Evaluating the Efficiency of Fresh and Modified Manganese Oxide Bone Char for the Removal of Fluoride from Water: An Isotherm Study

The purpose of this research was to study both fresh and manganese oxide modified bone char as an adsorbents for the removal of excess fluoride from drinking water. This research was an experimental (laboratory) study. Fresh bone char was obtained from raw bone pyrolysis at 450 °C. For bone char modification thermo-chemical reaction and a manganese compound was applied. Adsorbent surface characteristics and specifications were prepared by a conventional method, BET, BJH, XRD, respectively. The effect of fluoride concentration, the amount of adsorbent and pH on the adsorption capacity were investigated. Also the adsorption data were analyzed using the Langmuir, Freundlich and Temkin adsorption isotherm. The results showed that the adsorption of fluoride in bone char types often follows Freundlich isotherm. Increased concentrations will increase the adsorption rate. An increase in the rate of adsorbent led to increasing the adsorption capacity and can reduce the removal efficiency. The optimum mass of adsorbent and pH were 0.5g and 7 respectively. Modification of Bone char with manganese oxide increases the specific surface area and a higher efficiency in the removal of fluoride will be adsorbed. Results show that this adsorbent can be used for the removal of fluoride in water operating (operational conditions) environments and after adsorption processes would not need to stabilize PH.