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GoalLow cost/indigenous techniques for treating fluoride-contaminated water, keeping in mind that limited maintenance is possible in rural areas. Or identifying alternatives to drinking water.How do we approach this ?
A compilation of Fluoride Treatment MethodsThe defluoridation methods are divided into three basic types depending upon the mode of action : - Based on some kind of chemical reaction with fluoride : Nalgonda technique, Lime ...
- Based on adsorption
process : Bone charcoal, processed bone, tricalcium phosphate,
activated carbons, activated magnesia, tamarind gel, serpentine,
activated alumina, plant materials, burnt clay ...
- Based on ion-exchange process : Anion/Cation exchange resins
(Filtration : a) Reverse Osmosis Filtration; b) Activated Alumina Defluoridation Filter; c) Distillation Filtration) | Method | Process | Resources / Salient Features
| Cost | | Nalgonda Technique | The Nalogonda technique (named after the village in India where the
method was pioneered) employs flocculation principle 1. Nalgonda
technique is a combination of several unit operations and the process
invloves rapid mixing, chemical interaction, floculation,
sedimentation, filtration, disinfection and sludge concentration to
recover waters and aluminium salts. Alum (hydrated aluminium salts) - a
coagulant commonly used for water treatment is used to flocculate
fluoride ions in the water. Since the process is best carried out under
alkaline conditions, lime is added. For the disinfection purpose
bleaching powder is added. After thorough stirring, the chemical
elements coagulate into flocs and settle down in the bottom. The
reaction occurs through the following equations
2 Al2 (SO4)3 .
18H2 O + NaF + 9Na2CO3 → [5Al(OH)3.Al(OH)2F] + 9Na2SO4+NaHCO3 + 8 CO2 +
45 H2O 3 Al2 (SO4)3 . 18H2 O + NaF +17NaHCO3 → [5Al(OH)3.Al(OH)2F] +
9Na2SO4+ 17 CO2 + 18 H2O
| Salient features of Nalgonda technique
- No regeneration of media
- No handling of caustic acids and alkalies
- Readily available chemicals used in conventional municipal water treatment are only required
- Adaptable to domestic use
- Flexible upto several thousands m3 / d
- Applicable
in batch as well as in continuous operation to suit needs simplicity of
design, construction, operation and maintenance
- Local skills could be readily employed
- Higly efficient removal of fluorides from 1.5 to 20 mg/L to desirable levels
- Simultaneous removal of colour, odour, turbidity, bacteria and organic contaminants
- Normally associated alkalinity ensures fluoride removal efficiency
- Sludge generated is convertible to alum for use elsewhere
- Little wastage of water and least disposal problem
- Needs minimum of mechanical and electrical equipment
- No energy except muscle power for domestic equipment
- Economical - annual cost of defluoridation (1991 basis) of water at 40
lpcd works out to Rs.20/- for domestic treatment and Rs.85/- for
community treatment using fill and draw system based on 5000 population
for water with 5 mg/L and 400 mg/L alkalinity which requires 600 mg/L
alum dose.
- Provides defluoridated water of uniform acceptable quality
| | | Precipitation methods | - Method
involving the addition in sequence, of an alkali, chlorine and
aluminium sulphate or aluminium chloride or both was developed. It is
cheap and is used extensively in India.
- Though lime
softening accomplishes fluoride removal, its high initial cost, large
dosage and alkaline pH of the treated water renders it unsuitable for
field application. Large dosage and alkaline pH of the treated water
renders it unsuitable for field application.
| - Alkali, chlorine;
- Aluminium sulphate or aluminium chloride
| cheap | | Activated alumina | - Activated
alumina is a granular, highly porous material consisting essentially of
aluminum trihydrate. It is widely used as a commercial desiccant and in
many gas drying processes.
