Fluoride occurrence, health issues, and removal using adsorption process

Abstract

Safe drinking water is a key ingredient to a sustainable life for mankind. Fluoride is considered a micronutrient required in a minute quantity for the proper functioning of bones and teeth in humans. However, its higher concentration could lead to toxic effects on skeletal and dental health. The amount of fluoride required can be easily achieved through the consumption of vegetables, cereals, and drinking water (within desirable limits). Fluoride beyond the limits in groundwater has become a major issue in most of the states of India while Rajasthan has been considered as most severely affected with fluorosis where all the districts were reported with a high concentration of fluoride in groundwater. Adsorption technique was recently developed as a low-cost method that can potentially remove excess fluoride from groundwater. Numerous adsorbent developed so far has been discussed in this review to explore their potential for defluoridation. The ability of this method greatly depends on the development of adsorptive materials. It was found after the literature survey that several types of adsorbent using chemicals as well as vegetative waste have been developed and studied to quantify the removal capacity of fluoride from water. However, their utility on the water is still needed to be studied to explore these adsorbents for commercial use leading to the improvement in water quality.