338774160-Water-Treatment-Plant-Design-Project_2.pdf

Dalhousie University (Sexton Campus)
Department of Civil & Resource Engineering
CIVL 4440 – Water and Wastewater Treatment
Water Treatment Plant Design Project
GROUP #7
Oguz Avci B00572497
Firas Freja B00590689
Jason Beanlands B00494520
Jessica Goodland B00472850
Ahmed Abu Laila B00685906
Submitted to:
Dr. Margaret Walsh
Client:
Town of Ferguson
December 9th, 2016

Water Treatment Plant Design Project 1
1
i. Letter of Transmittal
Dear Prof. Walsh,
Enclosed is the report you commissioned on September 9, 2016 on the proposal
encompassing a design for a new water treatment plant to replace the existing facility in the
Town of Ferguson following the regulations of the Environment Act. The main findings of the
report are seen below:
pH = 6.4, N = 1.47 NTU, UV254 = 0.09, Color = 11 ptco, TOC = 3.574 mg/L, DOC = 3.484 mg/L
We would like to thank you for the information and the scope you provided in terms of
approaching design.
We would also like to thank Sean MacIsaac for his assistance in the lab along with his help in
technical parameters of the project throughout the semester.
We hope with our design; Town of Ferguson will have access to a higher quality of drinking
water with no threat to their health.
Regards,
Oguz Avci.

2
ii. Executive Summary
In order to understand and learn the principles and scope of designing a drinking water
treatment plant, a consulting project for the Town of Ferguson was initiated. The project
included a set of tests and optimizations on the water characteristics which would allow for
the design of a new water treatment plant. The major objective of the plant was to produce
safe drinking water which was ensured to meet the current environmental standards.

3
TABLE OF CONTENTS
i. Letter of Transmittal..........................................................................................................................1
ii. Executive Summary........................................................................................................................2
LIST OF TABLES.....................................................................................................................................................4
LIST OF FIGURES...................................................................................................................................................4
1. Introduction...................................................................................................................................................5
2. Literature Review........................................................................................................................................5
3. Experimental Results.................................................................................................................................5
3.1. Source Water Parameters and Metals Data...............................................................................5
3.2. Jar Test Results and Alum Doses...................................................................................................6
4. Design Description......................................................................................................................................7
4.1. Coagulator – Flocculator Design....................................................................................................8
4.2. Clarification Design.......................................................................................................................... 12
4.3. Filtration Design ............................................................................................................................... 14
4.4. Disinfection Design.......................................................................................................................... 15
5. Conclusions................................................................................................................................................. 17
6. Recommendations ................................................................................................................................... 18
7. References................................................................................................................................................... 19
8. Appendix...................................................................................................................................................... 20

4
LIST OF TABLES
Table 1 - Initial water conditions with TOC and DOC.............................................................................6
Table 2 - Jar Test Results....................................................................................................................................7
Table 3 - Plant Design and Criteria ................................................................................................................8
Table 4 - Beaker Lake Metals Data (Metals in Analysis)..................................................................... 21
LIST OF FIGURES
Figure 1 - Summary of Beaver Lake Metals Data......................................................................................6
Figure 2 - TOC values for corresponding Alum doses ............................................................................7
Figure 3 - Filtration Process [3] ......................................................................................................................8
Figure 4 - Flocculator Basin Front view [3]............................................................................................. 10
Figure 5 - Flocculator Basin Top view (with compartments) [3].................................................... 10
Figure 6 - Flocculator Paddle Blades Figure (Front View) [3] ......................................................... 11
Figure 7 - Flocculator Paddle Side View [3]............................................................................................. 11
Figure 8 - Pilot-Scale comparison of DAF to plate sedimentation for crypto log removals
under summer and winter conditions [5]................................................................................................ 13
Figure 9 - Pilot-Scale comparison of DAF to plate sedimentation for turbidity and particle
count under winter conditions [5].............................................................................................................. 13
Figure 10 - Filtration Design Process [7].................................................................................................. 14
Figure 11 - Outline of proposed process sequence for Ferguson water treatment plant [5]18

