Magnetization and functionalization of activated carbon prepared by oak shell biowaste for removal of Pb²⁺ from aqueous solutions

<p>In this research, the chemically treated activated carbon prepared by oak shells was magnetized and functionalized by dithizone. The adsorbent was then characterized by Fourier transform infrared, X-ray diffraction, scanning electron microscope, TG–DTG, and vibrating sample magnetometer techniques and its performance for removal of Pb²⁺ from aqueous solutions was studied under different experimental conditions. Under optimized condition, the adsorption capacity of 255 mg g⁻¹ was obtained which was higher than the reported values. The adsorbent was selective in the presence of 500 mg L⁻¹ of Na⁺, K⁺, and Mg²⁺, 200 mg L⁻¹ of Zn²⁺ and and 80 mg L⁻¹ of Hg²⁺. The experimental data was fitted to the Langmuir isotherm and pseudo-second-order kinetic models. The adsorbent was separated by magnetic field and regenerated by HCl solution.