This document describes an investigatory project on sterilizing water using bleaching powder. It discusses the need for water purification, provides background on bleaching powder and its use in water treatment. The experiment aims to determine the dosage of bleaching powder required to disinfect different water samples. The procedure involves preparing a bleaching powder solution, using it to treat water samples, and titrating to determine residual chlorine and required dosage. The results will show the amount of bleaching powder needed to disinfect 1 liter of each water sample.
STERELISATION OF WATER WITH BLEACHING POWDER VinayakSoni15
CHEMISTRY INVESTIGATORY PROJECT CLASS 12 [STERELISATION OF WATER WITH BLEACHING POWDER ] HOPE IT WILL HELP YOU FURTHER.
IMPORTANT:- RESULT MAY NOT BE ACCURATE TO SUBJECT.
THIS PROJECT MAERIAL HAS BEEN GATHERED FROM MANY INTERNET RESOURCES.
water supply in NZ, potable water process in NZ, household supply of water in NZ, sedimentation of water for supply, coagulation of water for supply, filtration of water for supply, disinfection of water for supply, storage of water for supply, reticulation of water for supply
STERELISATION OF WATER WITH BLEACHING POWDER VinayakSoni15
CHEMISTRY INVESTIGATORY PROJECT CLASS 12 [STERELISATION OF WATER WITH BLEACHING POWDER ] HOPE IT WILL HELP YOU FURTHER.
IMPORTANT:- RESULT MAY NOT BE ACCURATE TO SUBJECT.
THIS PROJECT MAERIAL HAS BEEN GATHERED FROM MANY INTERNET RESOURCES.
water supply in NZ, potable water process in NZ, household supply of water in NZ, sedimentation of water for supply, coagulation of water for supply, filtration of water for supply, disinfection of water for supply, storage of water for supply, reticulation of water for supply
Water is one of the most important substances on earth. All plants and animals must have water to survive. If there was no water there would be no life on earth.It is most important that the water which people drink and use for other purposes is clean water. This means that the water must be free of germs and chemicals and be clear (not cloudy).
AquaH2O Water filtration - water purificationAlg Colombo
Be Healthy!
Drink Clean Water...
By
Best Quality Brands Private Limited
No 383 2/1, Serpentine Road, Colombo 8, Sri Lanka
www.bestqb.lk; info@bestqb.lk
Water purification methods are very necessary at industrial level. Its also necessary to purify water for drinking purpose and its use in agricultural areas.
Water is the driving force of nature. It is a necessity for all living beings and it in order to survive we must consume clean and hygienic water. However, today with the growth of industrial sector, pollution has increased to a whole new level. Huge amount of pollution leads to contamination and contaminated water leads to diseases. This is the main reason we need to filter the water we consume.
Presentation given at seminar "Biological nutrient removal, operation management, and troubleshooting at wastewater treatment plant" in Pietari 13.12.2012
THESE SLIDES ARE PREPAREED TO UNDERSTAND about ENVIRONMENTAL HEALTH PROBLEMS IN INDIA IN EASY WAY Important links- NOTES- https://mynursingstudents.blogspot.com/ youtube channel https://www.youtube.com/c/MYSTUDENTSU... CHANEL PLAYLIST- ANATOMY AND PHYSIOLOGY-https://www.youtube.com/playlist?list=PL93S13oM2gAPM3VTGVUXIeswKJ3XGaD2p COMMUNITY HEALTH NURSING- https://www.youtube.com/playlist?list=PL93S13oM2gAPyslPNdIJoVjiXEDTVEDzs CHILD HEALTH NURSING- https://www.youtube.com/playlist?list=PL93S13oM2gANcslmv0DXg6BWmWN359Gvg FIRST AID- https://www.youtube.com/playlist?list=PL93S13oM2gAMvGqeqH2ZTklzFAZhOrvgP HCM- https://www.youtube.com/playlist?list=PL93S13oM2gAM7mZ1vZhQBHWbdLnLb-cH9 FUNDAMENTALS OF NURSING- https://www.youtube.com/playlist?list=PL93S13oM2gAPFxu78NDLpGPaxEmK1fTao COMMUNICABLE DISEASES- https://www.youtube.com/playlist?list=PL93S13oM2gAOWo4IwNjLU_LCuhRN0ZLeb ENVIRONMENTAL HEALTH- https://www.youtube.com/playlist?list=PL93S13oM2gAPkI6LvfS8Zu1nm6mZi9FK6 