Project Of 

Chemistry
Steriliz ation Of Water By
Sterilization
Using Bleaching Powder
 This Project
Project deals with the process
process of
purifying water and make it t for drinking
y the
the techni!ue
techni!ue called
called Sterilization of
Water using Bleaching Powder

TRIBHUWAN KUMAR
 A CHEMISTR
CHEMISTRY
Y INVESTIGA
INVESTIGATOR
TORY
Y PROJECT 
PROJECT 
B" ## T$%B&UW'( )U*'$

+lass #,%%
 Index
J +erticate Of 'uthenticity
J 'cknowledgement
J %ntroduction
 (eed Of Water
 Purication of Water
 (eed for a stale purication technology
J  Theory
 &istory Of water purication
 Bleaching powder and its preparation
 Use of Bleaching powder in sterilization of water
J -.periment
 'im
 Pre#re!uisite )nowledge
 $e!uirement
 Procedure
J $esult
J Biliography

+erticate Of 'uthenticity
certify that TRIBHUWAN KUMAR of class ,%% has
 This is to certify
project on the topic / Sterii!"tion of
successfully completed this project
W"ter #y $sin% Be"chin% Po&der 0 under the guidance of *$1
 T1(1
 T1(1 2&' 3 *$1
*$1 S1 S'$)'$1
S'$)'$1
 This Project
Project is asolutely genuine and does not indulge plagiarism
plagiarism
of any kind1

 The reference
reference taken
taken in mailing this project
project has een declared
declared at
at
the end of this pro44ject1

%nternal Signature5#

-.ternal Signature5#
Signature5#

'cknowledgement
% feel proud to present my project in +hemistry on the topic
/Sterii!"tion of W"ter #y $sin% Be"chin% Po&der 01
 This project
project wouldn6t ha7e een completed without
without the proper
proper
guidance of my +hemistry teacher *$1T( 2&' who guided me
throughout this project in e7ery possile way1 ' project in7ol7es
7arious di8cult la e.periments
e.periments which ha7e to e carried out y
the student to otain the oser7ation and conclude the report on a
meaningful note1 These e.periments are 7ery critical and in case
of failure9 may result in disastrous conse!uences1 Therey % would
like to thank *$1 T( 2&' for guiding me on a step y step asic
and ensuring that % completed all my e.periment
e.periment with ease1

% would also like to thank *r1 S1S'$)'$ and *$ P$':&'( for their
7ital support and co#operation1

't last % would like to thank my parents and all those without
whom this project would not ha7e een completed1

%ntroduction
Need of &"ter
Water is an important and essential ingredient in our !uest forfo r sur7i7al on
this planet1 %t is 7ery essential for carrying out 7arious metaolic processes
in our ody and also to carry out &emogloin throughout the ody1 ody1

' daily a7erage of ; gallon per man is su8cient for drinking and cooking
purposes1 ' horse9 ullock9 or mule drinks aout ;; gallons at a time1
Standing up9 an a7erage allowance of < gallons should e gi7en for a man9
and ;4 gallons for a horse or a camel1 'n elephant drinks =< gallons9 each
mule or o. drinks > to ? gallons9 each sheep or pig > to ? pints1 These are
minimum !uantities1

One c$#ic foot of &"ter ' ( %"ons )" %"on ' *+ #s,- 1

%n order to fulll such a huge demand of water9 it needs to e puried and

supplied in a orderly and systematic way1

But with the increasing world population9 the demand for drinking water has
also increased dramatically and therefore it is 7ery essential to identify
resources
resources of water from which we can use water for drinking purposes1
*any a7ailale resources of water do not ha7e it in drinkale form1 -ither
the water contains e.cess of +alcium or *agnesium salts or any other
organic impurity or it simply contains foreign particles which make it unt
and unsafe for :rinking1
P$ri.c"tion of W"ter
 There are many methods for the purication
purication of water1
water1 Some of them are
are

 Boiling
 @iltration
 Bleaching powder treatment
 SO:%S ASolar Water :isinfection

*, Boiin%
Boiling is perhaps the most commonly used water purication techni!ue in
use today1
today1 While in normal households it is an e8cient techni!ueC it cannot
can not
e used for industrial and large scale purposes1 %t is ecause in normal
households9 the water to e puried is 7ery small in !uantity and hence the
water loss due
due to e7aporation is
is almost negligile1
negligile1 But in %ndustrial or large
scale purication of water the water loss due to e7aporation will e !uite
high and the amount of puried water otained will e 7ery less1

