Facile one pot preparation of magnetic chitosan-palygorskite nanocomposite for efficient removal of lead from water

• Published in: Journal of Colloid and Interface Science
• Main Author: Rusmin R.; Sarkar B.; Mukhopadhyay R.; Tsuzuki T.; Liu Y.; Naidu R.
• Format: Article
• Language: English
• Published: Academic Press Inc. 2022
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85116630799&doi=10.1016%2fj.jcis.2021.09.109&partnerID=40&md5=bc7d58d82dc8f90cf82b81196d625667

Development of polymeric magnetic adsorbents is a promising approach to obtain efficient treatment of contaminated water. However, the synthesis of magnetic composites involving multiple components frequently involves tedious preparation steps. In the present study, a magnetic chitosan-palygorskite (MCP) nanocomposite was prepared through a straight-forward one pot synthesis approach to evaluate its lead (Pb2+) removal capacity from aqueous solution. The nano-architectural and physicochemical properties of the newly-developed MCP composite were described via micro- and nano-morphological analyses, and crystallinity, surface porosity and magnetic susceptibility measurements. The MCP nanocomposite was capable to remove up to 58.5 mg Pb2+ g−1 of MCP from water with a good agreement of experimental data to the Langmuir isotherm model (R2 = 0.98). The Pb2+ adsorption process on MCP was a multistep diffusion-controlled phenomenon evidenced by the well-fitting of kinetic adsorption data to the intra-particle diffusion model (R2 = 0.96). Thermodynamic analysis suggested that the adsorption process at low Pb2+ concentration was controlled by chemisorption, whereas that at high Pb2+ concentration was dominated by physical adsorption. X-ray photoelectron and Fourier transform infrared spectroscopy results suggested that the Pb adsorption on MCP was governed by surface complexation and chemical reduction mechanisms. During regeneration, the MCP retained 82% Pb2+ adsorption capacity following four adsorption–desorption cycles with ease to recover the adsorbent using its strong magnetic property. These findings highlight the enhanced structural properties of the easily-prepared nanocomposite which holds outstanding potential to be used as an inexpensive and green adsorbent for remediating Pb2+ contaminated water. © 2021 Elsevier Inc.