MSN- https://www.youtube.com/playlist?list=PL93S13oM2gAOdyoHnDLAoR_o8M6ccqYBm HINDI ONLY- https://www.youtube.com/playlist?list=PL93S13oM2gAN4L-FJ3s_IEXgZCijGUA1A ENGLISH ONLY- https://www.youtube.com/playlist?list=PL93S13oM2gAMYv2a1hFcq4W1nBjTnRkHP facebook profile- https://www.facebook.com/suresh.kr.lrhs/ FACEBOOK PAGE- https://www.facebook.com/My-Student-S... facebook group NURSING NOTES- https://www.facebook.com/groups/24139... FOR MAKING EASY NOTES YOU CAN ALSO VISIT MY BLOG – BLOGGER- https://mynursingstudents.blogspot.com/ Instagram- https://www.instagram.com/mystudentsu... Twitter- https://twitter.com/student_system?s=08 #PEM, #water,#waterborne,#ICDS,#diseases,#ASSESSMENT, #APPEARENCE,#PULSE,#GRIMACE,#REFLEX,#RESPIRATION,#RESUSCITATION,#NEWBORN,#BABY,#VIRGINIA, #CHILD, #OXYGEN,#CYANOSIS,#OPTICNERVE, #SARACHNA,#MYSTUDENTSUPPORTSYSTEM, #rashes,#nursingclasses, #communityhealthnursing,#ANM, #GNM, #BSCNURING,#NURSINGSTUDENTS, #WHO,#NURSINGINSTITUTION,#COLLEGEOFNURSING,#nursingofficer,#COMMUNITYHEALTHOFFICE,#HEALTHPROBLEMS
Water is one of the most important substances on earth. All plants and animals must have water to survive. If there was no water there would be no life on earth.It is most important that the water which people drink and use for other purposes is clean water. This means that the water must be free of germs and chemicals and be clear (not cloudy).
AquaH2O Water filtration - water purificationAlg Colombo
Be Healthy!
Drink Clean Water...
By
Best Quality Brands Private Limited
No 383 2/1, Serpentine Road, Colombo 8, Sri Lanka
www.bestqb.lk; info@bestqb.lk
Water purification methods are very necessary at industrial level. Its also necessary to purify water for drinking purpose and its use in agricultural areas.
Water is the driving force of nature. It is a necessity for all living beings and it in order to survive we must consume clean and hygienic water. However, today with the growth of industrial sector, pollution has increased to a whole new level. Huge amount of pollution leads to contamination and contaminated water leads to diseases. This is the main reason we need to filter the water we consume.
Presentation given at seminar "Biological nutrient removal, operation management, and troubleshooting at wastewater treatment plant" in Pietari 13.12.2012
THESE SLIDES ARE PREPAREED TO UNDERSTAND about ENVIRONMENTAL HEALTH PROBLEMS IN INDIA IN EASY WAY Important links- NOTES- https://mynursingstudents.blogspot.com/ youtube channel https://www.youtube.com/c/MYSTUDENTSU... CHANEL PLAYLIST- ANATOMY AND PHYSIOLOGY-https://www.youtube.com/playlist?list=PL93S13oM2gAPM3VTGVUXIeswKJ3XGaD2p COMMUNITY HEALTH NURSING- https://www.youtube.com/playlist?list=PL93S13oM2gAPyslPNdIJoVjiXEDTVEDzs CHILD HEALTH NURSING- https://www.youtube.com/playlist?list=PL93S13oM2gANcslmv0DXg6BWmWN359Gvg FIRST AID- https://www.youtube.com/playlist?list=PL93S13oM2gAMvGqeqH2ZTklzFAZhOrvgP HCM- https://www.youtube.com/playlist?list=PL93S13oM2gAM7mZ1vZhQBHWbdLnLb-cH9 FUNDAMENTALS OF NURSING- https://www.youtube.com/playlist?list=PL93S13oM2gAPFxu78NDLpGPaxEmK1fTao COMMUNICABLE DISEASES- https://www.youtube.com/playlist?list=PL93S13oM2gAOWo4IwNjLU_LCuhRN0ZLeb ENVIRONMENTAL HEALTH- https://www.youtube.com/playlist?list=PL93S13oM2gAPkI6LvfS8Zu1nm6mZi9FK6 MSN- https://www.youtube.com/playlist?list=PL93S13oM2gAOdyoHnDLAoR_o8M6ccqYBm HINDI ONLY- https://www.youtube.com/playlist?list=PL93S13oM2gAN4L-FJ3s_IEXgZCijGUA1A ENGLISH ONLY- https://www.youtube.com/playlist?list=PL93S13oM2gAMYv2a1hFcq4W1nBjTnRkHP facebook profile- https://www.facebook.com/suresh.kr.lrhs/ FACEBOOK PAGE- https://www.facebook.com/My-Student-S... facebook group NURSING NOTES- https://www.facebook.com/groups/24139... FOR MAKING EASY NOTES YOU CAN ALSO VISIT MY BLOG – BLOGGER- https://mynursingstudents.blogspot.com/ Instagram- https://www.instagram.com/mystudentsu... Twitter- https://twitter.com/student_system?s=08 #PEM, #water,#waterborne,#ICDS,#diseases,#ASSESSMENT, #APPEARENCE,#PULSE,#GRIMACE,#REFLEX,#RESPIRATION,#RESUSCITATION,#NEWBORN,#BABY,#VIRGINIA, #CHILD, #OXYGEN,#CYANOSIS,#OPTICNERVE, #SARACHNA,#MYSTUDENTSUPPORTSYSTEM, #rashes,#nursingclasses, #communityhealthnursing,#ANM, #GNM, #BSCNURING,#NURSINGSTUDENTS, #WHO,#NURSINGINSTITUTION,#COLLEGEOFNURSING,#nursingofficer,#COMMUNITYHEALTHOFFICE,#HEALTHPROBLEMS
