borang pengesahan status tesis - Universiti Teknologi Malaysia

Transcription

PSZ 19 : 16 (Pind. 1/97)
UNIVERSITI TEKNOLOGI MALAYSIA
UNIVERSITI TEKNOLOGI MALAYSIA
BORANG PENGESAHAN STATUS TESIS♦
JUDUL : DEVELOPMENT OF A DECISION SUPPORT SYSTEM FOR
DRINKING WATER TREATMENT PROCESS DESIGN
(WATER-DSS)
SESI PENGAJIAN : 2005/2006
___________________CHUANG KUANG HONG
(HURUF BESAR)
Saya
.
mengaku membenarkan tesis (PSM/Sarjana/Doktor Falsafah)* ini disimpan di Perpustakaan
Universiti Teknologi Malaysia dengan syarat-syarat kegunaan seperti berikut :
1.
2.
3.
4.
Tesis adalah hakmilik Universiti Teknologi Malaysia.
Perpustakaan Universiti Teknologi Malaysia dibenarkan membuat salinan untuk tujuan
pengajian sahaja.
Perpustakaan dibenarkan membuat salinan tesis ini sebagai bahan pertukaran antara
institusi pengajian tinggi.
** Sila tandakan ( 9 )
SULIT
(Mengandungi maklumat yang berdarjah keselamatan atau
Kepentingan Malaysia seperti yang termaktub di dalam
AKTA RAHSIA RASMI 1972)
TERHAD
(Mengandungi maklumat TERHAD yang telah ditentukan
organisasi/badan di mana penyelidikan dijalankan)
9
TIDAK TERHAD
Disahkan oleh
.
(TANDATANGAN PENULIS)
.
(TANDATANGAN PENYELIA)
Alamat Tetap :
SATU, JALAN SERIKAYA SATU,..
SEGAMAT BARU,
85000 SEGAMAT, JOHOR.
Tarikh: 5.07.2006
CATATAN:
PROF. DR. ZAINI BIN UJANG
(Nama Penyelia)
Tarikh: 5.07.2006 .
* Potong yang tidak berkenanan.
** Jika tesis ini SULIT atau TERHAD, sila lampirkan surat daripada pihak
berkuasa/organisasi berkenaan dengan menyatakan sekali sebab dan tempoh tesis ini perlu
dikelaskan sebagai SULIT atau TERHAD
♦ Tesis dimaksudkan sebagai tesis bagi Ijazah Doktor Falsafah dan Sarjana secara
penyelidikan, atau disertasi bagi pengajian secara kerja kursus dan penyelidikan, atau
Laporan Projek Sarjana Muda (PSM)
“I hereby certify that I have read this project report and in my opinion this project report
is sufficient in terms of scope and quality for the award of the degree of
Master of Engineering (Environmental Management).”
Signature
:
Name of Supervisor :
Date
:
PROF. DR. ZAINI BIN UJANG
5.07.2006
Development of A Decision Support System
for Drinking Water Treatment Process Design (WATER-DSS)
CHUANG KUANG HONG
A project report submitted in partial fulfilment of the requirement for the
award of the degree of Master of Engineering (Environmental Management)
Faculty of Civil Engineering
Universiti Teknologi Malaysia
JULY, 2006
ii
“I hereby declare that all the materials presented in this thesis are the result of my
own research except as cited in the references.”
Signature
:
Name
:
CHUANG KUANG HONG
Date
:
5 JULY 2006
iii
To my beloved parents, Heng Siaw Ling & friends,
Thank you for your support, guidance and confidence in me.
iv
ACKNOWLEDGEMENT
First of all, I would like to express a zillion thanks to my supervisor, Prof. Dr.
Zaini B. Ujang. He has taught me much with examples and advice. Despite his daily
hectic schedule, he has taken the trouble to guide and support me.
Secondly, I would also like to express my deepest thanks to Miss Dewi, Miss
Fazlin and Mr. Shukor who had shared their experience with me and guided me in
my project.
Furthermore, I would like to thank to Mr. Azmi, who is supervising the
operation of Sayong Water Treatment Plant, Kota Tinggi, Johor. He was willing to
share his experience during his work in plant.
Never the less, my project will never be success without Tang Kok Mang and
Khaw Boon Chai. They guided me along the building process of WATER_DSS
using visual basic 6.0. I will also not forget few close friends such as Lee Xia Sheng
and Low Chin Yen that has been support bring me up when I falls in the process of
work.
Lastly, my family and girl friend, Heng Siaw Ling has given me the biggest
support in whatever way. They play the important roles not only in my project, but in
my life.
Again, I appreciate to all those involved directly and indirectly helping me
out which I can’t state out every one of them. A special expression of gratitude is
extended to everyone for their tolerance and patience in doing all the things.
v
ABSTRACT
A decision support system (DDS), named WATER-DSS has been developed
to assist engineers and researchers on drinking water treatment plant. The objective
of WATER-DSS was to assist designers to perform process design for drinking water
treatment. WATER-DSS contains two main components: (i) knowledge-based
information and (ii) programming tool. The design of drinking water treatment plant
in WATER-DSS depends on the characteristic of raw water and the water quality
objectives. Visual Basic 6.0 was selected to develop WATER-DSS because its
capability of object oriented programming. WATER-DSS has user-friendly
interfacing capability, which provides the parameters inputs, standard parameters
value list, raw water treatment process information, graphical and explanations
features .WATER-DSS was validated by the manual calculations and has shown the
relationship between WATER-DSS output and manual calculation output is
significant.
vi
ABSTRAK
Satu sistem sokongan keputusan, yang dinamakan WATER-DSS telah
dibangunkan untuk membantu para jurutera and dalam proses merekabentuk system
logi air. Objektif pembinaan WATER-DSS adalah untuk membantu jurutera dan
penyelidik membuat keputusan dalam merekabentuk proses awal loji rawatan air.
WATER-DSS mengandungi dua bahagian: (i) Pengetahuan, dan (iii) Perisian
Pengaturcaraan. Rekabentuk proses awal rawatan air mentah dalam WATER-DSS
adalah bergantung kepada parameter air rawatan. Visual Basic 6.0 dipilih sebagai
perisian rekabentuk kerana keupayaan bahasa pengaturcaraannya. WATER-DSS
mempunyai halaman yang mudah difahami dan dikenalpasti yang terdiri daripada
ruang untuk memasukkan parameter air, senarai nilai standard quality air, maklumat
proses air rawatan mentah, gambar beserta ulasan yang berkaitan. Keputusan yang
diperolehi melalui WATER-DSS menunjukkan hubungan yang erat dengan kaedah
pengiraan manual.
