“SAMRAKSHANA”

The Total Protection With Affection

ADITYA VIDYASHRAM RESEDENTIAL SCHOOL

Poraiyur, Villianur, Puducherry – 605110

CBSE AISSCE:XII – 2024 – 2025

ALL INDIA SENIOR SCHOOL CERTIFICAE EXAMINATION
CHEMISTRY (043)
Investigatory Project
CERTIFICATE
Name: S DHANUSH Std & Sec : XII – B1

Registration Number:

Certified that this is a bonafide Practical Record / Investigatory project work done by the
above mentioned student in our school laboratory during Senior Secondary course, in the year 2024 –
2025.

SUBJECT TEACHER PRINCIPAL

Record/Project Submitted for the CBSE – AISSCE Practical examination held on ___/___/2025

INTERNAL EXAMINER EXTERNAL EXAMINER

 ACKNOWLEDGEMENT

I would like to extend my sincere and heartfelt obligation towards all those who
have helped me in making this project. Without their active guidance , help,
cooperation and encouragement, I would not have been able to present the
project on time.

I am extremely thankful and pay my sincere gratitude to my teacher

MR. SRIGAND for his valuable guidance and support completion of this
project.

I extend my sincere gratitude to my principal Mr. Dr. Nadesan Kangueyan

for the moral support extended during tenure of this project.

I also acknowledge with the deep sense of reverence, my gratitude towards my

parents, other faculty members of the school and friends for their valuable
suggestions given to me in completing the project.
 CERTIFICATE

This is to certify that the project work on METHODS OF PURIFICATION

OF WATER based on the curriculum of CBSE has been completed by
S DHANUSH of class– XII-B1 of Aditya Vidhyashram Residential School,
Puducherry.

The above mentioned project work has been completed under my guidance
during the academic year 2024 – 25.

Signature of the Guide Teacher

 INDEX
 Certificate
 Acknowledgement
 Topic
 Introduction
 Coagulation and Flocculation
 Sedimentation
 Filtration
 Water Chlorination
 Disinfection
 Distillation
 Reverse Osmosis(RV)
 Activated Carbon Filtration
 Ion Exchange
 Ceramic Filtration
 Conclusion
 Bibliography
 TOPIC

Methods of Purification of Water

 INTRODUCTION
Introduction to Methods of Purification of Water
Water is essential for human survival, and access to clean drinking
water is a fundamental human right. However, many communities
around the world face challenges in accessing safe and clean drinking
water due to various contaminants and pollutants present in the water.
Water purification is the process of removing these contaminants and
pollutants to produce water that is safe for human consumption,
industrial use, and other purposes.
Why is Water Purification Important?
Water purification is crucial for several reasons:
 Human Health: Contaminated water can cause waterborne
diseases, such as cholera, diarrhea, and typhoid fever, which can
be life-threatening.
 Environmental Protection: Contaminated water can harm
aquatic life and ecosystems.
 Industrial Processes: Clean water is essential for various
industrial processes, such as manufacturing, mining, and energy
production.
 Agriculture: Clean water is necessary for irrigation and crop
production.
Types of Contaminants in Water
Water can be contaminated with various types of pollutants,
including:
 Physical Contaminants: Sediment, silt, and other suspended
particles.
 Chemical Contaminants: Heavy metals, pesticides, and
industrial chemicals.
  Biological Contaminants: Bacteria, viruses, and other
microorganisms.
 Radiological Contaminants: Radioactive substances.
Goals of Water Purification
The primary goals of water purification are:
 Remove Contaminants: Eliminate or reduce contaminants to
safe levels.
 Improve Taste and Odor: Make the water palatable and
pleasant to drink.
 Meet Regulatory Standards: Comply with local and
international water quality standards.
Methods of Water Purification
Various methods are employed to achieve these goals, including:
 Physical Methods: Sedimentation, filtration, and distillation.
 Chemical Methods: Coagulation, disinfection, and ion
exchange.
 Biological Methods: Activated carbon filtration and ultraviolet
(UV) light disinfection.
In the next section, we will delve into the details of each method,
exploring their principles, advantages, and limitations.
 COAGULATION AND
FORCCULATION
Coagulation
Coagulation is the process of adding chemicals to water to remove
dirt and other suspended particles. The chemicals neutralize the
electrical charges of the particles, allowing them to stick together and
form larger clumps, called flocs.
Coagulation Process:
1. Chemical Addition: Coagulant chemicals, such as alum
(aluminum sulfate), ferric chloride, or polymers, are added to
the water.
2. Mixing: The water is mixed rapidly to distribute the coagulant
evenly.
3. Neutralization: The coagulant neutralizes the electrical charges
of the particles, allowing them to stick together.