5
1. INTRODUCTION
The objective of the design project is to understand and learn the principles and scope of
designing a drinking water treatment plant.
2. LITERATURE REVIEW
The water treatment standard of NS (2012) is to ensure public health through the
development of potable water treatment systems which produce drinking water that is free
of microbial pathogens. Plant design with multi-barrier treatment strategies that
incorporate both physical removal and chemical inactivation have been decided to be the
critical factors in ensuring the systems meet environmental regulations and follow the water
quality standards. Therefore, the group was responsible for the design of a new water
treatment plant which would provide safe drinking water for the Town of Ferguson.
The current facility at Ferguson is an old one following old methods. There is an absence of
coagulation or flocculation along with no filtration or chlorine disinfection. Beaver Lake is
currently the primary water source for the current Ferguson water treatment plant. A series
of test were run on the Beaver Lake water as seen in the Appendix.
3. EXPERIMENTAL RESULTS
3.1. Source Water Parameters and Metals Data
An initial lab experiment was conducted in order to analyze the raw water characteristics
taken from Beaver Lake. The parameters were: pH, turbidity, UV254, color, metals (Mn, Fe,
Al (ppm)), TOC (Total Organic Carbon) & DOC (Dissolved Organic Carbon). The group went
through the equipment (in no specific order) in order take samples of the raw water. The
test parameters were decided before the lab initiated. After the samples were processed, the
lab technician (Sean MacIsaac) sent the TOC, DOC and metals values. These values were used
in the project as the design criteria. A summary of the results is below:

6
Table 1 - Initial water conditions with TOC and DOC
Source Water Parameters:
N: 1.47 NTU
UV254: 0.09
Color: 11 ptco
pH: 6.4
TOC: 3.574 mg/L
DOC: 3.484 mg/L
Figure 1 - Summary of Beaver Lake Metals Data
3.2. Jar Test Results and Alum Doses
The second lab experiment consisted of determining the buffering capacity of the sample
water along with running a jar test to observe the settling rate of coagulated particles. The
group had decided on the coagulant doses ahead of the lab. The alum dose needed in each
sample was calculated to be 15.4 µg/L. The calculation is as seen in the appendix. The first
part of the lab was to determine the buffering capacity. This was done by recording the pH
of the sample while the amount of acid/base was used to achieve the target pH which was
decided to be: 6.0. The pH values along with the acid/base added were recorded. Having
finished this part of the lab, the jar test was initiated. This part consisted of the analysis of
particle settling. The doses from the initial part of this lab were used in the jar test in both a
slow mix speed and then a rapid mix speed. A summary of the results is below:
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
23Na (Sodium) 24Mg (Magnesium) 39K (Potassium) 44Ca (Calcium)
QUANTITY
(MG/L)
METALS SPECIFICATION
Beaver Lake Metals Data

7
Table 2 - Jar Test Results
Alum Added
(mg/L)
TOC
(mg/L)
0 3.570
10 3.111
20 2.919
30 3.375
40 2.728
50 2.860
Figure 2 - TOC values for corresponding Alum doses
The final lab experiment was a UV testing of the water which was done by lab technician
Sean MacIsaac. The detailed summary of the results and the criteria are as seen in the
appendix section of this report.
4. DESIGN DESCRIPTION
Design of any water supply system is regulated by Water and Wastewater Facilities and
Public Drinking Water Supplies Regulations as dictated in the Facility Classification
Standards [1]. There are four classes of water treatment facilities, each being designated
through a points system as shown in Table 1 of the Facility Classification Standards [1]. The
design of the wastewater treatment facility will attempt at reaching the best class possible
through the accumulation of most points with regards to the cost of the facility. A summary
0.000
0.500
1.000
1.500
2.000
2.500
3.000
3.500
4.000
0 10 20 30 40 50 60
TOC
(mg/L)
Alum Dose (mg/L)
TOC vs. Alum Dose