- The studies, perhaps the
earliest, have demonstrated the high potential of activated alumina for
fluoride uptake. An initial concentration of 5 mg/L was effectively
brought down to 1.4 mg/L before regeneration and to 0.5 mg/L on
regeneration with 2N HCl. The bed was regenerated with a solution of 2%
Na OH,5% NaCl,2N HCl,5% NaCl and 2N HCl. The removal capacity of the
medium was found to be about 800 mg/L of fluorid e/L of Alumina. Many
modifications of process was suggested by subsequent workers, several
patents based on the use of Aluminum oxide for fluoride removal were
issued 1. Filter alum was used to regenerate activated alumina bed. The
capacity of alumina to remove fluoride was reported to be proportional
to the amount of filter alum used for regeneration up to a level of
about 0.2kg of alum per litre of alumina. At this level the fluoride
removal capacity was approximately 500 mg of fluoride per litre of
alumina. Similar studies employing activated alumina was later
conducted by many workers and all these works confirmed the ability of
activated alumina for higher uptake of fluoride from water. Some
researchers have concluded that removal was the result of ion
exchange, but investigations by others have shown that the process
is one of the adsorption and follows the Langmuir isotherm model.
- Activated
Alumina can be regenerated with HCl, H2SO4, Alum or NaOH. The use of
NaOH needs to be followed by a neutralization to remove residual NaOH
from the bed. Fluoride removal by activated alumina is strongly pH
dependent. Batch adsorption data14 showed very little removal at pH
11.0 and optimum removal at pH 5.0.Hence raw water pH & regenerated
bed pH need to be ad justed accordingly.
- The ability
of activated alumina to remove fluoride depends on other aspects of the
chemistry of water as well. Such factors as hardness, silica and boron,
etc., if present in water will interfere with fluoride removal and
reduce the efficiency of the system.
- The use of
activated alumina in a continuous flow fluidized system is an
economical and efficient method for defluoridating water supplies15.
The process could reduce the fluoride levels down to 0.1 mg/L. The
operational, control and maintenance problems, mainly clogging of bed,
may be averted in this method.
| - Activated alumina
- Na OH,
- NaCl
- 2N HCl
- H2S04
- Filter alum
Advantages:
- It requires minimum contact time for maximum defluoridation.
- Percentage of regeneration is considerably high.
- There is very little attritional loss ( to a negligible extent) during the regeneration at the initial stage of operation
- It is indigenously available and cheap.
- Defluoridation capacity at neutral pH is appreciable, although it has greater defluoridation efficiency at low pH.
- Its defluoridation capacity is independent of temperature.
- The
effect of other ions present in drinking water, like chlorides,
sulphates and carbonates, over the defluoridation efficiency of
activated alumina is minimum, eventhough the presence of bicarbonate
ions show considerable influence in the process of defluoridation.
For cost and more details - see :
| Economical and efficient
| | Bone Char | - The
uptake of fluoride onto the surface of bone was one of the early
methods suggested for defluoridation of water supplies. The process was
reportedly one of the ion exchange in which carbonate radical of the
apatite comprising bone, Ca(PO4)6.CaCO3, was replaced by fluoride to
form an insoluble fluorapatite. Bone char produced by carbonizing bone
at temperature of 1100-1600ºC had superior qualities than those of
unprocessed bone and hence replaced bone as defluoridating agent
| The fluoride removal capacity of the product is 1000 mg/L
| - | Contact Precipitation
| It
is a technique by which fluoride is removed from the water through the
addition of calcium and phosphate compounds and then bringing the water
in contact with an already saturated bone charcoal medium.
| | | | Degreased and alkali treated bones | - Degreased
and alkali treated bones are effective in the removal of fluoride from
initial fluoride concentration ranging from 3.5 mg fluoride/L to 10 mg
fluoride/L to less than 0.2 mg fluoride/L
- Bone contain calcium
phosphate and has a great affinity for fluoride. The bone is degreased,
dried and powdered. The powder can be used as a contact bed for removal
of fluoride in water. The exhausted bed is regenerated with sodium
hydroxide solution
| - | - | | Synthetic tri-calcium phosphate | - The
product is prepared by reacting phosphoric acid with lime(Bulusu). The
medium is regenerated with 1% NaOH solution followed by a mild acid
rinse
| It has a capacity to remove 700 mg fluoride/L | - | Florex
| - A
mixture of tri-calcium phosphate and Hydroxy -apatite, commercially
called Florex, showed a fluoride removal capacity of 600 mg of fluoride
per litre and is regenerated with 1.5% sodium hydroxide solutio n.