Flocculation
Flocculation is the process of slowly mixing the water to allow the
flocs to grow and stick together, forming larger and heavier particles
that can be easily removed.
Flocculation Process:
1. Slow Mixing: The water is mixed slowly to allow the flocs to
grow and stick together.
2. Floc Growth: The flocs grow and become heavier, making them
easier to remove.
 3. Settling: The water is sent to a sedimentation basin where the
heavy flocs settle to the bottom.
Diagram: Coagulation and Flocculation Process
Advantages:
 Effective against a wide range of contaminants
 Can remove suspended solids, bacteria, and viruses
 Relatively low cost
Limitations:
 Requires careful control of coagulant dosage and mixing
 Can produce large amounts of sludge
 May not remove dissolved contaminants
Common Coagulants:
 Alum (aluminum sulfate)
 Ferric chloride
 Polymers (e.g., polyaluminum chloride)
Common Flocculants:
 Polymers (e.g., polyacrylamide)
 Inorganic salts (e.g., calcium chloride)
By understanding the coagulation and flocculation process, water
treatment plants can effectively remove contaminants and produce
clean and safe drinking water.
 SEDIMENTATION
What is Sedimentation?
Sedimentation is the process of removing suspended solids and
contaminants from water by allowing them to settle to the bottom of a
tank or basin. This process is also known as clarification or settling.
How Sedimentation Works:
1. Flocculated Water: Water that has undergone coagulation and
flocculation is sent to a sedimentation basin.
2. Settling: The water is allowed to sit in the basin, allowing the
heavy flocs to settle to the bottom.
3. Clear Water: The clear water on top is removed and sent to the
next step in the treatment process.
4. Sludge Removal: The settled sludge is removed from the
bottom of the basin and sent to further treatment or disposal.
Types of Sedimentation:
1. Gravity Sedimentation: Uses gravity to settle particles.
2. Lamella Sedimentation: Uses inclined plates to increase
settling surface area.
3. Tilted Plate Sedimentation: Uses tilted plates to increase
settling surface area.
Advantages:
 Effective against suspended solids and contaminants
 Relatively low cost
 Simple operation and maintenance
Limitations:
  Requires careful control of flow rates and settling time
 May not remove dissolved contaminants
 Can produce large amounts of sludge
Applications:
 Drinking water treatment
 Wastewater treatment
 Industrial process water treatment
By removing suspended solids and contaminants through
sedimentation, water treatment plants can produce clear and clean
water for various uses.
 FILTRATION
What is Filtration?
Filtration is the process of removing suspended particles and
contaminants from water by passing it through a physical barrier,
known as a filter. The filter traps the contaminants, allowing clean
water to pass through.
Types of Filtration:
1. Mechanical Filtration: Uses a physical barrier to remove
particles.
2. Activated Carbon Filtration: Uses activated carbon to remove
impurities and improve taste and odor.
3. Biological Filtration: Uses living organisms to remove
impurities.
4. Membrane Filtration: Uses semi-permeable membranes to
remove impurities.
Filtration Process:
1. Pre-treatment: Water is pre-treated to remove larger particles
and contaminants.
2. Filtration: Water passes through the filter, trapping
contaminants.
3. Post-treatment: Filtered water may undergo additional
treatment, such as disinfection.
Advantages:
 Effective against a wide range of contaminants
 Can improve taste and odor
  Relatively low cost
Limitations:
 May not remove dissolved contaminants
 Requires regular maintenance and replacement of filters
 Can be prone to clogging
Applications:
 Drinking water treatment
 Wastewater treatment
 Industrial process water treatment
 Swimming pool water treatment
Common Filter Types:
 Sand filters
 Cartridge filters
