FLUORIDE POLLUTION AND IT'S REMEDIES

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CHANDUBHAI.S.PATEL INSTITUTE OF
TECHNOLOGY TOPIC - FLUORIDE POLLUTION AND ITS
REMEDIAL MEASURES
Faculty of Technology Engineering
(CSPIT) Dept. of Civil engineering
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GUIDED BY SHWETA SHARMA MITALI VEDANTI

SUBMITTED BY GAJERA VAIDIK-D15CL155 RADH
ANPURI SADAB-D15CL156 PRAJAPATI NIRAV-D15CL157
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• Fluoride Is The 13th Most Abundant Naturally
  Occurring Element In The Earths Crust. Which Has
  Been Found By Henri Moissan In 1886.
• The Concentration Of Fluoride In Water Is
  Directly Proportional To The Degree Of Fluorosis.
• Enamel Mottling Is Widespread In Area With Water
  Having Fluoride Content Of 3 Ppm.
• The Highest Fluoride Concentration Ever Found In
  Natural Water Was 2800 Mg/L, Recorded In Lake
  Nakuru In The Rift Valley In Kenya.
• 19 states in India have groundwater that is rich
  in fluoride
• By UNICEF and WHO.

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The main fluoride bearing areas are Gujrat,
Rajasthan, Andrha Pradesh where about 50 to 100
of districts are affected.
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• SOURCES OF FLUORIDE
• Major source is from
  
  fluoride in vegetation
  
  water artesian wells.
  

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Fluoride In Soils
Fluoride In Humans
cryolite
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• Natural Disaster
  
  Anthropogenic Sources

Forest fire
Volcanic disaster
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Uses of Fluoride

• Hydrogen fluoride is used
• In Aluminium production
• In Chlorofluorocarbon (CFCs) production
• In the production of aluminium fluoride, sodium
  fluoride and other fluoride salts.
• Petroleum, chemical, and plastics industries.
• To clean metals, bricks, or remove sand from
  metal castings.
• To enamel, polish glass and galvanize iron.

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Point Sources of Fluoride

• The primary sources of fluoride emissions are the
  industries that
• manufacture it or use it in production
• Aluminium industry,
• Oil drilling and refining,
• Chemical and plastics industries,
• Agricultural and pesticide chemical
  manufacturers,
• Dye manufacturers,
• Manufacturers of metal parts.

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• Consumer products

Toothpaste, pesticides, ceramic and glass
polishing and frosting materials, special dyes,
drinking water in some areas may be naturally or
artificially enriched in fluoride.
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Fluoride Cycle

• When fluoride is emitted to the air as a gas or
  particulate it may be carried by the wind and
  deposited on surrounding vegetation and soil. The
  gas dissolves in clouds, fog, rain, or snow. This
  impacts the environment as wet acid deposition
  ('acid rain'). In the environment it will react
  with other chemicals present (ammonia, magnesium,
  calcium) to form salts, neutralising the acid.
• Industrial emissions of fluoride compounds can
  produce elevated concentrations in the
  atmosphere. Hydrogen fluoride will exist as a
  particle, which may dissolve in clouds, fog,
  rain, dew, or snow. In clouds and moist air it
  will travel along the air currents until it is
  deposited as wet acid deposition (acid rain, acid
  fog, etc). In waterways it rapidly mixes with the
  water.

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• Fluoride Pollution
• Hydrogen fluoride dissolves in water
• to make hydrofluoric acid. Hydrogen
• fluoride will corrode most substances
• except lead, wax, polyethylene,
• and platinum.
• Hydrogen fluoride is used to
• manufacture other fluorine-based
• chemicals including Sodium fluoride,
• which is a white powder, although
• sometimes it is dyed blue for
• identification purposes.

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• EFFECTS OF FLUORIDE POLLUTION
• Low levels of fluoride in drinking water (0.5 to
  1 mg/l) protect against dental caries
• High levels of fluoride in drinking water (above
  1.5 mg/l) will lead to adverse health impacts
  ranging from dental fluorosis to skeletal
  fluorosis
• Fluoride levels in water beyond desirable /
  permissible limits is typically found in
  groundwater and not surface water.
• Skeletal Fluorosis

Dental Fluorosis
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• WATER FLUORIDATION
• 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.
• 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.

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• DEFLUORIDATION
• 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.
• BASIC 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

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• REMEDIAL MEASURES METHODS FOR FLUORIDATION
• Nalgonda technique of defluoridation.
• it was developed by NEERI at Nagpur in 1974.The
  process comprises addition in sequence of sodium
  aluminate (filter lime ), lime bleaching powder
  to the fluoride water followed by flocculation,
  sedmentation, filtration.
• MECHANISM
• The unit holds 22L OF WATER ,which filter into
  upper chamber.

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• Operation maintenance of Nalgonda technique
• Fill 22 L of test water in the upper chamber.
• Add the required dose of Aluminium salt solution.
  
• mix it rapidly for a period for 30-60 sec with a
  speed of 10-20 rpm.
• With he help of chemical a tiny Floc are formed.
• Then mix for a period of 10-15 min with a speed
  of 2-4rpm.

• Factors that influence sedimentation are
• Size, shape, density, nature of the particles.
• Viscosity, density, temp of water.
• Surface over flow rate.
• Velocity of water.
• Effective depth of settling water.

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Salient features of Nalgonda technique
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• Reverse Osmosis and Electro dialysis
• In reverse osmosis, the hydraulic pressure is
  exerted on one side of the semi permeable
  membrane which forces the water across the
  membrane leaving the salts behind.
• In electro dialysis, the membranes allow the ions
  to pass but not the water. The driving force is
  an electric current which carries the ions
  through the membranes
• Electro dialysis is highly energy intensive and
  expensive. Both processes are very complicated
• Defluoridation by electrolysis
• The basic principle of the process is the
  adsorption of fluoride with freshly precipitated
  aluminum hydroxide, which is generated by the
  anodic dissolution of aluminum or its alloys in
  an electro chemical cell.

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• CASE STUDY
• DEVELOPMENT OF DEFLUORIDATION PLATS ON INDIA
• Household Chemo-defluoridation Unit

1. https//www.youtube.com/watch?vgKWiGikB2M8
2. http//www.neeri.res.in/content/household-chemo-de
   fluoridation-unitoverlay-contextcontent/househol
   d-chemo-defluoridation-unit

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• Electrolytic Defluoridation (EDF) Technique

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