REMOVAL OF COBALT (II) IONS FROM AQUEOUS SOLUTION ON ZINC(II) IONS DOPING CHITOSAN/HYDROXYAPATITE COMPOSITE

In the present investigation, bio-inorganic composite, which was synthesized with chitosan and hydroxyapatite by adding zinc(II) ions, have been prepared by precipitation method and was characterized by Fourier Transform infrared (FTIR) spectroscopy and energy dispersive X-ray analyzer (EDXA). Then, the composite was Used for removal of Cobalt(II) from synthetic aqueous solution. The effects of initial pH, contact time, kinetic and isothermal adsorption were studied in detail using batch adsorption at different temperature. The results showed that Cobalt(II) ions can be efficiently removed and also demonstrated that the kinetic data were best described by the pseudo-second-order model (R-2>0.99), While thermodynamic investigation of Cobalt(II) ions adsorption by zinc(II) doping Chitosan/hydroxyapatite (Zn-HAPCS) composite confirmed a spontaneous adsorption. Further investigations demonstrated that the adsorption pattern fitted well with Langmuir model (R-2>0.99), but less-satisfied with Freundlich model (R2<0.95).