs and desired outcomes. Since PMMA is relatively inexpensive and
fabrication is simple, modular design easily accommodates such alterations.
4.2.1 Flow Control
Flow control throughout the pilot plant is achieved by either overflow devices such as weir boxes,
pumps in combination with valves, or pumps with digital flow controllers. Valves are maintained
manually. Flow rate measurements are made manually on a regular basis using a stopwatch and
graduated cylinder, or by reading in-line rotameters.
4.2.2 Sludge Removal
Sludge removal was not considered in the design because continuous plant operation is unlikely to
exceed one week. Sludge build-up has not been a concern for any study conducted to date. Sludge is
appropriately removed from each process between runs. Similarly, none of the units other than the
filters have overflow capacity. The system should be operating 24 hours a day when running a test.
4.3.3 Coagulant and Feed Systems
Coagulant solution was pumped from a 2-L glass graduated cylinder through !/4-inch PTFE tubing
directly into the rapid mix chamber using a peristaltic pump. The tubing was inserted into a channel at
a corner of the rapid mix chamber. The tubing was positioned so that the coagulant was dispensed at
the tip of the mixer blades.
In the original pathogen pilot studies, a solution containing Cryptosporidium parvum oocysts was
pumped from a glass flask through a 0.03-in diameter tubing into the raw water feed line between the
constant head tank and the rapid mix chamber (Figure B9, Appendix B) using a peristaltic pump. A V/t-
inch static mixer was added to the raw water line after the feed location for mixing. Both
Cryptosporidium parvum oocyst and coagulant feed solutions were continuously mixed by magnetic
stirrers and stirrer bars.
4-15
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Water Treatment Pilot Plant Design Manual Chapter 4 - Pilot Plant Design Principles
4-16
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Water Treatment Pilot Plant Design Manual Chapter 5 - Operation
Chapter 5 - Operation
The pilot plant operated continuously over four- to seven-day periods (24 hours per day) in the
conventional mode, although the plant has been operated in the direct filtration mode in subsequent
studies. For the original pathogen study, each test run was dedicated to the study of the removal of
Cryptosporidium parvum oocysts and other microbiological parameters from drinking water under
differing water quality and pilot plant operating conditions. The impact of a number of variables was
explored. These variables included, but were not limited to, coagulant type (alum, ferric chloride,
polymeric coagulants), pH (enhanced coagulation), and possibly source water. The pilot plant operated
to achieve optimal turbidity reduction.
Optimal coagulant dose was based on jar testing. When considering operation under enhanced
coagulation, operating conditions were based on total organic carbon (TOC) removal guidelines
described under the proposed Enhanced Surface Water Treatment Rule(22). In addition, the pilot plant
intentionally operated under non-ideal conditions to examine relationships between plant failure and
oocyst removal. Statistical correlations between potential surrogate parameter removals such as
particle counts, bacterial endospores, and Cryptosporidium oocyst removal were tested.
5-1
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Water Treatment Pilot Plant Design Manual
Chapter 6 - Data Collection
Chapter 6 - Data Collection
The most difficult and uncertain task associated with this project dealt with water quality sampling.
The problem with sampling was the low flow through the system. Sampling may lead to significant
draw down in the system, which can create operational concerns. The sampling protocol for any study
should be well planned. For example, sampling should start from the end of the plant and move
forward. If possible, on-line instrumentation should be used to gauge temperature, pH, turbidity, and
particle counting. In order to develop a detailed sampling protocol, first a shakedown and test runs
should be completed. A list of proposed samples and ideal sample sites is summarized in Table 5. The
frequency of sampling will change with study objectives and analytical capacity.
Table 5. Proposed sample types and sites.
S^ple Type and Size
ICP metals, 30 mL (Nalgene®)
pH, 30 mL (glass vial)
TIC, 30 mL (glass vial)
Wet chemistry (alkalinity, Cl, NCb, NH3,
PO4), 250 mL (Nalgene®)
Turbidity, 30 mL (glass vial)
Particle counting, 150 mL, (glass bottle)
Microbiological
(aerobic bacterial endospores, etc.)
Cryptosporidium parvum
Organics
Sample Location (s)
raw, settled, filtered
raw, settled, filtered
raw, settled, filtered
raw, settled, filtered
raw, settled, filtered
raw, settled, filtered
raw, settled, filtered
raw, settled, filtered
raw, settled, filtered
Sample Time
(hours)
every 8
every 4
every 8
every 8
every hour
every 2
every 4 to 8
every 4 to 8
every 8
6-1
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Water Treatment Pilot Plant Design Manual Chapter 7 - Prototype Pilot Plant System
Chapter 7 - Prototype Pilot Plant System
A prototype pilot plant system consisting of all unit processes was constructed in stages for test and
evaluation purposes. The prototype system was based on an earlier design. Problems discovered during
its operation have led to several modifications. The final pilot plant design described in previous
sections incorporated all changes made during operation of the prototype system.
The 1.1 x 1.3-in and 2.5 x 1.5-in paddles were used for the rapid mix and flocculation chambers,
respectively. The system was operated on a number of occasions at various stages of construction
under real conditions, using Ohio River water and alum coagulation. Alum levels were determined
through jar testing and were based on turbidity reduction. The jar test protocol was designed to
simulate mixing conditions within the pilot plant and is outlined in Table A5 (Appendix A). A six
paddle stirrer jar test apparatus9 with 1.5-L rectangular PMMA jars was used.
The first test run was conducted over a brief, five-hour period with the filters offline. The turbidity,
pH, and temperature of both raw and settled waters were measured and recorded every 30 minutes
(average raw water quality is shown in Table A6 [Appendix A]). An alum dose of 30 mg/L as Ah
(864)3 = 14H2O was used, and the system was started with the sedimentation basin drained to a level of
four inches above the bottom. As the water cascaded into the sedimentation basin from the flocculation
chamber, sediment at the bottom of the basin that had settled over previous trial runs was stirred-up.
Monitoring results showed that settled turbidity levels continued to decrease after five hours of
operation (Figure BIO, Appendix B), while pH dropped by approximately one unit in response to alum
addition. Two conclusions were drawn from the test run results:
(1) Five hours was not enough operation time for the system to reach equilibrium, and
(2) The system should be started when the sedimentation basin is full to reduce disturbing previously
settled material.
' Coffman Industries, Westford, MA.
7-1
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Water Treatment Pilot Plant Design Manual Chapter 7 - Prototype Pilot Plant System
The second test run was conducted over an 11.5-hour period, and was initiated with a full
sedimentation tank and an alum dose of 30 mg/L (filters were not on-line). Raw water quality data
(Table A6, Appendix A) showed a considerable settling problem in the 5,500-gal storage reservoir,
despite the existing operation of a recirculation pump intended for mixing. Raw water turbidity had
dropped from 12.9 to 4.50 nephelometric turbidity units (NTU) over a 3-day period. Test run results
showed that settled pH and turbidity values had leveled off after about seven hours of operation, which
suggested that the system had reached equilibrium (Figure Bl 1, Appendix B). Visual examination of
the system showed an expected development of floe through the flocculation chambers, and a realistic
floe settling pattern through the sedimentation basin. Settled turbidity levels (1 to 2 NTU) were well
within expectations and representative of full-scale operation.
The third test run was conducted continuously over a 36-hour period and was the most extensive run
conducted without the filters online. Turbidity, pH, particle counts, and temperature were monitored
hourly, while TOC, aerobic spore forming bacteria, and heterotrophic bacteria were measured every
eight hours. A detailed record log and monitoring checklist consisting of water quality measurements
and pilot plant operational parameters was established. The checklist was incorporated into a log book
and the data gathered during the run was later transferred to a computer spreadsheet (Table A7,
Appendix A). Graphs of raw and settled water quality fluctuations over the test run are shown in
Figures B12 to B16 (Appendix B). A submersible pump was placed into the storage reservoir six hours
into the test run to provide additional mixing. The addition of the pump immediately increased
paniculate parameters, which then remained relatively steady for the remainder of the study run (see
Table A5, Appendix A, for raw water quality). A small fluctuation in temperature that corresponded to
building heating and cooling schedules was noted. Results showed excellent removals (>92%) for all
parameters (Table A8, Appendix A). TOC removal was also within the expected range at 20%.
•''.„
A step input tracer study(23) focusing on the rapid mix chambers, flocculation chambers, and
sedimentation basin was conducted to hydraulically define the prototype system. Potassium chloride
(KC1) was chosen as the tracer because it was readily available, non-reactive, and could be easily
monitored. Total dissolved solid (TDS) concentration was used to monitor salt movement through the
pilot plant. TDS provided an instantaneous surrogate measurement of KC1 and was measured with a
hand-held TDS meter10.
KC1 was fed at the rapid mix chamber in place of alum. The spiked KC1 concentration met several
criteria: (1) the salt feed rate was insignificant relative to water flow rate, (2) the resulting TDS
1 Myron L Company, Carlsbad, CA.
7-2
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Water Treatment Pilot Plant Design Manual Chapter 7 - Prototype Pilot Plant System
contribution was significantly higher than background water level, (3) the resulting TDS concentration
was lower than the upper limit of the TDS meter (2000 ppm), and (4) KC1 feed solution was under-
saturated. A KC1 concentration of 800 mg/L was experimentally determined (Figure B17, Appendix B)
to meet these criteria. This level contributed an approximately 5-fold TDS increase relative to the raw
water (Ohio River water) of 200 ppm. A 72 g/L KC1 feed solution was prepared in deionized water and
fed into the rapid mix chamber at a rate of 5 mL/min.
The pilot plant was operated for one theoretical detention time (four hours) prior to the addition of
tracer in order to establish normal flow patterns. Two sets of data were collected: one for the rapid mix
chamber and flocculation chambers and one for the rapid mix chamber, flocculation chambers, and
sedimentation basin. The sampling duration was three to four times the theoretical detention times,
during which time, at least 30 samples were planned in order to establish statistical validity ^l
Approximately 50 mL TDS samples were withdrawn using a pipette at the exit of the sedimentation
basin and at the last flocculation chamber at set times. Rapid mix TDS, temperature throughout the
system, salt feed, and raw water feed rates were also monitored regularly. Samples were first taken
from the furthest location from the raw water inlet and were then moved forward for subsequent
samples.