8
follows as shown in the appendix section. Normally, a pre-design evaluation and report is
needed [2] although in this case, required information is provided at the project briefing as
shown in the appendix.
Figure 3 - Filtration Process [3]
4.1. Coagulator – Flocculator Design
The coagulation/flocculator design based on the design specifications are as seen below. The
design of the coagulation/flocculator goes hand in hand with the wastewater treatment plant
which is why it was included in addition to the wastewater treatment plant.
Flow of 50000 m3/s was chosen as it is a standard value for a treatment facility of this size.
Table 3 - Plant Design and Criteria
*All data is taken from Water System Guidelines [2]. All
assumptions are made from there. Page numbers are mentioned.
Population: 10500
Growth: 0.1%
Future: 50 years pg.90
Net: 11025
Flow: 0.3 m/s pg.97
Q: 50000 m3/s
Gt: 50000 pg.98
[HRT] t: 30 s
Gavg: 27.78
G1: 40 s-1

9
G2: 30 s-1
G3: 20 s-1
V: 1041.67 m3/s
V1=V2=V3 347.22 m3/s
Design:
3 compartment, tapered paddle
flocculator
Basin Design
Ts: 16 ◦C
Tw: 2 ◦C
Tdesign: 9 ◦C
depthmax: 5 m
widthmax: 12 m
freeboard: 0.5 m
D: 4.5 m
length: 6.43 m
Paddle / Blade
Design
Clearance: 0.2 m
paddle arm length (la): 4.1 m
Blade/Wall Spacing: 0.2 m
Wheel Spacing: 0.3 m
length of blades (bt): 11 m
each paddle blade (b): 3.67 m
area of blade/tank x-sec: 17.50%
area of blade (Ac): 54 m2
area of paddle total (Apt): 9.45 m2
# of wheels: 3
# of blades per wheel: 4
each paddle area (Ap) 0.79 m2
width of paddle blade
(wp):
0.21 m
Power
Requirements:
Tdesign: 9 ◦C
Dynamic Viscosity (μ): 0.001344 Ns/m2
P1: 747 W
P2: 420 W
P3: 187 W
Rotational
Speed
CD: 1.8
k: 0.25 no stators
ρ: 999.1 kg/m3
Pp: 0.401 N3(ro
4-ri
4)
ro: 2.05 m
Outer
Paddles
ri: 1.84 m
Ppo: 2.531 N3
ro: 1.025 m Inner
Paddles
ri: 0.81 m

10
Figure 4 - Flocculator Basin Front view [3]
Figure 5 - Flocculator Basin Top view (with compartments) [3]
TOP VIEW
lc = length of compartment
Compartment 1 Compartment 2 Compartment 3
Ppi: 0.270 N3
For P1: 747 = 16.80082 N3
For P2: 420 = 16.80082 N3
For P3: 187 = 16.80082 N3
N1: 3.54 rpm
N2: 2.92 rpm
N3: 2.23 rpm
5m 4.5m = d
Water depth in
compartment
wc = 12m
FRONT VIEW

11
Figure 7 - Flocculator Paddle Side View [3]
la
SIDE VIEW
d=4.5m
FRONT VIEW
30cm 30cm 20cm
20cm
wc
= 12m
b
Figure 6 - Flocculator Paddle Blades Figure (Front View) [3]

12
4.2. Clarification Design
There are two basic options for the clarifying process that proceeds the coagulation and
flocculation chambers; Dissolved Air Flotation (DAF) and Sedimentation. The purpose of
both of these clarification methods is to separate particulate matter from the liquid.
Sedimentation involves passing the water through a sedimentation basin, where flocculated
particles fall to the bottom across the length of the chamber and are removed as a sludge.
The key parameters in sedimentation are the settling velocities of the particles, and the
surface overflow rate (SOFR) which is a function of the chambers area and the flow rate. DAF
injects air bubbles into the water to push the flocculated particles to the surface where they
can be skimmed off [4].
The difference in methodology produce some significant advantages to DAF over
conventional sedimentation. DAF requires a smaller size of flocculated particle when
compared to sedimentation as it larger particles fall faster and smaller particles float more
easily. The size difference means that DAF requires lower doses of coagulant and less time
in flocculation chambers than conventional sedimentation [4]. DAF also has the advantage
of having s significantly higher hydraulic loading rate than sedimentation (two to 12 times
higher) which means that the same flow rate can be accommodated by a proportionally
smaller area and the retention time is much lower as well [4]. Furthermore, the sludge that
is removed from the DAF process has a higher solids content and requires less dewatering.
All of this means DAF requires significantly less infrastructure costs to clarify the same
amount of water. Alternatively, DAF does require some equipment that sedimentation does
not, specifically a saturator and compressor for air flow, a recycling pump and a recycling
pump. However, the primary downside to DAF are the power costs required by the need to
constantly pump the recycled water back into the process.
Typically, DAF is preferable in source waters that are prone to algal blooms, and
contain low turbidity, low alkalinity and high coloration. The surface water being drawn
from Beaver lake is typically of fairly high quality already, with low turbidity and color
values, so this the water characterization fits somewhat well into the optimum profile for
DAF clarification. Beyond this, DAF clarification is noted for working more consistently with
seasonal temperature fluctuations. Specifically, DAF maintains its efficacy in temperatures

