Surface‐functionalization of activated carbon with polyglucosamine polymer for efficient removal of cadmium ions

In this work, a polymer‐activated carbon composite was prepared by grafting polyglucosamine polymer on the surface of activated carbon, which was produced by a carbonation/calcination/oxidation process of the Date palm pits. The obtained composite was confirmed by different techniques, including, X‐ray, infrared, thermal analysis, scanning electron spectroscopy, and Brunauer‐Emmett‐Teller protocol surface area measurements. Subsequently, a comprehensive adsorption study was performed to assess the synergetic effect of the composite structure on the adsorption behavior of Cd 2+ ions. The adsorption capacity of Cd 2+ ions reached 35.0 mg/g at optimum adsorption conditions of pH 5.5, a composite dose of 200 mg, and a contact time 120 minutes. The kinetic, isothermal, and thermodynamics results indicated chemisorption, an exothermic, and a spontaneous adsorption process. The adsorption mechanism of the composite correlated to the functional groups (NH 2 and COOH) and the cavities of the composite (surface area 699.11 m 2 /g, pore volume 0.28 cm 3 /g), which potentially contributed to the capture of the Cd 2+ ions. From the recyclability point of view, the composite was able to maintain around 89% of its initial adsorption capacity after the third adsorption‐desorption cycle.