Figure B18 (Appendix B) shows the raw tracer study data (background TDS subtracted out) for the
rapid mix and flocculation chambers (and connecting fittings) and then the rapid mix and flocculation
chambers, and the sedimentation basins (and connecting fittings). The steepness in the two curves
suggests good mixing throughout and eliminates any concern for flow problems, such as short-
circuiting. The full TDS spike concentration was reached in each portion of the plant after
approximately 4 and 2.5 times the theoretical detention times of the rapid mix and flocculation
chambers (61.5 min.) and the entire system (301.5 min.), respectively. These relatively short times are
reasonable and further support the conclusion that short-circuiting, dead zones, and other flow and
mixing constraints through the prototype system are not issues of concern. The tracer data was
eventually used to determine appropriate sampling times during spiking events (e.g., Cryptosporidium)
and to calculate contact time (CT) values when considering disinfection practices (Figures B19 and
B20, Appendix B).
A step input tracer test was also used to evaluate flow conditions through filter #2 and #3. The test
results, plotted in Figures B21 and B22 (Appendix B), showed that salt breakthrough profiles were
nearly identical and that steady state salt concentration was reached after approximately two theoretical
filter retention times (21 min). The curves were relatively steep suggesting relatively plug-flow
conditions.
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Water Treatment Pilot Plant Design Manual Chapter 7 - Prototype Pilot Plant System
A pulse input tracer study ^ was conducted on the flocculation unit. The results were compared to
curves for a number of theoretical continuous-flow stirred tank reactor (CSTR) scenarios. 30 ml of
saturated KC1 solution was added at the point where water from the rapid mix chamber entered the first
flocculation chamber. Conductivity was measured in water samples taken at the point where water
exited the last flocculation chamber in order to evaluate salt flow through the unit.
The pulse input tracer study showed that the water flow pattern through the prototype flocculation unit
resembled a 1- to 2-CSTR system (Figure B23, Appendix B). Under ideal plug flow conditions, the
unit would behave as a 4-CSTR system. The results suggested that some short-circuiting had occurred
in the flocculation system, which could lead to insufficient mixing or incomplete floe formation. The
problem was corrected by changing the baffle opening size between chambers from the original design
specification of Va-in to 1-in. The mixers were also raised from Va-in to 1 Va-in off the bottom of the
tank to avoid sweeping water through the openings. Following the modifications (which are reflected
in the design specifications presented in this manual), the tracer study was repeated. The results of the
second test (shown in Figure B24, Appendix B) showed that the modifications increased the number of
CSTR's by two to three units, which was considered acceptable.
-'„:'-„
Two test runs (83 and 59 hours) were conducted using Ohio River water spiked with 4.5-micrometer
(um) diameter fluorescent polystyrene beads. These runs were performed to further evaluate treatment
effectiveness and reliability, as well as the Cryptosporidiumparvum oocyst feed system. Alum dose
was optimized for turbidity reduction based upon j ar tests. Average water quality variables at various
locations in the pilot plant treatment train are shown in Tables A9 and A10 (Appendix A). The feed
system was configured to feed beads into the raw water at a concentration of approximately 1,000
beads/mL.
Log reductions of particles, aerobic bacterial endospores, turbidity, and synthetic beads are
summarized in Tables Al 1 and A12 (Appendix A), and Figures B25 and B26 (Appendix B). Bead
values for 59-hour runs were not available at the time of report preparation. One log reduction of
particles, turbidity, bacterial endospores, and beads was observed after sedimentation. Filtration
generally increased the total reduction of particles, beads, and endospores through Filters 1 and 2 to a
log greater than 3.5. During the 83-hour test run, filter 3 was consistently less efficient than Filters 1
and 2 with respect to particle and turbidity reduction. However, filter 3 removed beads and spores
more effectively than Filters 1 and 2. Laboratory notes showed that the operators often had trouble
maintaining constant flow from the filters, and that Filter 3 was more problematic than the others. The
prototype pilot plant used a single-speed gear pump and needle valve system to control flow through
the filters. Operators noted that the original set flow could be recovered from a filter after the flow had
7-4
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Water Treatment Pilot Plant Design Manual Chapter 7 - Prototype Pilot Plant System
dropped by simply tapping the needle valve. The flow problems and inconsistent filter performances
were believed to be caused by small particles or air bubbles collecting at the needle valve. The single-
speed gear pumps were replaced with digitally controlled variable speed gear pumps (described in
earlier report sections) before beginning the 59-hour run. During this run, flow through the filters
remained constant and variations in filter performance were greatly reduced.
Thus far, only filtered turbidity levels (Figures B27 and B28, Appendix B) have been used to measure
treatment performance for regulatory purposes. Although a turbidity level of 0.3 NTU in at least 95%
of the measurements taken each month is currently recognized as a regulatory standard by water
utilities, many systems have established filtered turbidity goals as low as 0.1 NTU. The mini pilot plant
consistently produced water with a turbidity less than 0.1 NTU, well below the standards set for full-
scale systems.
7-5
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Water Treatment Pilot Plant Design Manual Chapter 8 - System Modifications
Chapter 8 - System Modifications
Since EPA's initial conventional/direct filtration mini pilot plant was constructed to study pathogen
removal, three additional plants have been built. Over the years, a number of studies have been
undertaken within EPA's Office of Research and Development to address a wide range of drinking
water research needs. Some of these studies examined the role of water quality and plant configuration
on the removal of iron and arsenic from water, and the effect of ozonation and biological treatment
filtration. Minor additions or modifications to the original pilot plant design were made to conduct
these studies.
The arsenic removal and ozonation studies are just two examples of the types of studies that can be
conducted to examine the role of treatment processes and plant configuration, among other things, on
water quality. Only minor additions or modifications to the initial conventional/direct filtration mini
pilot plant were made in order to meet these and other alternative research objectives. To illustrate the
ease and flexibility of the pilot plant design, brief descriptions of these modifications are discussed in
Sections 8.2 and 8.3.
\. II' IN n
Arsenic and iron removal optimization pilot studies are exceptionally useful for predicting the effects
of system modifications related to arsenic and iron removal (e.g., adding a strong oxidant, changing the
point of oxidant application, adjusting the pH, increasing iron concentration, and replacing filter media
with arsenic adsorption media). Before full-scale treatment changes are made and unnecessary costs
incurred, pilot-testing some of the above system modifications can help utilities predict how changes to
their system and source water treatment will alter the water quality, as well as the capacity of that
system to remove iron and arsenic.
Modifications were made to the original pathogen treatment system to run tests that would more
accurately simulate the conditions found in a typical iron removal treatment system. As illustrated in
Figure 1, ferrous iron, Fe(II), and arsenite, As(III), where added to the water in-line just ahead of the
rapid mix chamber. By removing the mixing paddles, the flocculation chamber was modified to
resemble a contact vessel typically used in full-scale iron removal systems. The sedimentation step was
bypassed because the additional contact time was not necessary and the water was passed through filter
8-1
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Water Treatment Pilot Plant Design Manual
Chapter 8 - System Modifications
media. Fe(II) and As(III) were added prior to the rapid mix chamber to simulate their respective forms
observed in groundwaters. One specific set of experiments was designed to evaluate the point of
chlorine addition (necessary to oxidize arsenite). There were two primary experimental processes run:
(1) chlorine addition preceding Fe(II) and As(III) addition, enabling the oxidation of iron and arsenic
to occur at the same time, and (2) chlorine was added to the treatment process just before entering the
filter media; therefore, iron oxidation with oxygen occurred before arsenic oxidation.
Figure 1 illustrates how the pilot plant can be easily modified to address specific research questions,
like how changing the point of oxidant addition (specifically a strong oxidant, in this case free
chlorine) impacts removal efficiency. Additional experiments were run that also bypassed the
contactor for both oxidant application points to test the need for contact time.
Experiment 1
Experiment 2
CI2 addition
Fe(ll),As(lll) addition
Fe(ll),As(lll) addition
The dotted line represents
additional experiments in
which the contactor was
bypassed.
Filter 1
Filter 2
Filters
Filter 4
Filters
Filter 6
Figure 1. The effect of changing the point of oxidant application on removal efficiency.
8-2
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Water Treatment Pilot Plant Design Manual Chapter 8 - System Modifications
"• .: .' ', : ati*; " ">
While the original Cryptosporidium study evaluated the control of the pathogens using conventional
treatment methods (i.e., coagulation, flocculation, sedimentation, and filtration), a second study
(referred to below as Phase 2) was conducted at the pilot plant that evaluated the control of these
pathogens as a function of filter biological activity and pre-oxidation by ozone. This second study
required modifications to the conventional treatment system, as shown in Figure 2. Ozone was
produced by passing oxygen gas through a liquid-cooled corona discharge ozone generator (Figure 2).
The feed gas ozone concentration was measured with a commercial ozone monitor. Ozone feed gas
passed through a sintered stone diffuser at the bottom, while raw water flowed counter-current through
the top of the 3.8-centimeter (cm) inside diameter glass contactor. The water in the contactor was
maintained at a height of 170-cm. The theoretical detention time was 4.3-min. Tracer study results
indicated that the detention times necessary for the effluent tracer concentration to reach 10% and 90%
of the influent value were 2.5 and 7.7 min, respectively. During Ohio River Water (ORW) acclimation,
the transferred ozone dose, transferred ozone/dissolved organic carbon (DOC) ratio and contactor
effluent liquid phase residuals were 2.1 (o = 0.13) mg/L, 0.80 (o = 0.062) mg/L, and 0.50 (o = 0.052)
mg/L, respectively. With EFL water, the transferred ozone dose, transferred ozone/DOC ratio and
contactor effluent liquid phase residuals were 5.1 (o = 0.55) mg/L, 1.0 (o = 0.13) mg/L, and 0.90 (o =
0.27) mg/L, respectively.
In Trials 1 and 2 during Phase 2, the pilot plants were run for 9.5 and 13.5 hours, respectively. Trial 3
lasted for 36 hours. The extra run time in Trial 3 was necessary to ensure that the sedimentation basin
effluent water quality and Cryptosporidium concentrations had stabilized. During Trial 2, Plant 2
influent water was ozonated to achieve a transferred ozone dose of 8.7 mg/L (o = 1.4), a transferred
ozone/TOC ratio of 3.8 and a contactor effluent liquid phase ozone residual of 0.27 mg/L (o = 0.085). .
Pilot-scale trials were carried out in two phases to evaluate the impacts of pre-ozonation, pre-
chlorination, and filter biological activity on the filtration removal of seeded Cryptosporidium oocysts.
The principal goal was to evaluate the impact of variations in filter biological activity. As it turned out,
the pre-ozonation and pre-chlorination used to generate differences in filter biological activity had a
larger impact on Cryptosporidium removals than did the respective filter biological activities. Pre-
oxidation with ozone or chlorine was associated with up to 1-log lower Cryptosporidium removals.