vii
CONTENT
CHAPTER
I
II
ITEMS
PAGE
TOPIC
i
AUTHENTICATION
ii
DEDICATION
iii
ACKNOWLEDGEMENT
iv
ABSTRACT
v
ABSTRAK
vi
CONTENT
vii
LIST OF TABLE
xi
LIST OF FIGURES
xii
INTRODUCTION
1.1
Research Background
1
1.2
Problem Statement
2
1.3
Objective of Study
2
1.4
Scope of Study
2
LITERATURE REVIEW
2.1
Introduction
3
2.2
Objective of Water Treatment
3
2.2.1
4
Pre-treatment
viii
2.2.1.1 Screens
4
2.2.1.2 Grit Chamber
4
2.2.2 Aeration
2.2.2.1 Type of Aerator
6
2.2.3 Pre-Chlorination
8
2.2.4 Coagulation and Flocculation
8
2.2.5
2.2.6
2.3
5
2.2.4.1 Coagulant
9
2.2.4.2 Type of Flocculators
10
Sedimentation
12
2.2.5.1 Type of Sedimentation tank
13
Filtration
13
2.2.6.1 Types of Filtration Technology
15
2.2.6.2 Membrane and RO filtration
16
2.2.7 Disinfection
17
2.2.8 Fluoridation
17
2.2.9
18
pH adjustment
Water Quality
18
2.3.1
Physical Quality
18
2.3.1.1 Colour
18
2.3.1.2 Turbidity
20
2.3.1.3 Total Dissolved Solid
20
2.3.1.4 pH
20
2.3.2 Chemical Quality
21
2.3.2.1 Mercury
21
2.3.2.2 Arsenic
21
2.3.2.3 Lead
21
2.3.2.4 Copper
22
2.3.2.5 Chlorine
22
2.3.2.6 Manganese
22
2.3.2.7Ammonia
22
2.3.2.8 Nitrate
23
2.3.2.9 Iron
23
2.3.2.10 Fluoride
23
2.3.2.11 Hardness
23
ix
2.3.3
2.4
2.3.2.12 Aluminium
24
Microbiological Quality
24
Water Parameters Removal by Water
24
Treatment Process
2.5
2.6
2.7
III
Engineering knowledge
25
2.5.1 Engineering Knowledge Principles
25
Programming Tool using Visual Basic
26
2.6.1
27
Behaviour present in Visual Basic
2.6.2 User-friendly Interface design
29
Security System by Password
29
LITERATURE REVIEW
3.1
Development of WATER-DSS
31
3.2
Forms of WATER-DSS Project in Visual Basic
32
3.2.1 Security of WATER-DSS
32
3.2.2
Welcome frame
33
3.2.3
Parameter Input Form
35
3.2.4
Water Treatment Process form
39
3.2.5
Pre-treatment Form
43
3.2.6
Aeration Form
45
3.2.7
Coagulation, Flocculation and
45
Sedimentation
3.2.8
Filtration Form
46
3.2.9
Summary Form
47
3.2.10 Thank You Form
IV
50
RESULT AND DISSCUSION
4.1
General
51
4.2
Application of WATER-DSS
51
4.3
Validation of Result
51
4.4
Discussion
52
x
V
CONCLUSION
5.1
Conclusion
55
5.2
Suggestion
55
5.3
Error in Study
56
REFERENCES
58
xi
LIST OF TABLE
TABLE NUMBER TOPIC
PAGE
2.1
Design Criteria for screens
4
2.2
Grit chamber design criteria
5
2.3
Types of aerators
7
2.4
Cascade aerator typical design criteria
8
2.5
Common coagulants and doses
9
2.6
Comparison of Basic approaches to flocculation
10
2.7
Baffle channel typical design criteria
12
2.8
Types of sedimentation process
14
2.9
Typical design criteria for rectangular
15
sedimentation tank
2.10
Typical design criteria for rectangular rapid
17
sand filter
2.11
Water parameters limitation in Malaysia
19
2.12
General effectiveness of water treatment
25
processes removal
3.1
Category of water parameters
35
3.2
Simplify removal percentage by process
43
treatment and further treatment action
4.1
Comparison WATER-DSS result and
Microsoft Excel result
53
xii
LIST OF FIGURES
FIGURE NUMBER TOPIC
PAGE
2.1
Aeration process
5
2.2
Cascade aerator plan layout
6
2.3
Coagulant dosing equipments
9
2.4
Baffle channels
11
2.5
Baffle channels plan layout
11
2.6
Sedimentation tank
13
2.7
Sedimentation tank layout plan
14
2.8
Four types of common filters
16
2.9
Rapid sand filtration tanks
16
3.1
WATER-DSS development structure
31
3.2
Forms in WATER-DSS
32
3.3
Password form
32
3.4
Welcome form
34
3.5
Parameter Input form
36
3.6
Water treatment process form
39
3.7
Pre-treatment form
44
3.8
Aeration form
45
3.9
Filtration form
48
3.10
Thank You form
50
51
CHAPTER 1
INTRODUCTION
1.1
Research Background
The concept of DSS emerged in the 1970s, as a family of computer systems
in the field of decision theory (Gorry and Scott, 1971) showing a great potential in
the field of environment management. In the last decades, numerous DSS have been
developed in the field on environmental management to assist designers in making
decision related to various aspects of planning, monitoring and design facilities. DSS
development integrates various concepts such as spreadsheets, databases, networks,
hypermedia, expert systems, visual programming, intelligent agents, neural networks,
etc. (Beynon et al., 2002).
Any system supporting decision-making, including
executive information systems, executive support systems, geographic information
systems and software agents, may be called a DSS (Power, 1997).
DSS serves three main purposes. DSS gives us a framework to assemble our
process understanding and to explore the implied system behaviours that come from
that understanding. The second purpose is as a mechanism for testing data, to check
for inconsistencies and errors, and fill in missing information. The third is to explore
scenario options under a range of different output conditions (Silberstein, 2005). In
an engineering field, DSS can assist engineer to perform complete calculation design
procedures in a short time compared to manual calculation (Sairan, 2005).
2
Conventional water treatment plant include screening, grit removal, aeration,
coagulation, flocculation, sedimentation, filtration, fluoridation, disinfection and
conditioning. The treatment processes of raw water before it can be used for public
consumption must be based on removal level of impurities to comply with various
guidelines. The quality of water depends upon it physical, chemical, microbiological
and radiochemical characteristic. The extent of treatment depends upon the quality
of the raw water and the desired quality of treated water. The treated water
constituents should meet the standard set by The Ministry of Health, Malaysia.
1.2
Problem Statement
Most of the design procedures for water treatment plant have been developed
using manuals or spreadsheet calculations which are time consuming and costly.
Therefore, a DSS is required to speed up the design process and reduce the design
cost. In this study, a DSS called WATER-DSS will be developed to reduce the
design time and cost.
1.3
Objective of Study
The main objectives of this study are to:
i) To develop an easier, cheaper and user-friendly DDS to assist in selecting
appropriate and essential procedures for water treatment process.
ii) To validate the DSS with manual or spreadsheet calculation.
1.4
Scope of Study
The scope of the study covers conventional drinking water treatment process
in Malaysia.
3
CHAPTER 2
LITERATURE REVIEW
2.1
Introduction
In order to set up a useful program for water treatment plant design, a set of
technical knowledge and data needs to be gathered. Examples of technical
knowledge are conventional water treatment processes, parameter removal by
different treatment processes and coagulants used. Apart from that, laws, regulations
and specifications also need to be considered. After that, a program is needed to
design, program and assess the collected knowledge.
2.2
Objectives of Water Treatment
The main objective of treating water intended for public water supplies is to
produce a supply water that is chemically and bacteriological safe for human
consumption (Montgomery, 1985). In this study, conventional treatment is defined as
pre-treatment,
aeration,
coagulation,
fluoridation, conditioning and disinfection.
flocculation,
sedimentation,
filtration,
4
2.2.1
Pre-treatment
Pre-treatment normally is the first step after water intake from water
resources. Screens and grit chamber are commonly used in this early treatment
process (Degremont, 1979).
2.2.11 Screens
Bar screens are used to separate physical solids that are likely to create
problems in subsequent treatment stages. This is to protect the plant against the entry
of large objects likely to cause blockage in different parts of the installation. Screens
are usually distinguished by three types: fine screen, medium screen and coarse
screen. The design criteria of bar screen are presented in Table 2.1.
Table 2.1: Design Criteria for Screens
1.
4.
5.
6.
Criteria
Type of
screen
Type
Fine screen
Medium
screen
Coarse screen
Cleaning
purpose
-
Flow velocity
Head losses
-
Description
Spacing from 3 - 10 mm
Provision for cleaning should be constructed
in the form of access walkways located 1 m
above normal water level.
Average 0.6-1.0 m/s, maximum 1.2-1.4 m/s
0.05-0.15 m
(Tay, 2000)
2.2.1.2 Grit Chamber
Grit chamber is to remove the gravel, sand and other mineral particles which
would otherwise form deposits in channels and piping, to protect pump and other
equipment against abrasion and to avoid overloading subsequent treatment stage
(Prosser, 1977). The design criteria of grit chamber in Malaysia are presented in
Table 2.2.
5
Table 2.2: Grit chamber design criteria
1
2
3
4
5
Design criteria
Smaller particle to settle
Mean horizontal velocity
Maximum horizontal velocity
Deposition of suspended solid
Grit capacity
Description
0.2 mm
50-60% velocity of 0.2 mm dia particles
120% of mean horizontal velocity
200 mg/L
7 days of 24 hours operation/day
(Tay, 2000)
2.2.2
Aeration
Aeration is the process of bringing water and air into close contact in order to
remove dissolved gases, such as carbon dioxide, and to oxidize dissolved metals such
as iron. It can also be used to remove volatile organic chemicals (VOC) in the water.
Aeration is often the first major process at the treatment plant. During aeration,
constituents are removed or modified before they can interfere with the treatment
processes (Hand et al., 1999). Example of the aeration treatment process is shown in
Figure 2.1. The figure and following site plant picture is taken from Sayong Water
Treatment Plant, Kota Tinggi, Johor.
Figure 2.1
Aeration process
6
2.2.2.1 Type of Aerator
Normally there are four basic types of aerators as below, more detail of
aerators are presented in Table 2.3 (Crittenden et al., 2005). Different types of
aerator serve different type of needs and loading rate.
i) Droplet or thin-film air-water contactors
ii) Diffusion or bubble aerators
iii) Aspirator-type aerators
iv) Mechanical aerators
In Malaysia, almost all water treatment plant apply the droplet or thin-film
air-water contactors which consists of 87% cascade aerators, other 7% and 4% made
up from multiple tray and spray aerator respectively (The Malaysia Water
Association, 2005). Figure 2.2 shows the cascade aerator layout while cascade
aerator design criteria are provided in Table 2.4 (Mariappan, 2005).