 /, 0itr"tion
@iltration is also used for remo7ing foreign particles from water1 One major
drawack of this purication process is that it cannot e used for remo7ing
foreign chemicals and impurities that are miscile with water1

1, SO2IS )So"r W"ter 2isinfection-

SO:%S or Solar Water :isinfection is recommended y the United (ations for
disinfection of water using soft drink ottles9 sunlight9 and a lack surface##
surf ace##
at least in hot nations with regularly intense sunlight1

Water#lled
ater#lled transparent ottles placed in a horizontal position atop a Dat
surface in strong sunlight for around 7e hours
h ours will kill microes in the
water1
water1 The process is made e7en more safe and eEecti7e if the ottom half
of the ottle or the surface itFs lying on is lackened9 andGor the Dat surface
is made of plastic or metal1 %tFs the comination of heat and ultra7iolet light
which kills the organisms1
 The major drawack of this purication
purication techni!ue is that it cannot e used
in countries with cold weather1
weather1 'lso9 the time consumed for Purication
process is more and it also needs a Hlackened6 surface9 much like solar
cookers1

Need for " st"#e 3$ri.c"tion techni4$e

 Therefore we need a purication techni!ue
techni!ue which can e used anytime and
anywhere9 does not re!uire the use of any third party content and which is
also economically feasile on oth normal scale and large scale1

&ence we look at the method of purication of water using the techni!ue of

treatment y leaching powder commonly known as / Chorin"tion01

Theory

History of &"ter 3$ri.c"tion in

i n di5erent 3"rts
of the &ord,
%n ;?<I it was disco7ered that a cholera epidemic spread
spread through water1
water1 The
outreak seemed less se7ere in areas where sand lters were installed1
British scientist 2ohn Snow found that the direct cause of the outreak was
water pump contamination y sewage water1
water1 &e applied chlorine to purify
the water9 and this pa7ed the way for water disinfection1 Since the water in
the pump had tasted and smelled normal9 the conclusion was nally drawn
that good taste and smell alone do not guarantee safe drinking water1
water1 This
disco7ery led to go7ernments starting to install municipal water lters Asand
lters and chlorination9 and hence the rst go7ernment regulation of pulic
water1
%n the ;?J4s 'merica started uilding large sand lters to protect pulic
health1 These turned out to e a success1 %nstead of slow sand ltration9
rapid sand ltration was now applied1 @ilter
@ilter capacity was impro7ed y
cleaning it with powerful jet steam1 Suse!uently9 :r1
:r1 @uller found that rapid
sand ltration worked much etter when it was preceded y coagulation
and sedimentation techni!ues1 *eanwhile9 such waterorne illnesses as
cholera and typhoid ecame less and less common as water chlorination
won terrain throughout the world1

But the 7ictory otained y the in7ention of chlorination did not last long1
'fter
'fter some time the negati7e eEects of this element were disco7ered1
+hlorine 7aporizes much faster than water9 and it was linked to the
aggra7ation and cause of respiratory disease1 Water
Water e.perts started looking
for alternati7e water disinfectants1 %n ;J4= calcium hypo chlorite and ferric
chloride were mi.ed in a drinking water supply in Belgium9 resulting in oth
coagulation and disinfection1

 The treatment and distriution of water for safe

safe use is one of the greatest
greatest
achie7ements of the twentieth century1 Before cities egan routinely
treating drinking water with chlorine Astarting with +hicago and 2ersey +ity
in US in ;J4?9 cholera9 typhoid fe7er9 dysentery and hepatitis ' killed
thousands of U1S1 residents annually1
annually1 :rinking water chlorination and
ltration ha7e helped to 7irtually eliminate these diseases in the U1S1 and
other de7eloped countries1 *eeting the goal of clean9 safe drinking water
re!uires
re!uires a multi#arrier approach that includes5 protecting source water
from contamination9 appropriately treating raw water9 and ensuring safe
distriution of treated water to consumers6 taps1 :uring the treatment
process9 chlorine is added to drinking water as elemental chlorine Achlorine
gas9 sodium hypochlorite solution or dry calcium hypochlorite1 When
applied to water9 each of these forms /free chlorine90 which destroys
pathogenic Adisease#causing organisms1 'lmost all systems that disinfect
their water use some type of chlorine#ased process9 either alone or in
comination with other disinfectants1 %n addition to controlling disease#
causing organisms9 chlorination oEers a numer of enets including5 K
$educes
$e duces many disagreeale tastes and odorsC K -liminates slime acteria9
molds and algae that commonly grow in water supply reser7oirs9 on the
walls of water mains and in storage tanksC K $emo7es chemical compounds
that ha7e unpleasant tastes and hinder disinfectionC and K &elps remo7e
iron and manganese from raw water1
water1 's importantly9 only chlorine#ased
chemicals pro7ide /residual disinfectant0 le7els that pre7ent microial re#
growth and help protect treated water throughout the distriution system1