This work generated a wealth of Cryptosporidium removal data that may be used for treatment
guidance and full-scale plant design specifications.
8-3
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Water Treatment Pilot Plant Design Manual
Chapter 8 - System Modifications
Filter 1
Filter 2
t t
Ch backwash Ch backwash
Flocculation and Sedimentation bypassed
during Phase 2, Trials 1 and 2
Filter 3
Filter 4
Filters
Bypass during Phase 2 Trial 1
Ch addition during Phase 2 Trial 1
t t
Ch backwash Ch backwash
Filters
Figure 2. The effect of changing the point of oxidant application on removal efficiency.
8-4
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Water Treatment Pilot Plant Design Manual Chapter 9 - References
Chapter 9 - References
1. D'Antonio, R.G., Winn, R.E., Taylor, J.P., Gustafson, T.L., Current, W.L., Rhodes, M.M., Gary,
G.W. Jr, and Zajac, R.A (1985). "A Waterborne Outbreak of Cryptosporidiosis in Normal Hosts."
Annals of Internal Medicine, Dec; 103(6 (Pt l)):886-8.
2. Gallaher, M. M., et al. (1989). "Cryptosporidiosis and Surface Water." Amer. Jour. Public Health,
79:39.
3. Rose, J. B. (1988). "Occurrence and Significance of Cryptosporidium in Water." Jour. AWWA
80:53.
4. Hayes, E. B., et al. (1989). "Large Community Outbreak of Cryptosporidiosis Ddue to
Contamination of a Filtered Public Water Supply." New Eng. Jour. Med., 320:21:1372.
5. Goldstein, S. T., et al. (1996). "Cryptosporidiosis: An Outbreak Associated with Drinking Water
Despite State-of-the Art Water Treatment." Ann. of Int. Med., 124:5:459.
6. MacKenzie, W. R., et al. (1994). "A Massive Outbreak in Milwaukee of Cryptosporidium Infection
Transmitted Through Public Water Supply." New England Jour, of Med., 331:3:161.
7. Fox, K. R. & Lytle, D. A. (1996). "Milwaukee's Crypto Outbreak: Investigation and
Recommendations." Jour. AWWA, 88:9:87.
8. U.S Department of Health and Human Services (revised 2009). "Biosafety in Microbiological and
Biomedical Laboratories," 5th Edition." U.S. Department of Health and Human Services, Public
Health Service, Center for Disease Control, and National Institutes of Health, HHS Publication
No. (CDC) 21-1112.
9. Miltner, R. J., Rice, E.W., Stevens, A. A. (1990). "Pilot-Scale Investigations of the Formation and
Control of Disinfect! on Byproducts." AWWA Annual Conference, Cincinnati, Ohio.
10. Miltner, R. J., Nolan, S.A., Dryfuse, M.J., Summers, R.S. (1994). "Evaluation of Enhanced
Coagulation for DBF Control." National ASCE Conference on Environmental Engineering,
Boulder, CO.
11. Miltner, R. J., et al. (1994). "The Control of DBFs by Enhanced Coagulation." Proc. AWWA
Annual Conference, New York, NY.
12. James M. Montgomery Consulting Engineers (1985). "Water Treatment Principles and Design."
John Wiley and Sons, New York.
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Water Treatment Pilot Plant Design Manual Chapter 9 - References
13. American Water Works Association (1990). "Water Quality and Treatment." Fourth Edition,
McGraw Hill, Inc.
14. Reynolds, T. D. (1982). "Unit Operations and Processes in Environmental Engineering."
Wadsworth, Inc., Belmont, CA.
15. Clark, J. W., Viessman, W. & Hammer, M. J. (1977). "Water Supply and Pollution Control." Third
Edition, IEP-A Dun-Donnelley, New York.
16. Huck, P. M. & Anderson, W. B. (1991). "State-of-the-Art Report: Drinking Water Treatment Pilot
Plants." Project Report ET006 submitted to the Ontario Ministry of the Environment, University
of Waterloo.
17. American Water Works Association (1971). "Water Quality and Treatment." Third Edition,
McGraw Hill, Inc.
18. Sanks, R. L. (1980). "Water Treatment Plant Design." Ann Arbor Science, Ann Arbor, (1980).
19. Fahien, R. W. & Smith, J. M. (1955). "Mass Transfer in Packed Beds." AIChE Journal, 1:1:28.
20. Chu, C. F. & Ng, K. M. (1989). "Flow in Packed Tubes with a Small Tube to Particle Diameter
Ratio." AIChE Journal, 35:1:148.
21. Cohen, Y. & Metzner, A. B. (1981). "Wall Effects in Laminar Flow of Fluids through Packed
Beds." AIChE Journal, 27:5:705.
22. U.S. Environmental Protection Agency (1993). "Draft Guidance Manual for Enhanced Coagulation
and Enhanced Precipitative Softening." U.S. Environmental Protection Agency, Washington, D.C.,
EPA815-R-99-012.
23. Teefy, S. (1996). "Tracer Studies in Water Treatment Facilities: Protocol and Case Studies."
AWWARF.
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Water Treatment Pilot Plant Design Manual
Appendix A: Tables
Appendix A: Tables
Table A6. Pilot plant coagulation design summary and comparisons
Design Parameter
Mixing Chamber Shape
Mixer Speed [rpm]
Retention Time in Flash Mix [sec]
G [I/sec]
Physical Dimensions LxWxH [in]
Volume of Water [L]
Flow [L/min] ([gpm])
Typical
Pilot Plant3
square, rectangular, tube, cylindrical
118 to 1700
8 to 180
800 to 1250
numerous
6 to 450
3. 8 to 450(1 to 48)
Mini
Pilot Plant
square
100
90
195
3.2x3.2x7.5
0.675
0.45(0.12)
Full-Scale
System
numerous
varies
—
800 to 5000b
numerous
—
—
a Typical pilot plant specifications were summarized from a critical evaluation of 19 pilot plants primarily located in the United States and Canada:
Huck, P. M. & Anderson, W. B. (1991). "State-of-the-Art Report: Drinking Water Treatment Pilot Plants." Project Report ET006 submitted to the
Ontario Ministry of the Environment, University of Waterloo(16).
b American Water Works Association (1990). "Water Quality and Treatment." Fourth Edition, McGraw Hill, Inc.(13)
A-l
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Water Treatment Pilot Plant Design Manual
Appendix A: Tables
Table A7. Pilot plant flocculation design summary
Design Parameter
Physical Dimensions LxWxH [in]
Number of Compartments within Tank
Velocity Gradient [I/sec]
Mixer Speed [rpm]
Volume of Water (total for all units) [L]
Flow [L/min] ([gpm])
Detention Time (total for all units) [min]
and comparisons.
Typical
Pilot Plant3
numerous
Ito4
7 to 185
10 to 85
92 to 1143
3. 8 to 450(1 to 48)
8 to 189
Mini
Pilot Plant
29.25 x 7.5 x 11.5
4
56.2,30.6, 19.9, 10.8
30,20, 15, 10
27
0.45(0.12)
90
Full-Scale
System
numerous
> 2 to 3b
50 to 10b
2tol5c
numerous
numerous
>20
a Typical pilot plant specifications were summarized from a critical evaluation of 19 pilot plants primarily located in the United States and
Canada: Huck, P. M. & Anderson, W. B. (1991). "State-of-the-Art Report: Drinking Water Treatment Pilot Plants." Project Report ET006
submitted to the Ontario Ministry of the Environment, University of Waterloo(16).
b James M. Montgomery Consulting Engineers (1985). "Water Treatment Principles and Design." John Wiley and Sons, New York(12).
0 American Water Works Association (1990). "Water Quality and Treatment." Fourth Edition, McGraw Hill, Inc.(13)
A-2
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Water Treatment Pilot Plant Design Manual
Appendix A: Tables
Table A8. Summary of sedimentation basin design.
Parameter Typical
Pilot Planta
Q [mL/min] 6,400 to 150,000
Detention time [hr] 1 .6 to 9
Volume, gal [ft3] 7 to 132
Surface area [ft2]
Length: width
Depth [ft]
Surface loading rate [gpd/ft2]
Settling velocity (Vs) [cm/sec]
Overflow velocity (V0) [ft/min]
Re @ 10°C
Inlet velocity (v) [ft/sec]
Weir loading [gpd/ft]
Organics
Pilot Plant
6,400
8.6
872(117)
33.3
2.08
3.5
73
0.0035
0.016
24
>0.31
304
Modified
Organics
Pilot Plant
6,400
5.4
548 (73)
20.9
4.16
3.5
116
0.0055
0.032
29
>0.31
304
Mini
Pilot Plant
450
3
21.4(2.86)
2.85
2.85
1.0
60
0.0028
0.016
6.2
85
Full-Scale
System
numerous
2to4b
numerous
numerous
3to5c
numerous
500 to 1200C
0.024 to 0.085,
Avg. = 0.045
0.5 to 5.7b, 0.5 to 3C
< 2000C
0.5to2.0c
< 50,000
a Typical pilot plant specifications were summarized from a critical evaluation of 19 pilot plants primarily located in the United States and Canada: Huck, P. M.
& Anderson, W. B. (1991). "State-of-the-Art Report: Drinking Water Treatment Pilot Plants." Project Report ET006 submitted to the Ontario Ministry of the
Environment, University of Waterloo(16).
b American Water Works Association (1971). "Water Quality and Treatment." Third Edition, McGraw Hill, Inc.(17)
0 James M. Montgomery Consulting Engineers (1985). "Water Treatment Principles and Design." John Wiley and Sons, New York(12).
-------
Water Treatment Pilot Plant Design Manual
Appendix A: Tables
Table A9. Pilot plants filter design
Design Parameter
Filter Shape
Filter Internal Diameter [in]
Column Height [in]
Filter Material of Construction
summary and comparisons.