Figure 2.2
Cascade aerator plan layout
7
Table 2.3: Types of aerators
Type of Aerators
Droplet or thinfilm air-water
contactors
Contacting
device
Spray
aerator
Spray tower
Cascade
Multiple
tray
Diffusion or
bubble aerators
Diffuser
Dispersed
air
Aspirator-type
aerators
Mechanical
aerators
Hydraulic
aspirator
Mechanical
aspirator
Mechanical
aerator
Process description
Water to be treated is sprayed through nozzles to
form disperse droplets; typically a fountain
configuration
Water to be treated is sprayed downward through
nozzles to form disperse droplets in a tower
configuration; typically countercurrent flow.
Water to be treated flows over the side of sequential
pans, creating a waterfall effect to promote droplettype aeration.
Water to be treated trickles by gravity through trays
containing media to produce thin-film flow. Typical
media used include coarse stone or coke
Fine bubbles are supplied through porous diffusers
submerged in the water to be treated.
Compressed air is supplied through a stationary
sparser orifice-type dispersion apparatus located
directly below a submerged high speed turbine
A gas stream is educed into the liquid stream with a
venture-type device
A hollow-blade impeller rotates at a speed sufficient
to aspirate and discharge a gas stream into the water
Surface aerators and aeration pumps are primary
types of mechanical aerators
Method gas
transfer
Natural aeration
through
convection
Forced-draft
aeration
Typical application
H2S, CO2, and marginal VOC
removal; taste and odour
control, oxygenation
H2S, CO2, and VOC removal;
taste and odour control
Loading
factor
Surface area
of 0.1-0.3
m2.s/L
-
Aeration
primarily by
natural
convection
Natural or
forced-draft
aeration
Compressed air
or ozone
Compressed air
or ozone
Compressed
ozone, CO2, Cl2
Compressed air
or ozone
Mechanical
agitation of water
into surrounding
air
CO2 removal; taste and odour
control, aesthetic value,
oxygenation
H2S, CO2, removal; taste and
odour control
CO2, Fe and Mn removal;
taste and odour control
Ozonation, esp. when high
concentrations of Fe and Mn
are present
Ozonation, CO2 addition Cl2
disinfection
Ozonation, CO2 addition
0.007-0.014
m/s
0.1-1 L air/L
water
-
O2 absorptio, VOC removal
when <90% removal required
-
(Crittenden et al., 2005)
51
Table 2.4: Cascade aerator typical design criteria
1
2
3
4
5
6
7
8
Design criteria
Number of steps
Space requirement
Head required
Tread of step
Rise of step
Velocity of water in the
Collecting channel
CO2 removal efficiency
H2S removal efficiency
Typical value
3 to 6 normally (maximum could be More
than 10, in fact more the number, higher
the efficiency)
0.015 - 0.045 m2/m3.h
0.50 - 3.0 m
20 - 40 cm
20 - 40 cm
0.6 m/s - 0.9 m/s
20 - 45%,
35%.
(Mariappan, 2005)
2.2.3
Pre-Chlorination
Pre-chlorination is chlorination prior to filtration. The objectives of pre-
chlorination are (Tay, 2000):
i) It allows a prolonged contact period for very effective disinfection of heavily
polluted waters,
ii) It neutralise free ammonia in the water.
2.2.4
Coagulation and Flocculation
The terminology of coagulation has not been standardized. However in most
of the water treatment literature, coagulation refers to all the reactions and
mechanisms that result in particle aggregation in water being treated, including in
situ coagulant formation, particle destabilization and physical inter-particle contacts.
The physical process of producing inter-particle contact is termed flocculation
(Letterman et al., 1999).
In most treatment plants, the mixture remains in the tank for 10 to 30 seconds
to ensure full mixing. The amount of coagulant that is added to the water varies
widely due to the different source water quality (Viessman, 2005). The Figure 2.3
shows the added coagulant into the aeration tank.
9
2.2.4.1 Coagulant
One of the more common coagulants used is aluminium sulphate, sometimes
called as alum (Edzwald, 1993). Aluminium sulphate reacts with water to form flocs
of aluminium hydroxide. Another iron (II) is other common coagulants. The use of
Fe (II) appears to be the most promising of the ClO2 removal techniques and has
been successfully used in laboratory and, to some extent, in pilot and full-scale
studies Another coagulant is iron (III) which is lower costs and in some cases slightly
better removal of natural organic contaminants. (Griese et al., 1991).
The coagulant and dosage selected for particular water should be based on the
“jar test”. The jar test evaluates the actual performance of different coagulants at
various concentrations in particular water. Table 2.5 shows four common coagulants
with typical dosage ranges (Tay, 2000).
Figure 2.3
Coagulant dosing equipments
Table 2.5: Common coagulants and doses
1
2
3
4
Coagulant
Aluminium Sulphate, AL2 (SO4)
Ferric Sulphate, Fe2 (SO44)3
Ferrous Sulphate, FeSO4
Sodium Aluminates, NaAlO2
Typical dose range, mg/L
10-50
10-50
5-25
5-30
(Tay, 2000)
10
2.2.4.2 Type of Flocculators
Flocculator commonly divided into three types which are horizontal shaft
with paddles (HSP), vertical shaft with turbines (VST) and baffle channel (BF).
Information on how these approaches compare to each other with respect to a
number of design and operational issues is presented in Table 2.6 (Crittenden et al.,
2005).
In Malaysia, the most common type of flocculator used is the baffle channels
(category under HF) which make up 88% of the coagulation and flocculation process
(The Malaysia Water Association, 2005). Figure 2.4 illustrate the baffle channels.
Figure 2.5 shows the baffle channels plan layout and design criteria is presented in
Table 2.7.
Table 2.6: Comparison of Basic approaches to flocculation
Process Issue
Type of floc
produced
Head loss
Operational
flexibility
Capital cost
Construction
difficulty
Maintenance
effort
Compartmentalization
Advantages
Disadvantages
Mechanical flocculator
HSP
VST
Large & fluffy
Small to medium,
dense
None
None
Good, limited to low
Excellent
G
Moderate to high
Moderate
Moderate
Low to moderate
Hydraulic flocculator
BF
Very large and fluffy
Moderate to poor
Moderate to poor
Low to moderate
Low to moderate
Moderate
Low to moderate
Low to moderate
Moderate
Excellent
Excellent
Produces large floc,
reliable, no head loss,
one shaft for several
mixers
Flocculator can be
maintained or replaced
without shutdown, no
head loss, very
flexible, reliable
Difficult to specify
proper impellers and
reliable gear drives in
competitive bidding
process
Simple, effective, easy
and low cost
maintenance, no
moving parts, produced
very large flocs
Little flexibility
Compartmentalization more
difficult, replacement
required shutdown
11
Figure 2.4
Baffle channels
Figure 2.5
Baffle channels plan layout
12
Table 2.7: Baffle channel typical design criteria
Type
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Flow
m3/h
0-50
51-70
71-90
91-110
111-130
131-150
151-200
201-250
251-300
301-350
351-400
401-450
451-500
501-550
551-600
A
B
C
3200
3900
4500
5000
5300
5500
6000
6500
7100
7700
8200
8800
9100
9600
10000
2400
2500
2600
2700
2900
3100
3400
3600
3800
4100
4100
4000
4100
4300
4400
2100
2100
2200
2300
2300
2400
2600
2800
2900
2900
3100
3200
3300
3300
3400
Approx. Baffle Spacing Design Criteria
D
E
F
100
125
180
Energy Gradient
-1
-Stage1 25s
-1
-Stage2 17s
-1
175
230
310
-Stage3 12.5s
180
235
315
Retention per stage
E ≤ 1.0m
340
420
700
Elevation of inlet
penstock may be
necessary to achieve
free discharge
conditions
(Tay, 2000)
2.2.5 Sedimentation
Water exiting the flocculation basin enters the sedimentation basin, also
called as settling basin. This process is accomplished by allows large floc-particle
masses to settle prior to filtration (Jakubowski and Craun, 2002). The sedimentation
basin is best located close to the flocculation basin so the transit between does not
permit settlement or floc break up. Sedimentation basins can be in the shape of a
rectangle, where water flows from end to end, or circular where flow is from the
centre outward.
The amount of floc that settles out of the water is dependent on the time the
water spends in the basin and the depth of the basin (Gregory, 1999). The retention
time of the water must therefore be balanced against the cost of a larger basin. The
minimum retention time is normally four hours. A deep basin will allow more floc to
settle out than a shallow basin. This is because large particles settle faster than
smaller ones, so large particles bump into and integrate smaller particles as they
settle. In effect, large particles sweep vertically though the basin and clean out
smaller particles on their way to the bottom. Figure 2.6 shows sedimentation tank.
13
Figure 2.6
Sedimentation tank
2.2.5.1 Type of Sedimentation tank
Sedimentation basin design is based on applied theoretical principles and
practical consideration, including basin location in the overall process treatment
train, basin size and basin geometry. Two popular types of sedimentation tank which
are usually found are conventional rectangular basin and solid contact clarifiers.