 Activated carbon filters
 Reverse osmosis (RO) filters
 Ultrafiltration (UF) filters
By removing suspended particles and contaminants through filtration,
water treatment plants can produce clean and safe water for various
uses.
 WATER CHLORINATION
What is Water Chlorination?
Water chlorination is a disinfection process that involves adding
chlorine or chlorine compounds to water to kill or inactivate
microorganisms, such as bacteria, viruses, and protozoa.
How Water Chlorination Works:
1. Chlorine Addition: Chlorine is added to the water supply.
2. Disinfection: Chlorine kills or inactivates microorganisms.
3. Residual Chlorine: A residual amount of chlorine remains in
the water to maintain disinfection.
Types of Chlorination:
1. Free Chlorination: Chlorine is added directly to the water.
2. Combined Chlorination: Chlorine and ammonia are added to
form chloramines.
3. Ozonation-Chlorination: Ozone and chlorine are used in
combination.
Benefits of Water Chlorination:
1. Effective Disinfection: Chlorine is effective against a wide
range of microorganisms.
2. Low Cost: Chlorine is a relatively low-cost disinfectant.
3. Easy to Implement: Chlorination is a simple process to
implement.
Risks and Limitations:
1. Disinfection Byproducts (DBPs): Chlorine can form DBPs,
which can be harmful.
 2. Chlorine Taste and Odor: Chlorine can give water an
unpleasant taste and odor.
3. Corrosion: Chlorine can corrode pipes and infrastructure.
Alternatives to Water Chlorination:
1. Ozonation
2. Ultraviolet (UV) Light Disinfection
3. Chlorine Dioxide Disinfection
By understanding water chlorination, we can appreciate its role in
providing safe drinking water while also acknowledging its
limitations and potential risks.
 DISINFECTION
What is Disinfection?
Disinfection is the process of killing or inactivating microorganisms,
such as bacteria, viruses, and protozoa, in water. This process is
crucial to prevent the spread of waterborne diseases.
Methods of Disinfection:
1. Chlorination: Adding chlorine or chlorine compounds to water.
2. Ultraviolet (UV) Light Disinfection: Exposing water to UV
light.
3. Ozonation: Adding ozone gas to water.
4. Boiling: Heating water to a rolling boil.
5. Solar Disinfection (SODIS): Exposing water to sunlight in a
clear plastic bottle.
Disinfection Process:
1. Pre-treatment: Water is pre-treated to remove particles and
contaminants.
2. Disinfection: Water is disinfected using one of the methods
above.
3. Post-treatment: Disinfected water may undergo additional
treatment, such as storage or distribution.
Advantages:
 Effective against a wide range of microorganisms
 Can be used in combination with other treatment processes
 Relatively low cost
Limitations:
  May not remove other contaminants, such as heavy metals or
pesticides
 Can produce disinfection byproducts (DBPs)
 Requires careful control of disinfectant levels
Applications:
 Drinking water treatment
 Wastewater treatment
 Swimming pool water treatment
 Industrial process water treatment
Common Disinfectants:
 Chlorine
 Ozone
 UV light
 Chlorine dioxide
 Bromine
By killing or inactivating microorganisms through disinfection, water
treatment plants can produce safe and clean water for various uses.
 DISTILATION
What is Distillation?
Distillation is a water purification process that involves boiling water
and then collecting the condensed steam, which is free from many
contaminants. This process is effective against a wide range of
contaminants, including:
 Heavy metals
 Bacteria
 Viruses
 Protozoa
 Dissolved solids
How Distillation Works:
1. Boiling: Water is heated to its boiling point, producing steam.
2. Separation: The steam is separated from the contaminants,
which remain in the boiling chamber.
3. Condensation: The steam is cooled and condensed, producing
pure water.
4. Collection: The pure water is collected and stored.
Types of Distillation:
