Enhanced removal of Pb (II) and Cd (II) ions from aqueous systems using coated magnetic nanoparticles in activated carbon derived from corncob waste

The study investigated the use of a cheap, high-efficiency, and eco-friendly adsorbent as an alternative to activated carbon coated Maghemite nanoparticles (& gamma;-Fe3O4) for removing lead and cadmium ions from aqueous solutions. The Maghemite nanoparticles were synthesized using a sol-gel method. The characteristics of the adsorbent SEM, FT-IR, XRD and pHZPC, were analysed. The adsorption isotherm data were examined, and the data showed good fit with the Langmuir, Temkin and Freundlich isotherm models. The maximum adsorption capacity for Pb (II) and Cd (II) ions, as determined by the Langmuir isotherm, was found to be 127 mg/g and 100 mg/g, respectively. The kinetics of adsorption were studied using four kinetic models: pseudo-first order, pseudosecond order and Elovich model. Among these, the pseudo-second order kinetic model showed a good fit with high correlation values. Thermodynamic parameters such as the change in free energy (& UDelta;G degrees), enthalpy (& UDelta;H degrees), and entropy (& UDelta;S degrees) were calculated. These parameters indicated that the sorption of Pb (II) and Cd (II) ions is feasible, spontaneous, and endothermic. Overall, the results demonstrated that Maghemite nanoparticle coated activated carbon derived from agricultural biomass could be an attractive option for removing metals from industrial effluents. This alternative adsorbent offers advantages such as cost-effectiveness, high efficiency, and environmental friendliness in the removal of lead and cadmium ions from aqueous solutions.