ក្រសួងអប់រ ំ យុវជន និងរីឡា
វិទ្យាស្ថានបច្ចេរវិទ្យារម្ពជា
ុ
ម្ហាវិទ្យាល័យគីម្ីឧសាហរម្ម
គច្ក្ោងសញ្ញ
ា បក្រវិសរ
វ រ
ក្បធានបទ្យ: ការសិរាអំពីដំច្
រម្ម្ៃគុ
ើ រការក្បក្ពឹរតិរម្មទ្យឹរនិងការវាយ
ភាពម្នទ្យឹរពិស្ថរររ ៉ែធម្មជារិកាយា
និសស ិរ
: អ៊ន បៃយ
ឯរច្ទ្យស
:
វិទ្យាស្ថស្តសត និងបច្ចេរវិទ្យាអាហារ
ក្គូទ្យទ្យួលបនទរ
:
ុ
ប
ឆ្ន ំសិរា
២០២៤-២០២៥
:
ឌ ិ រ ឯរ ច្ពក្ជម្ុននី
MINISTERE DE L’EDUCATION,
DE LA JEUNESSE ET DES SPORTS
INSTITUT DE TECHNOLOGIE DU CAMBODGE
FACULTE DE GENIE CHIMIQUE ET ALIMENTAIRE
MEMOIRE DE FIN D’ETUDES
Titre : Etude sur le processus de traitement et l’évaluation de la qualité de
l’eau minérale naturelle de boisson Chez Kiia
Etudiante
:
ORN Phloy
Spécialité
:
Sciences et Technologies des Aliments
Tuteur de stage
:
Dr. EK Pichmony
Année scolaire
:
2024-2025
ក្រសួងអប់រ ំ យុវជន និងរីឡា
វិទ្យាស្ថានបច្ចេរវិទ្យារម្ពជា
ុ
ម្ហាវិទ្យាល័យគីម្ីឧសាហរម្ម
គច្ក្ោងសញ្ញ
ា បក្រវិសរ
វ រ
របស់នស
ិ ស ិរ: អ៊ន បៃយ
កាលបរ ិច្ចេទ្យការពារនិច្រេបបទ្យ: ម្ងៃទ្យី០៨ រែររកដា ឆ្ន ំ២០២៥
អនុញ្ញ
ា រឱ្យការពារគច្ក្ោង
នាយរវិទ្យាស្ថាន:
ម្ងៃទ្យី
រែ
ក្បធានបទ្យ: : ការសិរាអំពីដំច្
គុ
ឆ្ន ំ២០២៥
ើ រការក្បក្ពឹរតិរម្មទ្យឹរនិងការវាយរម្ម្ៃ
ភាពម្នទ្យឹរពិស្ថរររ ៉ែធម្មជារិកាយា
សហក្ាស
: ឌីភីអុិនវី ែូ អិលធីឌី
ក្ពឹទ្យធបុរស
: ប
ឌ ិ រ អុិន សុែនាង
ក្គូទ្យទ្យួលបនទរ
ុ
: ប
ឌ ិ រ ឯរ ច្ពក្ជម្ុនី
អនរទ្យទ្យួលែុសក្រូវរនងសហក្ាស
: ច្ប ម្ៃរ ័រន
ុ
រាជធានីភនំច្ពញ
MINISTERE DE L’EDUCATION,
DE LA JEUNESSE ET DES SPORTS
INSTITUT DE TECHNOLOGIE DU CAMBODGE
FACULTE DE GENIE CHIMIQUE ET ALIMENTAIRE
MEMOIRE DE FIN D’ETUDES
DE Mlle ORN Phloy
Date de soutenance : le 08 Juillet 2025
« Autorise la soutenance du mémoire »
Directeur de l’Institut :
Phnom Penh, le
2025
Titre : Etude sur le processus de traitement et l’évaluation de la qualité de l’eau
minérale naturelle de boisson Chez Kiia
Etablissement du stage : DPNV Co., Ltd
Doyen
: Asst. Prof. Dr. IN Sokneang
Tuteur de stage
: Dr. EK Pichmony
Responsable de l’établissement : Be Chairat
PHNOM PEN
ACKNOWLEDGEMENT
My name is ORN Phloy, a fifth year student in the Faculty of Chemical and food
Engineering at Institute of Technology of Cambodia- Tbong Khmum campus. I would like to
show my deepest thank to all the people who had spent the meaningful time supporting,
advising, and helping me to the completion of this thesis.
First and foremost, I would like to express my sincere gratitude to my parents for their
strong support, love, and encouragement. They always provide me the energy and support in
every situation. Without them, I might not be able here today.
Secondly, I would like thanks to His Excellency Prof. Dr. PO Kimtho, Director
General of Institute of Technology of Cambodia, and Asst. Prof. Dr. IN Sokneang, Dean of
the Faculty of Chemical and Food Engineering for his good governance and good leader in the
department and I also want to show my gratitude to all the teachers for guidance and sharing
in both knowledge and skill to me.
Thirdly, I would like to take this opportunity to show my deep sense of gratitude to my
advisor, Dr. EK Pichmony, for spending her valuable time guiding me. This thesis would not
be completed without her kind support, pieces of advice, and encouragement during this
pandemic and I am greatly honored to be her advice. Her suggestions were invaluable as I was
doing research and writing this thesis.
Fourthly, I would like thank to
ឥឥឥឥឥឥឥឥឥឥឥ
i
អត្ថបទសង្ខេប
ii
RESUME
iii
ABSTRACT
iv
ABBREVIALTIONS AND SYMBOLS
pH
TDS
ClO3
US EPA
EU
WHO
FMCG
FAO
VOCs
DO
2009/54/EC
TOC
NOM
(DAF)
RO
UF
NF
RO
v
TABLE OF CONTENT
ACKNOWLEDGEMENT .............................................................................................. i
RESUME ......................................................................................................................iii
ABSTRACT ................................................................................................................. iv
ABBREVIALTIONS AND SYMBOLS ....................................................................... v
TABLE OF CONTENT ................................................................................................ vi
LIST OF FIGURES ....................................................................................................... x
LIST OF TABLES ........................................................................................................ xi
1. INTRODUCTION ..................................................................................................... 1
1.1. Background ......................................................................................................... 1
1.2. Objective ............................................................................................................. 2
1.3. Scope limitation .................................................................................................. 2
2. LITERATURE REVIEW .......................................................................................... 3
2.1. History of the Company (DPNV Co., Ltd) ......................................................... 3
2.2. Water Sources ..................................................................................................... 3
2.2.1. Groundwater ................................................................................................ 5
2.2.2. Quality Characteristics of Water.................................................................. 7
2.2.3. Natural Mineral Waters ............................................................................... 7
2.3. Drinking Water Standards .................................................................................. 9
2.4. Various Methods Of drinking treatment water ................................................. 10
2.4.1. Particles of Concern in Water Treatment .................................................. 11
2.4.2. Screening ................................................................................................... 12
2.4.3. Coagulation-Flocculation .......................................................................... 12
2.4.4. Dissolved Air Flotation.............................................................................. 13
2.4.5. Clarification ............................................................................................... 13
2.4.6. Filtration .................................................................................................... 14
2.4.7. Membrane Filtration .................................................................................. 14
vi
2.4.8. Adsorption ................................................................................................. 15
2.4.9. Ion exchange .............................................................................................. 15
2.4.10. Advanced Oxidation Processes................................................................ 16
2.4.11. Disinfection.............................................................................................. 17
2.5. Natural Mineral Water Treatment .................................................................... 17
2.6. Physicochemical ............................................................................................... 18
2.6.1. Iron ............................................................................................................. 18
2.6.2. Manganese ................................................................................................. 19
2.6.3. Turbidity .................................................................................................... 19
2.6.4. Chloride ..................................................................................................... 20
2.6.5. TDS ............................................................................................................ 21
2.6.6. Color .......................................................................................................... 22
2.6.7. Ozone ......................................................................................................... 22
2.6.8. Temperature ............................................................................................... 23
2.7. Faecal indicators in Drinking Water ................................................................. 24
2.7.1. E.coli .......................................................................................................... 24
2.7.2. Total coliform ............................................................................................ 25
2.7.3. Total plate count ........................................................................................ 25
2.8. Water treatment plant ....................................................................................... 26
2.8.1. Bag filter .................................................................................................... 28
2.8.2. Mn and Fe filter ......................................................................................... 28
2.8.3. Ultrafiltration ............................................................................................. 29
2.8.4. Ultraviolet .................................................................................................. 30
2.8.5. Ozone ......................................................................................................... 32
3. MATERIAL AND METHODS ............................................................................... 34
3.1. Sampling ........................................................................................................... 34
3.2. Material ............................................................................................................. 34
vii
3.3. Calibration ........................................................................................................ 36
3.4. Physicochemical parameters ............................................................................. 37
3.4.1. Manages ..................................................................................................... 39
3.4.2. Iron ............................................................................................................. 39
3.4.3. Chloride ..................................................................................................... 40
3.4.4. Color .......................................................................................................... 40
3.4.5. Ozone ......................................................................................................... 40
3.4.6. Total dissolved solids ................................................................................ 41
3.4.7. Turbidity .................................................................................................... 41
3.4.8. pH .............................................................................................................. 42
3.5. Micrological ...................................................................................................... 42
3.5.1. Prepare agar ............................................................................................... 42
3.5.2. Total Plate Count ....................................................................................... 42
3.5.3. E.Coli and Total plate count ...................................................................... 42
4. RESULT AND DISCUSSION ................................................................................ 43
4.1. Efficiency remove Mn ...................................................................................... 43
4.2. Efficiency Removes Iron .................................................................................. 44
4.3. During storage mineral water ........................................................................... 45
4.3.1. Turbidity .................................................................................................... 46
4.3.2. Color .......................................................................................................... 47
4.3.3. Iron ............................................................................................................. 47
4.3.4. Ozone ......................................................................................................... 48
4.3.5. pH .............................................................................................................. 49
4.3.6. Chloride ..................................................................................................... 49
4.3.7. Biological ................................................................................................... 50
5. CONCLUSION........................................................................................................ 52
REFERENCES ............................................................................................................ 53
viii
APPENDIXES ............................................................................................................. 54
5.1. Component of treatment water ......................................................................... 55
ix
LIST OF FIGURES
Figure 2.1. DPNV's natural mineral water production plant Kaiia................................ 3
Figure 2.2. Distribution of Earth's water Source (Chingoski and Petrevska 2021) ....... 4
Figure 2.3 Size range of particles of concern in water treatment ................................ 12
Figure 2.4 Schematics of membrane water treatment system(Goel et al. 2021) ......... 15
Figure 2.5 Kiia water treatment plant's production process ........................................ 27
Figure 2.6 Remove Iron and Manganese filter ............................................................ 29
Figure 3.1. Procedure of Manganese Analysis ............................................................ 39
Figure 3.2. Procedure of Iron Analysis ........................................................................ 39
Figure 3.3.Procedure of Chloride Analysis ................................................................. 40
Figure 3.4.Procedure of Color Analysis ...................................................................... 40
Figure 3.5. Procedure of Ozone Analysis .................................................................... 40
Figure 3.6. Procedure of Total Dissolved Solids ......................................................... 41
Figure 3.7. Procedure of Turbidity of Analysis ........................................................... 41
Figure 3.8. Procedure of pH analysis........................................................................... 42
Figure 4.1 Variation of TDS value during 0-10 week ................................................. 46
Figure 4.2 pH values of bottled water over a 10-week period ..................................... 49
Figure 4.3 Variation of chloride concentration during 0-10 week .............................. 50
x
LIST OF TABLES
Table 2.1. Comparison of the key differences surface water ........................................ 4
Table 2.2. Physicochemical properties of groundwater ................................................. 6
Table 2.3. Physicochemical properties of groundwater ................................................. 7
Table 2.4. Characteristics of the main natural mineral waters....................................... 8
Table 2.5 The contaminant guidelines from the US EPA, EU, and WHO .................... 9
Table 2.6 Most commonly used drinking water methods............................................ 11
Table 2.7. Classification of AOPs. .............................................................................. 16
Table 2.8 Disinfection methods ................................................................................... 17
Table 2.9 Total plate count bacteria genera commonly found in drinking water ........ 26
Table 2.10 Equipment in water treatment plant ........................................................... 27
Table 2.11 Reductions of microbial achieved by water treatment .............................. 30
Table 2.12 Ultraviolet Dosage Required For 99.9% Destruction of microbials.......... 31
Table 2.13 Ozone Disinfection Performance ............................................................... 33
Table 3.1 The equipment in lab ................................................................................... 34
Table.3.2. Specification of physicochemical parameters ............................................ 38
Table 3.3. Required Reagents for Testing ................................................................... 38
Table 4.1. Mn Removal Efficiency .............................................................................. 43
Table 4.2 Fe Mn Removal Efficiency .......................................................................... 44
Table 4.3 Turbidity Values of Naturel mineral Bottled Water during 0-10 week ....... 47
Table 4.4 Color Values of Naturel mineral Bottled Water during 0-10 week ............. 47
Table 4.5 Iron Concentration of Naturel mineral Bottled Water during 0-10 week .... 48
Table 4.6 Ozone Concentration of Naturel mineral Bottled Water during 0-10 week 48
Table 4.7 Microbial during storage at room temperature 0-10 week .......................... 50
xi
1. INTRODUCTION
1.1. Background
Water is a vital resource essential to all forms of life, serving both biological and
environmental roles. Water comprises from 75% body weight in infants to 55% in elderly and
is essential for cellular homeostasis and life(Popkin, D’Anci, and Rosenberg 2010). In 2022,
1.7 billion people globally used fecal-contaminated water sources (WHO, 2023). Drinking
water, or potable water, must be free from harmful contaminants such as microorganisms,
chemicals, and physical impurities to ensure it poses no health risks. Proper monitoring and
treatment of drinking water are vital in preventing waterborne diseases and maintaining public
health. Among the various sources of water available for human consumption, mineral drinking
water has gained widespread popularity due to its perceived health benefits and high purity.