Typical
Pilot Planta
cylinder
4 to 50
40 to 165
glass, acrylic, fiberglass,
Mini
Pilot Plant
cylinder
1.5
81
glass
Full-Scale
System
rectangular
<1100ft2(100m2)b
numerous
concrete
Bed Support
Filter Media Type
Media Uniformity Coefficient [mm]
Media Depth [in]
Hydraulic Loading Rate [m/hr] ([gpd/ft2])
Water Flowrate (L/min)
clear PVC, PMMAC
varies
typically anthracite/sand
anthracite: 0.99 to 1.5
sand: 0.4 to 1.5
5 to 20 (2.0 to 8.2)
0.68 to 11.0
coarse sand,
#3 & #4 gravel
anthracite/sand
anthracite: 0.97
sand: 0.46
15/15
4.9 (2 gpd/ft2)
0.097
gravel
anthracite/sand
<1.65d
24 to 35 sand &/or anthracited
5 to 25C
numerous
a Typical pilot plant specifications were summarized from a critical evaluation of 19 pilot plants primarily located in the United States and Canada:
Huck, P. M. & Anderson, W. B. (1991). "State-of-the-Art Report: Drinking Water Treatment Pilot Plants." Project Report ET006 submitted to the
Ontario Ministry of the Environment, University of Waterloo(16).
b James M. Montgomery Consulting Engineers (1985). "Water Treatment Principles and Design." John Wiley and Sons, New York(12).
0 Polymethyl methacrylate (PMMA) also commonly known by the name brand Plexiglass®
d American Water Works Association (1990). "Water Quality and Treatment." Fourth Edition, McGraw Hill, Inc.(13)
A-4
-------
Water Treatment Pilot Plant Design Manual
Appendix A: Tables
Table A10. Jar test and pilot plant operating variables.
Jar Test
Table All
Run#
1
2
3
3*
Process
Rapid Mix
Floe Chamber One
Floe Chamber Two
Floe Chamber Three
Floe Chamber Four
Settling Tank
Time
(min)
1.5
15
15
15
15
60
RPM
50
22
15
11
7
0
G
(sec -1)
192.61
56.22
31.65
19.88
10.09
0
Pilot Plant
Time
(min)
1.5
15
15
15
15
180
G
RPM (sec -1)
100 195.1
30 56.2
20 30.6
15 19.9
10 10.8
0 0
Average raw Ohio River water quality during pilot plant evaluation runs.
Duration Turbidity
Date (hours) (NTU)
4/11/1997 5 12.9
4/14/1997 11.5 4.5
4/23/1997 36 2.4
14.8
Temperature
pH
7.99
7.88
8.13
8.07
(°C)
65.1
67.4
21.3
21.7
Particles
total
-
-
589,000
4,900,000
(counts/10 mL)
3-6 um
-
-
17,500
466,000
Bacterial
endospores HPC TOC
(CFU/lOOmL) (CFU/mL) jig/L
.
.
22000 25450 1.91
Averages after the activation of the submersible pump
A-5
-------
Water Treatment Pilot Plant Design Manual
Appendix A: Tables
Table
•i
94/22/97
04/22/97
94/22/97
94/22/97
94/22/97
94/22/97
94/22/97
04/22/97
94/22/97
94/22/97
94/22/97
94/22/97
04/22/97
D4/ 22/97
04/22/97
04/22/97
94/22/97
94/22/97
94/23/97
D4/23/9('
94/23/97
04/23/97
94/23/97
94/23/97
94/23/97
94/23/97
04/23/97
94/23/97
94/23/97
94/23/97
94/23/97
94/23/97
94/23/97
04/23/97
04/23/97
94/ 23/97
94/23/97
A12. Monitoring log and checklist used during Test Run 3.
630AM
73DAM
839AM
939AM
10 30AM
1139AM
1239AM
130PM
2: 30PM
339PM
439PM
530PM
630PM
730PM
R30PM
930PM
1D:3DPU
1130PM
123OPM
130AM
230AM
330AM
430AM
539AM
6:3DAM
73OAM
830AM
930AM
103OAM
1130AM
1239AM
130PM
2:3DPM
33OPM
430PM
539PM
630PM
AvgO6
Avg7-36
AvgO-36
ELAFTIMEthrj)
0
1
2
3
5
6
7
B
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
TURBIDIT'i'-RAW
262
257
256
221
23
954
14 B7
1483
168
194
165
159
144
1622
151
149
147
1564
1642
162
1585
1533
1472
1515
15
1351
1372
14 04
1395
14 O1
132
1395
1399
1325
1334
V
14801
12 737
TUREIDITV-TREATED
11
089
986
191
104
1.02
083
998
996
11
1OB
999
1
106
119
1 16
108
996
1.12
994
091
1
1
109
1O5
106
1
106
104
1D4
998
1O6
IDS
133
121
W I
9962
1946
1032
3=
CC
X
u.
BO5
816
8 14
8 14
814
8 14
B 14
813
894
818
899
796
8 16
8 14
818
897
899
BOB
898
898
BD3
894
792
891
791
896
812
B
791
893
814
8 15
894
814
8 14
8 139
8973
BOB3
F.H-TREATED
745
743
741
748
745
735
734
736
734
731
737
716
744
733
726
722
733
72
7 15
723
723
722
728
724
727
738
745
736
727
743
754
751
746
745
746
r
7445
7331
735O
3:
•I
iC
LL.
z
Ul
214
214
213
214
209
21O
209
214
21
21
216
22
223
223
218
219
219
22
221
22
221
221
22
218
21 R
213
214
213
214
216
218
216
216
214
214
F
21333
21660
21606
TEMP -TREATED
208
21
2O6
2O6
205
2O2
202
202
2D4
203
2O8
215
219
214
215
216
218
217
219
22
22
22
216
214
2O8
207
203
204
2D6
205
207
2O6
206
2D6
r
29 TOO
21041
r
209B3
TOTAL PARTICLE COUNT
TREATED
172779
148489
128469
15G592
«2139
148412
14OO67
132960
139083
19O1BO
1601D3
16B7O4
174792
175124
171972
1721B5
172546
168492
172914
176211
174933
172157
173660
171991
169993
172310
171978
172582
1/2862
174156
•B2867
188447
195O59
194932
211706
231815
r
152813333
174862700
1711B78O6
PARTICLE COUNT 3-H. TREATED
10R35
9673
7761
7922
19132
8895
19593
woir
11548
1349O
17641
19262
21556
21D29
19O48
18413
18896
17902
19241
2O4O4
19274
17636
17883
18171
raw
19R52
M77
20453
20165
19305
21294
24533
27933
27899
32767
42769
9293 ODD
r
29299367
1B374972
TOTAL PARTICLE COUNT RAW
661R84
595792
574844
546192
589492
576136
117936O
1DB4B7O
2212960
378928O
3684420
53O512O
5155520
536560O
52716BO
5278960
54222OO
5434360
53S592O
546/68O
5534 12O
5423320
5417240
54466OO
5351360
543712O
5597960
5419560
5795960
538376O
5596880
55358DO
539456O
5530920
5O842OO
r
589223333
r
4895492759
4157275 143
PARTICLE COUNT :>H. RAW
ALUM FLOW RflTE rr-L/mir,
39/59
31488
23024 49/59
12892
12748 59/50
13668
»9SO 50/OK
12107O
120WO 50/OK
234640
58494O 5
527280
6186DO
555480
58120O 5
544040
534720 5
54O72O
549160 5
52332O
5610OO 51
54348O
5WOOO 51
501290
49389O 52/59
472490
48972O 5
5
474240 5 V59
453520
415920 5
476OOO
467000 5
43B48O
424O4O 5
442440
30764O 5
r
17466667
465729310
3BBBB42B6
RAW WATERFLOW RATE mlrmir,
ALUM VOLUME mL
48D/45D 1929
450/GK 1440
45O/GK 12OO
450/GK 680/1680
45D/QK 1060
45O
92O/192O
1620
1349
455 1060
460 740
46O/2OOO
455 1740
146O
454 1010
83O/2DOO
455 16/5
1430
469 «5O
835/2009
460 172O
46O
450 1149
90O/2OOO
450 1740
1450
450 1140/2000
176O
45O 148D
1120
459
SAMPLE ID TREATED
TO001
TR002
TROO3
IROO4
TROO5
TR906
TROO7
TROOB
TOD09
TR919
TO011
TRO12
TR013
TO0 14
TO0 15
TO016
TRO17
TR018
TO0 19
1RO2O
TOO21
TRO22
TR023
TOD24
TR025
TRO26
IRO27
TR028
TOO29
TR030
TRO31
TR032
TOO33
1RO34
TR935
TR936
•I
LL
Cj
S ^ s
S w ~* £
i/i Z i-^ Vi
R(4)OO1
R< 4)002
R(4)OO3
R(4)DO4
R(4)OO5
R(4)006
R(1D)OO7
R(W)OOR XXX
R(20)099
R(2O)O1O
R(20)011
R(4O)O12
R(40)013
R(4O)O14
R( 40)015
R(40)016 XXX
R(4O)O17
R(40)018
R(4O)O19
R(40)O2O
R(4O)D21
R( 40)022
R(40)D23
R{40)O24 X
R(40)025
R( 40)026
R<40)02?
R(40)028
R< 40)029
R( 40)030
R(4O)O31
R(40)032 XXX
R(4O)O33
R(40)O34
R(40)035
R(4D)D36
HPO
MINER SPEEDS
ALUM TUBE POSITION
X
X
X
X
XXX
X
X
X
XXX
X
X
X
X
XXX
X
A-6
-------
Water Treatment Pilot Plant Design Manual
Appendix A: Tables
Table A13. Average percent and log reductions for Test Run 3.
Parameter n
Turbidity 30
Total particles 29
3-6 um particles 29
Bacterial endospores 4
Heterotrophic plate count 4
Total organic carbon 4
Table A14. Water quality parameters for
Parameter
Turbidity, ntu
pH
Temperature, °F
Total particle counts, counts/10 mL
3-6 (J,m particle counts, counts/10 mL
Aerobic bacterial endospores, CFU/100 mL
Synthetic beads, beads/L
% Reduction Log Reduction
92.8
95.9
95.2
94.0
92.3
20
mini pilot plant
Stage n
Raw 67
Settled 67
Filter 1 67
Filter 2 67
Filter 3 67
Raw 17
Settled 17
Filter 1 17
Filter 2 17
Filter 3 17
Raw 41
Settled 51
Raw 35
Settled 35
Filter 1 35
Filter 2 35
Filter 3 35
Raw 35
Settled 35
Filter 1 35
Filter 2 35
Filter 3 35
Raw 6
Settled 6
Filter 1 6
Filter 2 6
Filter 3 6
Raw 5
Settled 4
Filter 1 2
Filter 2 5
Filter 3 5
1.
1.
1.
1.
1.
83-hour test
Mean
15.51
1.90
0.06
0.06
0.13
8.27
6.83
6.88
7.00
6.72
75.8
75.0
8415539
784171
2918
5138
20233
633079
91793
136
219
677
35000
2392
27
15
8
732000
69575
286
259
185
15
42
.35
.22
13
--
run.
