Synthesis and polymeric modification of hydroxyapatite from biogenic raw material for adsorptive removal of Co2+ and Sr2+.

A gamma induced copolymerization process was applied to modify hydroxyapatite prepared from eggshell. The composite material was characterized by different physicochemical methods, and then it was used for removal of Sr2+ and Co2+ ions from aqueous solutions as a function of pH, temperature, time, interfering ions, and initial Sr2+ and Co2+ concentrations by applying batch adsorption technique. The maximum removal was obtained at pH 6, and 8 for Sr2+ and Co2+ ions respectively. Sorbents regeneration was successful with HCl eluent. Results showed good fitting to Freundlich isotherm than Langmuir. Kinetic data was well described by pseudo-second order equation. [ABSTRACT FROM AUTHOR]