removal of pb(ii) from aqueous solutions using magnetic nanocomposite

In recent years, water pollution by heavy metal ions has been a widespread environmental problem because of non biodegradability, accumulation in environment and living body, discharge and harmful effects of these heavy metals [1]. heavy metals are mostly originated from industrial activities resulting in the release of toxic metals into the environment directly or indirectly, reaching the air, soil and water sources [2]. lead (pb) and its compounds can result in damage of living organisms, depending on the level and duration of exposure [4]. therefore, removal of toxic lead ions prior to disposal is very important task. in the present study, magnetic sepiolite nanocomposite was prepared via facile hydrothermal method. the formed nanocomposite was employed to removal of pb(ii) ions from water samples. the structure properties and morphology of the prepared nanocomposite were characterized by scanning electron microscopy (sem), fourier transform infrared spectroscopy (ftir), x- ray diffraction (xrd) transmission electron microscopy (tem), and vibrating sample magnetometer. the effect of several parameters including initial concentration of pb(ii) ions, ph, adsorbent dosage and contact time was examined to optimize the conditions for maximum removal of pb(ii) ions. equilibrium data and isotherm constants were evaluated using freundlich and langmuir models. the maximum adsorption capacity under optimal conditions was calculated 96.15 mg g-1. kinetic data were analyzed using the first-order and second-order lagergren equations. the pseudo-second-order kinetic model was fitted (r2 = 0.9998), which indicates that removal of pb(ii) ions could be controlled by the chemical adsorption process. the as-prepared magnetic sorbent was easily reused through sequential adsorption-desorption cycles, indicating that the resulting nanocomposite has an acceptable stability and reusability. this study shows that the prepared nanocomposite can be utilized as an efficient and magnetically separable sorbent for the environmental treatment.