Natural mineral water is distinct from regular drinking water due to its stable mineral content,
natural underground origin, protection from contamination, preserved purity, on-site hygienic
packaging, and limited permitted treatments to maintain its natural quality(FAO 2019).
Cambodia, a country with abundant natural resources, has witnessed increasing demand for
safe and high-quality drinking water in recent years. Bottled mineral water, such as the products
from DPNV Co., Ltd under the brand name “Kaiia” offers an accessible and reliable source of
clean water. It is a type of non-carbonated natural mineral water that naturally contains only
enough carbon dioxide to keep hydrogen carbonate salts dissolved, with no excess free CO₂
after permitted treatment and packaging. Permitted treatments for natural mineral water include
removing unstable elements like iron, manganese, sulfur, or arsenic through decantation or
filtration, possibly aided by aeration. These treatments must not alter the water's essential
mineral composition that defines its natural properties(FAO 2019). However, maintaining
consistent quality from source to consumer is critical. Factors such as treatment methods,
storage conditions, and packaging materials can significantly influence the safety and stability
of the final product. This study aims to understand the treatment process of natural mineral
drinking water and to evaluate its chemical and microbiological quality during storage at room
temperature. By comparing the results with international standards whith WHO and assesses
the safety of the production process. And assesses the safety and effectiveness of the production
process. The study will not only benefit consumers by ensuring safe water consumption but
also help companies improve production and quality control practices. Furthermore, it provides
valuable practical experience and contributes to the broader academic understanding of water
treatment and quality management.
1
1.2. Objective
❖ Main Objective
•
To study on treatment process of the registered bottled natural mineral water plant.
•
To assess the physicochemical and biological limits of bottled natural mineral water
under room temperature over time, then compare the limits with WHO standards.
❖ Specific Objectives
•
To study on detailed treatment process of the registered bottled natural mineral water
plant.
•
To evaluate changes in chemical limits (Turbidity, pH, TDS, Fe+2, Cl-, and O3) in over
a ten-week period.
•
To evaluate changes in total plate count, total coliform and E.coli in over a ten-week
period.
1.3. Scope limitation
The study focuses specifically on the effectiveness of removing iron and manganese
using the Fe and Mn filter component over a five-day period. This study is based on a water
flow rate of 12 m³/h. To evaluate changes in physicochemical parameters such as turbidity, pH,
total dissolved solids (TDS), ferrous ion (Fe²⁺), chloride (Cl⁻), and ozone (O₃), as well as
biological parameters such as total plate count, total coliform, and E. coli, a ten-week study
was conducted on bottled natural mineral water stored at room temperature. Weekly tests were
performed on water samples to monitor variations in these parameters over time.
2
2. LITERATURE REVIEW
2.1. History of the Company (DPNV Co., Ltd)
DPNV is a newly established Cambodian FMCG company founded by a group of local
investors, dedicated to producing and distributing food and beverage products that support
consumer health and wellbeing. Our flagship brand, Kaiia, offers natural mineral water sourced
from a deep, pristine underground spring approximately 100 meters below the surface in the
Aoral Mountain area, the highest peak in Cambodia. Our production facility spans nearly 40
hectares of land, surrounded by lush mountains and natural beauty, and is equipped with stateof-the-art technology operated by a highly skilled and experienced technical team to ensure the
highest product quality. At DPNV, we believe that true vitality comes from nature, and we are
committed to promoting wellness and helping our customers thrive through products that
embody natural purity and health. Kaiia Natural Mineral Water is drawn from the Aoral
Mountain Range, which holds the highest peak in Cambodia. It is extracted from underground
in a depth of 100 meters. This protected area provides a pure, natural and well-balanced mineral
water that is hidden in an aquifer deep below the earth’s surface.
Figure 2.1. DPNV's natural mineral water production plant Kaiia
2.2. Water Sources
Water resources are vital for drinking, agriculture, industry, and domestic use, including
energy production. Due to climate change and increasing scarcity, scientists are placing greater
focus on these resources. Although renewable, clean and reliable water is essential for
households, food production, energy, transportation, recreation, and ecosystems. Different
3
types of water resources are utilized based on their composition and specific human
applications.
Figure 2.2. Distribution of Earth's water Source (Chingoski and Petrevska 2021)
Water resources are commonly classified into three types such as surface water, groundwater,
and groundwater under the influence of surface water, as shown in Table 2.1.
Table 2.1. Comparison of the key differences surface water
Characteristic
Surface Water
Groundwater
Temperature
Changes seasonally
Turbidity
Mineral content
Often high due to
suspended solids
May be colored due to
decaying vegetation
Variable, typically lower
Remains stable
year-round
Usually clear and
low
Usually clear and
colorless
Higher and constant
Dissolved oxygen
Common and abundant
Organisms
Many types (bacteria,
plankton, etc.)
Eutrophication
Susceptible
Contamination
resistance
Recovery after
contamination
Easily contaminated
Color
Relatively fast
Typically absent or
very low
Primarily iron
bacteria
Not typically
susceptible
More difficult to
contaminate
Slow to very slow
4
Groundwater Under Influence
of Surface Water
May show some seasonal
variation
May increase during surface
events (rainfall, flooding)
May temporarily show coloration
after surface events
Variable, influenced by surface
interactions
Fluctuates based on surface water
infiltration
Mix of both, with surface
organisms during infiltration
events
May show temporary enrichment
during surface events
Vulnerable during surface water
infiltration events
Variable, depending on extent of
surface influence
2.2.1. Groundwater
Groundwater is the term used for naturally occurring water that is at various depths
below the Earth’s surface in the spaces between rock, sediment, or soil particles. Groundwater
occupies the largest percentage (29.7%) of the accessible water on Earth. However, an alarming
fact is that most of this water is polluted, leaving about 1% for daily use (Aranguren-Díaz et al.
2024). Groundwater is the most extracted resource in the world with an estimated extraction
rate of 982 km3 /year year (Marjuanto, Putranto, and Sugianto 2019). According to the WHO
Guidelines for Drinking-water Quality, groundwater is water that exists beneath the Earth's
surface and is typically drawn from wells and boreholes. It is often microbially safe and
chemically stable when sourced from deep and confined aquifers. However, shallow or
unconfined aquifers are more vulnerable to contamination from sources such as agricultural
runoff (including pathogens, nitrates, and pesticides), on-site sanitation, sewerage, and
industrial wastes. Groundwater contamination can generally be controlled through measures
like sealing boreholes properly to prevent ingress of surface water, casing bores to a suitable
depth, and protecting the local environment around the water source (Herschy 2012).
Figure 2.3. Multilayer aquifer (Aranguren-Díaz et al. 2024)
Nearly half of the world’s drinking water comes from groundwater due to its lower
exposure to contamination and evaporation, making it more reliable than surface water;
however, it can still contain harmful microorganisms such as viruses, bacteria, and parasites.
Fecal contamination is particularly dangerous, leading to serious gastrointestinal diseases like
cholera, salmonellosis, and shigellosis, while other pathogens such as Norovirus, Rotavirus,
5
Campylobacter, Legionella, Giardia, and Cryptosporidium have also been associated with
outbreaks. Some bacteria, including Bacillus megaterium and Staphylococcus, can survive in
groundwater for 10 to 100 days and may colonize springs and bottling plants, posing significant
health risks to consumers. Additionally, while primary metals like iron (Fe), copper (Cu), zinc
(Zn), selenium (Se), and nickel (Ni) are vital for human metabolism, non-essential heavy
metals such as chromium (Cr), cadmium (Cd), mercury (Hg), manganese (Mn), lead (Pb), and
arsenic (As) have no biological function and can be harmful to health at high concentrations.
To ensure the safety of mineral water, strict monitoring and regulatory measures are essential
(Aranguren-Díaz et al. 2024).
Table 2.2. Physicochemical properties of groundwater
Physicochemical
Property
Color
Odor
Taste
Electrical
Conductivity
pH
Temperature
Turbidity
Suspended Solids
Total Dissolved
Solids (TDS)
Hardness
Contaminants
Dissolved Gases
Salinity
REDOX Reactions
Dissolved Oxygen
Alkalinity
Ions
Description
Color in groundwater may result from the presence of organic material or chemical
elements like iron and manganese. These elements can react with oxygen, changing
the water's color. Standards help determine if coloration is acceptable.
The odor depends on the chemical composition of the water. It may arise from naturally
occurring substances or contaminants. Odor perception is subjective but important for
water quality assessment.
Taste is influenced by the water’s composition, source, temperature, and individual
perception. Minerals and organic compounds can impart distinct flavors.
Indicates the water’s ability to conduct electricity, which depends on the concentration
of dissolved salts and ions. Higher ion content increases conductivity.
Measures how acidic or basic the water is. Groundwater pH is generally neutral (around
7) but varies with the surrounding geology and presence of acidic or basic substances.
Groundwater is typically cooler than surface water because it is insulated by soil and
rock. It reflects local climate and depth of the water source.
Refers to water clarity. Low turbidity is common in groundwater due to natural
filtration, but drilling or development can cause temporary cloudiness.
Usually minimal in groundwater unless affected by disturbances. They may appear in
water from recently drilled wells or fractured aquifers.
Represents the concentration of all dissolved substances (organic and inorganic) in
water, including salts, minerals, and metals. TDS affects taste and can signal
contamination.
Caused mainly by calcium and magnesium ions. Hard water may lead to scale buildup
in pipes and may require treatment.
Groundwater can contain harmful substances such as heavy metals, pesticides, VOCs,
and industrial pollutants. These are often linked to human activities.
Gases like CO₂ and O₂ may be present. CO₂ affects pH and buffering, while O₂ levels
are linked to biological activity and can support or hinder microbial growth.
High in coastal or arid regions due to salt accumulation or seawater intrusion. Elevated
salinity makes water unsuitable for drinking or agriculture.
Redox (reduction-oxidation) conditions depend on microbial activity and the presence
of organic material, which affect the chemical state of elements in the water.
Indicates water’s ability to support aerobic organisms. Levels depend on depth,
pressure, temperature, and presence of organic material. Low DO can signal pollution.
The buffering capacity of water to neutralize acids. It’s mainly provided by carbonate,
bicarbonate, and hydroxide ions. Important for pH stability.
Groundwater contains various ions: cations (Ca²⁺, Mg²⁺, Na⁺, K⁺, Fe²⁺/Fe³⁺, Mn²⁺,
NH₄⁺) and anions (SO₄²⁻, Cl⁻, HCO₃⁻, NO₃⁻, CO₃²⁻, F⁻, PO₄³⁻, CN⁻, SiO₃²⁻). Their types
and levels depend on the local geology.
6
Metals
Minerals
May occur naturally or be introduced via human activity. Examples: copper,
chromium, cadmium, lead, mercury, and arsenic. High levels are often toxic.
Presence and type depend on surrounding rocks and soils. Common minerals in
groundwater include quartz, dolomite, feldspar, gypsum, and clays like
montmorillonite.
Table 2.3. Physicochemical properties of groundwater
Parameter
pH, units
EC, µS/cm
TDS, mg/L
Calcium, mg/L
Magnesium, mg/L
Sodium, mg/L
Potassium, mg/L
Chloride, mg/L
Sulphate, mg/L
Bicarbonate, mg/L
Fluoride, mg/L
Nitrate, mg/L
Total Alkalinity, mg/L CaCO₃
Total Hardness, mg/L CaCO₃
Ca²⁺/Mg²⁺
Min
3.8
75.88
40.40
4.00
5.00
1.13
2.00
5.40
2.00
6.10
0.11
0.25
5.00
5.00
0.20
Max
6.08
431.20
229.80
30.00
14.00
36.25
12.00
44.00
11.00
103.70
2.90
23.20
84.98
60.00
2.04
2.2.2. Quality Characteristics of Water
Water quality refers to the physicochemical, physical, and chemical properties that must
meet standards to ensure water is safe and acceptable for consumers. It is associated with the
absence of undesirable substances or contaminants, aligning water safety regulations closely
with those for food products. Water, like any food or drink, has sensory characteristics
ppearance, smell, odor, and flavor that must satisfy consumer expectations. Ideally, water
should be transparent, colorless, and free of taste and odor. Common sensory issues include
strong chlorine smell or taste, metallic taste, rotten egg odor, musty smells, color deviations,
and turbidity. Ultimately, whether due to source or treatment, water must meet both legal
standards and consumer expectations. In bottled water, it is critical that no foreign substances
migrate into the product, preserving its quality(Kekes, Tzia, and Kolliopoulos 2023).