They are presented in Table 2.8 (Crittenden et al., 2005). In Malaysia conventional
rectangular basin consists of 82% (The Malaysia Water Association, 2005). The
layout plan of rectangular basin is shown in Figure 2.7 while detail design criteria for
conventional rectangular basin are presented in Table 2.9.
2.2.6
Filtration
Filtration is one of the unit processes to produce drinking water (Cleasby and
Gary, 1999). Filtration is a process design follows after sedimentation. After
separating most floc, the water is filtered as the final step to remove remaining
suspended particles and unsettled floc. The most common type of filter is a rapid
sand filter.
14
Table 2.8: Types of sedimentation process
Typical
application
Advantages
Disadvantages
Typical
application
Conventional
Rectangular basin
More tolerance to shock loads,
predictable performance, easy
operation, low maintenance
cost, easy adapted for highrate settler modules
Subject to density flow
creation in basin, requires
careful design of inlet and
outlet structures, usually
requires separate flocculation
facilities
Many municipal and industrial
water works, particularly
suited to large-capacity plants
Solid contact clarifiers
Good softening and turbidity
removal, flocculation and
clarification in one unit, compact
and economical design
Sensitive to shock loads and
changes in flow rate, sensitive to
temperature change, 2 – 3 days
required to build up necessary
sludge blanket, higher
maintenance costs and need to
greater operator skill
Water softening, flocculationsedimentation treatment of raw
water that has constant quality
and rate of flow, plant treating a
raw water with low solids
concentration
Figure 2.7
Sedimentation tank layout plan
15
Table 2.9: Typical design criteria for rectangular sedimentation tank
1
2
3
4
5
6
7
8
9
10
11
Parameters
Minimum number of tanks
Water depth
Length-depth
Width-depth
Length-width
Overflow rate
Horizontal flow velocity
Detention time
Reynolds number
Froude number
Bottom slope
Typical value
2
3-5 m
15:1
5:1
4:1
1.5 m3/ m2/h
0.3-1.1m/min
4h
<20,000
>10-5
1:50
(Tay, 2000)
To clean the filter, water is passed quickly upward through the filter, opposite of the
normal direction (called back flushing or backwashing) to remove embedded
particles. Although other workers (Fitzpatrick, 1993) have confirmed the
effectiveness of collapse-pulsing as a backwash regime on a laboratory scale, it is
only slowly being adopted by the U.K. water industry. Some pilot scale trials have
been successful (Chipps et al., 1995) and have led to full scale implementation.
2.2.6.1 Types of Filtration Technology
In general two types of filtration are regularly found in filtration processes
which gravity filters and pressure filters (Tay, 2000). Gravity filters divided into four
types which consist of slow sand filters, rapid sand filters, high rate filters using dual
or multi media and roughing filters which are presented in Figure 2.8. Pressure filters
consists of rapid sand filters and high rate filters using dual or multi media. In
Malaysia, up to 92% of the plants used the rapid sand filtration (The Malaysia Water
Association, 2005). The typical design criteria of rapid sand filtration is presented in
Table 2.10. Figure 2.9 illustrates the rapid sand filtration tanks.
16
Figure 2.8
Four types of common filters
Figure 2.9
Rapid sand filtration tanks
2.2.6.2 Membrane and RO filtration
Membrane process is modern physicochemical separation techniques that use
differences in permeability as a separation mechanism. The operation is considered
to be simple and the operation stability high. The quality of the drinking water has
17
been excellent with the colour concentration around 5 mg Pt/l. (Ericsson and
Tragardh, 1997).
Table 2.10: Typical design criteria for rectangular rapid sand filter
1
2
3
4
5
6
7
8
9
10
11
12
13
Parameters
Num of filters
Length/breath ratio
Size of filter
Material construction
Tank depth
Water depth
Free board
Regeneration
Depth of sand
Effective size of sand
Uniformity coefficient
Acid solubility
Specific gravity
Typical value
minimum 3
10:9-10:6
2
Up to 150 m
R.C
3-4 m
>1.0 m
300 mm
Backwash
600-1000 mm
0.55-0.95
1.5-1.7
5%
2.55-2.65
(Tay, 2000)
2.2.7
Disinfection
Disinfection is normally the last step in purifying drinking water. Water is
disinfected to destroy any pathogens which passed through the filters (Haas, 1999).
Chlorine is the one of the most common disinfection chemical that being used. As in
Malaysia, most of the plants surveyed used chlorine as their disinfection agent (The
Malaysia Water Association, 2005).
2.2.8 Fluoridation
Fluoridation is the process where fluoride is added to water for the purpose of
preventing tooth decay. Fluoride is an essential component for normal mineralization
of bones and formation of dental enamel (Bell and Ludwig, 1970). Fluoride is
usually added after the disinfection process. 82% of sodium silicofluoride and 18%
of sodium fluoride is used in Malaysia in fluoridation process (The Malaysia Water
Association, 2005).
18
2.1.9
pH adjustment
If the water is acidic, lime or soda ash is added to raise the pH. 85% of
Malaysia plant using lime and 15% using soda ash process (The Malaysia Water
Association, 2005). Lime is the more common of the two additives because it is
cheaper, but it also adds to the resulting water hardness. Making the water slightly
alkaline ensures that coagulation and flocculation processes work effectively and
also helps to minimise the risk of lead being dissolved from lead pipes and lead
solder in pipe fittings.
2.3
Water Quality
The quality of water depends upon its physical, chemical, microbiological
and radiochemical characteristic. Obtaining a desired quality of drinking water often
requires treatment. The extent of treatment depends upon the quality of the raw water
and the desired quality of treated water (Tay, 2000). The overall accepted values for
quality of treated water are presented in Table 2.11.
2.3.1
Physical Quality
The principal physical characteristics of water are colour, turbidity, taste,
odour, pH, suspended and dissolved solids (Letterman et al., 1999).
2.3.1.1 Colour
Water should be as colourless as possible. Presence of water indicated the
presence of complex organic compounds, colloidal forms of iron and manganese, or
highly coloured industrial wastes. The standard for colour in drinking water is less
than 15 TCU (Tay, 2000). Colour in water can usually be reduced to within the
recommended limit by conventional treatment if the raw water does not contain more
19
Table 2.11: Water parameters limitation in Malaysia
Category/group
Microbiology
Group I
Physical
Group II
Inorganic
Group III
Thihalo-methane
Group IV
Group V
Radioactivity
Parameter
Total Coliform
E.coli
Faecal Streptococci
Viruses
Protozoa
Helminths
Turbidity
Colour
pH
Chlorine
Monochloramine
Total dissolve solids
Chloride
Ammonia
Nitrate
Iron
Fluoride
Hardness
Aluminium
Manganese
Mercury
Cadmium
Arsenic
Cyanide
Lead
Chromium
Copper
Zinc
Sodium
Sulphate
Chloroform
Bromoform
Dibromochlorome
Selenium
Silver
Magnesium
Nickel
Aldrin
DDT
Heptachlor
Alachlor
Chlorofuran
Cyanazine
Propanil
Benzena
Gross α
Gross β
Max accepted value
Absent in 100 ml sample
5 NTU
15 TCU
6.5-9.0
1.0 mg/L
3 mg/L
1000 mg/L
250 mg/L
0.5 mg/L
10 mg/L
0.3 mg/L
0.6-0.9
500 mg/L
0.2 mg/L
0.1 mg/L
0.001 mg/L
0.003 mg/L
0.01 mg/L
0.07 mg/L
0.05 mg/L
0.05 mg/L
1.0 mg/L
3 mg/L
200 mg/L
250 mg/L
0.2 mg/L
0.1 mg/L
0.1 mg/L
0.01 mg/L
0.05 mg/L
150 mg/L
0.02 mg/L
0.00003 mg/L
0.002 mg/L
0.00003 mg/L
0.02 mg/L
0.007 mg/L
0.0006 mg/L
0.02 mg/L
0.01 mg/L
0.1 Bq/L
1.0 Bq/L
(Ministry of Health Malaysia, 1983)
20
than 75 TCU. For higher levels, activated/powdered carbon or ozonation may be
required in addition to the conventional treatment.
2.3.1.2 Turbidity
Turbidity may be due to organic or inorganic impurities suspended in water.
In Malaysian waters, silt, clay and finely divided organic matter are the predominant
suspended solids. It is an indication of the clarity of water. The maximum turbidity
level allowed in drinking water is 5 NTU (Tay, 2000). Turbidity in raw water can be
reduced to accepted levels by appropriate coagulation, flocculation, sedimentation
and filtration.
2.3.1.3 Total Dissolved Solid
Total dissolved solid (TDS) is a quantitative measurement of the dissolved
salts in a water. For given water the dissolved solids concentration can be directly
related to the conductivity. The maximum accepted TDS in water treatment plant is
1000 mg/L (Tay, 2000).