@or more than a century9 the safety of drinking water supplies has een
greatly impro7ed y the addition of leaching powder1
powder1 :isinfecting our
drinking water ensures it is free of the microorganisms that can cause
serious and life#threatening diseases9 such as cholera and typhoid fe7er1 To
this day9 leaching powder remains the most commonly used drinking water
disinfectant9 and the disinfectant for which we ha7e the most scientic
information1 Bleaching powder is added as part of the drinking water
treatment process1
process1 &owe7er9 leaching powder also reacts with the organic
matter9 naturally present in water9 such as decaying lea7es1 This chemical
reaction forms a group of chemicals known as disinfection y#products1
+urrent scientic data shows that the enets of leaching our drinking
water Aless disease are much greater than any health risks from T&*s and
other y#products1 'lthough other disinfectants are a7ailale9 leaching
powder remains the choice of water treatment e.perts1 When used with
modern water ltration methods9 chlorine is eEecti7e against 7irtually all
microorganisms1
microorganisms1 Bleaching powder is easy to apply and small amounts of
the chemical remain in the water as it tra7els in the distriution system
from the treatment plant to the consumer6s tap9 this le7el of eEecti7eness
ensures that microorganisms cannot recontaminate the water after it lea7es
the treatment1

Wh"t is #e"chin% 3o&der "nd ho& is it

3re3"red6
Bleaching powder or +alcium hypochlorite is a chemical compound with
formula +aA+lO=1 %t is widely used for water treatment and as a
leaching agent leaching powder1 This chemical is considered to e
relati7ely stale and has greater a7ailale chlorine than sodium
hypochlorite Ali!uid leach1

%t is prepared y either calcium process or sodium process1

+alcium Process

= +aAO&= L = +l=M+aA+lO= L +a+l= L = &=O

Sodium Process

= +aAO&= L N +l= L = (aO&M+aA+lO= L +a+l= L = &=O L = (a+l

Ho& c"n this chemic" #e $sed to sterii!e

&"ter6
 This chemical can e used for sterilizing water y Using
Using < drops of leach
leach
per each half gallon of water to e puried9 and allowing it to sit
undistured for half an hour
h our to make it safe for drinking1 etting it sit se7eral
hours more will help reduce the chlorine taste9 as the chlorine will slowly
e7aporate out1 ' diEerent reference ad7ises when using household leach
for puricationC add a single drop of leach per !uart of water which is
7isily clear9 or three drops per !uart of water where the water is (OT
7isily clear1
clear1 Then allow the water to sit undistured for half an hour1
hour1

Wh"t "re the "ct$" 3rocesses in7o7ed in

disinfectin% "nd 3$rifyin% &"ter6
 The comination of following processes
processes is used for municipal drinking water
water
treatment worldwide5

;1 Pre#chlorination # for algae control and arresting any iological growth

=1 'eration # along with pre#chlorination for remo7al of dissol7ed iron and

manganese

N1 +oagulation # for Docculation

I1 +oagulant aids also known as polyelectrolyte6s

polyelectrolyte6s # to impro7e coagulation
and for thicker
thicker Doc formation
<1 Sedimentation # for solids separation9 that is9 remo7al of suspended solids
trapped in the Doc

>1 @iltration
@iltration # for remo7al of carried o7er Doc

1 :isinfection # for killing acteria

Out of these processes9 the role of Bleaching powder is only in the last step
i1e1 for :isinfection of water1

-.periment
Aim8
 To
 To determine the
the dosage of leaching powder
powder re!uired
re!uired for sterilization or
disinfection of diEerent samples of water1