2.2.3. Natural Mineral Waters
Directive 2009/54/EC of the European Parliament and Council defines natural mineral
water as microbiologically safe water obtained from protected underground sources, either
emerging naturally or extracted through boreholes, characterized by its original purity and
stable mineral composition. The directive classifies it into three types: Naturally Carbonated
7
(retains original CO₂ levels), Fortified with Gas from the Spring (CO₂ from the same source is
added), and Carbonated (external CO₂ is added). This water provides essential minerals like
calcium, magnesium, and bicarbonates, benefiting bone health, muscle function, and acid-base
balance. It is classified based on mineral content (e.g., weakly or strongly mineralized),
dominant components (e.g., bicarbonate, sulfate, chloride), and factors such as pH, temperature,
hardness, and osmotic pressure. These categories help preserve the water’s natural qualities
and provide clear information to consumers (Hippel 2012). Mineral waters contain various
chemical substances due to their geological origin and are classified based on factors like dry
residue, composition, pH, temperature, hardness, and osmotic pressure. According to EU
Directive 2009/54/EC, they are categorized. According to Table 2.4. show the characteristic
of the main natural mineral waters and their respective general therapeutic indications.
Table 2.4. Characteristics of the main natural mineral waters
Type of Natural
mineral water
Content of the main
mineral (mg/L)
Applications
Bicarbonate
>600 mg/L
Promote digestion, because neutralizes
gastric acidity.
Sulphate
>200 mg/L
Lightly laxative; it is suggested for
hepatobiliary diseases.
Chloride
>200 mg/L
Balance of intestine, bile ducts and
liver; laxative effect.
Calcic
>150 mg/L
It is suggested for adolescents,
pregnant women, subjects who don't
consume dairy products, elderly men;
contributes to prevent osteoporosis and
hypertension.
Magnesiac
>50 mg/L
Promote digestion.
Fluorurate
>1 mg/L
Strengthen teeth structure and prevent
dental decay; helps in osteoporosis.
Ferrous
>1 mg/L
It is suggested for anemia and iron
deficiency.
Sodium-rich
>200 mg/L
It is suggested for intense physical
activity (to replenish the salts leaked
through sweating).
Low-sodium
<20 mg/L
It is suggested in case of
hypertension.
8
Source:(Hippel 2012)
2.3. Drinking Water Standards
Drinking water standards differ worldwide, from highly advanced systems to more
basic ones. Generally, they are divided between developed nations with strict water quality
standards and developing countries still battling bacterial and chemical contamination. Many
reports highlight the ongoing water and sanitation challenges in these regions. The World
Health Organization provides standards intended to help developing countries launch safe
drinking water programs, although it recognizes that many may not fully meet them. Instead,
WHO suggests using the standards as guidelines to promote basic filtration and disinfection
practices. In the U.S., the Environmental Protection Agency sets drinking water standards,
while in the European Union, they are established by Council Directive 98/83/EC. Currently,
both the U.S. and the EU have regulations for inorganic compounds, volatile organic
compounds,
semi-volatile
organic
compounds,
disinfection
by-products,
microbial
contaminants, and radiological substances. However, not all countries adopt U.S. or EU
standards. Sensory standards for water mainly focus on consumer acceptability. In the
European Union and some member states, regulations require water to have an acceptable odor
and flavor without abnormal changes. The EU standard (EN 1622) introduces the Threshold
Odor Number and Threshold Flavor Number. If water is acceptable to consumers, testing is
not required; if not, these tests must be performed. Although compounds affecting sensory
quality usually occur at very low concentrations, they can still be identified using sensitive
methods like chromatography, colorimetric analysis, and separation techniques(Kekes, Tzia,
and Kolliopoulos 2023).
Mineral water standards require over 1 g of dissolved minerals per kg or specific
components above regional limits. Temperature and absence of pathogens are also regulated.
In 1969, WHO defined natural mineral water as uncontaminated groundwater with at least 1
g/kg of minerals or 250 mg of free CO₂, and health benefits approved by FAO/WHO
(1985)(Aranguren-Díaz et al. 2024).
Table 2.5 The contaminant guidelines from the US EPA, EU, and WHO
Contaminant
BACTERIA
Heterotrophic Plate count
Primary microbial drinking water
US EPA
European
Union
500 colonies/L
100 colonies/L
9
WHO
NG
E. coli
Fecal Coliforms
Total Coliforms
0/100 mL
0/100 mL
0/100 mL 5% of samples
0/100 mL
0/100 mL
0/100 mL 5% of
samples
PROTOZOA
Cryptosporidium,
Giardia (TT) 99.9% Removal
NF
lamblia
VIRUSES
Adenoviruses, Caliciviruses, (TT) 99.9% Removal
NF
Coxsackieviruses,
Echoviruses, Enteric Viruses,
Hepatitis Viruses, Norwalk
Virus, Rotavirus
Unique microbial drinking water
Contaminant
US EPA
European
Union
Pseudomonas aeruginosa
NG
0/250ml
Legionella
No limit
NG
Microcystin-LR
NG
NG
Clostridiumperfringens
NG
0/100ml
Noted: guideline, Notes, NF:Not Found, TT=Treatment Technique
0/100 mL
0/100 mL
0/100 mL 5%
of samples
NF
NF
WHO
NG
NG
1 g/L
NG
2.4. Various Methods Of drinking treatment water
The treatment of drinking water is a crucial process aimed at ensure that drinking water
meets safety and quality standard of water supplied for human consumption. This process
involves several stages and technologies designed to remove contaminants, pathogens, and
undesirable substances from raw water sources. Drinking water treatment methods encompass
physical and chemical approaches, which can be employed individually or in combination to
purify water based on regulatory standards and raw water characteristics, with the most
common methods categorized in Table 2.1 according to their nature (Kekes, Tzia, and
Kolliopoulos 2023).
10
Table 2.6 Most commonly used drinking water methods
Method
Nature of Purpose
Method
Screening
Physical
Removal of large solids and grits
CoagulationFlocculation
Chemical
Removal of particles that cause high turbidity and
a visible cloudiness
Dissolved Air Flotation
Physical
Removal of oil, grease, and suspended particles
Clarification
Physical
Removal of suspended particles such as slit, algae,
and agglomerates from coagulation-flocculation
Filtration
Physical
Removal of suspended particles, reduction of
turbidity, protection against cysts and pathogens
Membrane Filtration
Physical
Removal of almost every pollutant depending on
the type of membrane
Absorption
Physical
Synthetic organic chemicals, natural organic
compounds
or Chemical
Ion exchange
Advanced
Process
Disinfection
Chemical
Removal of very significant quantities of natural
organic matter
Oxidation Chemical
Degradation of organic, inorganic compounds and
emerging contaminants
Physical or Elimination of microorganisms, and organic and
Chemical
inorganic compounds that maybe harmful to
human health
2.4.1. Particles of Concern in Water Treatment
Water contains solids in three main forms: suspended particles, colloids, and dissolved
molecules. Suspended particles, such as sand and silt, range from large sizes down to about 10
µm and can be removed by physical methods like sedimentation and filtration. Colloids, which
are fine particles ranging from 10 nm to 10 µm, are more difficult to remove and are a key
focus in conventional water treatment. Dissolved molecules exist as individual molecules or
ions and cannot be removed by standard physical methods. Colloids are categorized as
hydrophobic (e.g., clay and metal oxides), which are unstable and easily destabilized, or
hydrophilic (e.g., soap), which are stable and hard to destabilize. Most small suspended solids
under 0.1 mm carry negative electrostatic charges, causing them to repel each other and remain
11
in suspension. This electrostatic repulsion makes colloid removal particularly challenging
during water treatment processes(Koohestanian, Hosseini, and Abbasian 2008).
Figure 2.3 Size range of particles of concern in water treatment
2.4.2. Screening
Raw water often contains large solids and grits that can damage treatment equipment
and increase maintenance costs, necessitating preliminary removal through screening, which
involves using coarse screens for large objects and fine screens for smaller debris that can cause
operational issues; screening systems can be mechanically cleaned to reduce labor costs and
improve efficiency or manually cleaned as a cost-effective option for small plants, although
manual cleaning requires frequent raking to prevent clogging(Kekes, Tzia, and Kolliopoulos
2023).
2.4.3. Coagulation-Flocculation
Coagulation–flocculation is a crucial step in drinking water treatment that removes
turbidity, suspended solids, and dissolved contaminants. Coagulants like aluminum sulfate,
ferric chloride, or polyaluminium chloride neutralize negatively charged particles in water.
This destabilization leads to flocculation, where particles collide and form larger flocs for
removal. Coagulant dosage affects efficiency and is divided into four zones: underdose (Zone
1), optimal (Zone 2), overdose causing restabilization (Zone 3), and sweep flocculation with
metal hydroxide formation (Zone 4). Key influencing factors include turbidity, TOC, pH,
alkalinity, temperature, and mixing. Enhanced coagulation and sweep flocculation are used for
12
challenging water conditions like high NOM or low particle concentration (Kekes, Tzia, and
Kolliopoulos 2023).
2.4.4. Dissolved Air Flotation
Dissolved Air Flotation (DAF) is an alternative to conventional clarification, typically
used after coagulation–flocculation, especially effective in treating water with high oil, grease,
or suspended particles. Its main advantage is lower capital cost. Unlike traditional clarification,
DAF removes impurities by introducing pressurized air into water, forming microbubbles that
attach to particles and float them to the surface, forming a sludge blanket that is mechanically
removed. DAF tanks (rectangular or circular) include a contact zone (bubble-particle
interaction) and a separation zone (sludge removal). System sizes range from 4 to 30 m³, with
flow rates of 1–200 m³/h and productivity around 500 L/h. DAF is mainly used to treat water
with low-density particles and effectively removes turbidity, natural organic matter, and algae.
Its efficiency depends on two key factors: having enough bubbles and ensuring effective
collision and attachment between bubbles and particles. Small bubbles are preferred, as they
offer a larger surface area for interaction. Efficiency is further improved by increasing contact
time, using chemical flocculants (like iron or aluminum salts), and adding polymers based on
feed water quality to help bubbles capture solids more effectively (Kekes, Tzia, and
Kolliopoulos 2023).
2.4.5. Clarification
Clarification is a water treatment process used after coagulation and flocculation and
before filtration, designed to remove suspended particles like silt, algae, mud, and flocs. In a
sedimentation tank, water velocity is slowed, allowing gravity to settle the particles.
Sedimentation, often performed in large rectangular or circular tanks, is the most common
clarification method. A standard horizontal clarifier holds around 63 m³ and operates at 5 to
150 m³/h. Key factors influencing clarification include detention time (longer allows better
adaptation), particle concentration (higher leads to faster settling), and temperature (higher
enhances settling). Larger particles settle faster, and still water allows quicker sedimentation
than moving water. Regular sludge removal is essential to maintain efficiency and prevent resuspension. Solids contact clarification (sludge blanket) improves sedimentation by forming a
sludge blanket that captures more particles as it grows. Periodic sludge removal is required to
prevent re-suspension and maintain efficient water treatment (Kekes, Tzia, and Kolliopoulos
2023).
13
2.4.6. Filtration
Clarification is a water treatment step after coagulation–flocculation and before
filtration, aimed at removing suspended particles like silt, algae, mud, and flocs. It typically
occurs in sedimentation tanks where slowed water flow allows particles to settle by gravity.
Common methods use rectangular or circular tanks; a standard horizontal clarifier holds ~63 m³
and operates at 5–150 m³/h. Key factors include detention time, particle concentration,
temperature, and particle size. Still water and larger particles improve settling. Regular sludge
removal is vital to prevent re-suspension. Solids contact clarification (sludge blanket) enhances
performance by capturing more particles as the blanket builds(Kekes, Tzia, and Kolliopoulos
2023).
2.4.7. Membrane Filtration
Membrane filtration is an advanced water purification method that uses selective,
porous barriers to separate contaminants, producing clean water (permeate) and concentrated
waste (retentate). It includes microfiltration, ultrafiltration , nanofiltration , and reverse osmosis
(RO), with MF and UF relying on size exclusion at low pressures, and NF and RO operating
under higher pressures via selective diffusion. Systems operate in dead-end or crossflow modes,
driven by transmembrane pressure. Membranes are made from organic (polymeric) or
inorganic (ceramic, metallic) materials; organics are cheaper and widely used, while inorganics
are more durable but costly. Asymmetric membranes, used in UF, NF, and RO, enhance
efficiency, whereas symmetric ones are typical for MF (Goel et al. 2021). Thin film composite
membranes offer high permeability but are prone to fouling, which can occur through pore
blocking or cake formation due to solids, organics, scaling, or microbes. Fouling is managed
through cleaning methods like backflushing and chemical cleaning, or prevented by proper
membrane selection, pretreatment, and operational control. MF and UF are cost-effective but
less capable of removing dissolved pollutants compared to NF and RO; RO excels in
desalination but is less used in drinking water due to its removal of non-harmful salts, while
NF effectively removes hardness, color, organics, and emerging contaminants (Kekes, Tzia,
and Kolliopoulos 2023).
14
Figure 2.4 Schematics of membrane water treatment system(Goel et al. 2021)
2.4.8. Adsorption
Adsorption removes pollutants from water using adsorbents like activated carbon,
which works through physical or chemical bonding. It reaches equilibrium when adsorption
equals desorption. Activated carbon, enhanced by thermal treatment, is highly porous and
effective against organic compounds, algal toxins, tastes, and odors. Two main types are
Granular and Powdered Activated Carbon . Efficiency depends on surface area, internal pore
volume, water quality (pH, temperature), and pollutant characteristics(Kekes, Tzia, and
Kolliopoulos 2023). Once exhausted, carbon can be thermally regenerated, though its
performance gradually declines with each cycle.
