What is Fluoride Nilogon?

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Fluoride Nilogon is a method for removal of excess fluoride from contaminated groundwater for drinking purpose through phosphoric acid - crushed limestone treatment based on precipitation-adsorption developed by Dr. Robin Kumar Dutta, Professor of Chemistry, and his research group in the Department of Chemical Sciences of Tezpur University.

The name ‘Fluoride Nilogon’ was coined in analogy to the name of ‘Arsiron Nilogon’, another technology developed by the same group for removal of arsenic and iron together from contaminated groundwater. The word ‘Arsiron’ was derived from Arsenic and Iron (Ars + iron = Arsiron). Here, ‘Nilogon’ is an Assamese equivalent of ‘removal’ in English and ‘अलगकरना’ in Hindi.

 

How is Fluoride Nilogon done?

 

In Fluoride Nilogon, the fluoride containing water, mixed with a small quantity of phosphoric acid, is put into a crushed limestone bed plug-flow reactor and kept for a residence time of at least three hours. Fluoride is removed in the reactor. The water is filtered using a sand-gravel filter after three hours.

 

How is Fluoride Nilogon filter made?

 

The unit consists of two-stages and can be custom designed. The first stage is the crushed limestone bed plug-flow reactor. The reactor can be made of any container, preferably a plastic bucket or plastic drum, fitted with a plastic tap towards the bottom. The second stage is a sand-gravel filtration made of a bucket or any other container with a plastic tap towards the bottom.