Water is the most crucial component and the building block of life on Earth. The world is facing water scarcity, affecting millions of people. Most of the population uses groundwater for drinking purposes. Groundwater can be contaminated by natural anthropogenic and industrial sources such as heavy metals, manganese, radioactive materials, nitrates, sulfates, iron, fluorides, arsenic, etc. In the Earth’s crust, fluorine ranks as the 13th most abundant element. Groundwater contains fluoride derived primarily from fluorspar, sedimentary rocks, cryolite, granite, fluorapatite, sellaite, dolomite, etc. The simultaneous presence of fluoride in groundwater is related to volcanic, geothermal, mining, and other activities. Although small amounts of fluorides are beneficial for dental and bone health in humans, fluoride in higher concentrations is detrimental to human health. Fluorides and other contaminants can affect health independently, synergistically, or antagonistically. The degree of leaching of crystalline minerals is directly related to the level of fluoride contamination. China, India, Mexico, and Pakistan are the countries most affected by groundwater fluoride contamination. Millions of people in China and India are at risk of fluoride. The following methods are currently used for fluoride removal: Chemical precipitation of coagulation, which also includes electrocoagulation floatation, Adsorption on special activated solids, ion exchange, and Membrane techniques, which include nanofiltration, reverse osmosis, electrodialysis methods, etc. Electrocoagulation and flotation techniques are relatively expensive due to high operational costs. Adsorption methods are the most widespread, but produce a significant amount of wastewater to recharge the adsorption beds. Based on the concentration of fluoride in water, these removal techniques can be applied sequentially to achieve the desired fluoride concentration that is safe to use. This chapter discusses in depth the global scenario of fluoride contamination in depth and briefly discusses its effects and possible ways to reduce and treat fluoride contamination.
