Removal of Fluoride from Water Using Low Cost Adsorbents

Fluoride is an essential constituent for both humans and animals depending on the total quantity ingested or its concentration in drinking water. The aim of this study is to find out the low cost treatment for removal of fluoride from drinking water. The current study can be implemented on a domestic basis. Batch and column adsorption studies were undertaken using the Beetroot seeds and Okra seeds as adsorbents. Studies were carried out under the varying conditions of the major parameters of adsorption, viz. pH, rate of stirring, contact time and dose of adsorbent. Initially the batch studies were undertaken for Beetroot seeds and were followed by Okra seeds. A combination of both adsorbents is also tried. All the experiments were carried out at pH=7. The fluoride adsorption is maximum for batch experiment at 90 minutes of contact time. It was found that the sufficient time for adsorption equilibrium of fluoride ion was around 2 hours. The removal of fluoride ions is maximum for the adsorbent dosage of both the seeds is around 8 gm/ lit. The adsorption of fluoride ion is maximum in the stirring speed of 150 rpm. Column analysis gave efficiency in initial stage of 78 percent for 0.4lit/hr flow rate and the efficiency goes on decreasing after some time. Fluoride determination was carried out with the help of visible Spectrophotometer (HACH DR 3900).