BUILDING SERVICES - WATER SUPPLY AND SANITATION Seminar on Water Fluridation & Defluridation

1. TREATMENT OF
BUILDING SERVICES
W A T E R | W AT E R S U P P LY A N D
S A N I TAT I O N
FLUORIDATION &
DEFLUORIDATIO
N

2. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
FLUORINE
• Fluorine is the 13th most
abundant naturally occurring
element in the Earth’s crust
and is the lightest member of
the halogens. It is the most
electronegative and reactive
of all the elements and as a
result, elemental fluorine does
not occur in nature but found
as a fluoride mineral
complexes.

3. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
W AT E R
• Water is frequently referred
to as a universal
solvent, because it has the
ability to dissolve almost all
substance; that comes in its
contact. Some elements are
essential in trace amount
for human being while
higher concentration of the
same can cause toxic
effects. Fluoride is one of
them.

4. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
C O N C E R N F O R WAT E R
T R EAT M E N T
• Due to rapid urbanization and growth of modern industries
(anthropogenic source of fluoride) as well as geo chemical
dissolution of fluoride bearing minerals (natural source of
fluoride), fluoride concentration is increasing in the
environment including water resources. The high
concentration in the drinking water leads to destruction of
enamel of teeth and causes a number of conditions referred
to collectively as fluorosis.

5. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
H E A LT H I M PA C T S
VA R I O U S H E A LT H I M PA C T S O F
FLUORIDE
• Fluoride inhibits enzymes that breed acid producing oral bacteria whose acid eats away
tooth enamel.
• Fluoride ions bind with calcium
ions, strengthening tooth enamel as it forms
in children.
• Dental fluorosis

6. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
F L U O R I D AT I O N
• Water fluoridation is the process of adding
fluoride to the water supply so the level
reaches approximately 0.7 ppm, or 0.7
milligrams of fluoride per liter of water; this
is the optimal level for preventing tooth
decay
• Fluoridation is a safe, effective, and
economical process endorsed by the
American Dental Association, the American
Water Works Association, and public health
groups worldwide.

7. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
W H A T I S W AT E R F L U O R I D A T I O N ?
• Small amounts of fluoride are present naturally in all
water sources.
• Water fluoridation is the precise adjustment of the
natural fluoride concentration in a public water
supply up to the level recommended for preventing
tooth decay.
• The common compounds which are added to water
are NaF (Sodium Fluoride), Na2SiF6 (Sodium Silica
Fluoride) e.t.c

8. • Fluoridation does not
affect the
appearance, taste, or
smell of drinking water. It
is normally
accomplished by adding
one of three compounds
to the water.

9. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
D E F L U O R I D AT I O N
• The process of water treatment that reduce the
concentration of fluoride in the water, in order to
make it safe for human consumption is
DEFLUORIDATION.
• Some water treatments that have the capacity of
reducing the fluoride concentration along with
most other anions, or anions and cations, in the
water, are not considered as Defluoridation
methods. Thus general demineralising methods
like distillation, reverse osmosis and electro
dialysis which are able to remove fluoride fully or
partly from the water, are not considered as
Defluoridation methods.

10. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
• On the other hand methods
that only remove fluoride
without any addition or
reduction of other parameters
are not yet discovered. That's
why the expression “fluoride
removal” lacks precision.
• Defluoridation is used to
characterise methods that
reduce the fluoride ion
specifically, without major
other changes to the quality of
the treated water.

11. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
BASIC REQUIREMENTS
Defluoridation devices should meet a number of the
following requirements:
•
•
•
•
•
Modest investment
Low maintenance cost
Simple design
Operable by villagers
Able to reduce fluoride content, e.g. from 5
to 0.5 mg/L
• Improve water quality in general

12. METHODS OF
D E F L U O R I D AT I O N
B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
• The activated carbons prepared from various
materials can be used as Defluoridation agents.
• During lime-soda process of water
softening, the fluorides are also removed along
with the removal of magnesium.
• The materials such as Calcium Phosphate, Bone
charcoal, synthetic tricalcium phosphate , etc.
may be added for the removal of excess fluoride
content in water.
• The water may be allowed to pass through filter
beds containing fluoride retaining materials.

13. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
CHALLENGES
Most of the above methods of Defluoridation
suffer from one or other disadvantages
such as:
• High Initial Cost
• Expensive regeneration
• Poor Fluoride removal capacity
• Hard to maintain

14. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
MODERN TECHNIQUES
• THE NALGONDA
TECHNIQUE (named
after the village in India where
the method was pioneered)
employs flocculation principle.
Nalgonda technique is a
combination of several unit
operations and the process
involves rapid
mixing, chemical
interaction, flocculation, sedim
entation, filtration, disinfection
and sludge concentration to
recover waters and aluminium
salts.

15. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N

16. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
A C T I VAT E D A LU M I N A
• Activated Alumina
(Al 2 O 3 ) has been
activated to become
adsorptive. The
method of activation is
done through
dehydration of
aluminium hydroxides
at temperatures of
300-600 o C

17. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
• Activated alumina is
used in an adsorption
process with very high
fluoride removal
efficiency. Though it
has been used
successfully to treat
water for a number of
contaminants, it has
the advantage of
having a very high
selectivity for fluoride.

18. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
BONE CHAR
• Bone char is the oldest known
technology for water
Defluoridation, being
successfully used since the
1940s.
• Bone char has also been used
successfully in the removal of
arsenic from water.

19. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
• Bone char is produced
with animal bones that
have passed through
calcination process.
Though raw bones have
some Defluoridation
value, it is small and
limited by the various
organics obstructing the
interfaces where
chemical reactions with
the fluoride take place.

20. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
• In order to produce bone char, animal bones must first be
collected. These bones can be collected from a variety of
sources including butchers, restaurants, ranchers, etc.
This can create an entirely new market by giving value to
what was previously viewed primarily as a waste material.
• Once the bones are collected, they are often
washed, rinsed, boiled, or sun dried to remove much of the
organics before they are actually charred to be used as
filter media.

21. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
CONCLUSION
• Fluoride in drinking water can cause beneficial or
detrimental effects depending on it concentration and the
total amount ingested.
• The Defluoridating materials being used at present are
relatively costlier. The investigations of feasible low
materials for fluoride removal are needed.
• Preliminary investigations provided an encouragement to
use the animal bone powder for further detailed
investigations. Animal bone powder is comparatively
cheap material available in abundant in nearby areas.

22. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
BIBLIOGRAPHY
• Water Supply & Sanitary Engineering – G.S.
Birdie, J.S. Birdie
• Water Supply & Sanitary Engineering – Rangwala.
• www.de-fluoride.net/defluoridation.html
• www.appropedia.org/Water_defluoridation
• http://en.wikipedia.org/wiki/Water_fluoridation

23. B U I L D I N G S E RV I C E S - WAT E R
S U P P LY A N D S A N I TAT I O N
ANSIF K HABIB
ROLL 5
SEMESTER 3
THANK YOU