Owing to high attritional losses, Florex was not successful and the
pilot plants using this material were abandoned
| - | - | | Activated Carbon | - Most
of the carbons prepared from different carbonaceous sources showed
fluoride removal capacity after alum impregnation. High Fluoride
removal capacities of various types of activated carbons had been
reported.
- Alkali digested alum impregnated paddy husk carbon was an efficient defluoridating agent.
- Investigations
have shown that carbonized saw dust when quenched in 2% alum solution
forms an excellent defluoridating carbon. The defluoridating process is
stoichiometric and equilibrium is established between carbon &
fluoride. On exhaustion (after continued use) the carbon can be
regenerated by passing 0.2 to 0.5% alum solutions.
- Activated
carbon prepared by other workers from cotton waste, coffee waste,
coconut waste etc., was tried for defluoridation but all these
materials proved to be of academic interest only
| - Alkali digested alum impregnated paddy husk carbon
- Alkali digested (1% KOH) & alum soaked (2% alum) carbon removed 320
mg fluoride per kg & showed maximum removal efficiency at pH 7.0.
| - | | Lime | - The
fluorides in waters containing Magnesium, when treated with lime, are
adsorbed on Magnesium hydroxide flocs enabling fluoride removal12,
25,26. In this case the water must be treated to a caustic alkalinity
of 30 mg fluoride/L, a pH of 10.5 or above and as such recarbonation is
necessary27. Magnesia and calcined magnesite have also been used for
fluoride removal from water and fluoride removal capacity was reported
to be better at high temperature
| - | - | | Ion Exchange Resins | - Strong
base exchange resins remove fluorides either on hydroxyl cycle or
chloride cycle along with anions. Since the proportional quantity of
fluoride as compared to other anions is very small, the effective
capacity of such resins works out quite low. Some inorganic ion
exchangers, eg. complex metal chloride silicates, formed from barium or
ferric chloride with silicic acid, also exchanged fluoride for chloride.
- Cation
exchange resins impregnable with alum solution have been found to act
as defluoridating agents. Alum treated cation exchange resins were used
for defluoridation. ‘Avaram Bark’ based cation exchange resins, had
been reported to work effectively in removing fluoride from water
- Polystyrene
anion exchange resins in general and strongly basic quaternary ammonium
type resins in particular are known to remove fluorides from water
along with other anions. The fluoride removals by various anion
exchange resins are given6 in the table
- Table 3 indicates that
the resins studied yields 20 – 145 bed volume of defluoridated water
per cycle. Subsequent experience showed that these resins lose their
fluoride removal capacity on prolonged use (10 – 15 cycles) and a total
replacement becomes necessary. A layer of white deposits was developed
over the resin beds, and this may be the reason for this drop in the
capacity.

| - Thus the anion exchange resins were found to be of relatively low
capacity for fluoride removal. The cost of anion resins is Rs. 20 to 35
per litre. The results indicate that anion exchange resins are not
economical for removing fluorides from water. Besides, the strong base
anion exchange resins impart a taste to the treated water that may not
be acceptable to the consumers.
| | | Cation Exchange Resins | - Performance
of Saw dust carbon (Defluoron–1), Carbion, Wasoresin – 14 and a
polystyrene cation exchange resin for fluoride removal were compared35
and the results of the study are summarized in the table.4
- During
the above studies the bed was regenerated with 200 ml of 1% alum
solution and washed with tap water when the residual fluoride
concentration reached 1.5 of fluoride
| - | - | | Magnesia | - Investigations
were conducted to study the usefulness of magnesia in fluoride removal.