Re4$irements8
Burette9 titration Dask9 ;44ml graduated cylinder9 =<4ml measuring Dask9
Da sk9
weight o.9 glazed tile9 glass wool1

Bleaching Powder9
Powder9 Qlass wool9 41; ( (a =S=ON solutions9 ;4R )% solution9
diEerent samples of water9 starch solution1

Pre9Re4$isite Kno&ed%e8
;1 ' known mass of the gi7en sample of leaching powder is dissol7ed in
water to prepare a solution of known concentration1 This solution contains
dissol7ed chlorine9 lierated y the action of leaching powder with water1
water1

+aO+l=L&=4 +aAO&=L+l=
 =1 The amount of +hlorine present in the ao7e solution is determined y
treating a known 7olume of the ao7e solution with e.cess
e.cess of ;4R
potassium iodide solution9 when e!ui7alent amount of %odine is lierated1
 The %odine9 thus lierated is then estimated y titrating it against a standard
solution of Sodium thiosulphate9 using starch solution as indicator
in dicator11

+l=L=)% =)+lL%=

%=L=(a=S=ON (a=SIO>L=(a%

N1 ' known olume

olume of one of the gi7en samples of water is treated with a
known 7olume of leaching powder solution1 The amount of residual
chlorine is determined y adding e.cess potassium iodide solution and then
titrating against standard sodium thiosulphate solution1 I1 @rom the readings
in = and N9 the amount of chlorine and hence leaching powder re!uired
re!uired for
the disinfection of a gi7en 7olume of the gi7en sample of water can e
calculated1

Proced$re8
;1 Preparation of leaching powder solution1 Weigh accurately =1<g of the
gi7en sample of leaching powder and transfer it to a =<4ml conical Dask1
'dd aout ;44#;<4ml of distilled water1 Stopper the Dask and shake it
7igorously1 The suspension thus otained is ltered through glass wool and
the ltrate is diluted with water Ain a measuring Dask to make the 7olume
=<4ml1 The solution otained is ;R leaching powder solution1

=1 Take =4ml of leaching powder solution in a Stoppard conical Dask and

add it to =4ml of ;4R )% solution1 Stopper the Dask and shake it 7igorously1
 Titrate this solution against 41;( (a=S=ON solution taken in the urette1
When the solution in the conical Dask ecomes light yellow in color9 add
aout =ml starch solution1 The solution now ecomes lue in color1 color1 +ontinue
titrating till the lue color just disappears1 $epeat
$epeat the titration to get a set of 
o f 
three concordant readings1

N1 Take ;44ml of the water sample in a =<4ml Stoppard conical Dask and
add it to ;4ml of leaching powder solution1 Then add =4ml of )% solution
and stopper the Dask1 Shake 7igorously and titrate against 41;( (a =S=ON
solution using starch solution as indicator as descried in step =1
I1 $epeat the step N with other samples of water and record the
oser7ations1

Res$t89
'mount of the gi7en sample of leaching powder re!uired to disinfect one
litre of water

Sample %  g

Sample %% g

Sample %%% g

Biliography
;1+alcium &ypochloride

http5GGen1wikipedia1orgGwikiGB
http5GGen1wikipedia1orgGwikiGBleachingVpowder
leachingVpowder

=1Water Treatment

http5GGen1wikipedia1orgGwikiGWaterVtreatment

N1Bleach

http5GGen1wikipedia1orgGwikiGBleach

I1:rinking Water Treatment5+ontinuous +hlorination

http5GGwww1ianrpus1unl1eduGepulicGpage
http5GGwww1ianrpus1unl1eduGepulicGpagesGpulication:1jsp
sGpulication:1jsp
pulication%dN<?
<1+hlorination of :rinking Water
Water

http5GGwww1water#research1netGwatertreatmentGchlorination1htm

>1+hlorination Of :rinking Water

www1edstrom1comGdocliGmiI;I1pdf 

1X:rinking Water Standards9X

www1epa1go7GsafewaterGmcl1html

?1 :%S%(@-+T%(Q "OU$ W- W'T-$5 S&O+) +&O$%('T%O(

http5GGwww1fcs1uga1eduGpusGP:@G&'
http5GGwww1fcs1uga1eduGpusGP:@G&'+-#?<?#I1pdf
+-#?<?#I1pdf i