2.4.9. Ion exchange
Ion exchange is an advanced method recently applied in drinking water treatment,
primarily to enhance processes like coagulation by effectively removing natural organic matter
(NOM), a key precursor to disinfection by-products (DBPs), and to soften water by eliminating
calcium and magnesium ions. This method uses resins either cationic or anionic depending on
the charge of the target ions, allowing positively or negatively charged contaminants to be
exchanged with ions on the resin surface. Once the resin becomes saturated, it can be
regenerated using a sodium chloride or brine solution, though the resulting waste contains high
15
levels of total dissolved solids (TDS) and requires proper disposal. The efficiency of ion
exchange depends on the properties of the contaminants and the resin’s affinity for specific
ions, with anion-exchange resins typically used for NOM and hazardous anion removal, and
cation-exchange resins for softening.
2.4.10. Advanced Oxidation Processes
Advanced Oxidation Processes (AOPs) are modern water purification technologies
designed to break down both organic and inorganic contaminants, including emerging
pollutants like pharmaceuticals, endocrine disruptors, and substances that cause bad taste or
odor. These processes rely on the production of hydroxyl radicals (*OH), which are highly
reactive and non-selective oxidants capable of rapidly degrading a wide range of compounds.
The radicals work either by attaching to carbon–carbon double bonds or by removing hydrogen
atoms from carbon, ultimately forming carbon-centered radicals that react with oxygen and
degrade into carbon dioxide and water. AOPs can be categorized into photochemical and nonphotochemical methods, depending on how the radicals are generated. AOPs (Advanced
Oxidation Processes) must be assessed for efficiency, adaptability to changes in water quality
(e.g., NOM, alkalinity), and safe integration with other treatment methods. While they
effectively degrade organic and inorganic pollutants, forming less toxic and more hydrophilic
byproducts, some transformation products may be more harmful than the original compounds,
so byproduct toxicity also needs careful evaluation.
Table 2.7. Classification of AOPs.
Classification of AOPs
Examples
Photocatalysis
Photo-Fenton reactions
Photochemical AOPs
Ozone + UV
Vacuum UV
UV + Hydrogen Peroxide
Ozonation at High pH
Fenton’s Reactions
Non-Photochemical AOPs
Ozone + Hydrogen Peroxide
Catalytic Ozonation
16
2.4.11. Disinfection
Raw water often contains harmful microorganisms such as bacteria, viruses, and
protozoa that can cause waterborne illnesses, along with organic and inorganic chemicals that
may pose health risks. Disinfection is used to eliminate these hazards and ensure water safety
for consumers(Kekes, Tzia, and Kolliopoulos 2023). This process can be achieved through
chemical or physical means, with the primary disinfection methods summarized in Table 2.8.
Table 2.8 Disinfection methods
Chemical methods
Physical methods
Chlorine
Heat
Chlorine's compounds
UV light
Iodine
Physical separation by MF
Bromine
Ozone
Chlorine, a potent and widely used oxidant, forms HOCl in water, which disrupts
microbial cell function; however, its residual requires careful monitoring due to toxicity and
sensorial impacts, sometimes necessitating dechlorination. Chlorine compounds like stable
chloramines and highly effective chlorine dioxide offer alternative disinfection capabilities.
Ozone, a strong oxidant unaffected by pH, is generated on-site but has higher costs. UV light,
a physical method, damages microbial DNA and can work synergistically with ozone, though
a chlorine residual might still be needed for distribution system protection(Smilanick 2003). A
significant concern with chemical disinfection is the formation of disinfection byproducts
(DBPs) from the reaction of disinfectants with natural organic matter and inorganic ions.
2.5. Natural Mineral Water Treatment
The treatment of natural mineral water is strictly regulated by Directive 2009/54/EC,
allowing only physical methods to preserve its essential mineral. Permitted treatments include
filtration or decanting, possibly after oxygenation, to remove unstable elements like iron and
sulfur compounds; the use of ozone-enriched air to eliminate iron, manganese, sulfur
17
compounds, and arsenic from certain waters; and the removal of other undesirable constituents.
Total or partial elimination of free carbon dioxide is also allowed, but only through physical
means. Chemical treatments, disinfection, or any addition that could alter the water's viable
colony count are strictly prohibited.
2.6. Physicochemical
2.6.1. Iron
Iron is a common element in drinking water, especially in groundwater and systems
with iron pipes. In natural fresh water, Fe ranges from 0.5–50 mg/L. In anaerobic groundwater,
ferrous iron can exist without discolouration, but oxidizes on contact with air into ferric iron,
creating visible deposits. While it is essential for human health, aiding in oxygen transport and
enzyme function, the World Health Organization (WHO) does not consider it a health risk at
typical levels in drinking water and therefore has not set a health-based guideline value.
However, when iron concentrations exceed 0.3 mg/l, it can cause reddish-brown stains on
laundry and fixtures, turbidity, and colour changes. It also encourages iron bacteria growth,
leading to slimy pipe coatings. Corrosion of iron pipes can be minimized by maintaining water
pH between 6.8 and 7.3, ensuring sufficient alkalinity and hardness, and using corrosion
inhibitors like phosphates. Though these inhibitors do not stop corrosion, they help reduce
visible effects by keeping iron in solution (Overview et al. 2004). Most groundwaters are
contaminated with divalent iron and manganese, typically resulting from the dissolution of
minerals like FeCO₃, MnCO₃, or FeS₂ in carbon dioxide-rich water. In treatment systems of
aeration followed by rapid filtration (no chemical dosage), manganese removal is possible due
to the manganese dioxide catalyst present on the grains of filtration material(Jez-Walkowiak et
al. 2017) . In contrast, under anaerobic groundwater conditions, they exist as soluble Fe²⁺ and
Mn²⁺. When groundwater is exposed to air, these ions oxidize to Fe³⁺ and Mn⁴⁺, which
hydrolyze to form insoluble Fe(OH)₃ (reddish-brown) and MnO₂ (brownish-black).(Sasáková
et al. 2021)
Iron removal from water can be achieved through several methods, each using specific
reagents or components. Oxidation–filtration uses air (aeration), chlorine, potassium
permanganate (KMnO₄), or ozone to oxidize soluble iron before filtration. Greensand filtration
employs manganese-coated greensand, pyrolysite, often regenerated with potassium
permanganate. Sequestration involves adding polyphosphates to bind and stabilize iron in
solution, preventing staining without removing the iron. Ion exchange uses standard softener
18
resins to remove dissolved iron, typically alongside calcium and magnesium. Biological
treatment relies on iron-oxidizing bacteria and specialized filtration media to convert and filter
out iron from the water(APPLEBAUM 1947). Colorimetric methods like the phenanthroline,
thiocyanate, and bipyridyl methods are used to detect iron by forming colored complexes, as
recognized by the (World Health Organization 1970).
2.6.2. Manganese
Manganese in drinking water raises both health and aesthetic concerns. The Maximum
Acceptable Concentration (MAC) is 0.1 mg/L, based on neurological effects, especially in
children, while the Aesthetic Objective (AO) is 0.02 mg/L to avoid discoloration and staining.
For effective control, municipal treatments like oxidation, filtration, adsorption, and biological
filtration are employed, with a treated water target of ≤ 0.015 mg/L. Technologies such as
manganese greensand, pyrolusite, and MnOx-coated media are highly effective, especially
when preceded by oxidation. Treatment performance depends on pH, oxidant type/dose, and
water quality factors like organic carbon content. At the residential scale, reverse osmosis, ion
exchange, and oxidizing filters can reduce manganese effectively, although no devices are
specifically certified for manganese. Managing manganese ensures both safety and consumer
satisfaction in drinking water supplies(WHO 2011).
2.6.3. Turbidity
Turbidity in drinking water refers to its cloudiness, caused by suspended particles like
clay, silt, organic matter, microorganisms, and chemical precipitates such as iron and
manganese. It is measured in nephelometric turbidity units (NTU), and levels above 4 NTU are
visible to the naked eye, appearing as a milky-white or muddy suspension. An acceptability
limit of ≤5 NTU. While turbidity itself may not pose direct health risks, it can indicate the
presence of harmful contaminants and significantly affects the appearance and acceptability of
water. Consumers often associate turbid water with being unsafe, especially if they are
accustomed to clear water, and may turn to alternative sources that are not necessarily safer.
High turbidity can interfere with disinfection processes by shielding microorganisms and
increasing chlorine demand. Ideally, large municipal systems should maintain turbidity levels
below 0.5 NTU before disinfection and aim for an average of 0.2 NTU or less (Overview et al.
2004).
19
Treatment methods include coagulation, sedimentation, and filtration, using coagulants
like aluminum sulfate or Moringa oleifera seeds, with Moringa achieving up to 99.5% turbidity
reduction (Lea, 2010). Recommended turbidity limits vary by treatment type generally ≤0.5
NTU for conventional filtration and <0.1 NTU for membrane filtration while levels below 1
NTU are preferred for disinfection and user acceptability. Turbidity in water can be measured
using several methods, each with unique benefits and limitations. The nephelometric method,
using NTU or FNU units, is accurate and sensitive (0.01–5 NTU) but requires power,
calibration, and technical expertise. The turbidimetric method, using FAU, is better suited for
highly turbid water (40–4000 FAU) but is less sensitive. The Jackson candle method (JTU) is
low-cost and simple but not field-suitable and limited in sensitivity. The turbidity tube (TU) is
cheap, robust, and easy to use in the field, though it offers limited precision and depends on
visual judgment, making results somewhat subjective(WHO/UNICEF 2017).
2.6.4. Chloride
Chloride in drinking water originates from natural sources such as the weathering and
leaching of sedimentary rocks, seawater intrusion, and various human activities including
sewage, industrial effluents, and urban runoff containing de-icing salts. It is commonly found
in groundwater and is present as sodium chloride (NaCl), potassium chloride (KCl), and
calcium chloride (CaCl₂). Chloride is a stable, negatively charged ion (Cl⁻) that dissolves easily
in water, contributing to salinity in both freshwater and brackish water. While chloride itself
poses no significant health risk at levels typically found in drinking water, the World Health
Organization (WHO) has not established a health-based guideline value. Instead, a taste-based
acceptability limit of 250 mg/l is recommended, as higher concentrations can impart a salty
flavor that affects water palatability. Taste sensitivity varies depending on the accompanying
cation, with thresholds ranging from 200–300 mg/l. High chloride levels can also accelerate
the corrosion of metal pipes, especially in low-alkalinity conditions, leading to increased
concentrations of metals like lead, copper, or iron in the water. Chloride can be removed using
reverse osmosis or ion exchange processes. Although not harmful at usual concentrations,
managing chloride levels is important for maintaining drinking-water quality, preventing
infrastructure damage, and ensuring consumer satisfaction(Overview et al. 2004).
Membrane technologies like reverse osmosis (RO) and nanofiltration (NF) use semipermeable membranes for efficient chloride separation, also removing other contaminants,
though fouling and maintenance are challenges (Jia et al. 2023). Coagulation and flocculation,
20
using coagulants like aluminum sulfate, aggregate particles including chloride-bound
particulates, with effectiveness dependent on pH and dosage, but may require additional
treatment for optimal chloride reduction (Chekli et al. 2017). Chloride in water can be measured
using several methods, Colorimetric method using para-amino-dimethylaniline and ferric
chloride; titration using standard silver nitrate solution with potassium chromate indicator;
colorimetric method; and titration with mercuric nitrate at approximately the equivalence
point(World Health Organization 1970).
2.6.5. TDS
Total Dissolved Solids (TDS) in drinking water refer to the combined content of all
inorganic salts primarily calcium, magnesium, sodium, potassium, bicarbonates, chlorides, and
sulfates and small amounts of organic matter dissolved in water. TDS originates from natural
geological sources, sewage, urban runoff, industrial wastewater, and, in some regions, road deicing salts. Although TDS levels do not pose a direct health risk, the World Health Organization
(WHO) has not established a health-based guideline value due to the absence of reliable data
on adverse health effects from typical concentrations in drinking water. Total Dissolved Solids
(TDS) in drinking water are governed by an acceptability guideline value of 500 mg/L and an
upper acceptability limit of 1000 mg/L; while typical levels pose no direct health risks, elevated
concentrations can negatively impact taste, and very high levels, exceeding 2000 mg/L, may
induce laxative effects, with TDS stemming from dissolved minerals like calcium, magnesium,
sodium, sulfates, and chlorides, and effective treatment methods for its reduction encompass
reverse osmosis and distillation. According to (Hoko 2005) show that palatability of drinking
water has been rated by panels of tasters in relation to its TDS level as follows: excellent,
less than 300mg/L; good, between 300 and 600mg/L; fair, between 600 and 900 mg/L;
poor, between 900 and 1200mg/L; and unacceptable, greater than 1200mg/L. Elevated
TDS can also lead to scaling in pipes, heaters, boilers, and household appliances, reducing the
operational efficiency of water systems. Due to its influence on aesthetic quality and
infrastructure performance, managing TDS is important, especially in regions where natural
levels are high or water treatment practices are limited(Overview et al. 2004).