1. Simple Distillation: A single boiling and condensation cycle.
2. Fractional Distillation: Multiple boiling and condensation
cycles to remove different contaminants.
3. Steam Distillation: Uses steam to distill water, effective against
volatile organic compounds (VOCs).
Advantages:
 Effective against a wide range of contaminants
  Produces very pure water
 Can be used in combination with other treatment processes
Limitations:
 Energy-intensive
 Requires careful control of boiling and condensation
temperatures
 Can be prone to scaling and corrosion
Applications:
 Drinking water treatment
 Industrial process water treatment
 Laboratory water treatment
 Desalination of seawater
Common Distillation Equipment:
 Boiling chambers
 Condensers
 Distillation columns
 Heat exchangers
By boiling and condensing water, distillation can produce very pure
water, effective against many contaminants.
 REVERSE OSMOSIS(RO)
What is Reverse Osmosis (RO)?
Reverse Osmosis (RO) is a water purification process that uses a
semi-permeable membrane to remove impurities from water. The
process involves applying pressure to force water through the
membrane, which has tiny pores that block contaminants.
How RO Works:
1. Pre-treatment: Water is pre-treated to remove larger particles
and contaminants.
2. Pressurization: Water is pressurized to force it through the RO
membrane.
3. Filtration: Water passes through the RO membrane, which
blocks contaminants.
4. Post-treatment: Filtered water may undergo additional
treatment, such as disinfection.
RO Membrane:
 Semi-permeable: Allows water molecules to pass through, but
blocks contaminants.
 Tiny pores: Pores are 0.0001 microns in size, blocking most
contaminants.
Contaminants Removed by RO:
 Dissolved solids: Heavy metals, salts, and minerals.
 Bacteria: E. coli, Salmonella, and other bacteria.
 Viruses: Rotavirus, Norovirus, and other viruses.
 Protozoa: Giardia, Cryptosporidium, and other protozoa.
Advantages:
 Effective against a wide range of contaminants.
  Produces very pure water.
 Relatively low maintenance.
Limitations:
 Requires regular replacement of RO membrane.
 Can be prone to scaling and fouling.
 May remove beneficial minerals from water.
Applications:
 Drinking water treatment.
 Industrial process water treatment.
 Wastewater treatment.
 Desalination of seawater.
 ACTIVATED CARBON
FILTRATION
What is Activated Carbon Filtration?
Activated carbon filtration is a water purification process that uses
activated carbon, a form of carbon that has been treated to increase its
surface area and adsorption capacity. Activated carbon removes
impurities from water through adsorption, a process where molecules
attach to the surface of the carbon.
How Activated Carbon Filtration Works:
1. Water Flow: Water flows through the activated carbon filter.
2. Adsorption: Impurities in the water attach to the surface of the
activated carbon.
3. Filtered Water: Clean water passes through the filter.
Types of Impurities Removed:
 Chlorine: Improves taste and odor.
 Organic Compounds: Pesticides, herbicides, and volatile
organic compounds (VOCs).
 Heavy Metals: Lead, mercury, and arsenic.
 Disinfection Byproducts: Trihalomethanes (THMs) and
haloacetic acids (HAAs).
Advantages:
 Effective against a wide range of impurities.
 Improves taste and odor.
 Relatively low cost.
Limitations:
 Requires regular replacement of activated carbon.
  May not remove all impurities, such as dissolved solids.
 Can be prone to channeling and fouling.
Applications:
 Drinking water treatment.
 Industrial process water treatment.
 Wastewater treatment.
 Swimming pool water treatment.
Types of Activated Carbon:
 Powdered Activated Carbon (PAC): Used in batch processes.
 Granular Activated Carbon (GAC): Used in continuous
processes.
 Block Activated Carbon: Used in residential and commercial
applications.
 ULTRAVIOLET(UV) LIGHT
DISINFECTION
What is UV Light Disinfection?