13
below 4°C [5], which this plant will be affected by during the winter months. This means less
modification during seasonal changes, and no need to heat the water, which represents
further energy savings. This can be seen in the following graphs representing pilot studies of
winter month usage of DAF versus plate sedimentation technologies [5]. These factors, as
well as the fact that there is precedence set by DAF plants already located in rural towns in
Nova Scotia, indicates a DAF clarification system is preferable for use in Ferguson and is
recommended by the consultation firm. Unfortunately, as bench scale testing was only
performed for sedimentation, it is recommended that further bench scale testing be
performed to verify the conclusions made.
Figure 9 - Pilot-Scale comparison of DAF to plate
sedimentation for turbidity and particle count under
winter conditions [5] Figure 8 - Pilot-Scale comparison of DAF to plate
sedimentation for crypto log removals under
summer and winter conditions [5]

14
4.3. Filtration Design
The filtration design of the water treatment facility fulfills the criteria of the AWWA
Committee of 1980 [6]. The criteria gives a limit on the color, turbidity, iron and manganese
contents of the influent water which have all been cleared for this treatment facility due to
the specifications of the influent water from Beaver Lake.
The project design is based on the conventional filtration based on the limitation of the
design due to population limit and the influent raw water source being an uncontaminated
water.
An optimum filtration design for this type of water treatment plan could also have been
Direct Filtration. This type of filtration is befitting the type of water treatment plant that is
taking place for this project. It omits sedimentation, less coagulation is used (to promote
formation of smaller, filterable flocs) which allows flocculation to occur in water above filter,
used mostly for smaller treatment facilities and puts importance on the influent water
quality [6].
Figure 10 - Filtration Design Process [7]

15
There are specific options for filtration membrane design. The selection is based on the type
of influent and the type of residue that is going through the filter.
 Microfiltration (MF): A membrane separation process using membranes with a pore size
of approximately 0.1 to 2 microns. Materials removed by microfiltration include sand,
silt, clays, Giardia lamblia, Cryptosporidium cysts, algae, and some bacterial species.
Microfiltration works best in combination with disinfection [7].
 Ultrafiltration (UF): The pore size of the membrane is approximately 0.01 to 0.1 microns.
All microbiological species are removed [7].
 Nano filtration (NF): The pore size of the membrane is approximately 0.001 to 0.01
microns. These are high pressure filtration and operating pressures are usually near
600kPa (90psi). NF can essentially remove all cysts, bacteria, viruses. NF protects from
DBP formation if the disinfectant residual is added after the membrane filtration step [7].
 Reverse Osmosis (RO): All inorganic contaminants from water can be effectively removed
by RO. Its pore size is <0.5 nanometers. Radium, natural, organic substances, pesticides,
cysts, bacteria and viruses can also be removed by RO. Disinfection is mandatory to
ensure the safety of the water [7].
Due to the nature of the design for this instance, it is estimated that the dual-media filtration
system with anthracite on top and sand on bottom will be sufficient to provide clean drinking
water to the town.
4.4. Disinfection Design
Disinfection design is based on the disease causing organisms. The type, size and volume of
these contaminants are of most importance. The microorganisms that are of concern for
humans are bacteria, viruses and protozoans [8]. The disinfection agents which are used
against these harmful contaminants are chosen due to their capacity. The disinfection agents
in discussion for this facility are:
1. Chlorine (Cl2): most widely used disinfectant and very sensitive to pH due to the
relationship with HOCl & OCl-. Need to keep and optimum pH (approximately 7.5 and
below) for most effective results [8].