Std. Deviation
0.65
0.29
0.02
0.02
0.03
0.09
0.10
0.20
0.24
1.10
0.50
1.18
689943
173228
1309
3390
6996
138357
34814
88
124
220
7668
531
32
9
4
178710
12583
297
60
112
Minimum
14.30
1.20
0.03
0.04
0.08
8.09
6.70
6.10
6.83
2.05
74.9
72.7
6035300
443990
1214
1094
8634
321830
38980
40
57
317
22000
1650
8
6
4
42500
58000
77
196
58
Maximum
17.17
2.74
0.14
0.12
0.25
8.37
7.03
7.10
7.94
7.17
77.0
76.8
9458700
1073930
5636
1094
41304
976800
159330
497
599
1201
44000
3000
92
32
12
979000
82000
496
436
267
A-7
-------
Water Treatment Pilot Plant Design Manual
Appendix A: Tables
Table A15. Water quality parameters
Parameter
Turbidity, NTU
pH
Temperature, °F
Total particles, counts/mL
3-6(im particles, counts/10 mL
Aerobic bacterial endospores,
CFU/100 mL
Synthetic beads, beads/L
for mini
Stage
Raw
Settled
Filter 1
Filter 2
Filter 3
Raw
Settled
Filter 1
Filter 2
Filter 3
Raw
Settled
Raw
Settled
Filter 1
Filter 2
Filter 3
Raw
Settled
Filter 1
Filter 2
Filter 3
Raw
Settled
Filter 1
Filter 2
Filter 3
Raw
Settled
Filter 1
Filter 2
Filter 3
pilot plant
n
45
45
44
44
44
13
13
13
13
13
23
28
24
24
24
24
24
24
24
24
24
24
6
6
6
6
6
5
4
2
5
5
59-hour test run.
Mean ltd
23.45
1.59
0.06
0.06
0.06
8.18
6.88
6.84
6.84
6.84
78.67
74.69
13109312
804969
2200
1336
1153
1020704
64033
130
153
77
48333
2008
101
3
2
594100
348000
286
306
139
. Deviatio
0.62
0.23
0.03
0.03
0.03
0.09
0.07
0.08
0.08
0.08
2.10
1.08
917017
130786
780
4991
502
112302
14076
87
134
74
10093
472
68
1
1
345015
62780
297
88
101
Minimum
22.30
1.12
0.01
0.01
0.00
8.01
6.78
6.74
6.68
6.69
75.50
73.20
10666200
532570
1044
544
531
773120
32800
35
19
13
38000
1400
36
1
1
42500
290000
77
196
58
Maximum
24.80
2.00
0.15
0.11
0.11
8.33
7.03
6.98
6.96
6.98
82.00
77.00
14255040
1056120
3865
4991
2320
1176350
84430
355
541
285
65000
2550
224
4
4
979000
410000
496
436
267
A-8
-------
Water Treatment Pilot Plant Design Manual
Appendix A: Tables
Table A16. Average log reductions during 83-hour test run.
Analysis
Total particles
3-6 um particles
Aerobic bacterial endospores
Synthetic beads
Turbidity
Stage
Settled
Filter 1
Filter 2
Filter 3
Settled
Filter 1
Filter 2
Filter 3
Settled
Filter 1
Filter 2
Filter 3
Settled
Filter 1
Filter 2
Filter 3
Settled
Filter 1
Filter 2
Filter 3
Avg. Log
n Reduction
35
35
35
35
35
35
35
35
6
6
6
6
4
2
5
5
67
67
67
67
1.0
3.5
3.3
2.6
0.9
3.7
3.5
3.0
1.2
3.3
3.4
3.7
1.0
3.5
3.5
3.7
0.9
2.4
2.4
2.1
Std. Deviation
0.09
0.20
0.34
0.13
0.20
0.23
0.28
0.17
0.17
0.42
0.25
0.32
0.09
0.51
0.11
0.35
0.07
0.15
0.12
0.11
A-9
-------
Water Treatment Pilot Plant Design Manual
Appendix A: Tables
Table A17. Average log reductions during 59-hour test run.
Analysis
Stage
Avg. Log
Reduction Std. Deviation
Total Particles
Settled 24
Filter 1 24
Filter 2 24
Filter 3 24
1.2
3.8
4.1
4.1
0.06
0.16
0.22
0.18
3-6 urn Particles
Settled 24
Filter 1 24
Filter 2 24
Filter 3 24
1.2
4.0
4.0
4.3
0.08
0.25
0.38
0.39
Aerobic bacterial endospores Settled
Filter 1
Filter 2
Filter 3
6
6
1.4
2.8
4.3
4.4
0.12
0.27
0.28
0.28
Turbidity
Settled 45
Filter 1 44
Filter 2 44
Filter 3 44
1.2
2.6
2.7
2.6
0.07
0.29
0.31
0.26
A-10
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Appendix B: Figures
Scale: 0.2"=1"
Top view
Raw water and
chemical feed
channel, radius= 1/4"
^
"^
T -
5" -
W :
5
>
~^^ ^^J
"^^ ^^n
3.2"
Side view
A
T
:t
; 7.5"
;
; 1
3.2"
[
A 3/4" diameter for
A 1/2" TFE bulkhead
7.75" "T"
I
4"
i_ i
3.7"
-^^ ^^J
3.2"
^ To floe ^
x basins \
1.6" \^
Rear view
7.5" 7.75"
Figure B3. Rapid mix chamber dimensions constructed of /4-inch polymethyl methacrylate (PMMA).
B-l
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Floe paddles
(a)
3"
9OC
General overhead view
2.0"
(b)
i.
1.5"
T
(a)
Rapid mix paddle
0.5"
2.5"
1.3"
I.
1.1"
(c)
0.75"
I.
T
0.5"
Figure B4. Mixing paddle options/alternatives constructed of stainless steel.
B-2
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Figure B5. Rapid mixing chamber with influent and alum feed lines.
B-3
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Side view
Scale: 0.2"=1"
7"
7"
7"
7"
^
i 1 ®
^
N
©
ll
0.5"
0.5" x— .
T(FBl)
v y
3/4" diameter for
1/2" TFE bulkhead
\
— £
CO
o>
»-
I
0.5"
1" ^
A
7.5"
7"
Inlet
From rapid mix
3/4" diameter for
1/4" TFE bulkhead
Front view
28 3/4"
I I
7.5"
7"
Outlet
To sedimentation
1"
3/4" diameter for
1/4" TFE bulkhead
Rear view
r^
T
Do
K
Figure B6a. Flocculation basin dimensions constructed of /4-inch polymethyl methacrylate (PMMA).
B-4
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
2"
LT>
C\i
LT>
O
9"
1"
0.5" 0.5"
0.25"
-7"
0.75"
0.25"
-7"
Scale: 0.2"=1"
T
°-5"
13"
Baffle (FB1)
Baffle FB2
Figure B7b. Flocculation baffle dimensions (constructed of %—in polymethyl methacrylate).
B-5
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Figure B8c. Flocculation chambers (side view).
Figure B9d. Flocculation chambers (top view).
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Scale: 0.2"=1"
Front view
SB1
From floe basin
3/4" diameter for
1/2" TFE bulkhead
15"
34.75"
-34.25"
GB2J
Metal support
rods
The location of
baffle SB2 is
adjustable.
Side view
^ To sand
• A v
; 3"
filters ;
-^ \
3/4" diameter for ^
1/2" SS bulkhead ;
^— *™ te^
Rear view
15" 15.25"
1
Figure B5a. Settling basin design constructed of %-inch polymethyl methacrylate (PMMA).
B-7
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Scale: 0.2"=1"
.. I
_ \^^ 14" ^ |
t ^
5" 0.25" ^-\ -^
|
I'
3"
y o.5"
3"
J
[ f
0.25" ^
n
a
c —
[
^
•^
H
H
ri
| 14"
-
2"
15
7
f
2"
-*
@ 3/8" diameter
2"
2"
2"
2"
T 0.5"
I,
4"
Baffle SB1
Baffle SB2
Figure B5b. Settling baffles design constructed of %-inch polymethyl methacrylate (PMMA).
B-S
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Figure BlOc. Sedimentation basin showing sludge accumulation after a 72-hr run.
B-9
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
/^^T/
I
S^N^^
v~"^[
threaded
S
\ i
' I' I' ' /
CO /
1/2" TFE
plate
\
TFE
hole
. — -J
~'"~' filter
^^ wall
insert
bolt/nut
X
TjPL .^-flange
111^
^\S^\^^ -^ gasket
i
/
M ^\ flange
^L^^
1/4" dia.
\ ^^ tubing
Figure Blla. Filter base design details (not drawn to scale).
B-10
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
9"
6'
Scale: 1"=10"
2.48'= Height of standing water
30" media (single or duel media)
4" course sand
T
6" #4 gravel
2 -e
6" #3 gravel
Figure B12b. Filter design and media configuration.
B-ll
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
From sedimentation
tankstandpipe
1/4" SS sample port
Figure B13c. Detail of filter top including filter splitter tube (not to scale).
B-12
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Figure B14d. Full view of filter setup.
B-13
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Figure B15e. Filter distribution network showing sample ports for settled water and filtrate.
B-14
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Figure B16f. Filter pump system and backwash pumps.
B-15
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
from weir
to next filter
from clearwell
headloss
tube
open
off
closed
l/y open
r
overfl
va
-Cs;
valve to control
„.., „,
filter flow
ope«
(X) valve
(3) 3-way valve
O pump
, . ..
to clearwell
T
sample
collect
on
Figure B17a. Water flow direction and filter configuration when in normal operation.
B-16
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
from weir
to next filter
headless
tube
closed (X)
from clearwell
/\7\
(X) closed
valve
(3) 3-way valve
pump
overflow
to waste
valve to control
filter flow
to clearwell
-<3>^
sample
collect
open
on
off
Figure B18b. Water flow direction and filter configuration when in backwash mode.
B-17
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Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Figure B19a. Filtrate clearwells showing lines leading to waste and to backwash.
B-18
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
from filter effluent
disinfectant feed
static mixer
non-load bearing lid
sample collection or
overflow to waste
to backwash pump
upflow
fitting and valve
to drain
Figure B20b. Schematic of future clearwell (not to scale).
B-19
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Figure B21. Raw water and alum feed systems for Cryptosporidium parvum oocyst.
