A statistical analysis of the results obtained from this experi- mental design was performed to determine the effect of pyrolysis conditions on the fluoride adsorption properties of bone char. In addition, this analysis was used to identify those operating param- eters of pyrolysis process that improve the performance of this adsorbent for fluoride removal from water. Statistica® software was used for data analysis.
The best pyrolysis conditions were identified and the syn- thetized adsorbent was used in additional removal experiments for determining kinetics, isotherms and thermodynamic parameters of the fluoride adsorption on bone char at different conditions of tem- perature and pH. Specifically, the optimized bone char sample was used for determining the fluoride adsorption rates at initial fluoride concentrations of 10, 30 and 50 mg/L, respectively. On the other hand, the fluoride adsorption isotherms using this bone char were obtained at pH 6, 7 and 8 and 20, 30 and 40 ◦ C. Residence time used for batch adsorption experiments ranged from 0.5 to 24 h. These results were used for the calculation of adsorption thermodynamic parameters.