2.3.1.4 pH
The pH value is a measurement of the acidity or alkalinity of water. It is one
of the most important parameter in water chemistry since many of the processes
involved in water treatment are pH-dependent. The recommended value of pH of
treated water is between 6.5 and 9.0. All treated water should be “conditioned” and
adjust before it is sent into the distribution system.
21
2.3.2
Chemical Quality
This is the most difficult group to deal with since conventional treatment
techniques generally are not effective. Therefore, first consideration should be given
to alternative sources and blending of sources. Fortunately they are not usually
present in concentrations anywhere near the maximum permissible levels. They are
generally found only when industrial contamination is present.
2.3.2.1 Mercury
Mercury is a toxic element and has no beneficial physiological function in
man. In drinking water it is predominantly in the inorganic form, which is poorly
absorbed. The concentration of 0.002 mg/L is the maximum allowable value
(Letterman et al., 1999).
2.3.2.2 Arsenic
The maximum allowable concentration in drinking water for arsenic is set at
0.05 mg/L (Tay, 2000). It can be found in surface waters from areas where there are
certain type of metalliferous ore.
2.3.2.3 Lead
Lead is a cumulative body poison and the hazards of exposure to lead have
been well documented. It is rare to find natural waters with a lead concentration more
than 0.02 mg/L (Tay, 2000). The maximum allowable value is 0.05 mg/L of lead.
22
2.3.2.4 Copper
Copper in drinking water can be derived from rock weathering, however the
principal sources are the corrosion of brass and copper piping and the addition of
copper salts when treating water supplies for algae control. Standard of 1.0 mg/L
copper concentration applies to water leaving the plant (Letterman et al., 1999).
2.3.2.5 Chlorine
Chlorine is the most commonly used agent for the disinfection of water
supplies. Chlorine is a strong oxidizing agent capable of reacting with many
impurities in water including ammonia, proteins, amino acids, iron, and manganese.
A maximum chlorine content of 1.0 mg/L has been recommended in treated water
treatment plant (Tay, 2000).
2.3.2.6 Manganese
Manganese resembles iron in its chemical behaviour and occurs in natural
waters, but normally in lower concentration then iron. Manganese can be a
troublesome element even when a present in small quantities. Manganese has a
common value 0.1 to 1 mg/L (Crittenden et al., 2005). It can be deposit out of the
distribution systems in the presence of oxygen.
2.3.2.7 Ammonia
Ammonia is one of the forms of nitrogen found in water. It is usually found
in most natural waters. They originate from various sources, some of which are
completely harmless, for example decomposing vegetation. Up to 0.5 mg/L are
accepted in treated water (Tay, 2000). Ammonia is effectively removed by
chlorination.
23
2.3.2.8 Nitrate
The nitrate is the final stage of oxidation nitrogen compounds and is related
to organic matter present in the water. Waters containing high nitrate concentrations
are potentially harmful. Upper limit of 10 mg/L of nitrate has been set for treated
water (Letterman et al., 1999).
2.3.2.9 Iron
Iron is found in most raw waters where it can impart a bitter taste when
present in large amounts, making the water unpalatable. Iron standard value is 0.3
mg/L in treated water (Crittenden et al., 2005). Currently treatment process involved
aeration follow by adequate coagulation, flocculation, sedimentation, filtration and
pH control.
2.3.2.10 Fluoride
Fluoride content of surface waters in Malaysia is usually low. Fluoride is
added to provide substantial protection against dental caries. However, too high
fluoride concentration in drinking water will lead to adverse health effects varying
from mottling of teeth to crippling fluorosis (Crittenden et al., 2005). A maximum
fluoride content of 0.9 mg/L has been recommended in treated water treatment plant.
2.3.2.11 Hardness
Water hardness is a measure of polyvalent cation contents, predominant of
calcium and magnesium, but also include strontium, barium etc, in term of CaCO3
equivalent in mg/L (Letterman et al., 1999). The conventional treatment hardness of
up to 500 mg/L is permitted.
24
2.3.2.12 Aluminium
The most usual source of aluminium in drinking water comes from corrosion
of aluminium utensils, tanks or pipes or from incorrect dosing of aluminium sulphate
as coagulant at the treatment works. Ideally water going into supply should contain
less than 0.2 mg/L (Tay, 2000).
2.3.3 Microbiological Quality
Microbiological quality of drinking water is the greatest importance and must
never be compromised. The microbe is believed exist when there is pollution.
Urgent measures must be taken out to find out the source. No faecal coliform should
present in 100 mL treated water (Tay, 2000).
2.4
Water Parameters Removal by Water Treatment Process
Several parameters in water that impact drinking water and treatment process
that may be used to remove them are reported in Table 2.12 (Crittenden et al., 2005).
The performance of these treatment processes for a given constituent is presented
subjectively in terms of removal efficiencies reported in various studies. The
information presented in Table 2.12 can be used as a general guideline when a
particular parameter must be removed. However, parameters that comprise
background water matrices can vary widely with respect to their number and
concentration and can impact treatment process performance.
25
Table 2.12
General effectiveness of water treatment processes removal
Type
Parameters
Inorganic
Arsenic (+3)
Barium
Chromium (+3)
Copper
Fluoride
Hardness
Iron
Lead
Manganese
Mercury
Nitrate
Perchlorate
Radium
Uranium
VOCs
SOCs
Colour
TTHMs
MTBE
NDMA
Organic
Aeration
P
P
P
P
P
P
F-G
P
F-G
P
P
P
P
P
G-E
P-F
P
G-E
G-E
P
Coagulation,
Sedimentation, Filtration
G-E
G-E
G-E
G
F-G
P
F-E
E
F-E
F-G
P
NA
P-F
G-E
P
P-G
P-G
P
P
NA
Note: P-poor (0-20% removal), F-fair (20-60% removal),
G-good (60-90% removal), E-excellent (90-100% removal)
2.5
Engineering knowledge
The process of building knowledge-based systems is called knowledge
engineering (KE). It has a great deal in common with software engineering, and is
related to many computer science domains such as artificial intelligence, databases,
data mining, expert systems, decision support systems and geographic information
systems. (Negnevitsky, 2004).
2.6.1
Engineering Knowledge Principles
Since the mid-1980s, knowledge engineers have developed a number of
principles, methods and tools that have considerably improved the process of
26
knowledge acquisition (Russell, and Norvig, 2003). Some of the key principles are
summarized as follows:
i) Knowledge engineers acknowledge that there are different types of knowledge,
and that the right approach and technique should be used for the knowledge required.
ii) Knowledge engineers acknowledge that there are different types of experts and
expertise, such that methods should be chosen appropriately.
iii) Knowledge engineers recognize that there are different ways of representing
knowledge, which can aid the acquisition, validation and re-use of knowledge.
iv) Knowledge engineers recognize that there are different ways of using knowledge,
so that the acquisition process can be guided by the project aims.
v) Knowledge engineers use structured methods to increase the efficiency of the
acquisition process.
2.7
Programming Tool using Visual Basic
Visual Basic (VB) is an event-driven programming language and associated
development environment prototyped by Alan Cooper as Project Ruby, then bought
and vastly improved upon by Microsoft.
Visual Basic was designed to be easy to learn and use. The language not only
allows programmers to easily create simple graphical user interface applications, but
also has the flexibility to develop fairly complex applications as well. Programming
in VB is a combination of visually arranging components or controls on a form,
specifying attributes and actions of those components, and writing additional lines of
code for more functionality. Since default attributes and actions are defined for the
components, a simple program can be created without the programmer having to
write many lines of code. Performance problems were experienced by earlier
versions, but with faster computers and native code compilation this has become less
of an issue (Corburn, 1999).
Although programs can be compiled into native code executables from
version 5 onwards, they still require the presence of runtime libraries of
approximately 2 MB in size. This runtime is included by default in Windows 2000
27
and later, but for earlier versions of Windows it must be distributed together with the
executable.
Forms are created using drag and drop techniques. A tools palette is used to
place controls (e.g., text boxes, buttons, etc.) on the form (window). Controls have
attributes and event handlers associated with them. Default values are provided when
the control is created, but may be changed by the programmer. Many attribute values
can be modified during run time based on user actions or changes in the
environment, providing a dynamic application. For example, code can be inserted
into the form resize event handler to reposition a control so that it remains centred on
the form, expands to fill up the form, etc. By inserting code into the event handler for
a key press in a text box, the program can automatically translate the case of the text
being entered, or even prevent certain characters from being inserted (Coburn,
1999)..
A Visual Basic application can consist of one or more windows, or a single
window that contains Multiple Document Interface (MDI) child windows, as
provided by the operating system. Dialog boxes with less functionality (e.g., no
maximize/minimize control) can be used to provide pop-up capabilities. Controls
provide the basic functionality of the application, while programmers can insert
additional logic within the appropriate event handlers (Mckeown 2004). For
example, a drop-down combination box will automatically display its list and allow
the user to select any element. An event handler is called when an item is selected,
which can then execute additional code created by the programmer to perform some
action based on which element was selected, such as populating a related list.