B-20
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
ffl
ft
8.2
8.0
7.8
7.6
7.4
7.2
7.0
6.8
0
Turbidity-Raw
Turbidity-Settled
pH-Raw
pH-Settled
234
Elapsed Time, hrs
14
12
10
8
H
Z
•V
£>
• rt
"O
• **
'_
0
H
0
6
Figure B22. Pilot plant Test Run 1 with Ohio River water treated by alum coagulation. Raw water
temperature was 18.1-18.9°C, and settled water temperature was 18.8-19.2°C.
B-21
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Water Treatment Pilot Plant Design Manual
Appendix B: Figures
Turbidity-Raw
Turbidity-Settled '_
pH-Raw
pH-Settled
7.0 -
4 6 8 10
Elapsed Time, hrs
12
14
Figure B23. Pilot plant test run 2 with Ohio River water treated by alum coagulation. Raw water
temperature was 19.4-20.0°C, and settled water temperature was 18.8-21.3°C.
B-22
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
22.5
22.0
I
0)
21.5
I 21.0
H
20.5
20.0
0
10 20
Elapsed Time, hrs
30
40
Figure B24. Temperature variation during pilot plant Test Run 3 with Ohio River water treated by alum
coagulation.
B-23
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
B
8.4
8.2
8.0
7.8
7.6
7.4
7.2
7.0
Raw
Settled
0
10 20 30
Elapsed Time, hrs
40
Figure B25. pH variation during pilot plant Test Run 3 with Ohio River water treated by alum
coagulation.
24
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
25
20 -
15 -
P
H
£
1 10
!a
H
5 -
o -
0
Raw
Settled
10 20
Elapsed Time, hrs
30
40
Figure B26. Turbidity variations during pilot plant Test Run 3 with Ohio River water treated by alum
coagulation.
B-25
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
1000000
-
o
s=
3
o
^CJ
'*-
PLH
E
100000
10000
1000
0
10 20
Elapsed Time, hrs
30
40
Figure B27. Three to six-micrometer (nm) particle variation during pilot plant Test Run 3 with Ohio
River water treated by alum coagulation.
B-26
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
10000000
_
o
c
o
u
r
O
H
1000000
100000
Raw
Settled
0
10 20
Elapsed Time, hrs
30
40
Figure 28. Total particle variation during pilot plant Test Run 3 with Ohio River water treated by alum
coagulation.
B-27
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
c/
Q
H
y = 1393x + 195.33
R2 = 0.9988
0.4
0.8 1.2
Concentration KC1, g/1
1.6
2.0
Figure B29. Impact of potassium chloride (KCL) on total dissolved solids (IDS) concentration of Ohio
River water.
B-28
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
1000 -
800 -
a 600 \-
c.
Q
H
400 I-
200 -
0
0
Col 1 vs Col 5
o Col 1 vs Col 9
200 400 600
Elapsed Time, minutes
800
Figure B30. Prototype mini pilot plant rising step tracer test results.
B-29
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
1.2
1.1
1.0
0.9
1 0.8
13
•1 0.7
0)
a 0.6
•3
€ 0.5
U
g 0.4
0.3
0.2
0.1
0.0
0
T10/T = 14/61.5 = 0.23
= 14 minutes
50 75 100
Elapsed Time, minutes
800
Figure B31. Prototype mini pilot plant rising step tracer results for rapid mix and flocculation processes
(Cs/Cs,o = normalized tracer concentration).
B-30
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
T10/T = 105/301.5 = 0.35
200 400 600
Elapsed Time, minutes
800
Figure B32. Prototype mini pilot plant rising step tracer results for rapid mix, flocculation, and
sedimentation processes (CS/CS,0 = normalized tracer concentration).
B-31
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
1.0
0.9
0.8
u
u
4)
g 0.5
o
U
0.4
g 0.3
0.2
0.1
0.0
0
1 2
Normalized Time, T/To
Figure B33. Normalized time vs. normalized concentration of Filter #2.
B-32
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
o
U
1.0
0.9
0.8
0.7
°'6
-*j
&
4)
a °-5
o
U
S 0.3
o
0.2
0.1
0.0
0
1 2
Normalized Time, T/To
Figure B34. Normalized time vs. normalized concentration of Filter #3.
B-33
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
1.0
0.8
o
U
s=
o
S 0.6
0)
o
e
o
U
.-
"«
•-
o
0.4
0.2
0.0
N =2
^ ^
^Experimental
N = 1 '• \ \
^CSTR A '->\\
0
1 2 3
Normalized Time, T/To
Figure B35. Pulse input tracer study results and theoretical CSTRs.
B-34
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
1.0
o
U
D
0.8
o
U
.s
I
o
0.4
0.2
0.0
0
123
Normalized Time, T/To
Figure B36. Pulse input tracer study results following flocculation unit modifications.
B-35
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
1 1 Total Particle Counts
V////A 3-6 mm Particle Cojjnts __
'Rx\S?xxJ Spores
•g&£28 Beads
•
•
•
•
•
•
•
n
V
V
\ B"3
^ 1
1
PI
\
y
y
j
y
y
X
y
y
x
x
X
y
y
X
X
X
X
X
X
y
X
X
x
x
X
x
X
X
x
X
X
y
J
s
y
\
\
\
V
s
x
s
s
s
X
X
s
s
s
\
s
X
X
s
s
s
x
X
s
s
s
X
!
,
1A
y
/,
y
y
/,
y
y
/,
y
y
/,
y
y
/,
y
y
/,
/
y
/
/
y
y
/,
y
y
/,
y
y
/,
y
'j
j
y
\
^
s
s
s
\
s
V
s
s
X
s
s
\
s
V
s
X
s
\
s
s
s
s
i
1
§
?
?
?
?
«
f
>
c
?
I
f
f
f
f
,
f
to
I
H
k$
?
§
<
2
>
?
<
c
?
c
<
c
%
?
c
£
1
«
>
<:
?
?
i
WJ-.
/
y
/
y
/,
y
y
/,
y
y
/,
y
y
/,
/
/
y
/,
y
y
/,
y
y
/,
y
/
y
/,
y
'j
j
y
\
S
^
\
s
\
X
s
X
X
V
x
x
X
X
\
X
x
V
x
x
X
x
x
s
s
j
-
•
•
•
•
-
-
••
•
_
•
o
2
wo
WD
«
o
Settled
Filter 1 Filter 2
Filter 3
Figure B37. Log removal comparisons (83-hour run).
B-36
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
o
WD
O
WD
CS
OJ
4.0
3.5
2.0
1.5
1.0
0.5
0.0
;l 1 Total Particle Counts
•Y////A 3-6 mm Particle <
•R^^N Spores
-
.
•
.
™
.
•
•
•
"
B
.
~
-
-
" ar-<
X
X
: ^
x
X
x
X
x
- X
x
X
x
c<
mnts
I
t
/
/
y
/
/
/
'/,
'/
/,
/
/
/
xxxxv
^
^
/
f
f
/
\
/
/
\
s
!
^
^
o
o
\
X
X
o
1
X
^
X
x
$
x
x
x
^
X
X
^
^
f
^
/
/
^
J
J
/.
'/,
'/
J
J
J
f
/
^^^^^:
^
j
j
f
/
^
/
/
\
j
\
I
I
X
^
X
X
s
x
X
^
s
s
x
X
X
X
X
x
1
^
^
X
X
X
s
X
X
X
^
X
x
^
1
s
\
s
s
^
*^
y
s
X
^
*^
y
y
y
X
y
^
^
^
\
X
X
X
x
X
X
X
X
x
X
X
x
X
X
•
-
-
.
-
•
™
.
•
-
^
™
m
m
~
-
-
•
•
m
-
m
m
-
.
Settled
Filter 1 Filter 2 Filter 3
Figure B38. Log removal comparisons (59-hour run).
B-37
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
10.00
H
Z
•V
£>
• rt
"O
• **
'_
3
H
1.00
0.10
0.01 -
Raw water
Settled water
Filter 1
Filter 2
Filter 3
w
vvtvdk
J>1'
,\fvVV \ T T
jrv
v w
*V
0 10 20 30 40 50 60
Elapsed time, hours
70
80
Figure B39. Turbidity values at locations in the pilot plant during 83-hour test run.
B-38
-------
Water Treatment Pilot Plant Design Manual
Appendix B: Figures
10
1 1
•V
-*•>
•3
>_
s
H
0.1
0.01
1 1 1 1 1 1
: -
'*p 'W^o'U
-------
Water Treatment Pilot Plant Design Manual
Appendix C: Calculations & Worksheets
Appendix C: Calculations & Worksheets
Table CIS. Rapid mix chamber calculations for paddle radius of 1.2-inches (in) and depth of 0.9-in. It is
assumed that each base is square with a flow rate of 450 mL/min.
Flow rate (iiil/inin) =
Total Residence Time (mill) =
Vol. rapid mix basin (L) =
Vol. rapid mix basin (it3) =
450
1.5
0.675
0.0238
Inputs
# of paddles =
Radius of paddles (in) =
Depth of each paddle (in) =
Cd =
Density (lbni/ft3) =
Dynamic Viscosity (Ib-sec/ft2) =
Calc.
Area of all paddles (ft2) =
4
1.10
1.3
1.2
62.4
1.90E-05
0.0397
Height
(cm)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
RPMs
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
135
140
145
150
155
Calculated
Base (cm')
26.0
18.4
15.0
13.0
11.6
10.6
9.8
9.2
8.7
8.2
7.8
7.5
7.2
6.9
6.7
6.5
6.3
6.1
6.0
5.8
5.7
5.5
5.4
5.3
5.2
Paddle Tip H2O
Velocity (ft/sec)
0.432
0.468
0.504
0.540
0.576
0.612
0.648
0.684
0.720
0.756
0.792
0.828
0.864
0.900
0.936
0.972
1.008
1.044
1.080
1.116
Height
Inches
0.39
0.79
1.18
1.57
1.97
2.36
2.76
3.15
3.54
3.94
4.33
4.72
5.12
5.51
5.91
6.30
6.69
7.09
7.48
7.87
8.27
8.66
9.06
9.45
9.84
Power
Ibs* ft/sec
3.722E-3
4.733E-3
5.911E-3
7.270E-3
8.824E-3
1.058E-2
1.256E-2
1.478E-2
1.723E-2
1.995E-2
2.294E-2
2.621E-2
2.978E-2
3.366E-2
3.786E-2
4.240E-2
4.729E-2
5.254E-2
5.816E-2
6.418E-2
Calc. Base
Inches
10.23
7.23
5.91
5.11
4.57
4.18
3.87
3.62
3.41
3.23
3.08
2.95
2.84
2.73
2.64
2.56
2.48
2.41
2.35
2.29
2.23
2.18
2.13
2.09
2.05
G
(I/sec)
90.7
102.2
114.2
126.7
139.6
152.9
166.6
180.6
195.1
209.9
225.1
240.6
256.4
272.6
289.1
306.0
323.1
340.6
358.4
376.4
G*t
(unitless)
2040
2300
2571
2851
3141
3440
3748
4064
4389
4723
5064
5413
5770
6134
6506
6885
7271
7664
8064
8470
Organics Pilot Plant
100
1.31
194
C-l
-------
Water Treatment Pilot Plant Design Manual
Appendix C: Calculations & Worksheets
Table C19. Rapid mix chamber calculations for paddle radius of
assumed that each base is square with a flow rate of 450 mL/m
Flow rate (ml/mm) = 450 Height
Total Residence Time (min) = 1.5 (cm)
1
Vol. rapid mix basin (L) = 0.675 2
Vol. rapid mix basin (ft3) = 0.0238 3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Inputs RPMs
# of paddles = 4 60
Radius of paddles (in) = 1.10 65
Depth of each paddle (in) = 1.3 70
Cd= 1.2 75
80
85
Density (lbm/ft3) = 62.4 90
Dynamic Viscosity (lb*sec/ft2) = 1 .90E-05 95
100
105
Calc. 110
Area of all paddles (ft2) = 0.0397 115
120
125
130
135
140
145
150
155
1.1-inches (in) and depth of 1.3-in. It is
in.
