Investigation of Fluoride Removal Efficiency from Aqueous Solution by Pistachio and Almonds Crust

Fluoride and its compounds are widely used in industries and then through effluent are released into the environment. The purpose of this study was to evaluate Efficiency of low cost adsorbents (pistachios coal) in the removal of fluoride from aqueous solutions.
For the preparation of adsorbent, crust of pistachios deride, then washed with distilled water, then powder in the furnace for burning for 2 hours at temperatures of 500, 600, and 700 °C. The effect of changing pH, burning temperature of adsorbent, stirring speed, initial concentration of fluoride, retention time and adsorbent dose was studied. Concentration of fluoride measured according to standard method using spectrophotometer the data were analyzed using Excel software.
The results of these experiments showed that the burning adsorbent, temperature 500 ° C, PH of solution in the neutral range (pH = 7), adsorbent dose of 2 g/L for absorbing almonds and adsorbent dose of 3 g pistachio, contact time of 40 minutes for both adsorbent, initial fluoride concentration (5ppm) for both absorbent without mixing, the optimal conditions for the efficiency of the absorber is as much as 90-80 percent.
According to the results, pistachio coal can be used with high efficiency for fluoride removal.