Development of a Novel CMC/f-GO-Glu Composite for Heavy Metal Remediation: Antioxidant, Antimicrobial, and Adsorption Studies

The present study focuses on the development of a carboxymethyl chitosan-functionalized graphene oxide (CMC/f-GO-Glu) composite for the enhanced removal of heavy metals like copper and chromium from aqueous solutions. Graphene oxide (GO) was synthesized using a modified Hummers' method and further functionalized with carboxylic acid groups. The CMC/f-GO-Glu composite was prepared by crosslinking carboxymethyl chitosan with functionalized graphene oxide using glutaraldehyde. The synthesized composite was characterized using FT-IR, XRD, and SEM techniques. The adsorption capacity of the CMC/f-GO-Glu composite towards copper and chromium was investigated through batch adsorption studies under optimized conditions. The composite exhibited excellent antioxidant and antimicrobial properties. Batch adsorption experiments revealed that the adsorption of both metals was highly dependent on pH, adsorbent dosage, contact time, and initial metal ion concentration. The Freundlich isotherm model fit the equilibrium data quite well, indicating multilayer adsorption. The Freundlich isotherm model fit the equilibrium data quite well. The adsorption mechanism was found to be dominated by chemical interactions such as electrostatic forces and coordinate bonding, along with the influence of the composite's chemical structure and intermolecular interactions. Desorption studies confirmed the reusability of the CMC/f-GO-Glu composite without significant loss in adsorption efficiency. The results demonstrate the potential of the CMC/f-GO-Glu composite as an excellent adsorbent to extract heavy metals from aqueous solutions, with promising applications in environmental remediation.