Magnetic hydroxyapatite nanoparticles (MNHAP) adsorbents were synthesized and were used for the
removal of Cd2+ and Zn2+ from aqueous solutions. The properties of this magnetic adsorbent were characterized
by scanning electron microscopy (SEM), energy dispersive analysis system of X-ray (EDAX),
X-ray powder diffraction (XRD) analysis, zeta potential, BET surface area measurements and magnetization
curves. Experiments were carried out to investigate the influence of different sorption parameters,
such as contact time, initial concentration of metal ions, the dosage of MNHAP, pH value of the solutions
and competitive adsorption behavior. Kinetic data are well fitted by a pseudo second-order model and
the equilibrium data are analyzed by Langmuir model very well with high correlation coefficient. From
the Langmuir isotherms, the maximum adsorption capacities of MNHAP adsorbents towards Cd2+ and
Zn2+ are 1.964 and 2.151mmolg−1, respectively. The results revealed that the most prominent advantage
of the prepared MNHAP adsorbents consisted in their separation convenience compared to the other
adsorbents.