Synthesis and application of magnetic chlorapatite nanoparticles for zinc (II), cadmium (II) and lead (II) removal from water solutions.

Magnetic chlorapatite nanoparticles (MNCLAP) was synthesized and used as adsorbent to remove Zn2+, Cd2+ and Pb2+ from aqueous solutions. The synthesized MNCLAP was characterized by scanning electron microscopy (SEM), energy dispersive analysis system of X-ray (EDAX), transmission electron microscopy (TEM) X-ray powder diffraction (XRD) and magnetization curves. Influence of different sorption parameters, such as equilibration time, initial heavy metal concentration, the amount of MNCLAP, pH values and competition adsorption were investigated in this study. Moreover, the desorption experiment was also carried out to explore the adsorption property of MNCLAP. The adsorption kinetic data has a very high correlation coefficient (R2=0.9999) with the pseudo-second-order kinetic model, and the Langmuir model was used in describing adsorption isotherms. The maximum adsorption capacities of MNCLAP adsorbent towards Zn2+, Cd2+ and Pb2+ were 1.1769, 1.1022 and 1.1546mmolg-1, respectively. EDTA solution was the best efficient eluant for heavy metal desorption with 25.94%, 22.95% and 32.84% released rate of Zn2+, Cd2+ and Pb2+, respectively. Experimental results revealed that the prepared MNCLAP combined both the properties of chlorapatite and magnetic material and it showed remarkable advantages in heavy metal removal from aqueous solutions.