These methods are broadly categorized under four main principles: Pressure-driven
processes like Reverse Osmosis, Ultra-filtration, and Nano-filtration; Concentration-based
methods including Desalination, Forward Osmosis, and Distillation; Ion-based techniques such
as Adsorption, Crystallization, Deionization, Ion exchange, and Precipitation; and
21
Electrochemical methods encompassing Electro-dialysis and Electro-coagulation. This
pictorial representation effectively summarizes the diverse approaches available for purifying
water by reducing its dissolved salt and mineral content (Pushpalatha et al. 2022). Electrolysis
reduced TDS by up to 22.7%, and heating to 50°C lowered it by 16%(Wang 2021). TDS can
be measured using SM 2540 B-D for levels between 2.5–200 mg/L. Major ions can be
measured individually using SM 2510 A 3020 . Conductivity-based methods like SM 2510 and
Hach Method 8160 offer faster estimates but require calibration for accuracy (Canda 2025).
2.6.6. Color
Color in drinking water is primarily an aesthetic concern rather than a health risk, and
the World Health Organization (WHO) has not set a health-based guideline value for it. Ideally,
drinking water should have no visible color, and any noticeable change can signal the presence
of contaminants or underlying issues. Color is typically caused by naturally occurring organic
matter mainly humic and fulvic acids from the soil, as well as by metals like iron and
manganese, either as natural impurities or as corrosion products. Industrial effluents can also
contribute to water discoloration and may be an early warning sign of pollution or a hazardous
situation. Most people can detect color in water at levels above 15 true color units (TCU), and
water with color below this threshold is generally acceptable to consumers. High levels of
natural organic carbon responsible for color can also increase the potential for disinfection byproduct formation during water treatment. Any significant or sudden change in water color
should prompt investigation to identify and address the source of contamination(Overview et
al. 2004).
Color can be removed from water using coagulation (chemical clumping), adsorption
(activated carbon), membrane filtration (physical separation), advanced oxidation (chemical
breakdown), electrochemical methods (electric treatment), and biological processes (microbial
degradation).Color testing methods include the Pt-Co method for Color Units, visual
comparison by eye, spectrophotometers for light absorbance, and colorimeters for quick digital
color intensity measurement. (Malakootian and Fatehizadeh 2010).
2.6.7. Ozone
Ozone in drinking water has no health-based guideline value due to its rapid decomposition,
with a recommended residual of ≥0.2 mg/L for effective disinfection; while posing no risk
when ingested, high ozone concentrations in air can cause respiratory problems; it originates
22
from ozonation processes used for disinfection, and no treatment is needed for its removal in
water as it naturally breaks down. Ozone (O₃), a potent oxidizing agent, effectively converts
dissolved manganese (Mn²⁺) into insoluble manganese oxides (MnO₂), a process that, while
removing the manganese, results in the formation of visible brown or black precipitates, which
can cause undesirable discoloration in drinking water (Overview et al. 2004). Ozone (O₃) has
been widely recognized for its efficacy in killing bacteria and improving the treatment quality
of drinking water. The strong oxidizing properties of ozone make it an effective agent for
microbial inactivation. Ozone interacts with bacterial cells mainly through oxidative stress,
leading to damage of cellular components, including membranes, proteins, and nucleic acids.
For instance, ozone can oxidize amino acids and disrupt the integrity of the bacterial cell
membrane, leading to cell death (Wani et al. 2015). Ozone is one such alternative that has been
successfully used in Europe for over a century. In the US over 250. Ozone oxidizes Fe(II) to
Fe(III), forming Fe(OH)₃ precipitate, which is filterable; 0.43 mg ozone per mg Fe(II) is
needed, with 0.50 mg/L typically used. Oxidation occurs between pH 6–9. For Mn(II), 0.88
mg ozone per mg is required, forming MnO₂ (filterable); excess ozone forms pink Mn(VII)
(permanganate), reversible in presence of organic material. Manganese oxidation is most
effective at pH ~8. (Drinking and Treatment 2025).
2.6.8. Temperature
Temperature reflects the average kinetic energy of particles, meaning higher
temperatures indicate faster movement and lower temperatures indicate slower movement. It
is measured in Celsius (°C), Fahrenheit (°F), or Kelvin (K), and plays a crucial role in
thermodynamics by helping to understand heat flow and changes in the states of matter.
Absolute zero (0 K or -273.15°C) is the point at which particle motion nearly ceases (Parker
1971). Temperature also plays a critical role in the chemical stability of bottled water. Studies
have shown that elevated temperatures, particularly above 40 °C, can lead to thermal
degradation of plastic bottles, resulting in significant alterations in the physicochemical
properties of the water contained within(Ahmed, Emad, and Bkary 2021). Conversely, lower
temperatures, such as refrigeration at 4 °C, have been associated with reduced leaching of these
harmful chemicals, suggesting that cooler storage conditions are preferable for maintaining
water quality (Edjere, Asibor, and Bassey 2016). According to (Ahmed, Emad, and Bkary
2021) the cooling and freezing bottled water affected its physicochemical properties pH and
TDS decreased, while fluoride and chloride levels increased. Some parameters exceeded safe
drinking limits. Heavy metals remained minimal, except small amounts of copper and zinc.
23
Different brands reacted differently to the same temperatures. Heating above 50 °C
significantly altered water quality, raising safety concerns. After 6 months of storage at room
temperature (18–250C), few quantitative and qualitative differences were found in the
microflora (Armas and Sutherland 1999).
2.7. Faecal indicators in Drinking Water
Faecal indicators are organisms used to assess the effectiveness of water treatment
processes and detect faecal contamination. Common indicators include total coliforms, faecal
coliforms, E. coli, Enterococci, and bacteriophages. These have been used for nearly a century
to evaluate the microbiological and sanitary quality of water. Enteric microorganisms, found
in the faeces of infected humans or animals, can contaminate drinking water directly or
indirectly. However, proper disinfection by water utilities significantly reduces waterborne
diseases and helps ensure safe drinking water(Singh 2015).
2.7.1. E.coli
Escherichia coli (E. coli) is a Gram-negative, rod-shaped bacterium measuring approximately
1.8 μm in length and 0.8 μm in diameter. In aqueous environments, its inactivation typically
follows first-order decay kinetics during disinfection. Ultraviolet (UV) radiation, particularly
within the germicidal range of 200–300 nm, is effective in disrupting microbial DNA, thereby
preventing replication and leading to cell death. For E. coli, a UV dose ranging from 3.0 to
6.6 mW/cm² is typically required to achieve 90% to 99% disinfection efficiency, making UV
treatment a viable method for microbial control in water systems.(McElmurry and Khalaf
2016). Gaseous ozone was tested on spinach to reduce E. coli and Listeria spp. A 1 ppm ozone
treatment for 10 minutes achieved a 1-log reduction. A stronger dose (10 ppm for 2 minutes)
also gave a 1-log reduction with no regrowth over 9 days(Wani et al. 2015). E. coli are a diverse
group of bacteria commonly found in the intestines of humans and warm-blooded animals.
Most strains of E. coli are harmless however, specific strains such as enterohaemorrhagic E.
coli, can cause severe foodborne disease (Overview et al. 2004). E. coli strains such as
enterohemorrhagic E. coli and enteroinvasive E. coli are known to cause severe
gastrointestinal symptoms, including acute diarrhea often accompanied by cramps and fever.
In Brazil, studies reveal that E. coli was detected in 14% of drinking water samples, with
untreated samples showing a much higher prevalence of 44.6%, indicating a strong link
between untreated water and health risks related to diarrhea (Schüroff et al., 2022). For
24
instance, studies indicate that up to 72% of groundwater sources in Metro City, Lampung,
Indonesia, contain E. coli levels that classify as high risk according to World Health
Organization (WHO) standards (Jannah and Putri 2021). Escherichia coli (E. coli) can grow in
a pH range of 4.4 to 9.0, with an optimal pH between 6.5 and 7.5. (Suehr et al 2020). It grows
at temperatures from ~10°C to ~50°C, with an optimum between 30°C and 37°C. E. coli
O157:H7 grows well at 30°C–42°C but poorly at 44°C–45°C and doesn’t grow below 10°C. It
is sensitive to pasteurization, with O157:H7 inactivated at 64.3°C in 9.6 seconds. Acid-resistant
strains like O157:H7 can survive at pH 4.5, and acid adaptation at pH 5.0 enhances survival in
pH 3–4, though it can’t survive below pH 2 (Ray and Bhunia 2021).
2.7.2. Total coliform
Total coliforms are a group of bacteria that are naturally found in the environment,
including soil, water, and the intestines of humans and warm-blooded animals. The total
coliform group belongs to the family enterobacteriacceae of growth at 37° C and includes the
aerobic and facultative anaerobic, gram-negative, non spore-forming, rod-shaped bacteria that
ferment lactose with gas production within 48 hours at 35 0C. This group include Escherichia
Coli, Enterobacter,Klebsiella, and citrobacter. These coliforms are discharged in high numbers
(2.10^9 coliform /day/capita) in human and animal feces, but not all them are of fecal origin.
These indicators are useful for determining the quality of potable water, shellfish-harvesting
waters, and recreational water (Hachich et al. 2012). Fecal coliforms or thermotolerant
coliforms include all coliforms that can ferment lactose at 44.5°C. The fecal coliform group
comprises bacteria such as Escherichia coli or Klebsiella pneumoniae. The presence of fecal
coliforms indicates the presence of fecal material from warm-blooded animals. However,
human and animal sources of contamination cannot be differentiated (Jacob 2020). According
to the U.S. Environmental Protection Agency's regulatory framework, the maximum allowable
concentration for total coliforms in drinking water is zero per 100 mL, indicating stringent
standards for water safety (Zhang et al. 2015).
2.7.3. Total plate count
Total plate count (TPC), also known as heterotrophic plate count, refers to the
enumeration of heterotrophic bacteria those that utilize organic nutrients for growth. These
bacteria are ubiquitous and can be found in various environments such as water, food, soil,
vegetation, and air. The TPC includes both primary and secondary bacterial pathogens,
encompassing a wide range of organisms. Among these are coliform bacteria such as
25
Escherichia, Klebsiella, Enterobacter, Citrobacter, and Serratia(Allen, Edberg, and Reasoner
2004)
Table 2.9 Total plate count bacteria genera commonly found in drinking water
Name of Bacteria
Acinetobacter
Actinomycetes
Alcaligenes
Aeromonas hydrophila
Arthrobacter
Bacillus
Beggiatoa
Citrobacter freundii
Corynebacterium
Crenothrix
Desulfovibrio
Enterobacter agglomerans
Enterobacter cloacae
Escherichia coli
Flavobacterium
Flavobacterium meningosepticum
Gallionella
Hafnia alvei
Klebsiella pneumoniae
Methylomonas
Micrococcus
Mycobacterium
Moraxella
Nitrosomonas
Nocardia
Proteus
Pseudomonas
P. cepacia
P. fluorescens
P. maltophilia
Serratia liquefaciens
Sphaerotilus
Sphingomonas
Staphylococcus
Streptococcus
Streptomyces
Yersinia enterocolitica
2.8. Water treatment plant
Water treatment ensures microbial safety by eliminating pathogens. It preserves
beneficial minerals using gentle processes, which maintain the water's health value. Treatment
also removes harmful contaminants like heavy metals to meet safety standards. Additionally,
it enhances taste and odor, improving water quality and appeal. According to Figure 2.4 depicts
a flowchart of the Kiia water treatment plant's production process, showing the journey from
borewell water through multiple purification stages (including bag filtration, UV sterilization,
and ultrafiltration), followed by bottling operations where PET bottles are manufactured, filled,
capped, coded, and labeled, then finally packed into cartons for warehouse storage.
26
Bag Filter UV Sterilizer Source Water Iron & Manganese Bag Filter Ultrafiltration UV Sterilizer Ultrafiltration Mineral Water
0.02 μm
5μm
Storage Tank Removal Filter
460 w
10μm
350w
Tank
Tank
O3 gas
Mineral Water for botte Rinsing,
Filling a d Cap Rinsing
Borewell
Ozone Generator
Label
Cap
Empty
Bottle
PET Blower
Full
Bottel
Rising-Fulling-Capping
Machine
Warehouse
Coding
Bottle
Lazer Coder
Full Bottle Inspector
OPP Labeling Machine
Labeling
Bottle
Preform
Full Paller
Coding Carton
Palletizing Machine
Empty Carton
Full Carton
Ink Coder
Carton Packing Machine
Figure 2.5 Kiia water treatment plant's production process
The Table 2.10 shows Equipment in water treatment plant, which lists various
components of the water treatment system and their functions. Each component is paired with
its specific function in the water treatment process, such as particle removal (especially
removing Mn, Fe, and TSS), storage, compression, or disinfection.
Table 2.10 Equipment in water treatment plant
Component
Function
Stainless steel air Tank
The air tank stores compressed atmospheric air at higher pressure
for use all treatment step.
27
Scroli air compressor
compresses atmospheric air to higher pressure for use in various
treatment processes.
Pump
Pumps are essential for ensuring water flows through all the
necessary stages of treatment.
Refrigerated Air Dryer
Removes moisture by cooling compressed air, preventing water
contamination.
Bag filter I
Remove sand, fine sand, vegetable matter, silts very large
particles, Fe
Bag filter II
Remove Suspended particles, sand, large particles.
Waw Water Tank
stores raw water before treatment, ensuring a steady supply and
allowing heavy particles to settle.
Remove Iron and
Manganese filter
Remove Manganese and Iron.
UF water tank
stores water that has passed through the ultrafiltration process,
serving as an intermediate storage point.
