Researchers at the Indian Institute of Technology (IIT) Hyderabad have used activated jamun seed powder to bring the fluoride content in drinking water to less than the WHO limit of 1.5 mg per litre. The results were published in the Journal of Environmental Chemical Engineering.
The team at IIT Hyderabad mixed the jamun seed powder thoroughly with potassium hydroxide and heated it to 900 degree C for an hour to produce activated jamun powder. The activation increases the pore volume several times and the surface area by more than 50 times. As a result, the fluoride adsorption efficiency increased several times. With fluoride adsorption capacity of 3.65 milligram per gram, activated jamun seed was close to tea ash (3.75 milligram per gram) but much higher than other substances such as banana peel, coffee husk, and coconut shell.
On heating the activated jamun powder to 50 degree C, the fluoride gets desorbed and the jamun powder can be reused up to five times. About 96% of the fluoride can be desorbed. So there is a loss of only 4% efficiency after each desorption.
Disposal of sludge Disposal of the fluoride sludge is another area that the team is working on.