2. DEFLUORIDATION BY LOW
COST BIO-ADSORBENTS
2
PRESENTED BY,
NAYANA.D
11144229
GUIDED BY ,
SIVA BALA P
ASST. PROFESSOR,CE
COLLEGE OF
ENGINEERING,PATHANAPURAM
4. FLUORIDE
4
Compound form of fluorine(F)
SOURCES OF FLUORIDE
1.Ground water –Fluoride bearing rocks
&industrial discharges
2.Food products
3.Medicaments & cosmetics
5. The permissible limits of fluoride
concentration in drinking water
5
NAME OF ORGANISATION PERMISSIBLE LIMIT
Bureau of Indian standards(BIS) 0.6-1.2 mg/lit
World Health Organisation (WHO) 1-1.5 mg/lit
Indian Council of Medical
Research(ICMR)
1 mg/lit
6. 6
FLUORIDE CONTAMINATION IN
GROUNDWATER
Excessive fluoride concentration reported in 28
developed and developing countries
India –
19 states are affected by fluoride problem
was first reported in 1937 in the state of U.P
The desert-ridden water scarce state of
Rajasthan tops the affected states
11. 1. PRECIPITATION METHODS
11
Addition of chemicals (coagulants) and precipitation of
soluble salts of fluoride
Limestone,alum,lime,Poly Aluminium chloride,Poly
aluminium Hydroxy sulphate
Eg: Nalgonda Technique
Limitations-Time consuming, requires more
diligence, large dosage of aluminium sulphate,sludge
transfer issue
12. 2.ION EXCHANGE PROCESS
12
Materials
1.Bone
exchange of carbonate radicals with fluoride
2.Bone char
consists of calcium phosphate and carbonate
3.Ion exchange resins
anion exchangers-Eg. Polyanion(NCL)
cation exchangers-Eg.Carbion,Polystyrene
4.Activated alumina
consists of aluminium oxide (Al2O3).
13. 3.MEMBRANE FILTRATION PROCESS
13
Reverse osmosis (RO)
the pressure is exerted on one side of the semi-permeable
membrane which forces the water across the membrane
leaving the pollutants behind
Electro dialysis
the membranes allow the ions to pass but not the water
14. 4.NANO FILTRATION
14
Nano filtration membranes have high retention of
charged particles.
Requires less pressure and capital
Limitations-
1.expensive
2.complicated
15. 5.ELECTRO-COAGUlATION
15
Utilizes electricity and sacrificial anodes to form the
active coagulants
Advantages-less space, no chemical storage, no pH
adjustments
Disadvantages-expensive and complicated
16. LIMITATIONS
16
1. High operational cost
2. Maintenance cost
3. Low fluoride removal capacities
4. Lack of selectivity for fluoride
5. Undesirable effects on water quality
6. Generation of large volumes of sludge
7. Complicated procedures involved in the treatment.
17. ADSORPTION
17
Adsorption is the bond of molecules species from
bulk solution for a surface of a solid by physical or
chemical forces.
Applications in water treatment
1. Removal of taste and odour causing compounds
2. Synthetic organic chemicals(SOCs)
3. Colour forming organics
4. Disinfection by products(DBPs)
5. Heavy metals
19. 19
3 phases of adsorption of fluoride.
1. diffusion or transport of fluoride ions to the external
surface of the adsorbent
2. adsorption of fluoride ions on to particle surfaces
3. the adsorbed fluoride ions probably exchange with
the structural elements inside adsorbent particles
20. ADVANTAGES OF ADSORPTION
20
1. High selectivity of adsorbents.
2. Low cost in installation and maintenance thus economic
compared to other methods of defluoridation
3. High efficiency, high productivity of fluoride removal and can
remove up to 90% of fluoride.
4. Easy post-treatment after adsorption.
5. Adsorption units are simple in their operation and design
21. Contn.............
21
6. Eco-friendly nature
7. Lack of sludge production
8. It is applicable in removal of fluoride even at low
concentration.
9. This method is also popular due to wide range of
availability of adsorbents.
10. Adsorption technique is efficient and can remove
ions over an extensive variety of pH to a lower
leftover concentration than precipitation
22. VARIOUS LOW COST ADSORBENTS
22
Industrial, agricultural wastes ,natural plant
products used as adsorbents
25. 25
Eggshell powder 2-6 5 2 94 R Bhavnik&N
K Mondal
Chalk powder 2-7 2 2 86
Maize husk
fly ash
2 0.04 2 86 Jadhav A V
Neem stem
charcoal
5 .1-.6 3 94 Chakrabarty
&Sharma(201
2)
26. ADVANTAGES OF LOW COST
ADSORBENTS
26
1. Offers efficiency of 50-96%
2. Cheap and easily available compared to
conventional adsorbents
3. Need less maintenance and supervision
4. Used adsorbents can be used as filler material,thus
disposed easily and safely.
29. EXPERIMENT
29
1. Materials used
Moringa oleifera seed powder
1 N nitric acid
0.5 N sodium hydroxide
2. Experimental setup and procedure
The fluoride removal studies by adsorption were conducted in 250 ml
conical flask using 100 ml of synthetic water sample containing different
pH and initial concentrations of fluoride ion. In these conical flasks
adsorbent with varied dosage was added. Then the contact period was
given for different particle sizes. After giving a required contact time, the
contents of the flasks were filtered using Whatmann’s filter paper number
41. The filtrate was used for fluoride ion estimation using SPADNS method.
The above procedure was repeated for different pH, contact times,
adsorbent doses, particle sizes and different initial fluoride ion
concentrations
33. OBSERVATIONS
33
1. The alkali treated Moringa Oleifera seed powder was
found better than acid treated Moringa Oleifera seed
powder for fluoride ion removal.
2. The removal by adsorption increases as the pH
value increases.
3. The removal by adsorption was found to be
optimum at adsorbent dose of 400 mg/lit.
4. The optimum contact times were 2 hrs and 2.5hrs
for 212 μ and 600 μ respectively.
34. CONCLUSION
34
Cost is of major consideration in developing
countries like India
Hence adsorption process using low cost adsorbents
that are abundant and easily available have been
investigated
35. 35
SCOPE OF FUTURE WORK
The present study have to be extended for
1. Variety of other adsorbents
2. Different particle size
3. Mixture of adsorbents
4. Large scale applications
36. REFERENCE
36
1. Suman Mann, Dr.Anubha Mandal, Performance of Low-Cost Adsorbents for the Removal of fluoride
ions – An overview , International Journal of Engineering Science and Innovative Technology
(IJESIT) Volume 3, Issue 3, May 2014
2. Prerna Kumari ,Effective bio-adsorbents for removal of fluoride from water:a review,International
Journal of Advance Research in Science and Engineering,Vol.No.4,August 2015
3. C M Vivek Vardha and J Karthikeyan ,Removal of fluoride from water using low cost
materials,Fifteenth International Water Technology Conference,2011,Egypt
4. Suman Mann, Dr.Anubha Mandal, Performance of Low-Cost Adsorbents for the Removal of fluoride
ions – An overview, International Journal of Engineering Science and Innovative Technology (IJESIT)
Volume 3, Issue 3, May 2014
5. N. Gandhi, D. Sirisha, K.B. Chandra Shekar and Smita Asthana, Removal Of Fluoride From Water
And Waste Water By Using Low Cost Adsorbents, International Journal of ChemTech Research
CODEN( USA): IJCRGG ISSN : 0974-4290 Vol.4, No.4, pp 1646-1653, Oct-Dec 2012
