High fluoride concentration in ground water has been reported in Begunia, Bolagarh blocks of Khurda district and Bhapur Block of Nayagarh District, Orissa. Preliminary geological & geochemical studies were carried out to trace the source of fluoride in ground water.
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‘Fluoride Contamination Status of Ground Water & Quality Management in Parts of Khurda & Nayagarh District, Orissa.’ D.K.Kar,Geologist B.K.Sahoo,Geologist Directorate of Ground Water Survey & Investigation: Orissa Abstract:- Water, the vital need for all living beings compels one to search for its abundance either surface or underground. In a rapidly growing urbanization where we live, the water resources base is steadily diminishing due to irregularities in climatic and deterioration of environmental conditions. Usual practice of anthropogenic activities lead towards increase of water related hazards, which are the main concern for us. Fluorosis is a chronic disease resulting from prolonged intake of excessive Fluoride mainly through drinking water. WHO recommends the fluoride concentration in water less than 1.5 mg/l to be safe for drinking purpose and any thing more than this may lead to dental, skeletal fluorosis. High fluoride concentration in ground water has been reported in Begunia, Bolagarh blocks of Khurda district and Bhapur Block of Nayagarh District, Orissa. Preliminary geological & geochemical studies were carried out to trace the source of fluoride in ground water. Rock/water samples were analyzed to determine fluoride concentration. Lithological control over high fluoride concentration in ground water is hypothesized. Garnetiferrous granite gneiss and Charnockites are the major litho units of the area having apatite, biotite , hornblende as accessory constituents. The leacheable fluoride in these mineral is reflected in the top aquifer system of the area. Regarding quality management, the most cost effective defluoridation techniques ( Nalagonda techniques ) are suggested towards reduction of high fluoride concentration in water. Key words :- Fluorosis, Potable water , W.H.O, Nalagonda techniques and DDFU. 1
Transcript
‘Fluoride Contamination Status of Ground Water & Quality Management in Parts of Khurda & Nayagarh District, Orissa.’
D.K.Kar,Geologist
B.K.Sahoo,Geologist
Directorate of Ground Water Survey & Investigation: Orissa
Abstract:-Water, the vital need for all living beings compels one to search for its
abundance either surface or underground. In a rapidly growing urbanization where we live, the water resources base is steadily diminishing due to irregularities in climatic and deterioration of environmental conditions. Usual practice of anthropogenic activities lead towards increase of water related hazards, which are the main concern for us. Fluorosis is a chronic disease resulting from prolonged intake of excessive Fluoride mainly through drinking water. WHO recommends the fluoride concentration in water less than 1.5 mg/l to be safe for drinking purpose and any thing more than this may lead to dental, skeletal fluorosis. High fluoride concentration in ground water has been reported in Begunia, Bolagarh blocks of Khurda district and Bhapur Block of Nayagarh District, Orissa. Preliminary geological & geochemical studies were carried out to trace the source of fluoride in ground water. Rock/water samples were analyzed to determine fluoride concentration. Lithological control over high fluoride concentration in ground water is hypothesized. Garnetiferrous granite gneiss and Charnockites are the major litho units of the area having apatite, biotite , hornblende as accessory constituents. The leacheable fluoride in these mineral is reflected in the top aquifer system of the area.
Regarding quality management, the most cost effective defluoridation techniques ( Nalagonda techniques ) are suggested towards reduction of high fluoride concentration in water.
Key words :- Fluorosis, Potable water , W.H.O, Nalagonda techniques and DDFU.
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Introduction
Fluoride is known to contaminate ground water globally. Sporadic incidences of high fluoride concentration in ground water have been reported from India. Ground water containing more than 1.5 mg/l (WHO specified permissible limit ) of fluoride pose serious toxicological and geo environmental problems in 17 states of India. In Orissa, this endemicity covering over 22 districts and around 3.5 million people are at a risk of developing fluorosis. Deformed body with bending of legs, mottling of teeth coupled with ageing problems is a general feature seen in these villages. In view of the gravity of the situation a preliminary geological and geo chemical study was carried out by the Directorate of Ground Water Survey and Investigation to trace the source of fluoride in ground water.Geological mapping in Parts of Khurda (Begunia and Bolagarh block) and Nayagarh (Bhapur block) district were carried out in 1:50,000 scale to identify lithological units responsible for fluoride contribution(Fig-1).
