Impact of fluoride in potable water - An outlook on the existing defluoridation strategies and the road ahead

To have or not to have fluoride in water is quite a debatable proposition although an upper limit of 1.0 mg L-1 is regarded as fairly safe. It has been known since long that small amount of fluoride is good to prevent tooth decay. However, the deleterious effects of excess fluoride in water have led to the evolution of diverse defluoridation strategies. With the growing concern in the development of novel and eco-friendly adsorbent materials, it is also important to improvise and re-examine the strengths and shortcomings of the various techniques. Fluoride, being a hard base, the modification of materials with hard cations such as Al(III) fosters effective coordination as Al-F bonding on the surface. Towards this direction, we present an overview on different methods to alleviate the fluoride contamination and assess the importance of inherently sustainable adsorbent materials that could propel more research and development towards realizing the goal of clean and safe drinking water. (C) 2019 Elsevier B.V. All rights reserved.