This document provides information on water purification methods at different scales. On a large scale, water is purified through storage, sedimentation, filtration (rapid sand and slow sand), and disinfection (usually chlorination). On a medium scale, adding bleach or chlorinated lime is common. On a small scale, boiling, distillation, and adding chemicals like bleach or iodine can purify water. The document also discusses rapid sand filtration versus slow sand filtration and different water quality testing standards.
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 purification methods are very necessary at industrial level. Its also necessary to purify water for drinking purpose and its use in agricultural areas.
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
Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water.
what is waterborne diseases? example,types of water borne diseases,disease pathway,route of infection,how climate control water borne disease trends,case study of cholera in south asia,application of remote sensing on study of waterborne diseases
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
A well is a dug hole on the ground which contains water and is maintained for drinking, domestic and other purposes.
There are two (2) main types of wells, namely: shallow well and deep well.
Shallow wells are dug into soils with pickaxe and shovels and are generally not more than 15m deep. They do not penetrate the bedrock found more deeply in the ground.
Deep wells are excavated over 30m deep. They also go beyond the bedrock into the confined aquifer
in the study of the breakpoints chlorination. what is the chlorine break point and how it is measures etc are questions is started in your mind. but in this slide we discussing about that questions.the advantages and disadvantages of the breackpoint clorination is very important.
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
Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water.
what is waterborne diseases? example,types of water borne diseases,disease pathway,route of infection,how climate control water borne disease trends,case study of cholera in south asia,application of remote sensing on study of waterborne diseases
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
A well is a dug hole on the ground which contains water and is maintained for drinking, domestic and other purposes.
There are two (2) main types of wells, namely: shallow well and deep well.
Shallow wells are dug into soils with pickaxe and shovels and are generally not more than 15m deep. They do not penetrate the bedrock found more deeply in the ground.
Deep wells are excavated over 30m deep. They also go beyond the bedrock into the confined aquifer
in the study of the breakpoints chlorination. what is the chlorine break point and how it is measures etc are questions is started in your mind. but in this slide we discussing about that questions.the advantages and disadvantages of the breackpoint clorination is very important.
New Technologies for Water Purification, Ion Exchange(India) LimitedIndia Water Portal
Presentation at the Seminar on Packaged Water Industry in India which was organised by Confederation of Indian Industry (CII) on 30th June 2009.
To know more click on the link http://indiawaterportal.org/post/6790
We thank CII and the presenters for giving us permission to make these presentations available online.
Introduction:
India, continue to lack behind in Sanitation; where the Prime Minister in recent past have taken appreciable initiatives to improve the Sanitation through his Clean India Campaign. One of Key components, looked upon in Clean India Campaign is Eradication of Open Air Defecation. It is estimated that nearly 636 million Indians lack toilets and about 70% of Population in Rural & Semi Urban India, defecate in Open. Though efforts are being taken by many government Initiatives; where subsidies are provided for construction of sanitary toilets/latrines at household level, the progress is very much slow in achieving total sanitation in India. This is mainly due to many myths and misconceptions related to Sanitary Toilets in rural India. Some of the notable Myths and Misconceptions are
Having Toilets at Home could smell awfully.
It needs lot of water to clean the toilet
Its more comfortable, pleasurable and convenient to defecate in open
Toilet is not Socio-Culturally acceptable at home
The size of the Pit ( Leech Pit) is not enough for the family and it would fill easily leading to burdens in cleaning the pit
Having a leech pit sanitary latrine at home could bring disputes with neighbors
Having a toilet at home would cost a lot of money
Septic tank is the right design than Leech Pit
The pits might over flow during rainy season
As looked upon above, irrespective of various schemes, initiatives and efforts by government and Non- government organization, to achieve 100% sanitation in India, tremendous efforts should be made to change the Knowledge, Attitude, Behaviour and Practices ( KABP) of rural masses towards affordability and usage of Sanitary Toilets. At this juncture, NALANTHA EDUCAITONAL TRUST appeals for support of benevolence for promoting toilets in rural hamlets of Tamilnadu, along with government Initiatives for construction and Usage of Toilet; for a cleaner and healthier India.
