CHEMISTRY INVESTIGATORY PROJECT
SESSION: 2025-26
Aim: Study of the Methods of Purification of
Water
Submitted To Submitted By
Ms. Himani Handa Name : SHUBHAM SINGHAL
PGT Chemistry Class/Section: XI-A
Admission
Number:13554
CERTIFICATE
This is to certify that SHUBHAM
SINGHAL, a student of class XI has
successfully completed the research
on the below mentioned project
under the guidance of Ms. Himani
Handa during the session 2025-26 in
partial fulfilment of the chemistry
practical examination conducted by
CBSE.
Signature of Internal
Examiner
ACKNOWLEDGEMENT
I wish to express my deep gratitude and
sincere thanks to Principal, Ms. Hema
Sangal for her encouragement and
constant support provided in the
accomplishment of this project.
I extend my hearty thanks to Ms. Himani
Handa my Chemistry teacher, who
guided me to successfully complete this
project. I take this opportunity to
express my deep sense of gratitude to
the lab assistant for his constant
support.
[Student’s
Signature]
SHUBHAM SINGHAL
S.NO. PARTICULAR PAGE
NO.
1. Aim 1
2. Introduction 2
3. Theory 3-6
4. Procedure 7-8
5. Observation 9
6. Result 10
7. Conclusion 11
8. Bibliography 12
Aim
To understand and evaluate various
methods of water purification by
studying their principles, processes, and
effectiveness, thereby gaining insights
into their practical applications for
ensuring safe drinking water
Introduction
Water is one of the most essential
resources for life. Despite its abundance,
clean and safe drinking water is
becoming scarce due to pollution,
urbanization, and industrialization.
Natural sources of water such as rivers,
lakes, and groundwater often contain
harmful microorganisms, suspended
particles, and chemical pollutants.
The global water crisis has made it
imperative to adopt efficient and
sustainable methods of water
purification. Access to potable water is
not just a basic necessity but a
fundamental right. Thus, it is crucial to
explore traditional and modern
purification techniques to ensure that
water meets the safety standards for
consumption.
This project aims to create awareness
about the importance of water
purification and encourages the adoption
of appropriate methods suited to various
environments and socio-economic
conditions.
Theory
Water purification methods are broadly
categorized into physical, chemical, and
biological techniques. Each method
works on distinct principles and has
unique advantages and limitations.
Understanding the underlying science
helps in choosing the right method
depending on the type of contamination
and the purpose.
1. Boiling – This is the simplest and
oldest method. By heating water to
its boiling point, harmful pathogens
such as bacteria, viruses, and
protozoa are killed. However, it does
not remove chemical impurities or
suspended solids.
2.Filtration – Physical filters like sand,
charcoal, or ceramic remove visible
particles, dirt, and some
microorganisms. Advanced filters can
even remove dissolved substances.
This method is efficient but may require
regular maintenance.
3.Sedimentation – Heavier particles in
water settle down when left
undisturbed. This is often the first
step before filtration or chlorination.
It is slow and ineffective against
microorganisms.
4.Distillation – Water is heated until it
vaporizes, then condensed back into
liquid. This process removes a wide
range of impurities, including salts
and heavy metals, but is energy-
intensive and slow.
5.Chlorination – Chlorine or its
compounds are added to kill
pathogens. It is cost- effective and
commonly used in community water
treatment plants. However, excess
chlorine can produce harmful by-
products.
6.Reverse Osmosis (RO) and UV Purifiers
– RO uses pressure to force water
through a semipermeable membrane,
removing even the
smallest particles and ions. UV purification
uses ultraviolet light to destroy bacteria and
viruses.
These methods are highly effective but
require electricity and maintenance.
Procedure
1. Collection of Sample: Tap water
samples were collected from various
sources, ensuring the presence of both
visible and invisible contaminants.
2. Segregation: The collected water
was divided into five equal
samples for testing different
purification techniques.
3. Boiling: Each water sample was
boiled continuously for 15 minutes.
4. Filtration: A candle-type household
filter was used to treat the water.
5. Sedimentation: Water was left
undisturbed in a transparent container
for 6–8 hours.
6. Chlorination: Bleaching powder was
added in the proportion of 1 mg per
liter.
5. RO/UV Purifier: A commercial
purifier was used to treat another
sample. Testing and Recording:
Physical characteristics such as
clarity, color,and taste were
observed. simple microbial tests
were performed using school lab
resources.
6.Analysis: Results were tabulated and
compared for each method.
7.Parameters Tested:
Parameter Methodology
pH Digital pH meter
TDS TDS meter (mg/L)
Chlorine Residue Orthotolidine test
Observation
Method Change Odor Microbial Remarks
in Clarity Removed Purity
Boiling High Yes High Effective in killing
pathogens
Filtration Moderate No Low Good for suspended solids
Sedimentation Low No Very Low Requires follow-up
treatment
Chlorination High Slight High Disinfects but may alter
smell taste
RO Purifier Very High Yes Very High Best quality and safe
drinking Water
Result
From the experimental data, it is evident that
RO and UV purification techniques provide the
highest level of water purity. Boiling and
chlorination are also reliable and accessible
alternatives in regions where advanced
technology is unavailable.
Filtration and sedimentation, while helpful, are
insufficient alone for ensuring microbiological
safety. Thus, they should be used in
conjunction with other techniques for better
outcomes.
Conclusion
This project successfully demonstrates
that water purification is vital for healthy
living and environmental sustainability.
Each method examined has specific use-
cases:
• Boiling is effective for emergency
situations.
• Chlorination is suited for large-scale
municipal systems.
• RO/UV systems are ideal for
households in urban areas with
contaminated water supplies.
• Filtration and sedimentation are
useful preliminary steps but need
supplementation.
A multidisciplinary approach involving
science, technology, and public awareness is
essential to solve the global clean water
challenge.
Governments, communities, and
individuals must work together to
implement affordable and scalable
purification systems
Bibliography
1. NCERT Chemistry Textbook Class XI
2. WHO Guidelines on Drinking Water
Quality –
https://www.who.int/water_sanitation_he
alth
3. Centers for Disease Control and
Prevention –
https://www.cdc.gov/healthywater/
4. Modern ABC of Chemistry
5. Britannica Science Encyclopedia
–
https://www.britannica.com/science
/water- purification
6. Research articles and journals on
water purification technologies
7. Indian Standard Drinking Water
Specifications – Bureau of Indian
Standards (IS 10500:2012)