Calculated Height Calc. Base
Base (cm) Inches Inches
26.0
18.4
15.0
13.0
11.6
10.6
9.8
9.2
8.7
8.2
7.8
7.5
7.2
6.9
6.7
6.5
6.3
6.1
6.0
5.8
5.7
5.5
5.4
5.3
5.2
Paddle Tip H2O
Velocity (ft/sec)
0.432
0.468
0.504
0.540
0.576
0.612
0.648
0.684
0.720
0.756
0.792
0.828
0.864
0.900
0.936
0.972
1.008
1.044
1.080
1.116
0.39
0.79
1.18
1.57
1.97
2.36
2.76
3.15
3.54
3.94
4.33
4.72
5.12
5.51
5.91
6.30
6.69
7.09
7.48
7.87
8.27
8.66
9.06
9.45
9.84
Power
lbs*ft/sec
3.722E-3
4.733E-3
5.911E-3
7.270E-3
8.824E-3
1.058E-2
1.256E-2
1.478E-2
1.723E-2
1.995E-2
2.294E-2
2.621E-2
2.978E-2
3.366E-2
3.786E-2
4.240E-2
4.729E-2
5.254E-2
5.816E-2
6.418E-2
10.23
7.23
5.91
5.11
4.57
4.18
3.87
3.62
3.41
3.23
3.08
2.95
2.84
2.73
2.64
2.56
2.48
2.41
2.35
2.29
2.23
2.18
2.13
2.09
2.05
G
(I/sec)
90.7
102.2
114.2
126.7
139.6
152.9
166.6
180.6
195.1
209.9
225.1
240.6
256.4
272.6
289.1
306.0
323.1
340.6
358.4
376.4
G*t
(unitless)
2040
2300
2571
2851
3141
3440
3748
4064
4389
4723
5064
5413
5770
6134
6506
6885
7271
7664
8064
8470
Organics Pilot Plant
100
1.31
194
C-2
-------
Water Treatment Pilot Plant Design Manual
Appendix C: Calculations & Worksheets
Table C20. Rapid mix chamber
that each base is square with a
Flow rate (ml/niln) =
Total Residence Time (min) =
Vol. rapid mix basin (L) =
Vol. rapid mix basin (ft ) =
Inputs
# of paddles =
Radius of paddles (in) =
Depth of each paddle (in) =
Cd =
Density (lbm/ft3) =
Dynamic Viscosity (lb*sec/ft2) =
Calc.
Area of all paddles (ft ) =
calculations for paddle radius of
flow rate of 450 mL/min.
450 Height
1.5 (cm)
1
0.675 2
0.0238 3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
RPMs
4 60
1.00 65
1.9 70
1.2 75
80
85
62.4 90
1.90E-05 95
100
105
110
0.0528 115
120
125
130
135
140
145
150
155
1.0-inch (in) and
Calculated
Base (cm)
26.0
18.4
15.0
13.0
11.6
10.6
9.8
9.2
8.7
8.2
7.8
7.5
7.2
6.9
6.7
6.5
6.3
6.1
6.0
5.8
5.7
5.5
5.4
5.3
5.2
Paddle Tip H2O
depth of
Height
Inches
0.39
0.79
1.18
1.57
1.97
2.36
2.76
3.15
3.54
3.94
4.33
4.72
5.12
5.51
5.91
6.30
6.69
7.09
7.48
7.87
8.27
8.66
9.06
9.45
9.84
Power
Velocity (ft/sec) lbs*ft/sec
0.393
0.425
0.458
0.491
0.524
0.556
0.589
0.622
0.654
0.687
0.720
0.753
0.785
0.818
0.851
0.884
0.916
0.949
0.982
1.014
3.716E-3
4.725E-3
5.901E-3
7.258E-3
8.808E-3
1.057E-2
1.254E-2
1.475E-2
1.720E-2
1.992E-2
2.290E-2
2.616E-2
2.973 E-2
3.360E-2
3.780E-2
4.233E-2
4.721E-2
5.245E-2
5.806E-2
6.406E-2
1.9-in. It
Calc. Base
Inches
10.23
7.23
5.91
5.11
4.57
4.18
3.87
3.62
3.41
3.23
3.08
2.95
2.84
2.73
2.64
2.56
2.48
2.41
2.35
2.29
2.23
2.18
2.13
2.09
2.05
G
(I/sec)
90.6
102.1
114.1
126.6
139.5
152.7
166.4
180.5
194.9
209.7
224.9
240.4
256.2
272.4
288.9
305.7
322.9
340.3
358.1
376.1
is assumed
G*t
(unitless)
2038
2298
2568
2848
3138
3437
3744
4061
4385
4718
5059
5408
5765
6129
6500
6879
7264
7657
8057
8463
Organics Pilot Plant
100
1.31
194
c-:
-------
Water Treatment Pilot Plant Design Manual
Appendix C: Calculations & Worksheets
Table C21. Flocculation calculations for paddle radius of 2-inches (in) and depth of 3-in. Assumptions: (1) four
flow basins, (2) each base is square, and (3) the flow rate = 450 mL/min.
Flow rate (ml/min) = 450
Total Residence Time (min) = 60
Vol.of each floe basin (L)= 6.75
Vol.of each floe basin (gal) = 1 .78
Vol.of each floe basin (ft3) = 0.238
Inputs
# of paddles = 4
Radius of paddles (in) = 2
Depth of each paddle (in) = 3
Cd= 1.2
Density (Ibm/ft3) = 62.4
Dynamic Viscosity (lb*sec/ft2) = 1 .90E-05
Calc.
Area of all paddles (ft2) = 0. 167
Height
(cm)
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
40
RPMs
5
7.5
10
12.5
15
17.5
20
22.5
25
27.5
30
32.5
35
37.5
40
42.5
45
47.5
50
55
Calculated
Base (cm)
21.2
20.5
19.9
19.4
18.8
18.4
17.9
17.5
17.1
16.8
16.4
16.1
15.8
15.5
15.3
15.0
14.8
14.5
14.3
14.1
13.9
13.7
13.5
13.3
13.0
Paddle Tip H2O
Velocity (ft/sec)
0.065
0.098
0.131
0.164
0.196
0.229
0.262
0.295
0.327
0.360
0.393
0.425
0.458
0.491
0.524
0.556
0.589
0.622
0.654
0.720
Height
Inches
5.9
6.3
6.7
7.1
7.5
7.9
8.3
8.7
9.1
9.4
9.8
10.2
10.6
11.0
11.4
11.8
12.2
12.6
13.0
13.4
13.8
14.2
14.6
15.0
15.7
Power
lbs*ft/sec
5.433E-5
1.834E-4
4.346E-4
8.489E-4
1.467E-3
2.329E-3
3.477E-3
4.951E-3
6.791E-3
9.039E-3
1.173E-2
1.492E-2
1.863E-2
2.292E-2
2.782E-2
3.336E-2
3.960E-2
4.658E-2
5.433E-2
7.23 1E-2
Calc. Base
Inches
8.4
8.1
7.8
7.6
7.4
7.2
7.1
6.9
6.7
6.6
6.5
6.3
6.2
6.1
6.0
5.9
5.8
5.7
5.6
5.5
5.5
5.4
5.3
5.2
5.1
G
(I/sec)
3.5
6.4
9.8
13.7
18.0
22.7
27.7
33.1
38.7
44.7
50.9
57.4
64.1
71.1
78.4
85.8
93.5
101.4
109.5
126.4
G*t
(unitless)
3117
5727
8817
12322
16198
20411
24938
29757
34852
40208
45814
51658
57732
64027
70535
77250
84165
91275
98575
113725
C-4
-------
Water Treatment Pilot Plant Design Manual
Appendix C: Calculations & Worksheets
Table C22. Flocculation calculations for paddle radius of 2.5-inches (in) and depth of 1.5 in. Assumptions: (1)
four flow basins, (2) each base is square, and (3) the flow rate = 450 mL/min.
Flow rate (ml/min) = 450
Total Residence Time (min) = 60
Vol.of each floe basin (L) = 6.75
Vol. of each floe basin (gal) = 1 .78
Vol. of each floe basin (ft3) = 0.238
Inputs
# of paddles = 4
Radius of paddles (in) = 2.5
Depth of each paddle (in) = 1.5
Cd= 1.2
Density (lbm/ft3) = 62.4
Dynamic Viscosity (lb*sec/ft2) = 1 . 90E-05
Calc.
