Ecofriendly synthesis of hydroxyapatite from fish scales and its application toward adsorptive removal of Pb(II)

This study depicts the preparation of hydroxyapatite (HP) from scales of Tor putitora fish. Chemical composition and surface structure of the prepared HP was evaluated using SEM, TGA, EDX and FTIR analysis. The prepared HP was tested for adsorptive removal of Pb(II) from contaminated water. Different factors, including concentration, pH, temperature, biosorbent dosage and time were investigated for Pb(II) removal by the prepared HP. It was deduced that with an increase in the initial metal concentration, adsorption of Pb(II) was increased and equilibrium position was obtained at 500 mg/L. For all except sodium hydroxide treated samples, pH of PZC was around 7.3. Also, maximum adsorption occurred in the initial 30 min. Freundlich-model fitted the equilibrium results well compared to the Langmuir-model. Results demonstrated that chemical modification of HP increased the Pb(II) adsorption and optimum adsorption took-place on phosphoric acid treated HP. These results exhibited the efficiency of prepared hydroxyapatite as bioadsorbent toward water disinfection.