A Review of Defluoridation Techniques of Global and Indian Prominence

Fluoride(F-) is the 13thmost abundant chemical element in the Earth's crust which has been widely recognised for its health benefits at low concentration but poses a serious threat to public health at very high doses. The world health organization has set the fluoride guideline limit of 1.5 mg/l in drinking water. Globally, over 260 million people drink water with high fluoride concentrations. Widespread distribution and high fluoride levels in the potablewater in most of the areas of the world has prompted substantial research and mitigation efforts to address the growing public health concerns related to fluoride contamination. With the recent advances in science, various defluoridation methods such as adsorption, ion exchange, precipitation-coagulation, membrane processes, biological defluoridation and even integrated approaches have been developed for the management of fluoride-contaminated aquatic environments. This review provides an up-to-date insight into thedefluoridation techniques developed and implemented throughout the world and highlightsthe advantages and disadvantages of each technique.The literature survey confirms that despite developing so many novel techniques for defluoridation over the years, there is still no effective fluoride removal technique that can achieve the desired results in a cost-effective and sustainable manner. Therefore, development of a commercially practical, economical, and sustainable technique is required to prevent people especially the most vulnerable from poor and developing nations (dependent on untreated water)from the hazards of fluoride contamination.