Performance Evaluation of Bauxite Activated Mines in Yazd Province in Order to Remove Fluoride from Drinking Water (Case Study: Kuhbanan Water)

Introduction: A high concentration of fluoride causes health problems in man. How to remove excess fluoride from water is the objective of this project. The study focuses on an evaluation of the performance of activated bauxite mines in Yazd province in order to remove fluoride from drinking water. Materials and Methods: This study was an experimental one and conducted on synthetic samples and water from May to November of ۲۰۱۳ in Kuhbanan region at the Environmental Health Engineering Research Center. Bauxite was taken from Sadr Abad and Shomal-e-Yazd mines. Bauxite analysis was performed using X- Rey Fraction and X-Ray Diffraction. The effects of pH, contact time, adsorbent dose and different concentrations of fluoride on defluoridation were determined. The optimal conditions were performed on real samples. In order to better understand the processes of absorption, synthetic and adsorption isotherms were studied. Fluoride content was determined by the SPADNS method and data analysis was performed by Excel. Results: The maximum removal efficiency for synthetic solution was obtained by ۲۵g/L bauxite of Sadr Abad mine and ۳۰g/L bauxite of Shomal-e-Yazd mine at pH ۷, the contact time of ۱۸۰ minutes as ۷۵.۳۱% and ۵۹.۹۰%, respectively and removal efficiency of actual samples in optimum conditions was ۵۱.۲۱% and ۳۶.۶۸%. Freundlich isotherm with a correlation coefficient greater than ۹۹% showed better results for both types of bauxite. Conclusion: bauxite from Sadr Abad mine is more efficient in comparison to bauxite from Shomal-e-Yazd mine.