2.7.1
Behaviour Present in Visual Basic
Visual Basic has the following special traits:
i) Boolean constant True has numeric value -1. In most other languages, True is
mapped to numeric value 1. This is because the Boolean data type is stored in the
same way as a 16 bit signed integer. In this construct -1 evaluates to 16 binary 1s (the
28
Boolean value True), and 0 as 16 0s (the Boolean value False). This is apparent when
performing a Not operation on a 16 bit signed integer value 0 which will return the
integer value -1. This inherent functionality becomes especially useful when
performing logical operations on the individual bits of an integer such as And, Or,
and Not (Coburn, 1999).
ii) Logical and bitwise operators are unified. This is unlike all the C-derived
languages (such as Java or Perl), which have separate logical and bitwise operators.
iii) Variable array base. Arrays are declared by specifying the upper and lower
bounds in a way similar to Pascal. It is also possible to use the Option Base statement
to set the default lower bound. Use of the Option Base statement can lead to
confusion when reading Visual Basic code and is best avoided by always explicitly
specifying the lower bound of the array. This lower bound is not limited to 0 or 1,
because it can also be set by declaration. In this way, both the lower and upper
bounds are programmable. In more subscript-limited languages, the lower bound of
the array is not variable.
iv) Ability to run the application without performing a full compile or making an
executable, allowing for edit-and-continue changes.
v) Relatively strong integration with the Windows operating system.
vi) Banker's rounding as the default behaviour when converting real numbers to
integers.
vii) Integers are automatically promoted to real in expressions involving the normal
division operator (/) so that division of an odd integer by an even integer produces
the intuitively correct result. There is a specific integer divide operator (\) which does
truncate.
29
2.7.2 User-friendly Interface design
Here are a few recommendations and examples for Microsoft Access
developers who want to make user-friendly interface Access database interfaces
(Mckeown 2004):
i) Colours - Choose screen colours with good contrast. If the first thing a person
notices when viewing the screen are the colours then you have gone too far in
colorizing your screen. The user should first notice the field labels followed by the
data MS Access developers. Bold black letters on grey background is preferred for
the boilerplate and black letters on white background is preferred for data. Use
colours to highlight important fields or data in your form designs. Consider making
required fields standout from other fields.
ii) Fonts - The fewer the fonts the better. Fonts without serifs tend to be easier to
read. Avoid using several different font sizes - stick to one or two. Don't use a lot of
italics, and underlines.
iii) Layout - When you have many fields to display on a form try to group them. For
instance you can group Name, Address, etc. together on the form and separate this
information from other supporting information in the data record. Don't forget to set
the tab order on your form correctly.
iv) Buttons - Avoid creating your own navigation and function buttons whenever
these buttons are already available in a standard Microsoft Access form. Examples
of some standard buttons/functions are Next Record, New Record, Sort, etc.
2.8
Security System by Password
Security is an important concept in information an system that is aimed to
protecting them from unauthorized entry (Chua, 1997). The user is usually given
passwords to enter the program. Passwords vary in the degree of public awareness,
security protection and frequency of change. The most public, and therefore least
30
secure, password might be one that is given to members of a group, a committee or
some other organization for instance, "public_library", "internet" or "AAA_finance"
are all examples of easily remembered passwords.
In controlling access to anything, trade-offs are made between security and
convenience. If a resource is protected by a password, then security is increased with
a consequent loss of convenience for users. The amount of security and
inconvenience inherent in a particular password system or policy are affected by
several factors addressed below. However, there is generally no one universal best
way to set a proper balance between security and convenience for all cases
(Mckeown, 2004).
31
CHAPTER 3
METHODOLOGY
3.1
Development of WATER-DSS
The DDS in this study is known as WATER-DSS. The development of
WATER-DSS
applies
methods
of
conventional
computing
practices
and
programming techniques. WATER-DSS was built by integrating the conceptual
design of drinking water treatment through conventional method into a computer
program, which has capability as a DDS. The structure design of WATER-DSS is
shown in Figure 3.1.
Student
Visual Basic
6.0
Lecturer
Regulator
Master
Student
End User
Contractor
Engineer
WATERDSS
Lecturer
Knowledge &
Expertise
PhD Student
Consultant
Articles
Authority
Manuals
Figure 3.1
WATER-DSS development structure
32
3.2
Forms of WATER-DSS Project in Visual Basic
WATER-DSS program is planned to provide the security system, welcoming
frame, parameter input, water treatment process, summary sheet and appreciation
frame. These forms are created in Visual Basic 6.0, as shown in Figure 3.2.
Figure 3.2
3.2.1
Forms in WATER-DSS
Security of WATER-DSS
One of the most widely used systems for providing protection for an
information system is to require a password that is known only to an authorized user.
User can assess WATER-DSS if they enter the correct password. If fail to do so, the
program will be terminated. A security Password form is created as Figure 3.3.
Title
Label
Textbox
Command1
Timer1
Background
Figure 3.3
Password form
33
Double click on command1, key in the below code.
Private Sub Command1_Click()
If Text1 = "FKA" Then
Timer1.Enabled = False
Form0.Hide
Form00.Show
Else
MsgBox ("Sorry, invalid password."), , "password"
End If
End Sub
Password of WATER-DSS is temporary set to “FKA”. To login WATER-DSS,
“FKA” has to be entered in the textbox in Figure 3.3. If user insert wrong password,
message box indicating “Sorry, invalid password.” will appear. To enhance the
security system, 20 seconds limitation is set for user to enter the correct password.
The code of timer1 is as below:
Private Sub Timer1_Timer()
MsgBox ("sorry, your time is up."), , "Bye bye.."
End
End Sub
3.2.2 Welcome frame
If correct password (“FKA”) is entered, a welcome screen is shown in Figure 3.4.
Double click on Command1 and insert the following code:
Private Sub command1_Click()
Form00.Hide
Form01.Show
End Sub
34
Textbox
Command1
Command2
Image
Figure 3.4
Welcome form
After enter the code, the form00 (Password form) will be closed and form01
(Parameter Input form) will be opened.
Double click on Command2 and insert the following code:
Form00.Hide
Form10.Show
End Sub
After enter the code, the form00 (Password form) will be closed and form01 (Thank
You form) will be opened.
To make sure the textbox is not changeable, textbox properties are edited and
changed to:
Name
: Text1
Text
: Welcome to WATER-DSS 2006
Font
: Time New Romans, Bold, 16
Tabstop
: False
Locked
: True
Backcolour
: &H00FFFFC0&
35
To set this form is not show in early program, double click on form background and
insert the following code:
Private Sub Form_Load()
Form00.Hide
End Sub
Images are input from the picture taken in the Sayong Water Treatment Plant, Johor.
3.2.3 Parameter Input Form
Parameter Input form is considered one of the most important form where user can
input all the collected data from field or site to do further checking. In the form,
textbox for parameter input is provided. Standard parameter value based on the
Malaysia National Water Quality Standards is also shown. Picturebox is prepared to
recognise the parameter values and present related treatment information if the
values exceed the range of requirement standard. The design interface of this form is
illustrated in Figure 3.5. In WATER-DSS, the parameters are basically divided into
four sections which are shown in Table 3.1
Table 3.1: Category of water parameters
1
2
Section
Physical
Inorganic
3
4
Metal
Microbiological
Parameter
Turbidity, colour, pH and chlorine.
Total Dissolve Solids (TDS), manganese, ammonia,
nitrate, iron, fluoride, hardness and aluminium.
Mercury, arsenics, lead and copper.
Faecal coliform.
36
Command1
Command2
Command3
Frame1
Frame2
Picturebox
Picture1, 2…
Frame3
Label
(Standard)
Frame4
Textbox
Text1, 2…
Figure 3.5
Parameter Input form
i) Double click on Command1 and insert the following code (this code also enables
the calculation to run if user not inserts all the input parameters):
Picture1.Cls
If Text1 <> vbnouncestring Then
If Text1 <= 5 Then strtitle$ = "No specific treatment required"
If Text1 <= 5 Then Picture1.BackColor = &HFFFFC0
If Text1 > 5 Then strtitle$ = "coag, floc, sediment and filtr"
If Text1 > 5 Then Picture1.BackColor = &HC0C0FF
Picture1.Print strtitle$
End If
Picture2.Cls
37
If Text2 > 15 Then strtitle$ = "coag, and filtr"
End If
Picture3.Cls
If Text3 >= 6.5 And Text3 <= 9 Then strtitle$ = "No specific
treatment required"
If Text3 >= 6.5 And Text3 <= 9 Then Picture3.BackColor =
&HFFFFC0
If Text3 < 6.5 Or Text3 > 9 Then strtitle$ = "pH adjustment-Lime"
If Text3 < 6.5 Or Text3 > 9 Then Picture3.BackColor = &HC0C0FF
End If
Etc……
End Sub
ii) Double click on Command2 and insert the following code:
Form01.Hide
Form02.Show
End Sub
iii) Double click on Command3 and insert the following code:
Form10.Show
38
End Sub
iv) The picturebox properties are edited and changed to:
Name
: Picture1, Picture2, Picture3 ….