Water Purification Plant ManufacturersManish Yadav
View comprehensive and updated listings of water purification plants, water purification plants manufacturers, water purification plants exporters with detailed company profile and contact details.
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?!
Components of Water Treatment Plant, Methods of Water Treatment, Process of Water Treatment such as Aeration, Sedimentation, Filtration and Disinfection etc.
WATER
In 1981, the 34th Word Health Assembly in a resolution emphasized that safe drinking water is a basic element for “primary health care” which is the key to the attainment of “Health for All by the year 2000 AD.”
More recently, Millennium Development Goals included safe water and sanitation in the attainable goals.
In 1990, more than 1 billion people in developing world lacked access to safe drinking water and nearly 2 billion lacked an adequate system for disposing off their excreta.
POTABLE WATER
Also called as “Safe and Wholesome Water”
Defined as water that is
Free from pathogenic agents
Free from harmful chemical substances
Pleasant to taste, i.e., free from colour and odour; and
Usable for domestic purposes
Uses of water
Domestic use
Public purposes
Industrial purposes
Agricultural purposes
Power production
Carrying away wastes
Sources of Water
Rain
Surface water
Impounding reservoirs
Rivers and streams
Tanks, ponds and lakes
Sea water
Ground water
Shallow wells
Deep wells
Springs
WATER PURIFICATION
Storage
Filtration
Chlorination
Storage
a) Physical Action
b) Chemical Action
c) Biological Action
Filtration
98 – 99% of the bacteria are removed by filtration apart from other impurities.
Two types of filters are in use
The Biologic or Slow sand filters
Rapid or Mechanical filters
1. Slow Sand or Biologic Filters
Elements:
Supernatant (raw) water
A bed of graded sand
An under drainage system
A system of filter control values
Supernatant (raw) water
Depth – 1 – 1.5 metres
A bed of graded sand
Vital layer
Slimy growth covering the surface of the sand bed
“Schmutzdecke/ Zoogleal/ Biological layer”
Consists of thread like algae, plankton, diatoms and bacteria.
It extends 2-3 cms into the top portion of the sand bed.
Formation of vital layer - “Ripening” of the filter.
It is the “Heart” of the slow sand filter.
It removes organic matter,
Holds back bacteria
Oxidizes ammonical nitrogen into nitrates and
Helps in yielding bacteria free water.
An under drainage system
Filter box – Open rectangular box of 2.5 – 4 meters deep
A system of filter control values
To maintain a constant rate of filtration
Venturi meter – measure the bed resistance or loss of head
2) Rapid/Mechanical filters
Steps involved
Coagulation
Rapid mixing
Flocculation
Sedimentation
Filtration
Filter bed:
Each unit of filter bed has surface of about 80 to 90 sq. feet
Sand is the filtering medium.
Back washing
Rapid sand filters require frequent washing either daily or weekly depending upon the loss of head.
Washing is accomplished by reversing the flow of water through sand bed which is called “Backwashing”.
Helps in dislodging the impurities and cleaning up the sand bed.
Time - 15 to 20 minutes
Chlorination:
Chlorine kills pathogenic bacteria but has no effect on spores and certain viruses except in high doses.
It oxidizes Fe, Mn and HS;
It destroys taste and odour-producing constituents
It controls algae and slime organism
2. Purification on Large scale
When sources of water are
Rivers,Streams,Lakes etc. then water is
Purified by
Storage
Sedimentation
Filtration(rapid sand & slow sand)
Disinfection(chlorination)
3. Purification on Medium Scale
When sources of water are
wells,Springs,Tanks etc.Then water is
purified by the addition of
Bleaching powder/Chlorinated Lime as it is
Cheep
Easy to use
Reliable and safe
4. Purification on Small
Scale(Domestic Methods)
BOILING: for 5-10 minutes kills almost
all organisms & removes temporary
Hardness.
DISTILLATION: not commonly used due
to higher cost, used in Labs. etc.