Area of all paddles (ft2) = 0 . 1 04
Height
(cm)
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
40
RPMs
5
7.5
10
12.5
15
17.5
20
22.5
25
27.5
30
32.5
35
37.5
40
42.5
45
47.5
50
55
Calculated
Base (cm)
21.2
20.5
19.9
19.4
18.8
18.4
17.9
17.5
17.1
16.8
16.4
16.1
15.8
15.5
15.3
15.0
14.8
14.5
14.3
14.1
13.9
13.7
13.5
13.3
13.0
Paddle Tip H2O
Velocity (ft/sec)
0.082
0.123
0.164
0.205
0.245
0.286
0.327
0.368
0.409
0.450
0.491
0.532
0.573
0.614
0.654
0.695
0.736
0.777
0.818
0.900
Height
Inches
5.9
6.3
6.7
7.1
7.5
7.9
8.3
8.7
9.1
9.4
9.8
10.2
10.6
11.0
11.4
11.8
12.2
12.6
13.0
13.4
13.8
14.2
14.6
15.0
15.7
Power
lbs*ft/sec
6.632E-5
2.238E-4
5.305E-4
1.036E-3
1.791E-3
2.843E-3
4.244E-3
6.043E-3
8.290E-3
1.103E-2
1.432E-2
1.821E-2
2.275E-2
2.798E-2
3.395E-2
4.073E-2
4.835E-2
5.686E-2
6.632E-2
8.827E-2
Calc. Base
Inches
8.4
8.1
7.8
7.6
7.4
7.2
7.1
6.9
6.7
6.6
6.5
6.3
6.2
6.1
6.0
5.9
5.8
5.7
5.6
5.5
5.5
5.4
5.3
5.2
5.1
G
(I/sec)
3.8
7.0
10.8
15.1
19.9
25.1
30.6
36.5
42.8
49.4
56.2
63.4
70.9
78.6
86.6
94.8
103.3
112.1
121.0
139.6
G*t
(unitless)
3444
6327
9741
13614
17896
22552
27553
32877
38506
44424
50617
57075
63785
70740
77931
85350
92990
100846
108911
125650
C-5
-------
Water Treatment Pilot Plant Design Manual
Appendix C: Calculations & Worksheets
Table C23, Flocculation calculations for paddle radius of 3-inches (in) and depth of 0.75-in. Assumptions: (1)
four flow basins, (2) each base is square, and (3) the flow rate = 450 mL/min.
Flow rate (ml/min) = 450
Total Residence Time (min) 60
Vol.of each floe basin (L)= 6.75
Vol. of each floe basin (gal) = 1 .78
Vol. of each floe basin (ft3) = 0.238
Inputs
# of paddles = 4
Radius of paddles [in] = 3
Depth of each paddle [in] = 0 . 75
Cd= 1.2
Density [lbm/ft3] = 62.4
Dynamic Viscosity 1 . 90E-05
[lb*sec/ft2] =
Calc.
Area of all paddles [ft2] = 0.063
Height
(cm)
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
40
RPMs
5
7.5
10
12.5
15
17.5
20
22.5
25
27.5
30
32.5
35
37.5
40
42.5
45
47.5
50
55
Calculated
Base (cm)
21.2
20.5
19.9
19.4
18.8
18.4
17.9
17.5
17.1
16.8
16.4
16.1
15.8
15.5
15.3
15.0
14.8
14.5
14.3
14.1
13.9
13.7
13.5
13.3
13.0
Paddle Tip H2O
Velocity (ft/sec)
0.098
0.147
0.196
0.245
0.295
0.344
0.393
0.442
0.491
0.540
0.589
0.638
0.687
0.736
0.785
0.834
0.884
0.933
0.982
1.080
Height
Inches
5.9
6.3
6.7
7.1
7.5
7.9
8.3
8.7
9.1
9.4
9.8
10.2
10.6
11.0
11.4
11.8
12.2
12.6
13.0
13.4
13.8
14.2
14.6
15.0
15.7
Power
lbs*ft/sec
6.876E-5
2.321E-4
5.501E-4
1.074E-3
1.856E-3
2.948E-3
4.400E-3
6.266E-3
8.595E-3
1.144E-2
1.485E-2
1.888E-2
2.358E-2
2.901E-2
3.520E-2
4.223E-2
5.012E-2
5.895E-2
6.876E-2
9.152E-2
Calc. Base
Inches
8.4
8.1
7.8
7.6
7.4
7.2
7.1
6.9
6.7
6.6
6.5
6.3
6.2
6.1
6.0
5.9
5.8
5.7
5.6
5.5
5.5
5.4
5.3
5.2
5.1
G
(I/sec)
3.9
7.2
11.0
15.4
20.2
25.5
31.2
37.2
43.6
50.3
57.3
64.6
72.2
80.0
88.2
96.6
105.2
114.1
123.2
142.2
G*t
(unitless)
3507
6443
9919
13862
18222
22963
28055
33476
39208
45234
51540
58115
64948
72030
79352
86906
94686
102685
110897
127941
C-6
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Water Treatment Pilot Plant Design Manual
Appendix C: Calculations & Worksheets
Table C24. Sedimentation calculation worksheet.
Q
(mL/min)
450
450
450
450
450
450
450
450
450
450
450
450
450
time
0*)
4
3
2
6
4
2
6
4
2
6
4
O
2
Volume
(gal)
28.5
21.4
14.3
42.8
28.5
14.3
42.8
28.5
14.3
42.8
28.5
21.4
14.3
Volume
(ft3)
3.81
2.86
1.90
5.71
3.81
1.90
5.71
3.81
1.90
5.71
3.81
2.86
1.90
Surface
loading
rate, SLR
(gpd/ft2)
1000
1000
1000
500
500
500
120
120
120
60
60
60
60
SLR
mL/min
(ft2)
2630
2630
2630
1315
1315
1315
316
316
316
158
158
158
158
Surface
area, As
(ft2)
0.17
0.17
0.17
0.34
0.34
0.34
1.42
1.42
1.42
2.85
2.85
2.85
2.85
Depth
(ft)
22.4
16.8
11.2
16.8
11.2
5.6
4.02
2.86
1.33
2.00
1.33
1.00
0.67
Re
0.56
0.84
1.70
2.20
2.90
5.70
3.70
5.10
6.20
8.10
C-7
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Water Treatment Pilot Plant Design Manual
Appendix C: Calculations & Worksheets
Table C25. Sedimentation basin design worksheet.
As Length
(ft2) (ft)
1.42 2.11
1.42 2.11
1.42 2.11
2.85 2.85
2.85 2.85
2.85 2.85
2.85 2.85
Width Depth
(ft) (ft)
0.67 4.02
0.67 2.86
0.67 1.33
1.00 2.00
1.00 1.33
1.00 1.00
1.00 0.67
Table C26. Filter
Loading Rate
gpm/ft2
2
4
6
(DxW) (W+2D) R
(Q/WxD)
Vo
A (ft2) P (ft) (A/P) (ft/min) Re
2.69 8.71 0.31
1.92 6.39 0.30
0.89 3.33 0.27
2.00 5.00 0.40
1.33 3.66 0.36
1.00 3.00 0.33
0.67 2.33 0.29
design parameters.
Q Q
ml/min m/hr
93 4.9
186 9.8
279 14.7
0.006 2.2
0.008 2.9
0.018 5.7
0.008 3.7
0.012 5.1
0.016 6.2
0.024 8.1
EBCT
min.
9.4
4.7
3.1
LAV
3.14
3.14
3.14
2.85
2.85
2.85
2.85
-------
Water Treatment Pilot Plant Design Manual Appendix C: Calculations & Worksheets
Table C27. Combined overflow for various filter configurations.
Combined
Number Q LR EBCT Q LR EBCT Q LR EBCT Overflow
Filters mL/min gpm/ft2 min. mL/min gpm/ft2 min. mL/min gpm/ft2 min. mL/min
3 93 2 9.4 93 2 9.4 93 2 9.4 171
2 186 4 4.7 93 2 9.4 171
2 93 2 9.4 93 2 9.4 264
1 279 6 3.1 171
1 186 4 4.7 364
1 93 2 9.4 357
C-9
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Water Treatment Pilot Plant Design Manual
Appendix C: Calculations & Worksheets
Table C28. Clearwell design worksheet.
Volume
(gal)
9.85
10
10
10
14.6
15
15
15
14.75
19.54
20
20
20
Length, L
(in)
9
12
12
12
15
12
12
12
9
15
12
12
12
Width, W
(in)
9
12
12
12
15
12
12
12
9
15
12
12
12
Height, H*
(in)
28
16
16
16
15
24
24
24
42
20
32
32
32
Volume
(ft3)
1.31
1.33
1.33
1.33
1.95
2
2
2
1.97
2.61
2.67
2.67
2.67
Q
(mL/min)
93
93
186
297
93
93
186
297
93
93
93
93
93
Filter
loading rate
(gpm/ft2)
2
2
4
6
2
2
4
6
2
2
2
4
6
Retention time,
(hrs)
6.68
6.75
3.38
2.12
9.87
10.14
5.07
3.18
10
13.2
13.5
6.75
4.14
* Level to overflow
C-10
-------
Water Treatment Pilot Plant Design Manual
Appendix C: Calculations & Worksheets
2000
1750 -
1500 -
1250 -
01
=3 1000
A
L.
M)
•"g 750
0
500 -
250 -
0 50 100 150 200 250 300 350 400 450 500
Mixer speed, rpm
Figure C41. Calculated velocity gradient for four rapid mix paddles having all three radii and depth sizes as
identified in Tables Cl through C3.
C-ll
-------
Water Treatment Pilot Plant Design Manual
Appendix C: Calculations & Worksheets
400
350 -
300 -
o 25°"
•N
"S
i 200 H
_o
"3
100 -
50 -
2.5" radius, 1.5" depth
2.0" radius, 3.0" depth
3.0" radius, 0.75" depth
0 10 20 30 40 50 60 70 80 90 100
Mixer speed, rpm
Figure Cl. Calculated velocity gradient for four flocculation mix paddles having all three radii and
depth sizes identified in Table C4 through C6.
C-12
-------
Water Treatment Pilot Plant Design Manual
Appendix D: Analysis Results
Appendix D: Analysis Results
-------
Water Treatment Pilot Plant Design Manual
Appendix D: Analysis Results
JS
4)
-
4)
PH
100
90
80
70
60
50
40
30
20
10
0
Effective Size = 0.46 mm
Uniformity Coefficient =
D60/D10 = 1.457
^i i i i \i i i i i i i i i i i\ i i i i i i i i i i i"
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
Particle Size, mm
Figure D2. Particle size distribution of fine sand filter media
D-2
-------
Water Treatment Pilot Plant Design Manual
Appendix D: Analysis Results
100
90
80
£ 70
.Sf
"S
60
50
40
30
20
10
0
1/3
1/3
2
-*j
4)
PH
1 • • • i • • • • i • • • • i • • • • i • •
Effective Size = 0.65 mm
- Uniformity Coefficient =
D60/D10 = 1.877
D60 = 1.22 mm
D10 = 0.65 mm
I .... l\, ... I .
0.2 0.4 0.6 0.8 1.0 1.2 1.4
Particle Size, mm
1.6 1.8 2.0
Figure D3. Particle size distribution of coarse sand filter media
D-3
------- |