Crystalline magnesium hydroxide was obtained by reacting a magnesium
salt with milk of lime. The precipitate was filtered, washed and dried.
The dried product was calcined at 1000°C for 3 hours to obtain
magnesia. Varying quantities of magnesia were added to one litre
aliquots of test water and stirred for 30 min using a jar test machine.
Fluoride contents were estimated on one hour settled sample.
- A
typical groundwater containing 10 mg/L fluorides, 60 mg/I hardness, 500
mg/L alkalinity and 7.6 pH was studied using magnesia (MgO)
concentrations of 10 - 1,500 mg/L. The treated water showed a pH above
9. The average fluoride concentration in the filtrate was 5.8 mg F/L
where the dose was 1,000 mg/L. The fluoride at 100, 250 and 500 mg/L
doses were 9.5, 8.9 and 8.4 mg F/L, respectively. A dose of 1,500 mg/L
magnesia and a contact period of 3 hr was required to reduce the
fluoride content in the water to 1 mg/L.
- The high initial cost,
large concentrations required, alkaline pH of the treated water and
complexity of the preparation of magnesia are the inhibitive factors to
render it acceptable in the field
| - The study established that magnesia removed the excess fluorides, but
large doses were necessary. Moreover the pH of the treated water was
beyond 10 and its correction by acidification or recarbonation was
necessary. All this adds to the cost and compleity of operations. The
acid requirement can be to the extent of 300 mg/L expressed in terms of
CaCO3/L
| Costly! | | Serpentine |
- Serpentine
is a mineral name, which applies to the material containing one or both
of the minerals, chrysotile and antigorite1. The composition of the
mineral closely corresponds to the formula Mg6Si4O10 (OH). The material
is green or yellow and is available in Andhra Pradesh. To test the
capacity of serpentine to remove fluorides from waters, the green and
yellow varieties were studied for their defluoridation capacity.
Extensive laboratory investigations were conducted with a view to
popularize the mineral, if found suitable as a defluoridating medium. A
comparative evaluation was made using green and Yellow varieties of
serpentine and the results are given in the table 5. It is concluded that cost of defluoridation is prohibitive with serpentine
| - Materials
like clays, minerals, ion exchange resins, activated carbons, activated
alumina, sulphonated coals and serpentine were tried for the removal of
excess fluorides from water. In- situ chemical treatment with lime,
magnesium salts, iron and aluminum salts were also studied. Those that
showed an encouraging trend on a bench scale were studied in detail.
These include ion exchange resins, saw dust carbon, coconut shell
carbon defluoron-1 carbion, magnesia, serpentine and defluoron-2. Ion
exchange resins, saw dust carbon, defluoron-1, magnesia and serpentine
did not prove useful beyond bench –scale.
| Costly! | | Lime stone, special soils and clay etc | - Recently
limestone and heat-treated soil were tried for fluoride removal.
Limestone was used in a two-column continuous flow system (limestone
reactor) to reduce fluoride concentrations from wastewaters to below
the MCL (Maximum contaminant level) of 4 mg/L. Calcite was forced to
dissolve and fluorite to precipitate in the first column. The degassing
condition in the second column caused the precipitation of the calcite
dissolved in the first column, thus returning the treated water to its
approximate initial composition.
- In laboratory experiments, the
fluoride concentration of the effluent from all tested feed waters
containing initial fluoride amounts from 10 to 100 mg/L. And a steady
state of the system performance was quickly achieved, For instance, in
an experiment when the input fluoride concentration was 100 mg/L,
effluent concentrations from both columns were below 4 mg/L after only
8 pore volumes had passed. The proposed reactor has potential
application to reduce concentrations from wastewaters of anionic
elements similar in charge and size to carbonate ion, such as Selenate
and arsenate and cations similar in size and charge to Ca2+ ,such as
Cd2+.