ADDITION OF CHEMICALS
Bleaching Powder: 5% solution is used
Dose: 3-6 drops/L contact time of ½ hour.
5. Contnd.-----------
Chlorine Tablets/Halazone Tablets. one
tablet/litre.
Iodine Solution: 02 drops of 2% Soln./litre
KMnO4: an amount that gives just pink
coloration to the Water.
Alum: used for turbid water in a dose of
0.1-0.4 grains/5 litres of Water.
6. Purification of water in
Emergency/Epidemic
Boiling: for 5-10 minutes.
High Test Hypo chlorite: used in granular
form Dose: 01gm./10 litres of water.
Liquid Bleach/5% Sodium Hypo chlorite
solution: Dose: 14 ml./1000 litres of water.
Bleaching Powder: used in a dose of
2.3gm./1000 litres of water.
7. Purification of water on Large
Scale
On large scale purification, water is
disinfected by addition of Chlorine after
filtration.
On large scale, water is purified through the
following processes.
8. Contnd.---------
A.STORAGE:
Not a sole measure of purification but
valuable as a preliminary to other
processes.
There is fall in ammonia & rise in nitrates
due to oxidation of organic matter by
aerobic bacteria.
9. Contnd.----------
Sedimentation, may be hastened by the
addition of Alum in a dose of 35 mg./ litre
for a detention period of 4-6 hrs.
Sedimentation will prevent clogging of the
filters.
Limitation to storage includes algae growth
which can be controlled by addition of
CuSo4 in a dose of 1-5 Kg. / 5000 cu.m.
10. Contnd.---------
B. FILTRATION:
Filtration through sand is the oldest and
universally, most accepted method through
out the world.
98-99% bacteria are removed along with
other impurities through filtration.
12. Slow Sand Filtration
Firstused in 1804 in Scotland &
subsequently in London.
During 19th.Century used through out the
world.
Slow sand filter consists of concrete/brick
work rectangular basin containing carefully
selected graded sand supported on gravel
and stones.
13. Contnd.-----------
ELEMENTS:
1. Supernatant (raw) water:
Upper most layer of raw water(1-1.5M)
It provides a constant head of water
It provides a waiting period of 3-12 hours
14. Elements contnd.-----
2. Sand Bed:
It is 1 M thick supported by a layer of fine and
then coarse gravel and finally by the stones.
3. Drainage System for filtered water:
It consists of perforated pipes
4. Filter Control Valves:
Valves & Devices incorporated in the outlet-
pipe system to maintain a constant rate of
filtration
Venturi meter measures bed resistance or loss of
head.
15. Actions of slow sand filter
Physical:
Mechanical straining/sedimentation
Chemical: Oxidation of organic matter by
aerobic bacteria.
Biological: Occurs through “Vital layer”
Efficiency of the filter depends upon the
“Vital layer”
16. Vital Layer
Slimy growth known as “Schmutzdecke”,
Vital layer, zoogleal layer or biological
layer
The layer is slimy & gelatinous,It consists
of threadlike algae & numerous forms of
life plankton, diatoms and bacteria
Ripening of the filter
Vital layer is the “heart” of slow sand filter
17. ADVANTAGES
Simple to construct and operate
Cost of construction cheaper than rapid
sand filter
Process: physical, chemical and biological
Bacterial count reduction is 99.9% to
99.99% and E.coli reduction is 99% to
99.9%
18. DISADVANTAGES
Old fashioned and outdated method of
water purification (but still in use)
Initial cost is low but maintenance cost is
much more than rapid sand filter
These filters need a lot of space
19. RAPID SAND FILTERS
In 1885, first rapid sand filters were
installed in USA, since that time they are
gaining considerable popularity in highly
industrialized countries as well as
developing world.
21. Contnd.----------
STEPS / PROCESSES IN RAPID SAND
FILTERS
1. COAGULATION:
Raw water is first treated with Alum in a
dose of 5-40 mgs./L
pH has to be adjusted by addition of lime or
soda ash as Alum needs CaCo3 to form the
flock.