Rock samples were analysed to determine the fluoride content, ground water samples over different periods from different sources were collected.
General geology
The present study stretches from 20o N to 20o 23’ N Latitude & 85o 12’ E to 85o 32’ E Longitude(Fig-1). The area forms a part of Easternghats super group of rocks and major Litho units are granite gneiss (garnetiferrous granite gneiss and quartzofeldspathic gneiss ) Charnockites & its derivative showing a regional trend varying from WNW – ESE to EW with moderate to high dip ( 45o to ) in either direction. Recent alluvial cover dominates rest of the area.Litology map is shown in fig-2.
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Methodology
During the study water samples from different bore wells, dug wells and ponds of various locations were collected for analysis of fluoride and other parameters. Geological mapping in 1:50,000 scale, rock samples were collected for microscopic and chemical analysis.
Discussion
Geochemistry of fluoride: Abnormal levels of fluoride in water is common in fractured hard rock zone composed of minerals like Fluorapatite, fluorite and fluoride replaceable hydroxyl ion in ferromagnesian silicates. Fluoride ion from this minerals leach in to the ground water and contribute to the high fluoride concentration. Rock minerals weather and form calcium and fluoride ions. However it is the leachable state of fluoride ions that determines the water fluoride levels. The leachability is governed by (i) pH of the draining solution,(ii) the dissolved carbon dioxide of the soil. The present study pertains the fluoride in phreatic ground water(top aquifer ) and it is in this regimen most of the hand pumps ,dug and bore wells are constructed.
Profile of fluoride in shallow ground water zone : High profile of fluoride in ground water is observed in some G.P of Bolagarh, Bhapur and Begunia as shown in Fig-3
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The present study shows that the occurrences of fluoride is very sporadic .The incidences of very high fluoride zones are limited to certain patches of Bolagarh and Bhapur block and is scattered in Begunia block.Village Balasingh of Bolagarh block,Khurda district shows maximum fluoride concentration 5.88 mg/l in groundwater. Bolagarh block shows a wide variation of fluoride concentration while in Begunia and Bhapur the fluoride concentration in ground water ranges from 1.5mg/l to 2.8 mg/l. The distribution of fluoride in phreatic ground water in different villages of the study area is given in Table-1 and the concentration of fluoride ranging above 1.5 mg/l in phreatic ground water of the study area is shown in Table-2.
Table-1 : Distribution of fluoride in phreatic ground water in different villages
District Block Fluoride concentration in mg/l.
No. of villages
Percent of total villages
Khurda Begunia 0.0 – 1.01 – 1.5
1.5 –3.0
3.0 - & above.
157
8
7
nil
91%
5%
4%
-
Total villages: 172
Bolagarh 0.0– 1.0
1 – 1.5
1.5 –3.0
3.0 - & above.
166
33
28
6
71%
14%
12%
3%
Total villages: 233
Nayagarh Bhapur 0.0– 1.0 128 85%
4
1 – 1.5
1.5 –3.0
3.0 - & above.