- Pleistocene soil available locally in Xinzhou, China was
able to remove fluoride from local ground water. X-ray diffraction
analysis revealed that the soil is composed principally of quartz (50-
60%), Illite (30-40%), goethite (5-10%) and feldspar (5-10%). A
substantial improvement in both permeability and the fluoride removal
capacity of the soil was achieved by heating it in a Muffle furnace. A
granular material can then be obtained by crushing the heated product
- The
experimental results showed that heating at 400-500ºC has the optimal
effect on the enhancement of the material’s fluoride removal capacity.
A preliminary column experiment showed that 4.0 kg of 400ºC
heat-treated soil can treat more than 300L of 5 mg/L fluoride feed
water before the effluent fluoride concentration reaches 1.0 mg/L. Once
the soil’s fluoride-sorption capacity had been reached, the material
could be regenerated in a cost effective way: rinse the soil first with
sodium carbonate solution, then with dilute HCl and finally with
distilled water twice. After being air-dried the material is ready for
reuse
- Attempts were made to use local Kenyan soil derived from
volcanic ash (ex: Ando soils or soils with andic properties) as a
fluoride sorbent37. The ability of Kenyan Ando soil to adsorb fluoride
was determined experimentally. These results were extended to possible
technical application using a one dimensional solute transport model.
Based on the result it is concluded that the use of Ando soils appears
to be an economical and efficient method for defluoridation of drinking
water on a small scale in rural areas of Kenya and other regions along
the Rift zone. Further research is warranted to evaluate its practical
applications and social acceptance.
- Fluoride sorption studies
were carried out on two clay minerals, montmorillonite KSF and kaolin,
and a silty clay sediment series (SCSS, used in earthenware making)
38.The function of fluoride concentration, clay concentration and pH in
clay-water suspensions was studied. Kaolinite, a dioctahedral two
layered (Silica + alumina) Silicate(1:2 type),exhibited very little
tendency for Fluoride sorption while montmorillonite,2:1 type material
characterized by Octahedral sheet of alumina sandwiched between two
tetrahedral sheets of silica, showed significant Fluoride sorption.
The
Fluoride sorption on montmorillonite KSF was found to be greatest at pH
1.9 ± 0.3,the natural pH of montmorillonite-water suspension. At pH 4.0
± 0.36, the percentage fluoride sorption on montmorillonite decreased,
followed by an increase around pH 5-6, after which the percentage
decreased with increasing pH. The applicability of the Freundlich
isotherm was also verified in case of montmorillonite KSF at low
fluoride concentrations. As a result of fluoride adsorption, increased
release of Fe2+, Cl-, NO3 - ions from montmorillonite matrix was
observed. There was no effect on SO4 2- or PO4 2- solubility. Fluoride
adsorption on SCSS was also significant and decreased regularly with increasing pH. - On
the basis of experimental data a plausible mechanism of fluoride
sorption by clay minerals is suggested. Based on the results of
fluoride sorption mentioned above, a pilot study on defluoridation of
water employing clay (SCSS) as an adsorbent was als o undertaken which
yielded promising results.
- Removal of fluoride by adsorption on
to low-cost materials like kaolinite, bentonite, charfines, lignite and
nirmali seeds was investigated

| -
| - | | Fly Ash | - Retention
of fluoride ion in dynamic experiments on columns packed with fly ash
was studied40 at 20ºC with a series of aqueous solutions containing
1,5,10,20,50 and 100 mg fluoride/L/ The flow rate through a 450-g bed
was £ 2ml/hr. At the lowest fluoride concentration(1 mg/L), the
fluoride level in the effluent initially increased and then gradually
decreased down to 0 mg/L after 120 hours. With higher fluoride
concentrations in the feed solutions, the fluoride concentration in the
effluent steadily decreased reaching 0 mg/L after 120-168 hours.
| The fly ash was an effective sorbent especially at high concentrations.
| - | Electro coagulation Electrochemical methods | - Electro
coagulation process with aluminum bipolar electrodes was used for
defluoridation process41. The influence of parameters such as
inter-electrode distance, fluoride concentration, temperature and pH of
the solution were investigated and optimized with synthetic water in
batch mode. The optimization process continued with Oued Souf water
(South Algeria) where the influence of current density and area/volume
ratio on the defluoridation process was evaluated. The electro
coagulation process with aluminum bipolar electrodes permitted the
defluoridation of Sahara water without adding salts to the treated
water. The aluminum–fluoride weight ratio attained was 17/1.
