Reporting in the journal Proceedings of the National Academy of Sciences, the researchers demonstrated that their novel polymer membranes can separate fluoride from chloride and other ions – electrically charged atoms — with twice the selectivity reported by other methods. They say the application of the technology could prevent fluoride toxicity in water supplies where the element occurs naturally at levels too high for human consumption.
It is well known that adding fluoride to a water supply can reduce the incidence of tooth decay, including cavities. Less well known is the fact that some groundwater supplies have such high natural levels of fluoride that they can lead to severe health problems.
Prolonged exposure to excess fluoride can cause fluorosis, a condition that can actually weaken the teeth, calcify tendons and ligaments, and lead to bone deformities. The World Health Organization estimates that excessive fluoride concentrations in drinking water have caused tens of millions of dental and skeletal fluorosis cases worldwide.
The ability to remove fluoride with a relatively inexpensive filtering membrane could protect communities from fluorosis without requiring the use of high-pressure filtration or having to completely remove all components and then re-mineralize the drinking water.
“The potential for ion-selective membranes to reduce excess fluoride in drinking water supplies is very encouraging,” said Ayse Asatekin, associate professor of chemical and biological engineering in the School of Engineering.
“But the technology’s potential usefulness extends beyond drinking water to other challenges. The method we used to manufacture the membranes is easy to scale up for industrial applications. And because the implementation as a filter can also be relatively simple, low cost, and environmentally sustainable, it could have wide applications to improving agricultural water supplies, cleaning up chemical waste, and improving chemical production,” Ayse added. (ANI)