STERILIZATION OF WATER USING BLEACHING POWDER PPTX..pptxDivyamMittal11
hey everyone ! here is new pptx of "sterilization of water using bleaching powder". CERTIFICATE OF AUTHENTICITY This is to certify that Anshul Kumar Pandey, a student of class XII has successfully completed the research project on the topic "Sterilization of Water by using Bleaching Powder" under the guidance of Mrs. Mohini Belani (Subject Teacher). This project is absolutely genuine and does not indulge in plagiarism of any kind. The references taken in making this project have been declared at the end of this report. Signature ( Subject Teacher) Signature ( Examiner) ACKNOWLEDGEMENT I feel proud to present my Investigatory project in Chemistry on the topic "Sterilization of Water using Bleaching powder" which aims at using Bleaching powder as a disinfectant and purifier to make water fit for drinking. This project wouldn't have been feasible without the proper and rigorous guidance of my Chemistry teacher Mrs. Mohini Belani who guided me throughout this project in every possible way. An investigatory project involves various difficult lab experiments which have to be carried out by the student to obtain the observations and conclude the report on a meaningful note. These experiments are very critical and in the case of failure, may result in disastrous consequences. Thereby, I would like to thank both Mrs.Belani and Lab Asst.Mr.Rajkumar for guiding me on a step by step basis and ensuring that I completed all my experiments with ease. Rigorous hard work has been put in this project to ensure that it proves to be the best. I hope that this project will prove to be a breeding ground for the next generation of students and will guide them in every possible way. Need of water Water is an important and essential ingredient in our quest for survival on this planet. It is very essential for carrying out various metabolic processes in our body and also to carry out Hemoglobin throughout the body. A daily average of 1 gallon per man is sufficient for drinking and cooking purposes. A horse, bullock, or mule drinks about 11 gallons at a time. standing up, an average allowance of 5 gallons should be given for a man, and 10 gallons for a horse or a camel. An elephant drinks 25 gallons, each mule or ox drinks 6 to 8 gallons, each sheep or pig 6 to 8 pints. These are minimum quantities. One cubic foot of water = 6 gallons (a gallon = 10 lbs.). In order to fulfill such a huge demand of water, it needs to be purified and supplied in a orderly and systematic way. But with the increasing world population, the demand for drinking water has also increased dramatically and therefore it is very essential to identify resources of water from which we can use water for drinking purposes. Many available resources of water do not have it in drinkable form. Either the water contains excess of Calcium or Magnesium salts or any other organic impurity or it simply contains foreign paruen
To study in detail about water purification techniquesSumit Tiwari
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Evolution of Drinking Water Quality and its Filtration Process in India.pptxkitz filters
Though the home-based water filtration process in the form of boiling water was adopted, it was not totally a success. Slowly, with time; a Drinking water filter got introduced in the market which proved to be a boon. The purified form of water was not only popular for domestic purposes but also helpful in increasing the longevity of appliances.
