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WELCOME

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DEFLUORIDATION BY LOW COST BIO-ADSORBENTS

PRESENTED BY, NAYANA.D 11144229

GUIDED BY ,SIVA BALA PASST. PROFESSOR,CECOLLEGE OF ENGINEERING,PATHANAPURAM

CONTENTS3

1. FLUORIDE-ILLEFFECTS,CONTAMINATION IN INDIA

2. METHODS OF DEFLUORIDATION

3. ADSORPTION-ADVANTAGES

4. LOW COST ADSORBENTS

5. CASE STUDY-MORINGA OLEIFERA A NATURAL

BIO-ADSORBENT

FLUORIDE4

Compound form of fluorine(F)

SOURCES OF FLUORIDE 1.Ground water –Fluoride bearing

rocks &industrial discharges 2.Food products 3.Medicaments & cosmetics

The permissible limits of fluoride concentration in drinking water

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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

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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

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FIG :Fluorosis prevalent states

MOST AFFECTED STATESRAJASTHANGUJARATANDHARA PREDESH

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FLUORIDE-”A DOUBLE EDGED SWORD”8

ADEQUATE INTAKE prevent tooth decay and cavities

Maintenance of healthy bones

EXCESSIVE INTAKE

Dental fluorosisMuscular –skeletal fluorosisDamages pineal glandAffects reproductive system and intelligenceThyroid disorderNeurological damage

FLUORIDATION DEFLUORIDATION

DEFLUORIDATION

DEFLUORIDATION9

Adjustment of level of fluoride in drinking water to the optimal level

METHODS OF DEFLUORIDATION

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Precipitation methodsIon exchange processMembrane filtration processNano-filtrationElectro-coagulationAdsorption

1. PRECIPITATION METHODS11

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

2.ION EXCHANGE PROCESS12

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).

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

4.NANO FILTRATION14

Nano filtration membranes have high retention of charged particles.

Requires less pressure and capitalLimitations- 1.expensive 2.complicated

5.ELECTRO-COAGUlATION15

Utilizes electricity and sacrificial anodes to form the active coagulants

Advantages-less space, no chemical storage, no pH adjustments

Disadvantages-expensive and complicated

LIMITATIONS16

1. High operational cost2. Maintenance cost3. Low fluoride removal capacities4. Lack of selectivity for fluoride5. Undesirable effects on water quality6. Generation of large volumes of sludge7. Complicated procedures involved in the

treatment.

ADSORPTION17

Adsorption is the bond of molecules species from bulk solution for a surface of a solid by physical or chemical forces.

Applications in water treatment1. Removal of taste and odour causing compounds2. Synthetic organic chemicals(SOCs)3. Colour forming organics4. Disinfection by products(DBPs)5. Heavy metals

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Fig: Various adsorbents used for defluoridation 18

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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

ADVANTAGES OF ADSORPTION20 

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

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

VARIOUS LOW COST ADSORBENTS

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Industrial, agricultural wastes ,natural plant products used as adsorbents

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Name of adsorbent

pH Dosage(g/L)

Contact time(hr)

Removal percentage

Reference

Clay material

2 5 to 10 3 40-50 Ravikumar and Nazeebkhan(2015)

Granular activated carbon and sewage sludge

neutral GAC-4SS-3

3 Poundyl and Sandhya (2015)

Tea ash 6 0.8 1 51.3-77.6 Mondal.et.al.,(2011)

Pumic 7 20 3 74.64 Malakootian et.al.,(2011)

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Neem leaves 2 10 1 90 Goswami(2015)

Bark of Babool

8 5 8 77.4 Mamdawan

Baggase Dust

6 1-20 5 84.4 Gupta.et.al.,

Rice husk 2-10 10 2 75 Deshmukh et.al(2009)

Citrus limonum(lemon)leaf

2-8 1-10 2.4 70 V.Jomae.et.al(2014)

Devadaru leaf powder

7 7-8 3 77 Bharali &Bhattacharya

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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(2012)

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ADVANTAGES OF LOW COST ADSORBENTS

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.

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CASE STUDY:DEFLUORIDATION BY MORINGA OLEIFERA-A NATURAL ADSORBENT

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Powdered seeds

Moringa oleifera seedsMoringa oleifera

plant

EXPERIMENT29

1. Materials used Moringa oleifera seed powder 1 N nitric acid 0.5 N sodium hydroxide

2. Experimental setup and procedureThe 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

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1.Optimum pH

Sl.No pH Acid washed powder

Alkali washed powder

%removal efficiency

% removal efficiency

1 1 39 -2 2 31 313 4 24 374 6 20 415 8 13 49.56 10 12 51

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2. Optimal contact time

Adsorbent dosage = 2.5 gm/litpH =8

Sr. No. Contact time 600 μ 212 μ

% removal efficiency

%removal efficiency

1 30 39 53  

2 60 48 62  

3 90 56 68  

4 120 61 70  

5 150 62 70  

3. Optimal adsorbent dosage32

pH = 8Optimum contact time = 2.5 hrs (600µ) = 2 hrs (212 µ)

Sr. No. Absorbent

dose

(mg)

600 μ 212 μ

% removal

efficiency

%removal

efficiency  

1 100 47 48  

2 200 58 62  

3 300 61 67  

4 400 68 76  

OBSERVATIONS33

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.

CONCLUSION34

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

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SCOPE OF FUTURE WORK

The present study have to be extended for

1. Variety of other adsorbents2. Different particle size3. Mixture of adsorbents4. Large scale applications

REFERENCE36

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 

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