Leaves and stem of Tulsi can detoxify water with high-fluoride content, and make it safe for human consumption

Syed Akbar

Hyderabad: In a major relief to millions of people living in fluoride-hit areas, a team of Indian researchers has found that the leaves and stem of Tulsi can detoxify water with high-fluoride content, and make it safe for human consumption. The quality of water one gets will be on par with the norms prescribed for fluoride content by the Bureau of Indian Standards (ISI).

Tulsi or Ocimum sanctum has natural bio-adsorbent properties i.e. the leaves and stem of this Indian herb serve as natural magnet to adsorb (attach) the fluoride molecules in water. All one has to do is to take a few leaves or stem pieces of Tulsi and dip them in a glass of water for 20 minutes. Remove the leaves or stem pieces and drink the water.

Researchers from the department of environmental sciences, Sardar Patel Mahavidyalaya, Chandrapur, have successfully demonstrated defluoridation of water using Tulsi as a bio-adsorbent. The team led by assistant professor RK Kamble used fresh and dried Tulsi leaves, stem pieces and extract obtained from the fresh leaves to remove fluoride content from water. They used both boiling and shaking methods. In the boiling method, they boiled the water with the Tulsi, and in shaking method, they kept Tulsi in water and gently shook the glass.

“With initial fluoride concentration of 5 ppm, it was observed that maximum 94 per cent of fluoride can be removed at a dose of 75 mg of fresh basil leaves for a sample of 100 ml for a contact period of 20 minutes,” Kamble pointed out.

Fresh basil stem with a dose of 100 mg/100 ml had a removal efficiency of 75 per cent, whereas for dry leaves and dry stem at a dose of 250 mg/100 ml, the removal efficiency was 78 per cent and 74 per cent respectively.

“This makes the fluoride concentration within the permissible limit of Indian standard for drinking water (IS 10500:1991, Fluoride 1.0-1.5 ppm). The efficiency of adsorption of fluoride ion was affected by pH, quantity and size of Tulsi parts used. This technique is cost effective, environment friendly and easy to understand and can be adopted in rural as well as urban background throughout the year,” he added.

About 10 lakh people in 500 villages in Nalgonda district alone are affected by the high fluoride content in water. The fluoride content in ground water in the district ranges between 0.4 ppm to 20 ppm.