Water :the universal need. As we all know water is most essential component to mankind yet its quality is in hazardous state and quantity is declining. This slide contains crucial information about water purification systems like what happens to water before we get it I'm our home?!
Water Quality and Contamina on 22 Usable wate.docxcelenarouzie
Water Quality and Contamina on
22
Usable water
Ground water
Surface water
Ground water contaminates
Water treatment
Drinking water quality
Figure 1: At any given moment, 97% of the planet’s water is in oceans. Only a small fraction of
the remaining freshwater is usable by humans, underscoring the importance of treating our wa-
ter supply with care.
It is no secret that water is one of the most valuable resources on Earth. Every plant and animal requires wa-
ter to survive, not only for drinking, but also for food production, shelter creation, and many other necessities.
Water has also played a major role in transforming the earth’s surface into the varied topography we see to-
day.
While more than 70% of our planet is covered in water, only a small percentage of this water is usable fresh-
water. The other 99% of water is composed primarily of salt water, with a small percentage being composed
23
of glaciers. Due to the high costs involved in transforming salt water into freshwater, the earth’s population
survives off the less than 1% of freshwater available. Humans obtain freshwater from either surface water or
groundwater.
Surface water is the water that collects on the ground as a result of precipitation. The water that does not
evaporate back into the atmosphere or infiltrate into the ground is typically collected in rivers, lakes, reser-
voirs, and other bodies of water, making it easily accessible.
Groundwater, on the other hand, is located underneath the ground. This water is stored in pores, fractures,
and other spaces within the soil and rock underneath the surface. Precipitation, along with snowmelt, infil-
trates through the ground and accumulates in available underground spaces.
Aquifers are areas in which water collects in sand, gravel, or permeable rock from which it can be extracted
for usable freshwater. The depth of aquifers varies from less than 50 feet to over 1,500 feet below the sur-
face. The water within an aquifer typically does not flow through, as it would through a river or stream, but in-
stead soaks into the underground material, similar to a sponge. As aquifers are depleted by human use, they
are also recharged from precipitation seeping into the ground and restoring the water level. However, many
times the recharge of the aquifers does not equal the amount of water that has been extracted. If that cycle
continues, the aquifer will eventually dry up and will no longer be a viable source of groundwater.
Evapora on
Cloud forma on
Precipita on
Groundwater
Evapora on
Transpira on
Precipita on
Precipita on
Figure 2: Water is a renewable source, purified and
delivered across the planet by the hydrological cycle.
24
While the water that precipitates in the form of rain is relatively pure, it does not take long for it to pick up con-
taminants. There are natural, animal, and human-made sources of water pollutants. They c.
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1. STERILIZATION OF WATER USING BLEACHING
POWDER
A CHEMISTRY INVESTIGATORY PROGECT
ANSHUL KUMAR PANDEY XII B
PTHIS PROJECT LOOKS AT THE TECHNIQUE CALLED STERILIZATION OF
WATER USING BLEACHING POWDER WHICH IS USED TO PURIFY WATER
AND MAKES IT FIT FOR
DRINKING.]
INDEX
1. Certificate of Authenticity
2. Acknowledgement
3. Introduction
-Need of Water
-Purification of Water
-Need for a stable purification technique
4. Theory
-History of Water purification
-Bleaching powder and its preparation
-Use of Bleaching powder in Sterilization of water
5. Experiment
-Aim
-Pre-Requisite Knowledge
-Requirements
-Procedure
1. Result
2. Bibliography
CERTIFICATE OF AUTHENTICITY
2. This is to certify that Anshul Kumar Pandey, a student of class XII has successfully
completed the research project on the topic “Sterilization of Water by using Bleaching
Powder” under the guidance of Mrs. Mohini Belani (Subject Teacher).
This project is absolutely genuine and does not indulge in plagiarism of any kind.
The references taken in making this project have been declared at the end of this report.
Signature ( Subject Teacher)
Signature ( Examiner)
ACKNOWLEDGEMENT
I feel proud to present my Investigatory project in Chemistry on the topic “Sterilization of
Water using Bleaching powder” which aims at using Bleaching powder as a disinfectant and
purifier to make water fit for drinking.