16
2. Chloramines: very stable in distribution system, not as strong an oxidizer as chlorine,
do not react to form triahalomethanes (THMs) [8].
3. Chlorine Dioxide (ClO2): very strong oxidant (1.4 x Cl2), do not react with organics to
form THMs & Haloacetic acids (HAAs) [8].
4. Ozone (O3): most powerful chemical oxident [8].
5. Ultraviolet Light (UV): UV is effective at inactivating pathogens than Cl2. There are
concerns with UV such as: measuring “dose”, lack of residual for distribution systems,
need to consider turbidity [8].
In terms of effectiveness to kill microorganisms, being non-toxic at controlled configurations
and being affordable makes chlorine the most attractive choice of disinfectant for the
purposes of this facility.
Since the plant is conventional filtration design and the Giardia 3-log removal has already
been achieved in the Protozoa credit, only the minimum surface water disinfection
requirement needs to be accomplished with a 0.5 log inactivation [9].
Potential design parameters:
Summer: T = 16oC, pH = 6.4, considering a common retention time of 30 mins (design).
Table 7-4 gives approximately >11 mg/L min for Ct for 0.5 log inactivation.
Therefore free chlorine: C = Ct / t = (11 mg/L min) / 30 mins = 0.367 mg/L chlorine needed.
Winter: T = 2oC, pH = 6.4, considering a common retention time of 30 mins (design).
Table 7-4 gives approximately >30 mg/L min for Ct for 0.5 log inactivation.
Therefore free chlorine: C = Ct / t = (30 mg/L min) / 30 mins = 1 mg/L chlorine needed.

17
5. CONCLUSIONS
Even with fairly clean surface water sources, it is still necessary to undergo a series of
rigorous process before drinking water can meet standards set out by the province and
provincial government. Site specific requirement make this even more necessary. Extensive
research and literature review can provide guidance as to which direction is preferable for a
water treatment sequence, but bench scale and pilot studies are necessary to fully
understand the effectiveness and efficiency of the processes under consideration. Although
one bench scale study has been carried out and proved to be useful, more are highly
recommended before moving forward with any large scale infrastructure spending. In spite
of this, a basic water treatment strategy and process sequence has been laid out consisting
of well understood and often used technologies both in the world and in the local (Atlantic)
region. The precedent set by the research and industry usage provides a measure of
confidence that the proposed solution will meet the standards it has set out to satisfy but
there is always room for improvement in terms of design efficiency. However, efficiency
should not be made at the compromise of safety, especially when dealing with a vital
resource like drinking water, where catastrophic failure could lead to a public health crisis.
Therefore, barring further bench scale and pilot testing, the current processes are deemed
the best candidates for safe and effective water treatment in the Ferguson area.

18
6. RECOMMENDATIONS
After taking into account all of the factors associated with the town of Ferguson including
drinking water source, socio-economic conditions, a literature review, relevant local
regulations and a bench scale study, a treatment plan and plant design has been successfully
determined. This plant follows the conventional treatment method with a process series
starting with screening, followed by coagulation, flocculation, clarification, filtration and
disinfection. The coagulation uses alum as a coagulant and requires rapid mixing and the
adjustment of pH to reach optimal conditions. The flocculation basin is a three stage slow
mixing chamber which reduces to TOC to more acceptable levels. Then the clarification
chamber utilizes direct air filtration technology to remove solids. The filtration system is a
traditional dual media filtration system containing anthracite and sand. Finally, the
disinfection process is Chlorine based to provide the sufficient 0.5log reduction in giardia
and to satisfy the need for residuals in the distribution system. Together these processes
provide a fairly simple, largely conventional water treatment process that should bring
Ferguson in line with modern standards for drinking water quality as well as federal and
provincial regulations and source specific requirements.
Figure 11 - Outline of proposed process sequence for Ferguson water treatment plant [5]