22. Contnd.---------
2. RAPID MIXING:
Water is mixed rapidly with Alum for a
few minutes in mixing chamber.
3. FLOCCULATION:
From mixing chamber water is moved into
the Flocculation chamber where it rests for
half an hour.
23. Contd.--------
4. SEDIMENTATION:
The coagulated water is now led into the
sedimentation tank where it is detained for
2-6 hours.
Flocculant precipitate together with
impurities & bacteria settle down in the
tank
24. Contnd.--------
5. FILTRATION
Partially clarified water is now subjected to
the rapid sand filtration.
Depth of the sand bed is 1 M & each rapid
sand filter unit has a surface of about 80-90
Sq.M.
Oxidation of NH3 also takes place in these
filters.
25. ADVANTAGES
Rapid sand filters deal with raw water
directly
Occupies less space
Filtration is rapid about 40-50 times as
compared to slow sand filters
Washing of filter is easy
More flexibility in operation
26. DISADVANTAGES
Preliminary treatment with Alum is
required
Operation is highly skilled
Removal of color material is less than slow
sand filter
Reduction of bacterial count is less than
slow sand filter
27. Comparison of Rapid and Slow
sand filters
Rapid.S.F.
Slow.S.F.
1. Space: Occupies little space-----Occupies large area
2. Rate of filtration: 5-15 cu.m./sq.m./hr.----- 0.1-0.4
3. Effective sand size: 0.4-0.7mm-----------------0.2-0.3mm
4. Preliminary treatment: Coagulation& sedimentation--plain
Sediment
5. Washing: By back washing--------By scraping the sand
6. Loss of head allowed: 6-8 feet--------------------4feet
7. Removal of turbidity: Good-----------------------Good
8. Removal of color: Good------------------------Fair
9. Removal of bacteria: 98-99 %--------------------99.9-99.99
28. DISINFECTION OF WATER
CHEMICAL METHODS / GERMICIDES
1. CHLORINE: is used for purification of water on large
scale
2. KMnO4: used for disinfection of water in wells especially
during epidemics
3. CuSO4/CaCl2: used for the removal of algae
4. Lime: used for muddy water
5. Ozonization & U.V. irradiation: both methods are used for
disinfection of water in swimming pools
6. Katadyn Silver: sand coated with silver used in slow sand
filters instead of plain sand
7. Charcoal: used as adsorbent to remove color,odor & taste
29. Disinfection of Wells
The most effective & cheapest method of
disinfecting wells is by bleaching powder
STEPS IN WELL DISINFECTION :
1. Find the volume of water in a well:
a. Measure the depth of water column..(h) M
b. Measure the diameter of well………(d) M
c. Substitute h and d in:
30. Cotnd…….
3.14 x (d)2 x h
Volume(litres)=------------------------------ x 100
4
d. One cubic meter = 1,000 litres of water
Find the amount of bleaching powder
required for disinfection:
Estimate the Chlorine demand of well
water by HORROCK’S APPARATUS
31. Contnd……..
3. Dissolve Bleaching Powder in water
4. Delivery of Chlorine solution into the well
5. Contact period
6. Orthotolidine arsenite test
32. Chlorination of water
It is the most widely used method for water
purification, both on large as well as on
small scale.
It is the most reliable and cheapest method.
It is supplement but not the substitute to
sand filtration.
33. Properties of Chlorine
Killing of pathogenic bacteria by inhibiting their
protein synthesis.
Oxidizes Iron, Manganese & Hydrogen Sulphide.
Destroys taste & odor producing constituents.
It controls algae growth.
It helps in coagulation and suspension of the
organic matter.
34. Action Of Chlorine
When chlorine is added to water it forms
HCl & HOCl.
The disinfecting action of chlorine is mainly
due to Hypochlrous acid & to a small extent
due to Hypochlorite Ions.
Hypochorous acid is 70-80 times more
effective than Hypochlorite Ions.
35. Actions of Chlorine depends
upon the……..