This project wouldn’t have been feasible without the proper and rigorous guidance of my
Chemistry teacher Mrs. Mohini Belani who guided me throughout this project in every
possible way. An investigatory project involves various difficult lab experiments which have
to be carried out by the student to obtain the observations and conclude the report on a
meaningful note. These experiments are very critical and in the case of failure, may result in
disastrous consequences. Thereby, I would like to thank both Mrs.Belani and Lab
Asst.Mr.Rajkumar for guiding me on a step by step basis and ensuring that I completed all
my experiments with ease.
Rigorous hard work has been put in this project to ensure that it proves to be the best. I hope
that this project will prove to be a breeding ground for the next generation of students and
will guide them in every possible way.
Needof water
Water is an important and essential ingredient in our quest for survival on this planet. It is
very essential for carrying out various metabolic processes in our body and also to carry out
Hemoglobin throughout the body.
A daily average of 1 gallon per man is sufficient for drinking and cooking purposes. A horse,
bullock, or mule drinks about 11 gallons at a time. standing up, an average allowance of 5
gallons should be given for a man, and 10 gallons for a horse or a camel. An elephant drinks
25 gallons, each mule or ox drinks 6 to 8 gallons, each sheep or pig 6 to 8 pints. These are
minimum quantities.
One cubic foot of water = 6 gallons (a gallon = 10 lbs.).
In order to fulfill such a huge demand of water, it needs to be purified and supplied in a
orderly and systematic way.
But with the increasing world population, the demand for drinking water has also increased
dramatically and therefore it is very essential to identify resources of water from which we
can use water for drinking purposes. Many available resources of water do not have it in
3. drinkable form. Either the water contains excess of Calcium or Magnesium salts or any other
organic impurity or it simply contains foreign particles which make it unfit and unsafe for
Drinking.
Purification of Water
There are many methods for the purification of water. Some of them are
1. Boiling
2. Filtration
3. Bleaching powder treatment
4. SODIS (Solar Water Disinfection) And the list goes on….
Boiling is perhaps the most commonly used water purification technique in use today. While
in normal households it is an efficient technique; it cannot be used for industrial and large
scale purposes. It is because in normal households, the water to be purified is very small in
quantity and hence the water loss due to evaporation is almost negligible. But in Industrial or
large scale purification of water the water loss due to evaporation will be quite high and the
amount of purified water obtained will be very less.
Filtration is also used for removing foreign particles from water. One major drawback of this
purification process is that it cannot be used for removing foreign chemicals and impurities
that are miscible with water.
SODIS or Solar Water Disinfection is recommended by the United Nations for
disinfection of water using soft drink bottles, sunlight, and a black surface– at least in
hot nations with regularly intense sunlight.
Water-filled transparent bottles placed in a horizontal position atop a flat surface in strong
sunlight for around five hours will kill microbes in the water. The process is made even more
safe and effective if the bottom half of the bottle or the surface it’s lying on is blackened,
and/or the flat surface is made of plastic or metal. It’s the combination of heat and ultraviolet
light which kills the organisms.
The major drawback of this purification technique is that it cannot be used in countries with
cold weather. Also, the time consumed for Purification process is more and it also needs a
‘blackened’ surface, much like solar cookers.
Needfor a stable purification technique
Therefore we need a purification technique which can be used anytime and anywhere, does
not require the use of any third party content and which is also economically feasible on both
normal scale and large scale.
Hence we look at the method of purification of water using the technique of treatment by
bleaching powder commonly known as “Chlorination”.
THEORY
History of water purification in different parts of the world.
4. In 1854 it was discovered that a cholera epidemic spread through water. The outbreak seemed
less severe in areas where sand filters were installed. British scientist John Snow found that
the direct cause of the outbreak was water pump contamination by sewage water. He applied
chlorine to purify the water, and this paved the way for water disinfection. Since the water in
the pump had tasted and smelled normal, the conclusion was finally drawn that good taste
and smell alone do not guarantee safe drinking water. This discovery led to governments
starting to install municipal water filters (sand filters and chlorination), and hence the first
government regulation of public water.
In the 1890s America started building large sand filters to protect public health. These turned
out to be a success. Instead of slow sand filtration, rapid sand filtration was now applied.
