Membrane Assisted Defluoridation Process for Safe Drinking Water
Introduction
India is one among 25 nations in the world where fluorosis problem is persisting due to consumption of excess fluoride bearing drinking water. 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 harmful 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.
* UF Membrane Unit shown in above fig. is a part of process. It is a separate technology available with BARC for transfer.
Advantages of the system
- 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.
- It can be operated with/without the use of electricity.
Applications
- This technology is extremely useful for removal of fluoride from ground/surface water to provide safe drinking water free from primary contaminant like fluoride as well as secondary contaminants like aluminium and microorganisms.
- Technology can be adopted at both domestic and community level and may work without electricity.
PROCESS
The technology of UF membrane assisted sorption process/device for removal of fluoride from ground/surface water used for drinking purposes consists of two steps:
- Sorption of fluoride on activated alumina sorbent.
- Separation of leached out secondary contaminant like aluminium using indigenously developed UF membrane device.
RAW MATERIALS
All the raw materials required for defluoridation are available in the local market.
Infrastructure
The development of fluoride decontamination process requires a small laboratory with few common equipments like pH meter, analytical balance and common glasswares.
Manpower
One Chemist and one skilled worker would be adequate for the purpose.
