Abstract: The rapid expansion of industrial activities has led to the severe contamination of water bodies with toxic heavy metals, necessitating the development of highly efficient and sustainable remediation technologies. In this study, a novel chitosan-modified graphene oxide (CS-GO) nanocomposite was successfully synthesized and evaluated for the targeted adsorption of Lead (Pb^2+) and Copper Cu^2+ ions from aqueous solutions. The structural, chemical, and morphological properties of the synthesized nanocomposite were comprehensively characterized using FTIR, XRD, SEM, and BET surface area analyses. Batch adsorption experiments were conducted to investigate the effects of critical operational parameters, including pH, adsorbent dosage, initial metal concentration, and contact time. The results revealed that maximum removal efficiency was achieved at an optimal pH of 5. 5 within 90 minutes of contact time. The adsorption kinetics were best described by the pseudo-second-order model, while the isotherm data fit seamlessly with the Langmuir model, suggesting monolayer chemisorption on a homogeneous surface. The maximum adsorption capacities (q₌₀ₗ) for Pb^2+ and Cu^2+ were exceptionally high, reaching 315. 4 mg/g and 210. 8 mg/g, respectively. Furthermore, thermodynamic evaluations confirmed that the adsorption process was spontaneous and endothermic in nature. The nanocomposite also exhibited outstanding stability and reusability, maintaining over 88% of its initial removal efficiency after five consecutive adsorption-desorption cycles. These findings demonstrate that the proposed CS-GO nanocomposite is a highly promising, economically viable, and scalable adsorbent for the advanced treatment of heavy metal-contaminated wastewater. Keywords: Graphene oxide, Nanocomposites, Heavy metal adsorption, Wastewater treatment, Adsorption kinetics, Chitosan.
Mushini Venkata Subbarao (2026) studied this question.