Preliminary Assessment of Defluoridation of Groundwater in Tamil Nadu, India, by Strychnos potatorum Seeds

Water is one of the natural resources required for life on earth. Contaminants (natural or manmade) in drinking water affect the human health. Because of the high cost of abstraction and the poor quality of groundwater, the significance of groundwater as an alternative water source is recognized. Unfortunately, groundwater is getting contaminated as a result of a variety of natural and human causes. One of the natural contaminant, fluoride (electronegative element) is present high in rocks as well as deep well/bore well water and causes dental fluorosis. Water samples were collected from selected villages of Dharmapuri and Krishnagiri district and analyzed for physicochemical parameters. The objective of our study is to find out the natural flocculant/coagulant potential of Strychnos potatorum seeds that could readily and easily eliminate chemicals and serves water as a common applicable technique, column adsorption. Total dissolved solids (TDS), Mg²⁺, and Ca²⁺ levels in water were moderately altered on incubation with biocoagulant, Strychnos potatorum seeds. P³⁻, S²⁻, and NO⁻₃, SO²⁻₄, and Cl⁻ levels were notably altered from the very high level to the permissible level as in soft water. The highlight of purification of water with Strychnos potatorum seeds is the drastic reduction in fluoride content, and the quantity of water was recommendable for drinking purposes as equivalent to soft water. This result significantly reveals soft water obtained after purification is found to be superior to reverse osmosis water with adequate minerals in potable water. Thus, natural biocoagulant sustains the quality of the drinking water and efficiently eliminates toxic fluoride. The present study concludes that natural contaminant fluoride in deep well and deep soil water could be effectively defluoridated by natural biocoagulant Strychnos potatorum seeds without altering physicochemical properties of drinking water.