Sodium itaconate grafted nanocellulose for facile elimination of lead ion from water

Nanocellulose from jute fiber was grafted with sodium itaconate through esterification with itaconic anhydride followed by replacement of surface protons with sodium ions. A tea-bag pouch containing sodium itaconate grafted nanocellulose (SINC) acted as a chemisorbant for lead ions through ion exchange when dipped in an aqueous solution. Surface morphology and surface modification of SINC were characterized by FTIR, SEM, EDX, TEM, AFM and BET N₂ adsorption isotherm techniques. The effective diminution of lead ion concentration was ascertained by AAS and ICP-MS methods. The impact of operating parameters like residence time, temperature, ion concentration and pH on the chemisorption capability was evaluated. The kinetic data conformed to the intra particle diffusion model and pseudo second order reaction. The Freundlich model was found to be the best for describing isotherm equilibrium. The maximum chemisorption capacity (mg g⁻¹) of SINC, nanocellulose itaconate and nanocellulose in aqueous solution for Pb²⁺ were found to be 85, 58 and 10 respectively at pH 5.5. The used SINC was easily regenerated via desorption of lead ion using NaCl. The regenerated SINC could be reused for four consecutive cycles with no loss of chemisorption efficiency. The SINC was also effective for removal of other metal ions such as chromium, cadmium and mercury. This is an easily synthesizable, adaptable and well-chemisorbing system with proven reusability. This could emerge as an economical alternative to the conventional cation exchange resins.