Upon designing carboxyl methylcellulose and chitosan-derived nanostructured sorbents for efficient removal of Cd(II) and Cr(VI) from water.

Considering that the hazardous heavy metal ions like Cd(II) and Cr(VI) are widely present in the environment, nowadays employing easy-to-handle adsorption-oriented processes are feasible choices towards efficient remediation of Cd(II) and Cr(VI) from aqueous systems. Herein we developed a novel amino-functionalized bead with cost-effectiveness, high sorption capacity and fast sorption kinetics to remove Cd(II) and Cr(VI) from aqueous solution. The carboxyl methylcellulose and chitosan-derived nanostructured sorbents synthesis were mainly through chitosan and dopamine self-polymerization, doped in sodium carboxymethyl cellulose, and glutaraldehyde cross-linking. The pH value, initial concentration and contact time were investigated. Experimental data were commendably described by Freundlich isotherm and Pseudo-second-order model. The maximum adsorption capacities of Cd(II) and Cr(VI) obtained from the experimental data were 470.0 mg/g and 347.0 mg/g, respectively. The adsorbents were collaboratively characterized by FT-IR, SEM, TGA, XPS, etc., and the adsorbent basically exhibited high complexation ability to Cd(II) and showed strong electrostatic effect with Cr(VI) under acidic conditions. The recycling characteristics suggested that it possesses an outstanding recyclability. The adsorbent may have a potential as high-value biological adsorbent to remove heavy metals and it deserves further research into the practical application.