B Nova De Fluoridation BARC Teachnology
While the desirable limit of fluoride in water is 1 mg/ litre (ppm), several states in the country have higher fluoride content in water. It causes dental, skeletal and non-skeletal fluorosis. Treatment of fluoride contaminated water by use of De-flouridation column and subsequent polishing by ultra filtration process ensures efficient removal of fluoride as well as secondary aluminum contamination. A comprehensive technology comprising re-generable deflouridation followed by ultrafiltration is developed in the Department.
Pure water is scarce and is not easily available to all. Deprived sections of the society consume contaminated water and take ill periodically, often resulting in epidemics. The water may be contaminated by natural sources or by industrial effluents. One such contaminant is fluoride. Fluoride is a salt of the element fluorine. Fluorine is the most highly reactive element of halogen family. Small amounts of it are found in seawater, bone, teeth and in ground water mainly as fluoride ion. Most fluoride associated with monovalent cations such as NaF and KF is water soluble, while the one formed with divalent cations such as CaF2 and PbF2 is generally insoluble. Fluoride is "more toxic than lead and less toxic than arsenic" and is an accumulative toxin. Fluoride has dual significance; if its content is less then it may result in problems like dental caries. World Health Organisation (WHO) recommends it in the range of 0.1 "&" 0.5 ppm. The standard of the United States is between 0.6 and 0.9 ppm, and of India 1 and 15 ppm. Thus the requirement of fluoride content varies among countries and depends on the geography and the age of people involved. 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 is the process of removal of fluoride ion in drinking water. The process Defluoridation refers to methods of water treatment that reduce the concentration of fluoride in the water, normally, in order to make it safe for human consumption. Some water treatments that have the capacity of reducing the fluoride concentration along with most other anions, or anions and cations, in the water, are not considered as defluoridation methods.
In affected areas fluoride concentration in ground water is found ranging from 1.5 to 39 ppm which is more than permissible limits (<1ppm). It is observed that 30 % districts are affected in Madhya Pradesh, Maharashtra, and Bihar, whereas 50% districts in Uttar Pradesh, Rajasthan, Gujarat, Andhra Pradesh and Tamil Nadu are affected by fluorosis. Fluoride in ground or surface water is a result of natural deposits or from industrial/mining contamination.
The membrane assisted sorption process for removal of fluoride from ground/surface water provide safe drinking water and solves the serious problem of aluminium contamination in the product water coming after defluoridation unit, which is more dangerous than fluoride. Therefore, by this process it is providing water not only free from fluoride but also free from secondary contaminants like aluminium and microorganisms which will be removed by ultrafiltration membrane. It is a simple, cost effective, adoptable at both domestic and community level and having capability of high decontamination.
ADVANTAGES
- It requires minimum contact time for maximum defluoridation.
- Defluoridation capacity at neutral pH is appreciable.
- Its defluoridation capacity is independent of temperature.
- Production of safe drinking water not only free from fluoride but also free from secondary contaminants like aluminium and microorganisms.
- No electricity is require.