Text
: (None)
Font
: Time New Romans, Italic, 12
Tabstop
: False
Locked
: True
Backcolour
: &H00FFFFC0&
v) Double click on form textbox and insert the following code:
Private Sub Text1_Change()
Form04.Text1 = Text1
End Sub
End Sub
End Sub
After these codes are entered, any data that input into these textbox will be
automatically transfer to textbox in form04 (Aeration form) and form09 (Summary
form).
39
3.2.4 Water Treatment Process form
This is the form where overall of conventional water treatment process is
presented. From here, user can select any process that he needs to get more
information. The design interface of the form is illustrated in Figure 3.6. Additional
information about pre-chlorination, coagulant, pH adjustment, fluoridation and
disinfection is supplied.
Command1
Command2
Command3
Command8
Command9
Command4
Command10
Command5
Command6
Command11
Command7
Command12
Command13
Command14
Figure 3.6
Water treatment process form
Command1, Command2, Command3, Command4, Command5, Command6
and Command7 are created to link user to Pre-treatment form, Aeration form,
Coagulation form, Flocculation form, Sedimentation form, Filtration form and
Summary form respectively. Below are codes that need to be entered after double
clicking on those commands.
Form02.Hide
Form03.Show
End Sub
40
Form02.Hide
Form04.Show
End Sub
Form02.Hide
Form05.Show
End Sub
Form02.Hide
Form06.Show
End Sub
Form02.Hide
Form07.Show
End Sub
Form02.Hide
Form08.Show
End Sub
For providing additional information, double click on command8, command 9,
command10, command11, command12, comman13, and insert the following code:
Private Sub Comman8_Click()
MsgBox ("Remove ammonia; 1 mg/L ammonia required 10 mg/L
Chlorine."), , "Pre-clorination"
End Sub
MsgBox ("Add fluoride to reduce dental decay"), , "fluoridation"
41
End Sub
MsgBox ("pH increase, encourage coagulation process"), ,
"Coagulation-lime"
End Sub
MsgBox ("Remove iron and manganese."), , "Coagulation-alum"
End Sub
MsgBox ("Increase pH up to drinking standard"), , "pH adjustment"
End Sub
MsgBox ("Disinfection, remove any potencial bacteria"), ,
"Chlorination"
End Sub
Command7 is the command buttons where user can straight forward go to the
summary form without going trough all detail process. After clicking this button, the
data need to transfer from Parameter Input form (Form01) into the Summary form
(Form09). At the same time, the analysed parameter value is straight presented in the
Summary form. The calculation is based on the percentage removal which is given in
Table 3.2. The output values that exceed or not in the range compare standard value
will automatic change to red colour. IF the parameter remains good quality from
input until output, the remark of “No specific treatment required” is shown. If
parameter can be treatment by the treatment process, the remark of “Can be treated
by treatment” is shown. Further action if needed is presented in Table 3.1. To this,
this code need to key in after double click on the Command7 button:
Form02.Hide
42
Form09.Show
If Form01.Text1 <> vbnouncestring Then
Form09.Text1 = Form01.Text1
Form09.Text18 = Form01.Text1 * 0.1
Form09.Picture1.Cls
If Form09.Text1 <= 5 Then strtitle$ = "No specific treatment
required"
If Form09.Text1 > 5 And Form09.Text18 <= 5 Then strtitle$ = "Can
be treated by treatment"
If Form09.Text18 > 5 Then strtitle$ = "Not suitable for water intake"
If Form09.Text18 <= 5 Then Form09.Picture1.BackColor =
&HFFFFC0
If Form09.Text18 > 5 Then Form09.Picture1.BackColor =
&HC0C0FF
If Form09.Text18 <= 5 Then Form09.Text18.BackColor =
&HFFFFC0
If Form09.Text18 > 5 Then Form09.Text18.BackColor =
&HC0C0FF
Form09.Picture1.Print strtitle$
End If
If Form01.Text2 <> vbnouncestring Then
Form09.Text2 = Form01.Text2
Form09.Text19 = Form01.Text2 * 0.9 * 0.55
Form09.Picture2.Cls
If Form09.Text2 <= 15 Then strtitle$ = "No specific treatment
required"
If Form09.Text2 > 15 And Form09.Text19 <= 15 Then strtitle$ = "Can
be treated by treatment"
If Form09.Text19 > 15 Then strtitle$ = "Not suitable for water intake"
If Form09.Text19 <= 15 Then Form09.Picture2.BackColor =
&HFFFFC0
If Form09.Text19 > 15 Then Form09.Picture2.BackColor =
43
&HC0C0FF
If Form09.Text19 <= 15 Then Form09.Text19.BackColor =
&HFFFFC0
If Form09.Text19 > 15 Then Form09.Text19.BackColor =
&HC0C0FF
Form09.Picture2.Print strtitle$
End If
Etc…………….
End Sub
Table 3.2: Simplify removal percentage by process treatment and further
treatment action
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Parameter
Turbidity
Colour
pH
Chlorine
TDS
Manganese
Ammonia
Nitrate
Iron
Fluoride
Hardness
Aluminium
Mercury
Arsenic
Lead
Copper
Total coliform
Aeration
10%
40%
10%
55%
10%
10%
40%
10%
10%
10%
-
CFSF
90%
45%
65%
90%
10%
85%
-
Fail meet standard after treat
Not suitable for water intake
check lime dosing
Check chlorine dosing
Add more coagulant
Add more chlorine
Add more coagulant
Stop Fluoride dosing, waiting dilution
Check dosing alum
Note: CFSF – Combination coagulation, flocculation, sedimentation, filtration.
3.2.5 Pre-treatment Form
Pre-treatment is a water treatment process to remove large objects such as
logs, sticks, fish, and plants. This is to prevent damage and avoid silting in treatment
plant. In this form, information about coarse screens and pre-sedimentation is given.
44
Pre-sedimentation form interface is shown in Figure 3.7. Calculation of removal
parameters is not included in this form.
Coarse
screen
Description
Design
criteria
Presedimentation
Additional
information
Command2
Command1
Command3
Figure 3.7
Pre-treatment form
To avoid this form shown at early, the code need to enter is (This code is used
to all other forms except the Password form):
Private Sub Form_Load()
Form03.Hide
End Sub
The Next command button is to bring user to the next form; Back command
button is to bring user back to Water Treatment Process form. In order to do so, the
following code need to key into the command button:
Form03.Hide
Form02.Show
End Sub
45
Form03.Hide
Form04.Show
End Sub
3.2.6 Aeration Form
Aeration is a process of bringing water and air into close contact in order to
remove dissolved gases and to oxidise dissolved metal that assist in removal iron and
manganese.
In this Aeration form, the interface is design as shown in Figure 3.8. Output
of parameters after this aeration treatment is calculated and presented in the output
textbox. Removal parameter percentage can refer in Table 3.2. If the output
calculated not reach the standard value, the textbox will change to red colour
Output
Text18, 19…
Input
Text1, 2...
Description
Design
criteria
Additional
Information
Command1
Figure 3.8
Standard
Aeration form
46
In this form, to calculate the output of the input parameter value, command1 as the
run button need to be entered the following code:
Text18 = Text1
If Text18 > 5 Then Text18.BackColor = &HC0C0FF
If Text18 <= 5 Then Text18.BackColor = &HFFFFC0
End If
Text19 = Text2 * 0.9
End If
Text20 = Text3
If Text20 < 6.5 Or Text20 > 9 Then Text20.BackColor = &HC0C0FF
If Text20 >= 6.5 And Text20 <= 9 Then Text20.BackColor =
&HFFFFC0
End If
Etc............
End Sub
3.2.7 Coagulation, Flocculation and Sedimentation
To simplify the WATER-DSS system, the removal parameters in coagulation,
flocculation, sedimentation and filtration is group into same category. This is mean
47
that, after removal parameters in process aeration, the next process showing
parameters removal is in Filtration form.
However, the coagulation, flocculation and sedimentation are presented in 3
different forms. This is to provide information like definition, design criteria for
typical treatment plant and some additional information such as coagulant used,
alternatives that can be considered. These entire form design interface are similar
with the Pre-treatment form.
3.2.8 Filtration Form
Filtration is a last step in water treatment to remove the residual suspended
solid in the water. As declared above, the removal of water parameters in this
Filtration form are including the coagulation, flocculation, sedimentation and
filtration itself. The removal of parameters is calculated in this form and presented in
Table 3.2. The design interface of Filtration form is similar with the Aeration form.
3.2.9
Summary Form
As the ultimate part of WATER-DSS, a summary of the water parameters
after go through complete treatment process (aeration, coagulation, flocculation,
sedimentation, and filtration) is presented in Summary form which is shown in
Figure 3.9. In this form, the input parameter is origin from the Parameter Input form.