Filter capacity was improved by cleaning it with powerful jet steam. Subsequently, Dr. Fuller
found that rapid sand filtration worked much better when it was preceded by coagulation and
sedimentation techniques. Meanwhile, such waterborne illnesses as cholera and typhoid
became less and less common as water chlorination won terrain throughout the world.
But the victory obtained by the invention of chlorination did not last long. After some time
the negative effects of this element were discovered. Chlorine vaporizes much faster than
water, and it was linked to the aggravation and cause of respiratory disease. Water experts
started looking for alternative water disinfectants. In 1902 calcium hypo chlorite and ferric
chloride were mixed in a drinking water supply in Belgium, resulting in both coagulation and
disinfection.
The treatment and distribution of water for safe use is one of the greatest achievements of the
twentieth century. Before cities began routinely treating drinking water with chlorine (starting
with Chicago and Jersey City in US in 1908), cholera, typhoid fever, dysentery and hepatitis
A killed thousands of U.S. residents annually. Drinking water chlorination and filtration have
helped to virtually eliminate these diseases in the U.S. and other developed countries.
Meeting the goal of clean, safe drinking water requires a multi-barrier approach that includes:
protecting source water from contamination, appropriately treating raw water, and ensuring
safe distribution of treated water to consumers’ taps. During the treatment process, chlorine is
added to drinking water as elemental chlorine (chlorine gas),
sodium hypochlorite solution or dry calcium hypochlorite. When applied to water, each
of these forms “free chlorine,” which destroys pathogenic (disease-causing) organisms.
Almost all systems that disinfect their water use some type of chlorine-based process,
either alone or in combination with other disinfectants. In addition to
controlling disease-causing organisms, chlorination offers a number of benefits
including:
Reduces many disagreeable tastes and odors;
Eliminates slime bacteria, molds and algae that commonly grow in water supply
reservoirs, on the walls of water mains and in storage tanks;
Removes chemical compounds that have unpleasant tastes and hinder disinfection;
and
5. Helps remove iron and manganese from raw water.
As importantly, only chlorine-based chemicals provide “residual disinfectant” levels that
prevent microbial re-growth and help protect treated water throughout the distribution
system.
For more than a century, the safety of drinking water supplies has been greatly improved by
the addition of bleaching powder. Disinfecting our drinking water ensures it is free of the
microorganisms that can cause serious and life-threatening diseases, such as cholera and
typhoid fever. To this day, bleaching powder remains the most commonly used drinking
water disinfectant, and the disinfectant for which we have the
most scientific information. Bleaching powder is added as part of the drinking water
treatment process. However, bleaching powder also reacts with the organic matter, naturally
present in water, such as decaying leaves. This chemical reaction forms a group of chemicals
known as disinfection by-products. Current scientific data shows that the benefits of
bleaching our drinking water (less disease) are much greater than any health risks from
THMs and other by-products. Although other disinfectants are available, bleaching powder
remains the choice of water treatment experts. When used with modern water filtration
methods, chlorine is effective against virtually all microorganisms. Bleaching powder is easy
to apply and small amounts of the chemical remain in the water as it travels in the distribution
system from the treatment plant to the consumer’s tap, this level of effectiveness ensures that
microorganisms cannot recontaminate the water after it leaves the treatment.
But what is bleaching powder and how is it prepared?
Bleaching powder or Calcium hypochlorite is a chemical compound with formula Ca(ClO) 2.
It is widely used for water treatment and as a bleaching agent bleaching powder). This
chemical is considered to be relatively stable and has greater available chlorine than sodium
hypochlorite (liquid bleach).
It is prepared by either calcium process or sodium process. Calcium Process
2 Ca(OH)2 + 2 Cl2 Ca(ClO)2 + CaCl2 + 2 H2O Sodium Process
2 Ca(OH)2 + 3 Cl2 + 2 NaOH Ca(ClO)2 + CaCl2 + 2 H2O + 2 NaCl
But how can this chemical be used to sterilize water?
This chemical can be used for sterilizing water by Using 5 drops of bleach per each half
gallon of water to be purified, and allowing it to sit undisturbed for half an hour to make it
safe for drinking. Letting it sit several hours more will help reduce the chlorine taste, as the
chlorine will slowly evaporate out. A different reference advises when using household
bleach for purification; add a single drop of bleach per quart of water which is visibly clear,
or three drops per quart of water where the water is NOT visibly clear. Then allow the water
to sit undisturbed for half an hour.