UV light disinfection is a water purification process that uses
ultraviolet light to kill or inactivate microorganisms, such as bacteria,
viruses, and protozoa. This process is effective against a wide range of
microorganisms and is often used in combination with other treatment
processes.
How UV Light Disinfection Works:
1. UV Light Exposure: Water is exposed to UV light, which
penetrates the cells of microorganisms.
2. DNA Damage: The UV light damages the DNA of the
microorganisms, preventing them from reproducing.
3. Inactivation: The microorganisms are inactivated or killed,
removing the risk of waterborne disease.
Types of UV Light:
 UV-C: Most effective against microorganisms, with a
wavelength of 254 nanometers.
 UV-B: Less effective than UV-C, but still effective against some
microorganisms, with a wavelength of 280-315 nanometers.
 UV-A: Least effective against microorganisms, but can still be
used for disinfection, with a wavelength of 315-400 nanometers.
Advantages:
 Effective against a wide range of microorganisms.
 Low maintenance and operating costs.
 No chemicals added to the water.
Limitations:
 Requires regular maintenance of UV lamps.
 May not be effective against particulate matter or dissolved
solids.
 Can be affected by water turbidity or color.
Applications:
 Drinking water treatment.
 Wastewater treatment.
 Swimming pool water treatment.
 Industrial process water treatment.
 ION EXCHANGE
What is Ion Exchange?
Ion exchange is a water purification process that removes impurities
from water by exchanging ions in the water with ions on a resin. This
process is effective against a wide range of impurities, including:
 Heavy metals
 Nitrates
 Sulfates
 Chlorides
 Fluorides
How Ion Exchange Works:
1. Water Flow: Water flows through the ion exchange resin.
2. Ion Exchange: Impurities in the water are exchanged with ions
on the resin.
3. Purified Water: Clean water passes through the resin.
Types of Ion Exchange:
 Cation Exchange: Removes positively charged ions (cations).
 Anion Exchange: Removes negatively charged ions (anions).
 Mixed Bed Ion Exchange: Combines cation and anion
exchange resins.
Advantages:
 Effective against a wide range of impurities.
 Can remove impurities that other processes can't.
 Relatively low maintenance.
Limitations:
 Requires regular regeneration of the resin.
 Can be affected by water flow rate and temperature.
 May not remove all impurities, such as dissolved solids.
Applications:
 Drinking water treatment.
 Industrial process water treatment.
 Wastewater treatment.
 Power generation water treatment.
Common Ion Exchange Resins:
 Strong Acid Cation (SAC) Resin
 Weak Acid Cation (WAC) Resin
 Strong Base Anion (SBA) Resin
 Weak Base Anion (WBA) Resin
 CERAMIC FILTRATION
What is Ceramic Filtration?
Ceramic filtration is a water purification process that uses ceramic
elements with small pores to remove impurities from water. This
process is effective against a wide range of impurities, including:
 Bacteria
 Viruses
 Parasites
 Particulate matter
 Sediment
How Ceramic Filtration Works:
1. Water Flow: Water flows through the ceramic element.
2. Filtration: Impurities are blocked by the small pores in the
ceramic element.
3. Purified Water: Clean water passes through the element.
Types of Ceramic Filtration:
 Porcelain Ceramic Filtration: Uses porcelain ceramic
elements.
 Silicon Carbide Ceramic Filtration: Uses silicon carbide
ceramic elements.
 Aluminum Oxide Ceramic Filtration: Uses aluminum oxide
ceramic elements.
Advantages:
 Effective against a wide range of impurities.
 Long-lasting and durable.
 Low maintenance.
  Chemical-free.
Limitations:
 May not remove dissolved solids or chemicals.
 Can be prone to clogging.
 Requires regular cleaning.
Applications:
 Drinking water treatment.
 Industrial process water treatment.
 Wastewater treatment.
 Swimming pool water treatment.
