Removing fluoride with nanoparticles

A low-cost method to remove fluoride from drinking water with specially made teabag-like pouches has been developed by a team of Indian researchers. 

This method uses pouches covered with nanoparticles synthesised from organically-grown jojoba seeds to remove fluoride from water. Jojoba is easily available and nanoparticles used (iron and aluminum) are synthesised from waste byproducts of the oil extraction process from jojoba seeds.

After synthesis, nanoparticles are soaked onto a foam material—polyurethane foam—wherein they get stuck to the surface of the foam. Infusion pouches or bags are then made from the nanoparticle-coated foam sheet. The nanoparticles on the pouches attract fluoride in the water and they too get stuck to the surface of the pouch. This process is a commonly used water purification method called adsorption. 

Researchers Dr Suphiya Khan and Sonu Kumari from the Department of Bioscience and Biotechnology at Banasthali Vidyapith in Rajasthan say the method is both cost effective and green. The estimated cost of each pouch is about Rs 3. All that one will need to do is dip the special pouch in water and it will remove fluoride from water. They have also tested the same method with infusion bags filled with tea as tea is known to accumulate a lot of fluoride.

Results of the fluoride analysis published in the journal Scientific Reports show that after 80 minutes of infusing, no more fluoride was collected as all the empty spaces on the surface were used up. When tested with pouches filled with tea, it was found that large amounts of fluoride got collected in black, green and jasmine tea samples tested, but black tea accumulated the highest amount. 

While small amounts of fluoride are required for the development of bones and teeth, an excess of it can cause fluorosis—a disease known to cause spotting of the teeth enamel, weak bones, thyroid and kidney problems. Fluoride-contaminated groundwater is a serious health issue in several parts of the country. (India Science Wire)