Synthesis of Fe-grown carbon nanofibers supported on porous carbon beads for the elimination of methylene blue, cadmium, and lead from aqueous and river water matrices

Water contamination by dyes and heavy metals poses serious risks to human health and aquatic ecosystems, necessitating efficient and sustainable remediation strategies. In this study, Fe-catalyzed carbon nanoforest composite beads (Fe–CNF/Beads) were successfully synthesized via a suspension polymerization-assisted approach and evaluated for the simultaneous removal of methylene blue (MB), Pb²⁺, and Cd²⁺ from aqueous media, river water (RW), and multicomponent systems (MB+Pb²⁺+Cd²⁺). The synthesized adsorbent was comprehensively characterized to examine its morphology, structural features, surface chemistry, and thermal stability. Batch adsorption experiments were conducted to investigate the effects of pH, contact time, and initial contaminant concentration. Kinetic studies revealed that the adsorption process followed the pseudo-second-order model, indicating the dominant role of surface interactions. Equilibrium data were fitted using Langmuir, Freundlich, and Redlich–Peterson (R–P) isotherms, with the R–P model providing the best fit, suggesting hybrid adsorption behavior. The maximum adsorption capacities obtained from the Langmuir model were 243.04 ± 24.79 mg/g for MB, 163.33 ± 7.98 mg/g for Cd²⁺, and 175.51 ± 19.93 mg/g for Pb²⁺. Fe–CNF/Beads also exhibited excellent performance in RW and multicomponent systems, together with good regeneration capability over five cycles, demonstrating their potential for practical wastewater treatment applications.

Keywords: CNF, Beads, Fe-impregnated nanocomposite, Multicomponent adsorption; Recycling