Common Ceramic Filter Types:
 Ceramic Water Filters
 Ceramic Cartridges
 Ceramic Membranes
 BENEFITS OF WATER
PURIFICATION
Water purification is the process of removing contaminants and
impurities from water, making it safe for drinking, cooking, and
other uses. The benefits of water purification are numerous,
including:
1. Improved Health: Removes harmful contaminants, reducing
risk of waterborne diseases.
2. Better Taste and Odor: Removes impurities that affect taste
and odor, making water more palatable.
3. Increased Safety: Removes pathogens, bacteria, and viruses,
making water safe for drinking.
4. Reduced Risk of Cancer: Removes carcinogenic contaminants,
reducing risk of cancer.
5. Improved Digestion: Removes impurities that can cause
digestive issues.
6. Reduced Risk of Kidney Stones: Removes minerals that can
cause kidney stones.
7. Improved Skin Health: Removes impurities that can cause skin
issues.
8. Reduced Risk of Neurological Disorders: Removes
contaminants that can cause neurological disorders.
9. Improved Overall Well-being: Provides clean drinking water,
essential for overall health.
10. Peace of Mind: Knowing your water is clean and safe to
drink.
Environmental Benefits:
1. Conservation of Water: Reduces water waste by removing
contaminants.
2. Protection of Aquatic Life: Removes contaminants that can
harm aquatic life.
3. Reduced Pollution: Removes contaminants that can pollute soil
and air.
Economic Benefits:
1. Reduced Healthcare Costs: Reduces healthcare costs by
preventing waterborne diseases.
2. Increased Productivity: Provides clean drinking water,
improving productivity.
3. Reduced Maintenance Costs: Reduces maintenance costs by
removing contaminants that can damage equipment.
By purifying water, we can enjoy numerous benefits that impact our
health, environment, and economy.
 CONCLUSION
We can conclude that Water purification is a crucial process that
ensures the quality and safety of our drinking water. The various
methods of water purification, including distillation, reverse osmosis,
activated carbon filtration, ultraviolet (UV) light disinfection, ion
exchange, ceramic filtration, and chlorination, each have their own
advantages and limitations.
By understanding the benefits and drawbacks of each method, we can
choose the most effective and suitable approach for our specific
needs. Additionally, it is essential to consider the importance of
regular maintenance and monitoring of water purification systems to
ensure their effectiveness and efficiency.
Ultimately, access to clean and safe drinking water is a fundamental
human right, and water purification plays a vital role in making this a
reality. By prioritizing water purification, we can protect public
health, support economic development, and preserve the environment
for future generations.
Key Takeaways:
1. Water purification is essential for ensuring the quality and safety
of drinking water.
2. Various methods of water purification exist, each with its own
advantages and limitations.
3. Regular maintenance and monitoring of water purification
systems are crucial.
4. Access to clean and safe drinking water is a fundamental human
right.
5. Water purification plays a vital role in protecting public health,
supporting economic development, and preserving the
environment.
 BIBLIOGRAPHY
1. https://www.pureitwater.com/blog/post/water-purification-
methods/
2. https://atlas-scientific.com/blog/water-purification-methods/
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2266879/
4. https://www.ecologixsystems.com/library-water-purification/
5. https://www.aosmithindia.com/easy-and-effective-ways-to-
purify-water/
6. https://www.pureitwater.com/blog/post/purified-water-process-
and-benefits
7. https://www.pureitwater.com/blog/post/water-purification-
methods#:~:text=In%20conclusion%2C%20there%20are
%20various,common%20methods%20of%20water
%20purification.