Ultrafilter
Remove Bacterial, viruses. TSS
Bag filter II
Remove large particle
UV
Kill Microorganism and reduce ozone
Ozone Mixing system
for filing
Kill Microorganism
2.8.1. Bag filter
Bag filters, characterized by their non-rigid, disposable fabric construction, are
primarily designed to remove particulate matter from fluids by trapping particles larger than
their pore size within a pressure vessel. The Bag Filter RT 80-3 model is constructed from 304
stainless steel. It has a maximum operating pressure of 0.6 MPa and is designed for normal
temperature conditions. It was manufactured in June 2022 by SG SHI GROUP. Aeration is
very effective for the oxidation of Iron II(Well Victorien Bienvenu 2021). According to
(Marjani, Nazari, and Seyyed 2009) showed that iron concentration decreased after aeration.
2.8.2. Mn and Fe filter
Pyrolusite and Stone are used in the RT-1600 SS Iron and Manganese. Filters stainless
steel (316L) filter for removing iron and manganese from water. It has a diameter of 1600 mm,
28
a height of 2250 mm, a flow capacity of 15 m³/h, and a max pressure of 0.6 MPa. It was made
in June 2022 This critical filtration equipment prevents water discoloration, metallic taste
issues, and potential plumbing damage by extracting these problematic minerals. These plants
achieved average treated water manganese concentrations between 0.001 mg/L and 0.024
mg/L(WHO 2011).
Water level: 60
cm
Figure 2.6 Remove Iron and Manganese filter
Pyrolusite is a highly pure natural manganese dioxide mineral, free from additives, used
as a catalyst for the oxidation and removal of iron and manganese in drinking water treatment.
It is applied in pressure or gravity filters, mixed with 20–50% by volume of sand with a grain
size of approximately 0.5–1.0 mm or 0.7–1.2 mm. Pyrolusite appears as dark brown grains
with a grain size of 0.355 ± 0.850 mm and an apparent density of 2,000 g/l.(PYROLUSITE
Application 2025).
2.8.3. Ultrafiltration
Membrane processes are divided into categories based on various factors, such as
driving force, membrane materials, membrane configuration, the size range of components
eliminated, and separation mechanisms. UF is also classified as a low-pressure (2–5 bar)
process. UF membranes generally operate by sieving. However, they have a more extensive
separation range than MF membranes (typically between 0.01 and 0.1 µm). They can eliminate
29
colloids, particles, pathogens, and viruses. The ultrafiltration process can successfully separate
proteins and other substances with high molecular weights from contaminated water(AbuZurayk et al. 2023). Cellulose ester membranes and glass fiber filters with pore sizes of 0.4 to
3 µm are effective in removing TSS (Kasper, Amaral, and Forsberg 2018). The Modul
ZeeWeed 1500-X is a commercial UF product characterized by a Polyvinylidene difluoride
membrane with a nominal pore size of 0.02 micron, enabling the rejection of larger particles
while allowing smaller molecules to pass. Its outside-in flow path describes the membrane
configuration. Operating under a low transmembrane pressure range of 0-276 kPa, typical of
UF, this module exhibits a flow range of 45-180 m3/day, indicating its throughput capacity for
separation processes in water treatment. Microbial removal by membranes depends on pore
size (micro/ultra/nano/RO), filter integrity, and resistance to chemical or biological degradation
(e.g., "grow-through"). Optimal performance is achieved when filtered water turbidity is < 0.1
NTU(CUMINGS 1962).
Table 2.11 Reductions of microbial achieved by water treatment
Treatment
process
Membrane
filtration
Microfiltration
Ultrafiltration
Nanofiltration
Enteric
pathogen
group
Viruses
Minimum
removal
(LRV)
>1
Bacteria
Protozoa
1
Maximum
removal
(LRV)
>.6.5
Notes
Microbial removal by membranes
depends on pore size
(micro/ultra/nano/RO), filter
>7 integrity, and resistance to
chemical or biological degradation
>7 (e.g., "grow-through"). Optimal
performance is achieved when
filtered water turbidity is < 0.1
NTU.
2.3
Reverse
osmosis
2.8.4. Ultraviolet
An Ultraviolet (UV) disinfection system uses electromagnetic energy from a mercury
arc lamp to penetrate the cell walls of microorganisms and disrupt their genetic material (DNA
and RNA). This UV radiation, produced by an electrical discharge through mercury vapor,
damages the genetic structure of the organisms, effectively destroying their ability to reproduce
30
and rendering them inactive. UV disinfection is most effective at wavelengths between 250–
270 nm. Lamps are usually 0.75 to 1.5 m long and 1.5 to 2.0 cm in diameter. Optimal lamp
wall temperature is 95–122°F. Contact time is short, about 20–30 seconds with low-pressure
lamps. UV disinfection effectiveness depends on wastewater quality, UV intensity, exposure
time, and reactor design. High levels of colloids and particles can reduce disinfection
efficiency.(States 1999) (States 1999).
All UV units have a maximum flowrate capacity and some have a minimum flowrate
as well. If the flow is too high, water will pass through without enough UV exposure. If the
flow is too low, heat may build up which can damage the UV lamp. UV units are most often
used in constant flow recirculating systems. Even The UV unit reduces the total bacteria count
from 2000 to 10 per milliliter which is 99.5% reduction, any surviving microorganism can
attach interior piping downstream of the UV, form biofilms, and multiply, reducing overall
system effectiveness(Edstrom Industries 2003).
Table 2.12 Ultraviolet Dosage Required For 99.9% Destruction of microbials
Bacteria
Bacillus anthracis
B. enteritidis
B. megatherium sp. (veg.)
B. megatherium sp. (spores)
B. paratyphosus
B. subtilis (vegetative)
B. subtilis (spores)
Clostridium tetani
Corynebacterium diphtheriae
Eberthella typhosa
Escherichia coli
Leptospira interrogans
Micrococcus candidus
Micrococcus sphaeroides
Mycobacterium tuberculosis
Neisseria catarrhalis
Phytomonas tumefaciens
Proteus vulgaris
Pseudomonas aeruginosa
Pseudomonas fluorescens
Salmonella enteritidis
Dosage
8,700
7,600
2,500
52,000
6,100
11,000
58,000
22,000
6,500
4,100
7,000
6,000
12,300
15,400
10,000
8,500
8,500
6,600
10,500
6,600
7,600
Mold Spores
Aspergillus flavus
Aspergillus glaucus
Aspergillus niger
Mucor racemosus A
Mucor racemosus B
Oospora lactis
Penicillium digitatum
Penicillium expansum
Penicillium roqueforti
Rhizopus nigricans
Dosage
99,000
88,000
330,000
35,200
35,200
11,000
88,000
22,000
26,400
220,000
Algae / Protozoa
Chlorella vulgaris (algae)
Nematode eggs
Paramecium
22,000
92,000
200,000
Virus
Bacteriophage (E. coli)
Hepatitis virus
Influenza virus
Polio virus
6,600
8,000
6,600
6,000
31
Salmonella paratyphi
Salmonella typhimurium
Salmonella typhosa (Typhoid)
Sarcina lutea
Serratia marcescens
Shigella dysenteriae (Dysentery)
Shigella paradysenteriae
Spirillum rubrum
Staphylococcus albus
Staphylococcus aureus
Streptococcus hemolyticus
Streptococcus lactis
Streptococcus viridans
Vibrio cholerae
6,100
15,200
6,000
26,400
6,200
4,200
3,400
6,160
5,720
6,600
5,500
8,800
3,800
6,500
Rotavirus
Tobacco mosaic
24,000
440,000
Yeast
Baker's yeast
Brewer's yeast
Common yeast
Saccharomyces cerevisiae
Saccharomyces ellipsoideus
Saccharomyces sp.
8,800
6,600
13,200
13,200
13,200
17,600
2.8.5. Ozone
Ozonation involves applying ozone (O₃), a strong oxidizing gas, to water to break down
organic and inorganic contaminants, effectively killing bacteria, viruses, and eliminating odors
to improve water quality. Studies show ozone is faster and more effective than chlorine against
viruses like poliovirus, even at low concentrations (~0.3 mg/L), but it lacks residual
disinfection to protect against post-treatment contamination (Safe Drinking Water Committee
1977).
Steps for Using Ozone in Water Treatment:
Step 1: Ozone Generation
➢
Ozone is produced on-site using ozone generators (by passing dry air or pure oxygen
through high-voltage electric discharge).
Step 2: Ozone Injection
➢
Inject ozone gas into the water through diffusers, venturi injectors, or contact chambers.
➢
Proper mixing is essential for effective disinfection and oxidation.
Step 3: Contact Time
➢
Maintain sufficient contact time to allow disinfection.
▪
Example: For viruses, 2-log inactivation at Ct₉₉ = 0.006–0.2 mg·min/L
32
▪
Contact chamber must be well-designed to avoid short-circuiting
Step 4: Degassing and Off-Gas Destruction
➢
Remove excess ozone gas from treated water.
➢
Use ozone destruct units (catalytic or thermal) to destroy leftover ozone before venting
to the atmosphere (for safety and compliance).
Table 2.13 Ozone Disinfection Performance
Pathogen
Type
Bacteria
Viruses
Protozoa
Log Reduction
(LRV)
2 LRV (99% kill)
2 LRV
2 LRV
Ct₉₉ (mg·min/L)
0.02
0.006–0.2
0.5–40
Notes
Very effective at low Ct
Highly effective
Depends on temperature;
Cryptosporidium varies widely.
Sauces:(CUMINGS 1962)
Notes:
•
Ct₉₉ = product of disinfectant concentration (mg/L) × contact time (min) needed for
99% inactivation.
•
Ozone is fast-acting and effective against bacteria, viruses, and protozoa.
•
No residual protection in the distribution system.
33
3. MATERIAL AND METHODS
3.1. Sampling
For the sample for testing the efficiency of removing Fe and Mn, 1L was taken per day
for 5 days (March 1–5, 2025). First, the sample was taken from a well about 2 meters away
from the treatment site. Then, the sample was taken from Bag filter I and finally from Fe and
Mn filter as shown in Figure 3.1. For the sample for testing the quality, it was stored at room
temperature in 22 bottles (bottled 500ml) start from 28/02/25 to 07/05/2025. It was storage at
room temperature and 2 bottles were taken per week, one bottle for testing TPC, Total coliform,
E.coli and another bottle for testing pH, Color, TDS, Turbidity, Fe, Ozone and Chloride.
Figure 3.1 Location for sampling
3.2. Material
It is very important to understand the equipment and material used in the chemical
and microbiological laboratories to gain a clearer understanding of their respective purposes,
as shown in Table 3.1.
Table 3.1 The equipment in lab
Equipment
Model
Heat magnetic stirrer
Function
Used for mixing Agar CCA and PCA with
distilled water, ensuring thorough dissolution
and homogenization.
Autoclave
CL-32L
Sterilizes items like plates, PCA media, bottles,
other equipment, NaCl solutions, using highpressure steam to kill microorganisms.
Water baths
Memmert
WNB7
Control Constant temperatures are maintained
for PCA media after sterilization.
Freezer
SNH-0205 Preserves water samples and media cultures.
OHAUS Analytical balance
Pioneer
PX
Provides precise measurements for media
preparation and NaCl.
Incubator
-
To maintain constant optimal temperatures for
bacterial growth and cultivation
Clean Benches
TLBCl1.2E
Provides a sterile workspace for aseptic
techniques, preventing contamination during
testing before placing samples in the incubator
34
Therma-Hygrometer
-
Monitors temperature and humidity conditions in
the laboratory.
Pure hit still
Basic/ph4
To produce distilled water
Therma-Hygrometer
To calibration verification temperature of
equipment such as incubators, freezers, and
water baths.
Name
Model
Function
HI83399 Multiparameter
Photometer
HI83399
Measures Color, pH, Mn, and various other
water quality parameters through colorimetric
analysis
pH meter
HI2210
Measures acidity/alkalinity of water samples,
Turbidity meter
HI 93703
Measure of water clarity.
TDS meter
Measures Total Dissolved Solids in water
samples.
Freezer
SNH-0205 Preserves water samples
Therma-Hygrometer
Monitors temperature and humidity conditions in
the laboratory.
EC/TDS/Temperature Tester
HI98312
Measures Electrical Conductivity and Total
Dissolved Solids.
Materials
Function
Nitrile gloves
Protect hands from chemicals, biological agents, and
contamination.
Safety goggles
Protect eyes from chemical splashes or microbial aerosols.
lab coat
Protect eyes from chemical splashes or microbial aerosols.
Safety shoe
Protect feet from chemical spills or dropped sharp objects.
Guardian Oli Hand Wash
Sanitize hands before and after lab work to maintain hygiene.
Scissors
Cut materials like packet.
Flexoffice Flexmarker
Write on the sample bottle.
Pen
Record observations and data during experiments.
Notebook
Maintain a record of procedures, results, and observations.
Test tube rack
Hold and organize test tubes during experiments.
Wash bottle
Dispense distilled water for rinsing glassware or adding water to
experiments.
35
Livi tissue paper
Clean lab surfaces or equipment gently.
pipette tips
Disposable tips for precise liquid transfer using micropipettes.
Volumetric Flask
Measure and prepare precise volumes of solutions.
Kimble Mixing Cylinder
Measure and mix liquid volumes accurately.
Nylon Syringe Filter
Filter samples to remove particles on test Color
Drying rack
Put the items away after washing.
Hair net
Prevent hair from contaminating samples.
Mask Medical
Prevent contamination of samples and protect user from aerosols.
