Fluoride contamination in drinking water from natural and man-made activities has been identified as one of the major global problems posing a serious threat to human health. The presence of fluoride at low concentrations (<1.5 mg / l) is beneficial for the calcification of tooth enamel and the maintenance of healthy bones. On the other hand, its presence in higher concentration becomes a monster and can cause dental, skeletal fluorosis as well as non-skeletal problems.Therefore, the need for a cost-effective, simple and user-friendly method for water defluoridation is being felt in these areas. Among several applied treatment technologies for the removal of fluoride, the adsorption process has been widely studied and offers satisfactory results especially with mineral-based and / or adsorbents modified on the surface. The literature shows that various adsorbents have shown good potential for fluoride removal. However, there is still a need to discover the practical utility of such commercially developed adsorbents, leading to improved control of pollution.
Many researchers have experimented and developed a variety of low-cost technologies to remove fluoride from water and wastewater. However, the selection of the appropriate treatment method depends on the local situation. In this experiment, the removal of fluoride from water by adsorption is studied. Clay & CaCO3 (eggshell powder) containing pellets as an adsorbent used to reduce fluoride contamination from water. The study was carried out on the adsorption of the fluoride ion to analyze the effect of various parameters such as pH, contact time, adsorbent dose and initial concentration. A batch adsorption study was conducted to analyze the adsorption of fluoride in groundwater.
The results obtained showed that sorption on clay & CaCO3 pellets could be an effective method for the removal of fluoride. The effectiveness of the pellets to remove fluoride from the water was 84.06% at pH 6.
5 ± 0.1, 72 hours contact, 70 g L-1 adsorbent and 2 mg L-1 fluoride initial. The pH change increased during defluorination. Higher F- shrinkage was noted when flow was lower and pellet size decreased.