- A
technology of defluoridation through Electrochemical route has been
developed42. 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
electrochemical cell.
- Constraints in the above
technology: Electricity is the main raw material and hence wherever
electricity is not available a suitable polar panel can be installed.
| - The process utilizes 0.3 to 0.6kwh of electricity per 1000 litres of
water containing 5- 10 mg/L of fluoride. The anode is continuously
consumed and needs to be replenished. The process generates sludge at
the rate of 80- 100 gm per 1000 litres (on dry basis).
| - | | Rare earth based materials | - New
water treatment processes have been developed for removal of hazardous
anions such as Fluoride, Arsenic, Selenium species, and phosphate from
water using rare earth based materials which have not been efficiently
utilized by industry in spite of their abundance43. The
state-of-the-art of rare earths in terms of cost, use and health
effects and the environmental problems associated with hazardous anions
in terms of treatment and toxicity are generally described. Solid
lanthanum and Yttrium ions have been used as adsorbents for removing
hazardous anions. Either lanthanum or Yttrium ions have been loaded on
porous silica or alumina beads to improve economic and engineering
performance; such rare earth impregnated materials have been
successfully applied to the treatment of synthetic as well as
industrial wastewaters.
- A rare earth metal-based inorganic
adsorbent, Cerium- Iron adsorbent (CFA), was developed and its
performance for fluoride removal from water was evaluated44. The
characteristics of the adsorbent were summarized. Experimental results
show that rare earth metal adsorbents had a relatively high adsorption
capacity and good kinetic property for fluoride ion removal. The
highest capacity was obtained at pH 3, then it decreased with the
increase of pH. The pH effect however, became inconspicuous when the pH
was over 5.The results show that the adsorption of fluoride on CFA
adsorption follows Freundlich isotherm in the tested range of fluoride
concentrations. The adsorption capacity could almost be recovered by
regenerating it with 1 molx1-1 NaOH solution
- An adsorbent,
which is a mixture of rare earth oxides was found to adsorb fluoride
rapidly and effectively45. The effect of various parameters such as
contact time, initial concentration, pH andadsorbent dose on adsorption
efficiency was investigated. More than 90% of the adsorption occurred
within the first 5-10 minutes. Adsorption was found to be dependent on
the initial fluorid concentration and adsorption behavior followed
Langmuir adsorption model. The optimum pH was found to be about 6.5.
The presence of other ions such as nitrate and sulphate did not affect
the adsorption of fluoride significantly (adsorption efficiency reduced
from 85 to 79%) indicating the selective nature of the adsorbent. The
adsorbed fluoride could be easily desorbed by washing the adsorbent
with a pH 12 solutions. This study clearly shows the applicability of
naturally occurring rare earth oxides as selective adsorbent for
fluoride from solutions
| - | - | | Tamarind Gel | The
concentration of fluoride from solution of sodium fluoride of 10 mg/L
could be brought down to 2 mg/L by the addition of tamarind gel alone
and to 0.05 mg/L by the addition of small quantity of chloride with the
tamarind gel. | - tamarind gel
- small quantity of chloride
| - | | Plant materials | The
plant materials such as barks of Moringa olifera and Emblica
officinalis , the roots of Vetiveria zizanoides and the leaves of
Cyanodon tactylon were found to be good defluoridating agents | - | - |
How is fluoride analysis done?
