A Review on Defluoridation of Water through Natural Adsorbents

Fluoride is often described as a 'double-edged sword' as in adequate ingestion is associated with dental caries, where as excessive intake lead to dental, skeletal and soft tissue fluorosis. Defluoridation of water done by natural adsorbents such as Drumstick seeds (MoringaOleifera), Roots of vetiver grass, Tamarind seeds, coconut shell carbon, rice husk carbon and algae like ulvafasciata species. Algae traditionally used as food supplement and are generally safe. Tamarind seed is a household material and is left as waste after removing tamarind pulp, this material is familiar with all kinds of people. It is simple viable defluoridation adsorbent that could be adopted easily by villagers. Tamarind seed sample in the free and fluoride loaded conditions were characterized by SEM (Scanning Electron Microscope) and FTIR (Fourier-Transform Infrared spectroscopy). Roots of Vetiver grass are another product have traditionally used for water purification. The roots were effective and could remove as much as 70% of fluoride from a sample. Drumsticks seeds (MoringaOleifera) act as a coagulant. They have been traditionally used for purification of turbid water. They have remarkable defluoridation efficiency, which was higher than that of activated Alumina. Natural adsorbents are easily available and are economic, which makes defluoridation process affordable, thus people can attain a good oral hygiene at affordable cost.