Organic matter
Metals
Bacterial content
Temperature & pH of water.
Suspended matter and,
Amount of free residual chlorine in water
36. Contnd………
Efficiency
of chlorine increases, when it
combines with Ammonia and……
Itdecreases, when it combines with
Sulphides, Ferrous salts & inert matter in
suspension form
37. Principles of Chlorination
Water to be chlorinated must be free from
turbidity
Chlorine demand of water should be
estimated
Contact period of one hour is essential to
kill the bacteria and viruses
Minimum recommended concentration for
free chlorine is 0.5mg. / liter
38. Chlorine demand of water
Is the difference between the amount of
chlorine added to water and the amount of
residual chlorine remaining at the end of a
specific period of contact (usually 60 min.)
at a given temperature and pH of water.
ACUAL DOSE OF CHLORINE:
It is the sum of chlorine demand of water
and free residual chlorine
39. Methods of Chlorination
1. Chlorine gas
2. Chloramine
3. Perchloron (H.T.H.)
TYPES OF CHLORINATION:
a. Superchlorination
b. Break Point Chlorination
40. Tests for the presence of
Chlorine in Water
Orthotolidine (O.T.) Test
Orthotolidine-Arsenite (O.T.A.) Test
Starch Iodide Test
41. Surveillance of drinking Water
1. Sanitary survey
2. Sampling
3. Bacteriological surveillance
4. Biological examination
5. Chemical surveillance
42. Sampling of Water
Collection, Storage & Transportation of water
samples from……
Taps
Rivers
Streams
Tanks
Wells
A. For Physical & Chemical Examination
B. For Bacteriological Examination
PERTICULARS OF A SAMPLE
45. Contnd……..
Toxic substances and a specific group of
chemicals causing Non-Specific diseases of
water
Poly-nuclear Aromatic Hydrocarbons and
Radioactive substances ( a group of
chemical substances of water affecting the
acceptability of water.
46. Bacteriological Standards
1.BACTERIAL STANDARDS :
W.H.O. recommended these standards in
1984 for Public water supplies
Ideally all samples taken from the
distribution system should be free from
Coliform organisms
In Practice this standard is not always
attainable
47. Recommended Standards for
Water samples collected
Throughout any year 95 % samples 100 ml.
each should not contain any Coliform
organisms
No samples should contain E.coli
No sample should contain more than 03
Coliform
Any two consecutive samples should not
contain Coliform
48. Contnd………
Incase of Individual / Small water
supplies such as from household Tap, Well,
Spring etc.
Coliform count should not exceed 10 /100
ml. and E.coli should be nil
49. Contnd………..
2. VIRAL STANDARDS :
W.H.O. Standards fix the limit for viruses
such as Eneroviruses, Retroviruses &
Adenoviruses in water supplies at 01 Plaque
forming unit
Faecal Bacteroiphage & Enteropathogenic
viruses should be completely absent
50. Bacteriological Indicators
These are based on organisms indicative of
faecal pollution, These organisms include!
1. E.coli and Coliform group as a whole
2. Faecal Streptococci
3. Clostridium Perfringens
4. Examination for Protozoa, Parasitic
worms & Larvae is also recommended
51. Contnd……..
Reasons why Coliform organisms are chosen
as indicators of Faecal Pollution
1. Constantly present in human intestine an
average person excretes 200-400 billions / day
of these organisms in faeces
2. They are foreign to potable water supplies
3. Easily detectable by ordinary cultural methods
4. Survival time is much better than other
organisms
5. Have greater resistance to natural forces of
purification
52. Contnd……..
FAECAL STREPTOCOCCI :
Faecal Strepococci occur regularly in much
smaller number than E.coli
Their presence is regarded as confirmatory
evidence of recent faecal contamination of
water in doubtful cases
53. Contnd………
CLOSTRIDIUM PERFRINGENS :
They are spore bearing organisms
Their presence along with Coliform indicate
recent water contamination
While the presence of their spores but the
absence of Coliform confirms remote
contamination of water