Plastic bottle
Store or dispense solutions or samples.
Small glass vial 10ml
Use with HI83399 Multiparameter Photometer
Lab Micro
Lighters
Ignite Bunsen burners or alcohol burners.
Stainless steel alcohol
burner
Heat samples or sterilize equipment using a flame.
Rocker 300 Oil-Free
Vacuum Pump
Creating Vacuum for Filtration in test CCA
Cellulose Nitrate Filter
Filter media used to capture microbes or particles in
microbiological analysis in test CCA
Aluminum foil
Cover containers to protect from light, contamination and
heating.
Glass bottle
To load sample test CCA and PCA
3.3. Calibration
Calibration of instruments like the HI83399 Multiparameter Photometer, pH meter,
TDS meter, and Turbidity meter is essential to ensure accurate and reliable water quality
measurements. Over time, sensors can drift due to environmental factors, usage, or aging,
which affects their performance. Regular calibration using certified standards corrects this drift,
maintaining the precision of results. Thus, calibration is a fundamental part of maintaining
equipment performance and data integrity.
HI83399 Multiparameter Photometer: Place the cuvettes HI83330-Zero, HI83330-420,
HI83330-466, HI83330-525, HI83330-575, and HI83330-610 one by one into the cuvette
holder, and press READ after inserting each cuvette. Check that the accuracy is within the
acceptable range. For the pH meter, first rinse the electrode with distilled water, then measure
36
the pH using the 7.01 buffer solution, and finally measure the pH using the 4.01 buffer solution.
For TDS meter (Automatic one-point calibration), Simply use the 1382 ppm (mg/L) TDS
calibration solution (1 sachet) wait until the screen displays 1382 ppm, then press OK.
For turbidity: three points (0 FTU, 10 FTU and 500 FTU)
Table 3.2 Solution for calibration equipment
Equipment
Solution for calibration
HI83399 Multiparameter Photometer
HI83330-Zero, HI83330-420, HI83330-466
HI83330-525, HI83330-575 and HI83330610.
pH meter
pH buffer solution: pH 4.01 and pH 7.01.
TDS meter
Solution concentration 1382 mg/L (ppm).
Turbidity meter
Solution: 10 FTU, 0 FTU and 500FTU.
Chemical paramw
3.4. Physicochemical parameters
Physicochemical testing in water treatment refers to the analysis of both physical and
chemical properties of water to assess its quality and safety. These tests are essential parts of
water treatment processes to ensure the water meets regulatory standards for consumption.
Table 3.2 showed parameters for physicochemical testing of drinking water treatment. Each
parameter is measured using specific analytical techniques, most utilizing LED light sources
with narrow band interference filters at specific wavelengths.
37
Table.3.2. Specification of physicochemical parameters
Parameters Rang
Resolution Accuracy
Light Source
Method
0-300 µg/L
1 µg/L
±10 µg/L ±3% of
reading at 25 °C.
LED with narrow band
interference filter @ 575 nm
Adaptation of the
PAN Method.
Fe
0.000-1.600
mg/L
0.001 mg/L
±0.010 mg/L ±8% of LED with narrow band
reading at 25 °C
interference filter @ 575 nm
Adaptation of the
TPTZ Method
Chloride
0.0-20.0 mg/L
0.1 mg/L
±0.5 mg/L ±6% of
reading at 25 °C
LED with narrow band
interference filter @ 466
Adaptation of the
Mercury (II)
Thiocyanate
Method
Color
0 to 500 PCU
1 PCU
±10 PCU ±5% of
reading at 25 °C
LED with narrow band
interference filter @ 420 nm
Colorimetric
Platinum Cobalt
Method
Ozone
0.00-2.00 mg/L 0.01mg/L
±0.02 mg/L ±3% of
reading at 25 °C
LED with narrow band
interference filter @ 525 nm
Colorimetric DPD
Method
TDS
0-2000 ppm
±2% F.S.
Not use
Gravimetric TDS
method.
Turbidity
0.00-1000 FTU 0.01(0.0050.00
FTU),1(50 1000 FTU)
±0.5 FTU or ±5% of Infrared LED / Life of
reading (whichever is instrument
greater)
pH
-2.00 to 16.00
pH
±0.01 pH
Mn
1ppm
0.01 pH
Nephelometry
method.
Table 3.3 showed the chemical reagents needed for performing the physicochemical water
quality.
Table 3.3. Required Reagents for Testing
Parameters
Code
Description
Mn
HI93748A-0
Manganese Low Range Reagent A 2 packets
HI93748B-0
Manganese Low Range Reagent B
0.40ml
HI93748C-0
Manganese Low Range Reagent C
2ml
HI93703-51
Dispersing Agent
6 drops
Iron
HI93746-0
Iron Low Range Reagent
2 packets
Chloride
HI93753A-0
Chloride Reagent A
1 ml
HI93753B-0
Chloride Reagent B
1 ml
HI93757-0
Ozone Reagent
1 packet
Ozone
38
Quantity
3.4.1. Manages
Manganese is a element that can cause discoloration and bitter taste in water when present
above certain levels.
Select the Manganese LR
method using the procedure
described in the METHOD
SELECTION section.
Fill a cuvette with
10 mL of sample
(up to the mark).
Added one packet of HI93748A-0 Manganese Low
Range Reagent A to cuvette. Replace the plastic
stoppers and the caps. Shake gently until completely
dissolved.
Added 0.2 mL of the HI93748B-0
Manganese Low Range Reagent B to
cuvette. Replace the plastic stoppers and
the caps. Invert gently to mix for about
30 s.
Inserted the cuvette
with the reacted
deionized water into
the holder and close
the lid.
Added 3 drops of HI93703-51
Dispersing Agent to each cuvette.
Replace the plastic stoppers and the
caps. Invert gently to mix for about
30 seconds.
Add 1 mL of the HI93748C-0 Manganese
Low Range Reagent C to cuvette, replace
the plastic stoppers and the caps. Shake
gently.
Figure 3.1. Procedure of Manganese Analysis
3.4.2. Iron
Select the Manganese LR
method using the procedure
described in the METHOD
SELECTION section.
Fill one graduated mixing Add one packet of HI93746-0
cylinder up to the 25 mL Iron Low Range Reagent,
mark with sample.
close the cylinder and shake
vigorously for 30s. This is the
blank.
Fill a cuvette with 10 mL of
the reacted sample (up to the
mark). Replace the rubber
stopper
Figure 3.2. Procedure of Iron Analysis
39
Insert the cuvette
into the holder
and close the lid.
3.4.3. Chloride
Select the Chloride method
using
the
procedure
described in the METHOD
SELECTION section.
Fill a cuvette with
10 mL of sample
(up to the mark).
Add 0.5 mL of HI93753A-0
Chloride Reagent A to each
cuvette using the 1 mL
syringe. Mix each cuvette by
inverting for approximately 30
seconds.
Add 0.5 mL of HI93753B-0 Insert the cuvette
Chloride Reagent B to each into the holder
cuvette using the 1 mL and close the lid.
syringe. Mix each cuvette by
inverting for approximately
30 seconds.
Figure 3.3.Procedure of Chloride Analysis
3.4.4. Color
Colour in water may be caused by the presence of minerals such as iron and manganese
or by substances of vegetable origin such as algae and weeds. Colour tests indicate the efficacy
of the water treatment system.
Select the Color of Water method
using the procedure described in
the
METHOD
SELECTION
section.
Filter 10 mL of sample through a
filter with a 0.45 µm membrane
into the cuvette , up to the 10 mL
mark. Replace the plastic stopper
and the cap.
Insert the apparent color
cuvette into the holder
and close the lid
Figure 3.4.Procedure of Color Analysis
3.4.5. Ozone
Select the Ozone method using the
procedure described in the
METHOD SELECTION section.
Add one packet of HI93757-0
Ozone Reagent. Replace the plastic
stopper and the cap. Shake gently
for 20 seconds.
Insert the cuvette into the holder
and close the lid.
40
Figure 3.5. Procedure of Ozone Analysis
3.4.6. Total dissolved solids
TDS Meter
Pour the sample into a plastic
beaker until it is 4 cm high.
Immerse the tip of the probe into the sample to be tested. Use
plastic beaker or containers to minimize any EMC
interference.
Figure 3.6. Procedure of Total Dissolved Solids
3.4.7. Turbidity
Turbidity in water is because of suspended solids and colloidal matter. It may be due
to eroded soil caused by dredging or due to the growth of micro-organisms. High turbidity
makes filtration expensive. If sewage solids are present, pathogens may be encased in the
particles and escape the action of chlorine during disinfection.
.
Turbidity meter
Fill the sample up to the cuvette
mark (10ml).
Insert the cuvette into the holder
and close the lid.
Figure 3.7. Procedure of Turbidity of Analysis
41
3.4.8. pH
pH measures hydrogen ion concentration and indicates water’s acidity or alkalinity. A
pH above 9.5 is highly alkaline, while below 3 is strongly acidic. Low pH aids chlorination but
may cause corrosion.
pH meter
Pour the sample into a beaker.
Submerge the electrode and the temperature probe
approximately 4 cm into the sample to be tested and
stir gently. Allow time for the electrode to stabilize.
Figure 3.8. Procedure of pH analysis
3.5. Micrological
3.5.1. Prepare agar
3.5.2. Total Plate Count
3.5.3. E.Coli and Total plate count
42
4. RESULT AND DISCUSSION
4.1. Efficiency remove Mn
The particle size of manganese solids formed post-oxidation indicates that while bag filters
might remove larger manganese particles, they would not effectively target dissolved forms of
manganese. It is difficult to remove Mn(II) ions through direct oxidation using dissolved
oxygen under neutral pH conditions. Only when pH > 8.5, can the oxidation of Mn(II) occur
(Jez-Walkowiak et al. 2017). According to (Health Canada 2019) show that Manganese can be
removed by adsorption on granular pyrolusite (MnO₂) without coating. It's often mixed with
sand, with ratios adjusted to manganese levels. Pyrolusite allows higher filtration rates than
greensand, lowering filter size and cost. Though data is limited, studies show 81–99% removal
efficiency, achieving treated water manganese levels of 0.001–0.024 mg/L, and below 0.02
mg/L in optimized systems. Table 4.1 shows that the Mn removal efficiency was 96.62%,
corresponding to 0.009 mg/L, indicating that the system is well optimized. This is supported
by numerous studies of drinking-water systems that have reported that manganese
concentrations above 0.02 mg/L cause complaints about discoloured water, staining of
plumbing fixtures and laundry, and general dissatisfaction with the water quality(Cancer 1972).
The effectiveness of adsorption depends mainly on the quality of the adsorbent. A high surface
area and large internal area improve adsorption capacity and rate. Key factors like temperature,
pH, and pollutant properties must also be considered(Kekes, Tzia, and Kolliopoulos 2023).
Table 4.1. Mn Removal Efficiency
Stage
Day
Well Water
1
0.267
Mn(mg/L)
Average
2
3
4
5
0.266 0.274 0.257 0.271 0.267
Fe and Mn
Filter
WHO
0.013
0.009
0.007
0.009 0.008 0.009
≤0.3
43
SD
Variance
Average
0.005
0.000
96.62%
0.002
0.000
0.03
Mn(mg/L)
0.025
< 0.02 mg/L in optimized systems
0.02
Treated water target of ≤ 0.015 mg/L
0.015
0.01
0.005
0
0
1
2
3
4
5
6
Time (day)
4.2. Efficiency Removes Iron
This step generally follows the first one (aeration) and contribute to remove the quantity
of Iron in water. Aeration consists of exposing water to the wind in order to oxidize Iron (II)
into (Fe(OH)3. Aeration is very effective for the oxidation of Iron II (Well Victorien Bienvenu
2021). It proceeds depends on several parameters including pH, temperature, concentration of
dissolved oxygen, and catalysts (Stumm and Lee 1961). Ferrous iron oxidation is first-order
with Fe²⁺ and O₂, and second-order with OH⁻ above pH 6. The rate increases 100× per pH unit
above 6, being very slow below pH 3, slow at 3–6, moderate at 6–8, and rapid above 8( Iron
Oxidation, Aeration Systems ,2025). According to (Marjani, Nazari, and Seyyed 2009) showed
that iron concentration decreased after aeration, with removal efficiencies of 14.06%to 38.81%.
Oxygen is necessary to convert the ferrous in to ferric. To oxidize the ferrous iron in to ferric,
the water must be kept in touch of air or oxygen. Iron oxidizes more efficiently at higher pH
levels, with optimal removal occurring between pH 8.0–8.5. pH is one of the very important
parameters of water. A large number of chemical reactions are pH dependent. So, it is outmost
necessary to know the pH of water. The influent iron concentration was 59.8 mg/L, and after
treatment using the Pyrolusite Process, the effluent iron concentration dropped to less than 0.05
mg/L, indicating that the system removed virtually all the iron with a 100% removal efficiency
(Hiremath et al. 2013).
