The Removal of Lead from Aqueous Solution Using Almond Green Hull (Prunus amygdalus-Fascionello) Waste Material Magnetized with Fe3O4

Abstract

Background: Nowadays, with extensive industrialization, pollution of heavy metals in the environment has increased significantly, which is considered a serious environmental risk for toxicity, carcinogenicity, and biological accumulation. Meanwhile, lead is one of the most important systemic toxic heavy metals, which attacks most organs of the body after adsorption. The aim of this research was to evaluate the efficiency of green almond hull (Prunus amygdalus- Fascionello) magnetized with Fe3O4 to remove lead from aqueous solution. Methods: In this study, the structural characteristic of green almond hull magnetized with Fe3O4 was investigated using a scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) techniques. Also, the effect of different parameters, including pH (2 to 10), mixing speed (0 to 250 rpm), adsorbent dose (1 to 7 g/L), initial concentration (10 to 100 mg/L), and contact time (5 to 200 minutes) was examined to study lead adsorption process by the desired adsorbent. Finally, the experimental data obtained from the equilibrium tests were analyzed using Freundlich and Langmuir isotherms models. Results: The results of this study showed that the maximum removal efficiency was obtained at pH 9 and adsorbent dose of 5 g/L. The removal efficiency was reduced by increasing the initial concentration of lead, and increasing contact time and mixing speed. The maximum lead adsorption at optimal conditions was 91.34%. The results also showed that the resulting data often followed the Langmuir isotherm. Conclusions: According to the results, it could be concluded that green almond hull (Prunus amygdalus-Fascionello) magnetized with Fe3O4 could be used as an affordable and proper adsorbent in removal of lead from aqueous solutions.