What are the actual processes involved in disinfecting and purifying water?
6. The combination of following processes is used for municipal drinking water treatment
worldwide:
1. Pre-chlorination – for algae control and arresting any biological growth
2. Aeration – along with pre-chlorination for removal of dissolved iron and manganese
3. Coagulation – for flocculation
4. Coagulant aids also known as polyelectrolyte’s – to improve coagulation and for
thicker floc formation
5. Sedimentation – for solids separation, that is, removal of suspended solids trapped in
the floc
6. Filtration – for removal of carried over floc
7. Disinfection – for killing bacteria
Out of these processes, the role of Bleaching powder is only in the last step i.e. for
Disinfection of water.
EXPERIMENT
Aim: To Determine the dosage of bleaching powder required for sterilization or
disinfection of different samples of water.
Requirements: Burette, titration flask, 100ml graduated cylinder, 250ml measuring flask,
weight box, glazed tile, glass wool.
Bleaching Powder, Glass wool, 0.1 N Na2S2O3 solution, 10% KI solution, different samples
of water, starch solution.
Pre-Requisite Knowledge:
1. A known mass of the given sample of bleaching powder is dissolved in water to
prepare a solution of known concentration. This solution contains dissolved chlorine,
liberated by the action of bleaching powder with water.
CaOCl2+H20 I >> Ca(OH)2+Cl2
2. The amount of Chlorine present in the above solution is determined by treating a
known volume of the above solution with excess of 10% potassium iodide solution,
when equivalent amount of Iodine is liberated. The Iodine, thus liberated is then
estimated by titrating it against a standard solution of Sodium thiosulphate, using
starch solution as indicator.
Cl2+2KI i > 2KCl+I2
I2+2Na2S2O3 i > Na2S4O6+2NaI
1. A known Volume of one of the given samples of water is treated with a known
volume of bleaching powder solution. The amount of residual chlorine is determined
by adding excess potassium iodide solution and then titrating against standard sodium
thiosulphate solution.
7. 2. From the readings in 2 and 3, the amount of chlorine and hence bleaching powder
required for the disinfection of a given volume of the given sample of water can be
calculated.
Procedure:
1. Preparation of bleaching powder solution. Weigh accurately 2.5g of the given sample
of bleaching powder and transfer it to a 250ml conical flask. Add about 100-150ml of
distilled water. Stopper the flask and shake it vigorously. The suspension thus
obtained is filtered through glass wool and the filtrate is diluted with water (in a
measuring flask) to make the volume 250ml. The solution obtained is 1% bleaching
powder solution.
2. Take 20ml of bleaching powder solution in a stoppered conical flask and add it to
20ml of 10% KI solution. Stopper the flask and shake it vigorously. Titrate this
solution against 0.1N Na2S2O3 solution taken in the burette. When the solution in the
conical flask becomes light yellow in color, add about 2ml starch solution. The
solution now becomes blue in color. Continue titrating till the blue color just
disappears. Repeat the titration to get a set of three concordant readings.
3. Take 100ml of the water sample in a 250ml stoppered conical flask and add it to 10ml
of bleching powder solution. Then add 20ml of KI solution and stopper the flask.
Shake vigorously and titrate against 0.1N Na2S2O3 solution using starch solution as
indicator as described in step 2.
4. Repeat the step 3 with other samples of water and record the observations.
RESULT
Amount of the given sample of bleaching powder required to disinfect one litre of water
Sample I =……….. g
Sample II=……….. g
Sample III=……….. g
BIBLIOGRAPHY
1.The Medical front-”Water Supply” http://www.vlib.us/medical/sancamp/water.htm
2. “Chemistry Projects” http://www.icbse.com
3.How to live on Very,Very Little-”Clean drinking water: How to develop low cost sources
of drinking water just about anywhere”
http://www.jmooneyham.com/watp.html
4.Calcium Hypochloride http://en.wikipedia.org/wiki/Bleaching_powder
5.Water Treatment http://en.wikipedia.org/wiki/Water_treatment
6.Bleach
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Extension, New York State College of Human Ecology,USA
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www.awwa.org/Advocacy/bluethumb98/consumer.cfm
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16.DISINFECTING YOUR WELL WATER: SHOCK CHLORINATION
http://www.fcs.uga.edu/pubs/PDF/HACE-858-4.pdf