16
6
nil
11%
4%
-
Total villages: 150
Table -2: Concentration of fluorides above 1.5 mg/l in phreatic ground water in different villages
District Block G.P. VillageFluoride
concentration range in mg/lt
Nayagarh Bhapur Basupalli Patharpunji 1.5 - 1.61
Chakradharprasad Anandpur 1.85
Dhanchangda Mahulapada 2.65
Karabara Tikiriapada 1.8
Salapada Kulab 1.95 - 2.05
Salapada 1.7
Khurda Begunia Botalama Akhupada 1.8
Kantabada Basudevpur 1.63
Radhakantapur Chakapada 1.54 - 1.7
Kalikaprasad 1.66 - 1.88
Radhakantapur 1.63
Suanala 1.61
Sagadabhanga Chhima 2.8
Bolagarh Arikama Bhabanipur 3.86
Badakumari Khalikot 2.16
District Block G.P. VillageFluoride
concentration range in mg/l
Khurda Bolagarh Badakumari Srichandrapur 1.54
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Bolagarh Bolagarh 2.45
Mardabadi 1.72
Nandapalli 1.81
Panchukota 1.62 - 2.58
Rampur 2.58
Dabardhuapatna Asanapalli 1.64
Belapadar 1.64 - 1.78
Chuda 1.53 -1.82
Dabardhuapatna 1.82 -1.92
Ghoradia 1.69
Gopalipada 1.68
Grameswar 1.71
Kapasia 1.69 - 1.71
Rameswar 1.55 - 1.64
Gediapalli Salatara 1.92
Gopalpur Abhilo 1.68
Dakhina Parikuda 1.72
Jaripada Jaripada 1.72 - 2.02
Kalanga Naupada 1.65
Khanguria Jadapada 1.68
Khalipatna 1.68
Sikharpada 1.71
Patapursasan Kharadapalli 2.08
Sagaragaon Balasingh 5.88
Balasinghpatna 1.52
Benagadia 1.63
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Godiali1.51 - 1.66
Pallibalsingh 2.82 -3.18
Patrabandha 2.56
Podapatna 1.82
Sagargaon 1.62 - 3.8
Singhipur 1.54 - 6.85
Sanapadar Bayapalli 1.51 - 2.1
Biswanathpur 2.1 - 2.16
The zone showing fluoride concentration in different ranges in Bolagarh block is shown in fig- 4
The level of fluoride in phreatic ground water when compared over different periods (Nov-2004,March- 2005,Jan-2006)shows variations.
Table- 3: Fluoride concentration in ground water during different periods in the study area
District Block Village SourceFluoride concentration in
mg/l in different period
Nov-04 Mar-05 Jan-06
KhurdaBolagarh
Balasinghpatna Dugwell 10.6 11.2 8.7
Sagargaon Tube well 3.08 3.72 3.2
Begunia Akhupada Tube well 1.8 2.1 1.54
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Nayagarh Bhapur Salapada Tube well 2.5 2.9 1.8
It is seen that the fluoride concentration is also climatically controlled. The seasonal variation of fluoride concentration in ground water is shown in fig- 5
General characteristic of ground water : The pH value of ground water in the study area varies from 7 to 7.5 indicating the alkaline condition which favours the solubility of fluorine bearing minerals.TDS varies from 72 mg/l to3831 mg/l. Bicarbonate content varies from 18.3mg/l to500.2 mg/l and this high value indicates intense chemical weathering of the parent granitic rock.
Probable source of fluoride: In an attempt to establish the geochemical source of fluoride in water, petrochemical data of the rocks of study area were collected to know their fluoride content and is given in Table-5.
Table-4: Fluoride content of various rock types in the study areaRock types Location fluoride content in PPM
Granite gneiss Sagargaon 1560
Khondalites Nagapalli 860
Quartzites Exposure near Kaligiri river 265
Charnockites Nagapalli 1292
8
0
2
4
6
8
10
12
Nov-04 Mar-05 Jan-06
Flu
ori
de
co
nce
ntr
atio
n i
n m
g/lt
Balasinghpatna Dugwell
Sagargaon Tube well
Akhupada Tube well
Salapada Tube well
Period of sampling
Seasonal Variation of Fluoride Concentration in Ground water
Biological appraisal: Several cases of Dental fluorosis, Skeletal and nonskeletal fluorosis are reported in the
area which are shown in the photographs.
Quality management
No effective cures are available for either form of Fluorosis. However the diseases are preventable if fluoride intake is controlled. Geoscientists have an important role to play in the identification and amelioration of problems in areas at risk. As fluoride concentration in ground water originates naturally in the area hence following measures are suggested for prevention and control of Fluorosis.