Table 4.2 Fe Mn Removal Efficiency
Each step
Fe(mg/L)
Well Water
1.18
1.107
Average Variance SD
1.032
1.03
44
1.087
0.003
0.061
Efficiency
Bag Filter
0.863
0.675
0.515
1.02
0.768
0.036
0.190
29.34%
Fe and Mn Filter
1.18
1.107
1.032
1.03
0.000
0.000
0.000
100%
WHO
≤0.3
4.3. During storage mineral water
4.3.1 Total Dissolved Solids
Based on the results shown in Figure 4.1, the Total Dissolved Solids (TDS) values of
bottled water samples stored over a 10-week period showed noticeable fluctuations. The TDS
initially measured 125 mg/L, increase to a maximum of 130 mg/L by week 6, likely due to
temperature-related changes that affect the solubility of dissolved minerals in water according
to WHO Water containing TDS concentrations below 1000 mg/litre is usually acceptable
(Shepherdson 1936). Previous findings by (Ahmed, Emad, and Bkary 2021) also indicated that
storage temperature can impact TDS levels, with their study reporting values between 75 mg/L
to 77 mg/L over three months. The palatability of drinking water has been rated by panels of
tasters in relation to its TDS level as follows: excellent, less than 300mg/L; good,
between 300 and 600mg/L; fair, between 600 and 900 mg/L; poor, between 900 and
1200mg/L; and unacceptable, greater than 1200mg/L (Hoko 2005). Despite these visual
fluctuations, statistical analysis showed that the changes were not significant (p > 0.05),
indicating that the mineral composition of the bottled water remained stable throughout the
storage period and confirming the reliability of the product under typical storage conditions.
45
TDS(mg/L)
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
-2 -1 0
1
2
3
4 5 6 7
Time(week)
8
9 10 11 12
Figure 4.1 Variation of TDS value during 0-10 week
4.3.1. Turbidity
In Table 4.1, the turbidity values of bottled water remained consistently at 0 NTU
throughout the 10-week observation period, significantly below the World Health
Organization’s recommended limit of <5 NTU for safe drinking water. This consistent clarity
reinforces the findings of (Ojekunle and Adeleke 2017), who concluded that properly treated
and stored bottled mineral water maintains its physical and chemical stability over time. The
absence of turbidity highlights the effectiveness of pre-bottling treatment processes and the
role of clean, airtight packaging in preventing external contamination from dust, microbes, and
other particulates. As noted by (Chan, Zalifah, and Norrakiah 2007), excessive turbidity can
shield harmful microorganisms from disinfectants, enabling their survival and even promoting
bacterial growth during storage. The recorded turbidity of 0 NTU indicates the absence of such
suspended particles, ensuring the water remains microbiologically safe. As (Bach et al. 2012)
explained, turbidity measures suspended solids rather than dissolved substances, so such
chemical shifts may occur without being reflected in NTU values. The consistent 0 NTU
readings throughout the storage period align with WHO standards and affirm that the bottled
water maintained high quality and safety throughout. This stability is crucial for protecting
public health by minimizing conditions that could support pathogen survival. Overall, the data
46
suggest that properly treated and packaged natural mineral water can retain its optimal turbidity
levels during standard storage durations, offering consumers confidence in the product’s safety
and compliance with WHO guidelines. The turbidity value in drinking water are good has
turbidity below 1 NTU, and water becomes visibly cloudy at 4 NTU and above(WHO/UNICEF
2017).
Table 4.3 Turbidity Values of Naturel mineral Bottled Water during 0-10 week
Time (week)
0
1
2
3
4
5
6
7
8
9
10
Turbidity (NTU) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
WHO
<5
4.3.2. Color
The study demonstrated exceptional color stability in natural mineral water, with
consistent values of 0 TCU recorded throughout the observation period well below the
(Herschy 2012) WHO recommended limit of ≤15 TCU according to the Table 4.2. The use of
advanced purification processes and sealed, food-grade packaging effectively eliminated
external contamination sources such as air, light, dust, and microbes, which can otherwise
trigger color changes. Color in water can be caused by dissolved and suspended materials(Iso
1892). WHO emphasized the interconnection between color and odor as sensory indicators of
water quality. Although the WHO’s color guideline is not directly related to health risks, it
serves as a visual indicator of treatment effectiveness and potential contamination. The
maintained 0 TCU readings affirm that properly treated and packaged mineral water retains
excellent aesthetic and quality characteristics under room temperature storage. These findings
highlight the importance of integrated control over chemical composition, treatment processes,
and packaging to meet both regulatory standards and consumer expectations. Discolored water
reduces public trust, increasing bottled water consumption, highlighting the need for both
chemical and aesthetic water quality improvements (Article 2023).
Table 4.4 Color Values of Naturel mineral Bottled Water during 0-10 week
Time (week)
Color (TCU)
0
1
2
3
4
5
6
7
8
9
10
0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
WHO
<15
4.3.3. Iron
According to Table 4.4, the iron (Fe) concentration in natural mineral bottled water
remained consistently at 0 mg/L throughout the 10-week monitoring period, well below the
47
World Health Organization (WHO) acceptability limit of 0.3 mg/L, which is based on taste and
color rather than health risks (Herschy 2012). This consistent absence of detectable iron
suggests the water is not only safe for consumption but also meets international aesthetic
standards. The data supports (Al-sulaiman 2015) findings, which reported no change in iron
levels even after six months of storage, indicating long-term stability. Similarly(Ahmed, Emad,
and Bkary 2021) found that despite temperature changes, heavy metal concentrations in bottled
water remained minimal or non-detectable, with only slight traces of copper and zinc reported.
The total absence of iron throughout the observation period implies that effective treatment
methods, high-quality source water, or natural filtration processes are in place to remove iron
before bottling. Moreover, the consistently zero values indicate that the bottling and packaging
process is secure and prevents external contamination or leaching of iron into the water during
storage. This stability is important, as elevated iron levels can cause unpleasant taste and
staining issues, even if not harmful to health.
Table 4.5 Iron Concentration of Naturel mineral Bottled Water during 0-10 week
Time (week)
Iron(mg/L)
0
1
2
3
4
5
6
7
8
9
10
0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
WHO
<0.3
4.3.4. Ozone
According to the Table 4.5. show that demonstrates ozone's instability in bottled water.
Starting at 0.19 mg/L in week 0, ozone levels drop to undetectable (0 mg/L) by week 1 and
remain absent through week 10. (Sasáková et al. 2021) show that ozone in potable water
decreases from 0.25 to 0 mg/L within just 120 minutes. This rapid decomposition is influenced
by water type, ozone generator equipment, and environmental conditions. While ozone may be
employed as an effective initial disinfectant due to its strong oxidizing properties, consumers
receive essentially ozone-free water after brief storage. With the WHO establishing no specific
guideline value for ozone , this rapid decomposition is advantageous as it eliminates concerns
about long-term exposure(Herschy 2012).
Table 4.6 Ozone Concentration of Naturel mineral Bottled Water during 0-10 week
Time (week)
0
1
2
3
4
5
48
6
7
8
9
10
WHO
Ozone(mg/L)
0.00 0.19 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
n/s
4.3.5. pH
The Figure 4.2 shows that the pH of bottled water remained stable over a 10-week
period, ranging from 7.04 to 7.17, with a slight decline to 7.0 by week 10. This near-neutral
pH stability indicates minimal chemical changes during storage. With a p<0.05, the variation
is not statistically significant, suggesting that time had little impact on pH levels.
Similarly(Ojekunle and Adeleke 2017) found no significant pH change in bottled water stored
for three months. The consistent pH reflects the effectiveness of bottling processes in
preserving water quality and ensuring product consistency. A stable pH is also important for
consumer trust, as it indicates freshness and safety. Even though slight changes occurred, they
remained within safe limits and posed no health risks, according to WHO guidelines. The
conclusion that bottled water maintains its pH stability during storage, contributing to its safety
and acceptability.
9
8
7
pH
6
5
4
3
2
1
0
1
2
3
4
5
6
7
Time (week)
8
9
10
11
Figure 4.2 pH values of bottled water over a 10-week period
4.3.6. Chloride
Based on the provided information, chloride concentration in bottled water shows
fluctuation over a 10-week period, ranging from 0.9 to 1.2 mg/L, with a P-value of 0.09
indicating no statistically significant change. These levels are considerably below the WHO
standard of 250 mg/L, which is the threshold where water begins to develop a salty taste (250500 mg/L range). The research suggests that heating bottled water above 50°C can increase
49
chloride concentration through enhanced leaching from bottle materials or shifts in water's
chemical equilibrium (Ahmed, Emad, and Bkary 2021). However, the graph shows that even
with potential variations, chloride levels remained well within safe consumption parameters
throughout the observation period.
1.5
Chloride(mg/L)
1.3
1.1
0.9
0.7
0.5
0.3
0.1
0
1
2
3
4
5 6 7
Time(week)
8
9
10 11
Figure 4.3 Variation of chloride concentration during 0-10 week
4.3.7. Biological
The Table 4.5 shows consistently zero bacterail all throughout the 10-week storage
period at room temperature. All the results show values maintained at 0 cfu / ml across all
measurement periods, aligning with WHO standards which also recommend 0 cfu / ml.
According to (Ojekunle and Adeleke 2017).Total coliform does not grow for 3 months at room
temperauture. But coliform counts can be affected by temperature and packaging material.
Regarding total plate count (TPC), the consistent zero readings throughout the 10-week period.
Bottled water that initially had 0 CFU / L showed no microbial growth in either winter or spring.
However, bottled water with an initial microbial count of 8 × 102 CFU / L in spring experienced
an increase to 1.7 × 104 CFU / L after 30 days (Carraturo et al. 2021) ( While the heterotrophic
plate count (HPC) alone does not directly correlate to general health risks. However, it raises
concerns about potential risks for immunocompromised individuals (Carraturo et al. 2021).
The absence of any microbial growth in the present study suggests either exceptionally
effective treatment processes, high-quality packaging materials, or optimal storage conditions.
Table 4.7 Microbial during storage at room temperature 0-10 week
Time(week)
0
1
2
3
4
5
6
50
7
8
9
10 WHO
Coliform
0
0
0
0
0
0
0
0
0
0
0
0 cfu/ml
E-coli
0
0
0
0
0
0
0
0
0
0
0
0 cfu/ml
Total plat count
0
0
0
0
0
0
0
0
0
0
0
n/s
51
5. CONCLUSION
Future work should focus on examining the impact of reiterating heating and cooling on the
bottled water quality.
Storage conditions are important for bottled water quality, and it should be kept between
room temperature and maximum 30 °C(Ahmed, Emad, and Bkary 2021).
• The results herein can be useful for regulating the optimum way for transportation and
storage of bottled waters.
52
REFERENCES
Schüroff, P. A., Andrade, F. B., & Pelayo, J. S. (2022). Virulence markers,
adhesion and biofilm formation of Escherichia coli strains isolated from drinking
water supplies of north Paraná State, Brazil. Journal of water and health, 20(9), 1416–
1424. https://doi.org/10.2166/wh.2022.128.
Suehr, Q. J., Chen, F., Anderson, N. M., & Keller, S. E. (2020). Effect of pH on survival of
Escherichia coli O157, Escherichia coli O121, and Salmonella enterica during
desiccation and short-term storage. Journal of Food Protection, 83(2), 211-220.
53
APPENDIXES
Date
week
28.02.25
07.03.25
14.03.25
18.03.25
25.03.25
04.04.25
11.04.25
18.04.25
25.04.25
02.05.25
07.05.25
WHO
0
1
2
3
4
5
6
7
8
9
10
Fe
Color Turbidity
pH
(mg/L)
(TCU)
(NTU)
0.000 0.000
0.00
7.04
0.000 0.000
0.00
7.17
0.000 0.000
0.00
7.12
0.000 0.000
0.00
7.06
0.000 0.000
0.00
7.20
0.000 0.000
0.00
7.04
0.000 0.000
0.00
7.09
0.000 0.000
0.00
7.06
0.000 0.000
0.00
7.05
0.000 0.000
0.00
7.01
0.000 0.000
0.00
7.00
0.3 15.000
5.00 6.5-8.5
Chloride TDS
(mg/L) (mg/L)
1.0
125
1.1
117
1.0
119
1.2
125
1.0
123
0.9
122
0.9
130
1.1
122
1.1
123
1.2
120
1.1 127
250
500
Ozone
(ml/l)
0.19
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Date
E.Coli (CFU / L) Total Coliform (CFU / L) TPC (CFU / L) E.Coli (CFU / L)
28.02.25
0
0.000 0.000
0.00
07.03.25
1
0.000 0.000
0.00
14.03.25
2
0.000 0.000
0.00
18.03.25
3
0.000 0.000
0.00
25.03.25
4
0.000 0.000
0.00
04.04.25
5
0.000 0.000
0.00
11.04.25
6
0.000 0.000
0.00
18.04.25
7
0.000 0.000
0.00
25.04.25
8
0.000 0.000
0.00
02.05.25
9
0.000 0.000
0.00
07.05.25
10
0.000 0.000
0.00
WHO
0.3 15.000
5.00
54
5.1. Component of treatment water
55
56
57
58
59
60
61
62
63
64
(Hippel 2012)
Ultrafiltration (UF) on its own was not effective in removing dissolved divalent
manganese (Mn(II)); however, the addition of a specific amount of humic acid (HA)
significantly improved the removal efficiency.
https://www.sciencedirect.com/science/article/abs/pii/S2213343722018048
Feng, C. L., Liu, C., Meng-Yao, Y. U., Chen, S. Q., & Mehmood, T. (2022). Removal
performance and mechanism of the dissolved manganese in groundwater using ultrafiltration coupled
with HA complexation. Journal of Environmental Chemical Engineering, 10(6), 108931.
Jacob, M. M. (2020, June 8). Indicator microorganisms.
https://merlinsmicroworld.blogspot.com/2020/06/indicator-microorganisms.html
65
66