Potentially low -cost drinking water defluoridation methods - a review

Abstract

Excessive fluoride in drinking water causes dental and skeletal health problems commonly known as fluorosis. Both high fluoride concentration and fluorisis are prevalent in many parts' of the Ethiopian rift valley. The recommended limit of fluoride by the World Health Organization (WHO) ranges from 0.5 - 1.5 ppm, whereas water with fluorid concentrations as high as 9 mg/l are used in some part of the Ethiopian Rift Valley. A number of studies have been conducted to identifY the fluoride concentrations in different areas and their effect on the population. However only limited research have been carried out to develop appropriate defluoridation techniques affordable for developing countries like Ethiopia. In this review, an extensive list of materials that are proposed for the treatment of fluoride has been compiled and evaluated to provide a' summary of available informatioln on a wide range of potentially low-cost methods. Techniques that can utilize locally available materials and simple technologies .have been given more emphasis. Future research directions for further improvements of proposed methods and the development of new defluoridation techniques based on locally available materials has been suggested.