Link to Water Quality Testing Kits :Fluoride Analysis Decision TreeFluoride Analysis Methods
Solutions attempted : What and where ?| Location | Problem | Causes | Solution(s) / Suggestion(s) | References | | Udaipur, Rajasthan | Fluorosis causes deterioration of bones and joints, thereby increasing medical expenditure and in some areas like Rajasthan, has prevented people from marrying their daughters in a village where drinking water is contaminated. | - Using water from deeper aquifers and
- Underground geology (availability of rocks rich in fluoride content) with no relation to the aquifer level.
| - Nalgonda technique (using alum, lime and bleaching powder to precipitate fluoride salts from water) as one of the earliest defluoriding techniques.
- A de-fluoridisation Corporate Social Responsibility project in Nalgonda cited by members appeared to be quite successful in providing safe drinking water to village people at a low cost.
- Phyto-remediation – using specific plants like water hyacinth to leach away contaminants from water, and accentuated the need for screening indigenous plant species for this purpose.
- Promotion of alternative sources of safe drinking water such as roof water harvesting
- Recharging aquifers could be one of the ways of dealing with excess fluoride.
- Need to develop an inter-sectoral approach to tackle the issue of fluoride. Firstly, surveillance on the incidence of contamination needs to be stepped up through regular testing of water samples. In this regard, members felt that ion-specific electrodes and photometers gave more accurate results than titration and other testing methods. They also suggested fully involving all relevant stakeholders such as schools, health authorities and local authorities in the mitigation efforts.
| For challenges and impact refer to http://www.solutionexchange-un.net.in/environment/cr-public/cr-se-wes-13120601-public.pdf
| | Ethiopia | - From 10 million people living in Ethiopia Rift Valley, about 8.5 million people are exposed for high fluoride contamination.
- In Ethiopian Rift Valley waters, fluoride varies from 0.5 to 264 mg/l (up to 26mg/lin drinking water sources).
- Over 40%of deep and shallow wells and springs in the rift valley have fluoride levels above the optimal (WHO) level of 1.5 mg/l
- Over 80% of the children in the rift valley have developed varying degrees of dental fluorosis
- Crippling skeletal fluorosis cases increasing (old people)
| - Addition by active volcanic and fumarolic activities in the area.
- High water -rock interaction in the area, particularly interaction of water with volcanic ash and volcano -sedimentary rocks.
- Low calcium concentrationin the area, which restricts the precipitation of F-as fluorite(CaF2).
| - Small scale Community Defluoridation Plants: 3 pilot sites –Use Nalgonda method (aluminum sulphateand lime)
- Household Defluoridation : Defluoridation kits - a 40 ltplastic bucket fitted with tap. Use aluminum sulphate
| For challenges and impact refer to http://www.cepis.ops-oms.org/bvsacg/e/foro4/19%20marzo/Strategies/Fluoride.pdf | Balisana
Village, Patan
District, Gujarat
| - The village in the dry Patan district
of Gujarat has been under the acute grip of fluoride pollution amidst
drought. Almost all of the villagers from early to middle aged population
are suffering from fluorosis or other fluoride related diseases.
- The woes of the villagers are not only related to drinking water
but are also with the crops they grow - as they are also laden with
traces of fluoride. At present, they have no solution.
| -- | - The villagers started a community
drive to solve the crisis, with help from Ahmedabad-based non governmental organisation,
UTTHAN. The vi lagers started to desilt a 3.05 metre (m) long canal through which they
diverted rainwater to a 300-year-old tank. About 82,000 cubic metre of silt has been
extracted from the tank at a cost of Rs 52 lakh. Sixty per cent of the cost came from the
government, 40 per cent was community shramdaan (voluntary labour).