Conclusion is made regarding to the outcome of the treatment compare to the
standard value.
48
Output
Text18, 19…
Input
Text1, 2…
Conclusion
Picture1, 2 …
Command1
Figure 3.9
Command2
Filtration form
User may do edition on desirable input and calculate for it outcome in this
form. To enable user calculate the new input in this form, this code is needed to enter
into the Command1:
Text18 = Text1 * 0.1
Picture1.Cls
If Text1 > 5 And Text18 <= 5 Then strtitle$ = "Can be treated by
treatment"
If Text18 > 5 Then strtitle$ = "Not suitable for water intake"
49
End If
Text19 = Text2 * 0.9 * 0.55
Picture2.Cls
If Text2 > 15 And Text19 <= 15 Then strtitle$ = "Can be treated by
treatment"
If Text19 > 15 Then strtitle$ = "Not suitable for water intake"
End If
Text20 = Text3
If Text20 < 6.5 Or Text20 > 9 Then Text20.BackColor =
&HC0C0FF
If Text20 >= 6.5 And Text20 <= 9 Then Text20.BackColor =
&HFFFFC0
Picture3.Cls
treatment required"
treatment required"
If Text20 < 6.5 Or Text20 > 9 Then strtitle$ = "check lime dosing"
If Text20 >= 6.5 And Text20 <= 9 Then Picture3.BackColor
= &HFFFFC0
If Text20 < 6.5 Or Text20 > 9 Then Picture3.BackColor =
&HC0C0FF
50
End If
Etc………
End Sub
3.2.9 Thank You Form
After finish using the WATER-DSS, an interface that appreciate user is
created. WATER-DSS is ended by click on the command button “Quit” shown in
Figure 3.9, and a Thank You form should pop out before the WATER-DSS is
completely end. Thank You form is shown in Figure 3.10.
Cancel
Command1
Figure 3.10
Thank You form
Command1 is used to terminate this WATER-DSS program and the code is:
End
End Sub
If user changes mind to continue using this program, he/she can simply click
on the cancel button shown in Figure 3.10.
51
CHAPTER 4
RESULT & DISSCUSION
4.1
General
Throughout the study, a decision support tool for design and process selection
of drinking water treatment plant using conventional method has been developed. It
has been given name of WATER-DSS.
4.2
Application of WATER-DSS
The WATER-DSS is a tool that assists decision making on the process of
drinking water treatment plant using conventional treatment methods. The process
consists of pre-treatment, coagulation, flocculation, sedimentation, filtration and
disinfection. The processes are selected based on the requirement to treat the raw
water, chemically, physically and microbiologically. Each parameters of water has it
own treatment procedure but often it can combine.
4.3
Validation Of Result
To validate WATER_DSS, three sets of data have been entered into the
Parameter Form and run. At the same time, manual calculations are made using
52
Microsoft Excel spreadsheet which refers Table 3.2. The output of WATER-DSS is
then verified using Microsoft Excel. The validation of WATER-DSS is presented in
Table 4.1.
4.4
Discussion
WATER-DSS has been successfully developed. Using WATER-DSS, user
can design the water treatment process as well as maintain the plant operation. This
application is simple through input parameter water quality that collected from the
side into WATER-DSS Parameter Input form. The result of parameters is analysed
and essential water treatment process is presented. The final result after treatment
using conventional method can be checked in the Summary form. In Summary form,
further treatment or action is suggested according to the output of treatment process.
If user desires to get more details information about the treatment processes,
he/she can enter the related treatment forms. In the detail treatment form, user can
gain information such as description of process, typical design criteria of treatment
plant, alternative suggestions of the practice and the removal of the parameters by
treatment. The entire form are interrelated and connected, user can freely enter any
form they wish to obtain the needed information.
WATER-DSS has been set only to allow the authorise user. This is to
enhance the security and privacy system. Virtually everyday news about hacker
breaking into a computer system for “fun” or with criminal intent can be observed
(Mckeown, 2004). If user fails to entry the correct passwords into the Password
form, they are denied to login WATER-DSS.
WATER-DSS has been developed as a user-friendly program. The form,
background, font, colour, title, textbox, picture, link are all design, arrange and set to
attractively, accordingly and systematically. User can easily run and access WATERDSS as they wish.
51
Table 4.1
Comparison WATER-DSS result and Microsoft Excel result
Parameter
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Turbidity
Colour
pH
Chlorine
TDS
Manganese
Ammonia
Nitrate
Iron
Fluoride
Hardness
Aluminium
Mercury
Arsenic
Lead
Copper
Total coliform
SET 1
Input W-D M-E
2
2
20
25
6.8
0.2
120
0
0.1
0.1
0.2
0.1
110
0.2
0
0
0.02
0
0
12.375 12.375
6.8
6.8
0.2
0.2
120
120
0
0
0.01
0.01
0.081 0.081
0.0135 0.0135
0.09
0.09
99
99
0.2
0.2
0
0
0
0
0.018 0.018
0
0
0
0
SET 2
Corr. Input W-D M-E
1
30
50
6
2
1500
0.3
0.5
7
0.25
0.2
450
0.2
0.01
0.03
0.04
0.4
0
3
50
6
2
1500
0.063
0.05
5.67
0.017
0.18
405
0.2
0.006
0.06
0.036
0.36
0
3
50
6
2
1500
0.063
0.05
5.67
0.017
0.18
405
0.2
0.006
0.06
0.036
0.36
0
Corr.
Input
1
60
80
8
1.5
900
0.3
0.5
8
0.5
0.5
550
0.4
0.03
0.03
0.06
0.9
2
SET 3
W-D M-E
6
39.6
8
1.5
900
0.063
0.07
6.48
0.034
0.45
495
0.4
0.018
0.027
0.054
0.81
2
Note: W-D: WATER-DSS result
M-E: Microsoft Excel result
Corr.: Correlation obtain using Microsoft Excel (1 = significant direct relation, 0 = not significant relation)
6
39.6
8
1.5
900
0.063
0.07
6.48
0.034
0.45
495
0.4
0.018
0.027
0.054
0.81
2
Corr.
1
51
WATER-DSS is also validated using Microsoft Excel. The comparison in
Table 4.1 prove the relationship between the WATER-DSS output and manual
calculation output is significant.
55
CHAPTER V
CONCLUSION
5.1
Conclusion
The conclusions of this study are as follows:
i) A DSS called WATER-DSS was successfully designed and developed
according to the planned output.
ii) Validation of WATER-DSS was conducted using comparison output
between WATER-DSS and Microsoft Excel and it show significant relationship.
5.2
Suggestion
To enhance WATER-DSS for future quality and value, some suggestion has
made:
i) Technical knowledge - There is more information need to be added into WATERDSS in the future development. Calculation forms such as coagulant dosing, output
of jar test, tank estimation, efficiency of treatment, cost analysis need to be provided.
All parameters exist in standard need to be offered to enable user to gain all the
needed data. More real water treatment plant data need to be collected especially the
56
removal percentage of parameters to verify the WATER-DSS program. Information
of alternative treatment process need to be included such as spray aerator,
mechanical flocculators, inclined parallel plate settler sedimentation tanks, slow sand
filters and etc. More pictures such as design layout plan of aerator, flocculator and
filtration tank can be added.
ii) Human Power - An expert in computer programmer is needed to assist in the
WATER-DSS development. With the computer knowledge of him/her, the WATERDSS can present more useful data, information in a user-friendly form.
iii) Computer system – WATER-DSS can provide storage of database information in
order to allow user to save, load and trace back their previous data and information.
Print function should be enabled to allow user to print any form that they require.
Password setting modify to changeable to let user change passwords periodically. A
form that store all the information on the site such as location, name of river, date,
temperature can be created to differential the study area. Flow of parameter is
suggested to be presented in graph so that the value changes throughout the treatment
process by process are clearly illustrated.
5.3
Error in Study
Throughout the study and development of WATER-DSS, some errors or
inaccuracies have been identified. Due to time constrain, the error was notable to be
corrected.
i) Knowledge-base information - The removal of parameters in WATER-DSS is
obtained from the Water Treatment Principle and Design textbook. The removal
percentage is a typical value which may different from one treatment plant to another
treatment plant. Further checking and validation need to be carried out to ensure the
quality and reliability of WATER-DSS. A categorization mistake has been made in
Parameter Input form. For example, arsenic is origin from metal class. The
parameters classification should be follow the Malaysia National Water Quality
Standard (2004). Parameter such as pH, chlorine, aluminium is not changed during
57
the WATER-DSS. More research and study need to be made to ensure the accurate
output of the entire parameters can be obtained.
ii) Computer program - The “print” command not yet being enabled. In future not
only this command button should be modified, command such as “save”, “load” and
“clear input” must be added.
58
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