Check against fluorosis:
a) Periodical survey of dental and skeletal fluorosis be made.b) All the bore wells and dug wells having F more than permissible limit i.e 1.5 mg/l should be
demarcated and abandoned. This water should not be used for drinking or cooking purpose.c) Provision should be made for alternative drinking water source.d) Selection of source be identified in areas with low alkalinity and high calcium content.e) Adequate calcium in daily diet and use of vitamins C must be practised in the endemic areas.
Biological control against fluorosis:
Biological defluoridation can serve as a best alternative to the conventional methods of defluoridation. Such methods would be cost effective and material employed would be biodegradable. Efforts are on in this direction and have yielded promising result.
Dr. Sriramchari (I.C.M.R) has suggested that inclusion of liquid concentrates of ripe tamarind fruit in the diet induces bio – unavailability of the fluoride ion thereby preventing the absorption of any fluoride by the body even when it is abundantly present in ground water.
Defluoridation techniques: The defluoridation techniques involve a number of methods described in brief.
A. High cost defluoridation techniques:
i) Ion exchange method: Before disinfection, a combination of cation exchanger and anion exchanger should be used to completely deionise the water. Then required amount of salt as per the B.I.S. standard can be added to the water.
ii) Reverse osmosis method: At high pressure, solvent is allowed to pass through a semi permeable membrane from a concentrated solution to a dilute solution. On this principle of reverse osmosis the fluoride concentration can be reduced.
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iii) Distillation method: Distillation separates salts completely from water; also disinfection is carried on simultaneously. Later on required amount of salt can be added to match the mineral water standard.
In fact, habitation in the rural areas cannot accept the above technology owing to its high operational cost, complexity of handling techniques etc. Hence some alternative techniques also have been developed so that people can accept the technology. These methods are given below. These methods for removal of excess fluoride in water are cost effective and easy to implement.
B. Cost effective Defluoridation techniques:
i) Nalagonda techniques: It is an economical way of defluoridation developed and proposed by NEERI (National Environment Engineering Research Institute), Nagpur (1987). This is a cheap and simple techniques based on insequence addition of bleaching powder, lime and alum to water & is vigorously stirred by which the fluoride settle as flocs. The treated water contains permissible amounts of fluoride. This technique can be easily adopted by villages at domestic and community level.
ii) Alumina based filters: Researches by IIT, Kanpur proved that activated alumina is more effective in removing excess fluoride. Thus activated alumina based Domestic Defluoridation Filter Unit (DDFU) need to be utilized in domestic level in each house.
Conclusion
The study revealed that high fluoride concentration more than 1.5 mg/l in ground water causes serious health hazards.So far as the origin of fluoride contamination is concerned, it can mainly attribute to be of natural rather than anthropogenic. High profile of fluorides in shallow zone ground water is due to the geochemical disposition. The toxicity of fluoride is also influenced by high ambient temperature, alkanity, calcium and magnesium contents in the ground water. Abnormal level of fluoride in water is common in fractured granitic, khondalitic & charnockitic rocks, which petrochemically contains higher concentrations of fluorides.
In general ground water contains more fluoride than surface water resources due to greater contact times with fluoride bearing minerals. The occurrences of fluoride concentration are always point specific. It is observed that
within one village different wells often show wide variation in fluoride content. This indicates that geological formation is not the only factor responsible for fluoride in ground water. The weathering of rocks, local hydrogeological conditions govern the fluoride content of ground water.
Practically no treatment is available for advanced stage of Fluorosis..So far as fluoride endemicity is concerned participative approach should be made both by the government and non-government organization towards popularizing the use of Domestic Defluoridation Filter Unit (DDFU) in the affected areas for reduction of fluoride concentration However, through public awareness people should be made aware of the excess fluoride menace and they should be advised to be refrained from consuming water having high fluoride concentration when and wherever detected. Further they should be aware of safe drinking water habits.