- A 12 kilo meter long bund was
reconstructed to hold the diverted rainwater. Adjacent to the tank, is a 45 m deep
recharge well that was fitted with an ultra-poly vinyl chloride (high density pipe). The
horizontal pipe carries water from the tank to the recharge well. Water from the well is
pumped into a storage tank near the well. (see figure: Harvesting rain to fight flouride
in Balisana village)
| http://www.rainwaterharvesting.org/Rural/Balisana1.htm http://www.rainwaterharvesting.org/catchwater/feb2002/technology.htm#water
| | Karnataka | - | - | - Locally Constructed Alternate Rainwater Based Drinking Systems using Slow Sand Filters.
| For challenges and impact refer to http://www.solutionexchange-un.net.in/environment/cr-public/cr-se-wes-13120601-public.pdf | | - | - An intake of more than 6 mg of fluorine per day results in fluorosis.
- Fluorine being cumulative bone-seeking mineral, the resultant skeletal changes are progressive.
- Fluoride increases the stability of crystal lattice in bone, but makes the bone more brittle. Drinking fluoridated water will double the number of hip fractures.
- The International Society for Fluoride Research (ISFR) has reported studies implicating fluoride in the rising rates of Down’s syndrome, chronic fatigue syndrome and sleep disorder.
| - | Defluoridation of water using inexpensive adsorbents | http://journal.library.iisc.ernet.in/vol200405/paper4/jamode.pdf | Guntakkal, Andhra Pradesh;) | Natural water contained more than 2ppm of water and disease was prevalent.
| - | A process involving paddy husk carbon impregnated with alum, which can be regenerated for use, several times again by alum, for the removal of fluoride from water. (Developed by Indian Institute of Science, Bangalore in 1952).
The process involved the impregnation of alum, and consisted of autoclaving paddy husk carbon by 1% sodium hydroxide and soaking overnight in 1% alum solution. Two liters of fluoride-containing water percolated through a bed of 20g of the material reduced the fluoride content from 2.5 ppm to 0.5 ppm. No alumnium ions were imparted to the water, but the turbidity of the water was removed in the process. The bed could be regenerated to be used for further fluride removal by passing 1% alum solution through it and washing it free of alum.
The methods was inexpensive and the materials easily available in the villages
| http://www.ias.ac.in/jarch/currsci/75/00000651.pdf | Sonebhadra District, UP
| Drinking water quality tests for fluoride content done by BSA in 1999 showed fluoride concentrations between 1.1 – 5.4 mg/L in surface water and 0.5 – 5.9 mg/L in groundwater. | Several industries like thermal power plants and Hindalco, situated in this area, are also potential sources of fluorides in water and air | - Community-Based Fluorosis Mitigation Planning : Activities like puppet shows, street plays, dialogues with the villagers, posters pasting and distribution of pamphlets on fluorosis were carried out in each targeted village. Mapping of the fluoride content in the different drinking water sources along with the affected households was also done in each village.
- AA kits were used (Activated Alumina)
- Different proposals :
- Conversion of existing safe dug well into a sanitary well
- Conversion of existing safe concrete well into a sanitary well
- Hand Pump with attached AA kit
- Borewell with hand pump and attached AA kit
- AA Domestic kit
- Individual Roof rain water harvesting
- Community Roof rain water harvesting
| http://www.indiawaterportal.org/tt/wq/res/DraftReportSonbhadra.pdf |
Country wise data on fluorosis with exposure to fluoride through drinking waterClick Here for details on different country data (extracted from the book " "Fluoride in drinking-water" by John Kirtley Fawell, K. Bailey, J. Chilton, World Health Organization, E. DahiQuestions- Is the "Fluorosis Mitigation Programme "(Department of Health) still active ? Can it help Jhabua ? Will the Department of Health (through this scheme) conduct a survey and follow-up ?
- How can we get the reports/data for the following :
- Extent of fluoride contamination in water (and other water analysis facts like pH, hardness ...)
- How many people (%) are currently drinking fluoride contaminated water ?
- The alternative mentioned was borewells. How far do the villagers have to walk to these wells ? Will Q-drums help in this case to ease the strain of walking ?
- Who do we have to work with to discuss this further ? Sampark ?
References |