Performance of fluoride adsorption by snail shell in aqueous

Corresponding author : jamalmehralipour@yahoo.com Introduction : Fluoride in low concentration is essential for human but in high concentration is very hazardous for human health. The efficacy of Snail Shell (SS) was investigated in this research work as an adsorbent for the elimination of fluoride from aqueous. Material and Methods : In this experimental study, the capability of SS to adsorb fluoride ions was conducted using a series of batch tests in a shaker-incubator instrument. For each batch run, 100 mL of solution containing a known initial concentration of Fluoride and with the preferred level of pH was shacked. The effects of selected parameters  such as pH (3-11), reaction time (5–60 min) cyanide concentrations (5–10 mg/L)  and the adsorbent dosage (0.25–2.5 g/L) were investigated on the removal fluoride as a target contaminate. Chemical composition SS were analyzed using a Philips model XL-30 scanning electron microscope (SEM) with energy-dispersive X-ray microanalysis (EDX). The concentration of Fluoride in solution before and after treatment was determined using the HACH method. Results : Analysis of the SS component using the EDX technique showed that the main part of it consisted of calcium and its other components were magnesium, aluminum and silicate. The experimental data showed that the maximum fluoride removal occurred at pH of 7, adsorbent dose (0.5 g/L) and 30 min contact time and 5 mg/lit initial concentration. The kinetic evaluation indicated that the pseudo-second-order kinetic had the best fit to the experimental results predicting a chemisorption process. The equilibrium adsorption of fluoride onto SS was well represented by the Langmuir equation. Conclusion : As a result, SS was revealed as a very efficient and low-cost adsorbent and a promising option for removing fluoride from industrial wastewaters. Key Words : Snail shell, Adsorption, Fluoride, Isotherm, Kinetic