Phosphorylated cellulose paper as highly efficient adsorbent for cadmium heavy metal ion removal in aqueous solutions

In search for more effective and eco-friendly adsorbent materials, this study comprehensively investigated Cd²⁺ adsorption onto phosphorylated cellulose paper (PCP). For this, cellulose microfibers (CMF) was extracted from Alfa fibers and phosphorylated using the solid-state phosphorylation approach. Then, the prepared PCP samples were characterized by SEM, EDX, XRD, FTIR, TGA, conductometric titration and zeta potential measurement. The adsorption of cadmium ions, the effect of time, pH and Cd²⁺ initial concentration were systematically studied in batch experiments. Based on the results, the highest adsorption capacity achieved was 479 mg of Cd²⁺ per g of PCP, which was remarkable compared to other modified cellulose capacities cited in the literature. Furthermore, the Cd²⁺ removal mechanism was investigated based on characterization results before and after adsorption and also based on the kinetics results. It was concluded that cation exchange and electrostatic attraction between phosphorylated cellulose and the cadmium ion mainly dominated the adsorption process. These findings highlighted that the phosphorylated cellulose paper has a broad application prospect in removal of divalent metal from aquatic solution.