19
7. REFERENCES
[1] Nova Scotia Environment, "Facility Classification Standards," Nova Scotia Environment,
Halifax, 2009.
[2] CBCL Limited, "Atlantic Canada Guidelines for the Supply, Treatment, Storage,
Distribution, and Operation of Drinking Water Supply Systems," Atlantic Canada Water
Works Association, Halifax, 2004.
[3] M. Walsh, "3.0 Coagulation & Flocculation," Dalhousie University, Halifax, 2016.
[4] M. Walsh, "4.0 Sedimentation & Dissolved Air Flotation," Dalhousie University, Halifax,
2016.
[5] J. K. Edzwald, Water Quality & Treatment: A Handbook on Drinking Water, Boston:
American Water Works Association, 2011.
[6] M. Walsh, "5.0 Filtration," Dalhousie University, Halifax, 2016.
[7] M. Walsh, "6.0 Membrane Filtration," Dalhousie University, Halifax, 2016.
[8] M. Walsh, "8.0 Disinfection," Dalhousie, Halifax, 2016.
[9] Nova Scotia Environment, "Nova Scotia Treatment Standards for Municipal Drinking
Water Systems," Nova Scotia Environment, Halifax, 2012.

20
8. APPENDIX
Project Specifications:
Town Specifications:
Population 10,500
Population Growth Rate: 0.1 %
Design Specifications:
Turbidity 0.1 NTU
Giardia Removal 3-log
Produce water that will satisfy current Nova Scotia treatment standards.
Preliminary Raw Water Information:
Average summer raw water temperature: 16oC
Average winter raw water temperature: 2oC
Distribution System Information:
The distribution system within the town consists of unlined cast iron pipes.
Bench-Scale Testing:
a. Raw water characteristics:
Source Water
Parameters:
N: 1.47 NTU
UV254: 0.09
Color: 11 ptco
pH: 6.4
b. Optimum coagulant chemistry and dose
c1v1=c2v2 647.5 g/L x v1 = 10 mg/L x 1L x 10-3 g v1 = 15.4 μL [Equation 1]
Buffering
Capacity
Trial pH Alum added (μg/L) pH
Base added (NaOH)
(μL)
New pH
1 6.00 15.4 5.05 650 5.99
2 5.99 15.4 5.05 800 5.99
3 5.99 15.4 5.02 825 6.01
4 6.01 15.4 5.01 825 6.02
5 6.02 15.4 5.00 835 6.00
c. Optimization of clarification process

21
Jar
Testing
Acid added
(mg/L)
H2SO4 (μg/L)
NaOH
(μg/L)
Base added (NaOH)
(μL)
Turbidity
(NTU)
0 450 1.21
1 drop 10 450 650 650 0.374
2 drops 10 450 800 1450 0.439
3 drops 10 450 825 2275 0.265
4 drops 10 450 825 3100 0.536
5 drops 10 450 835 3935 0.385
Target pH = 6.0 Original pH = 6.61
High: 295 RPM
2 minutes
Low: 40 RPM
20 minutes
d. Optimization of filtration process
Please refer to part 4 of this report goes for the design process in detail.
e. Optimum disinfectant chemistry and dose
TOC = 3.574 mg/L
DOC = 3.484 mg/L
Alum Added
(mg/L)
TOC
(mg/L)
0 3.570
10 3.111
20 2.919
30 3.375
40 2.728
50 2.860
Average dose: 3.094 mg/L
Lab Results:
Table 4 - Beaker Lake Metals Data (Metals in Analysis)
23Na (Sodium)
24Mg
(Magnesium)
39K
(Potassium)
44Ca
(Calcium)
27Al
(Aluminum) 56Fe (Iron)
ppb ppb ppb ppb ppb ppb
44943.33 1113.13 1018.83 8298.47 13.08 37.58
mg/L mg/L mg/L mg/L mg/L mg/L
44.94 1.11 1.02 8.30 0.01 0.04

338774160-Water-Treatment-Plant-Design-Project_2.pdf

Recommended

Recommended

More Related Content

Similar to 338774160-Water-Treatment-Plant-Design-Project_2.pdf

Similar to 338774160-Water-Treatment-Plant-Design-Project_2.pdf (20)

More from aloknayak47

More from aloknayak47 (15)

Recently uploaded

Recently uploaded (20)

338774160-Water-Treatment-Plant-Design-Project_2.pdf