Authors:
kamel Alzboon; kamel Alzboon kamel Alzboon;
Abstract:
This research aims to investigate the use of magnetic iron nanoparticles (FeN) for the removal of heavy metals under single and ternary scenarios. The methodology includes synthesis of FeN using chemical precipitation approach, batch experiments for single and ternary metals removal, isotherm and kinetic studies, thermodynamic study, and assessing the effect of different parameters on the adsorption process. The results showed that the maximum removal capacities of As, Cd, and Hg at the initial concentration of 200 ppm were 260, 280, and 127 mg/g in case of single metal removal against 91.5, 237.8, and 341.5 mg/g in case of ternary combination, respectively. The removal efficiency was affected strongly due to the presence of multiple metals; while As removal decreased sharply, Hg removal increased significantly. Adsorption selectivity is affected negatively by the increase in atomic weight and atomic radius. In the case of single metal removal, fitting of isotherm models can be ranked as Langmuir>Freundlich>Temkin>D-R for As and Cd and Temkin>Freundlich>D-R>Langmuir for Hg, while contradictory results were obtained in the case of ternary combination. Kinetic studies found that the adsorption follows the pseudo-second-order model. For all metals, the adsorption process is highly favourable at higher temperatures and is endothermic in nature. Coating of FeN with silica resulted in lower removal efficiency for all metals up to 50%. It can be concluded that FeN can be used successfully for the removal of heavy metals either through the single or ternary approach, but the single approach provides higher performance.
Keywords:
nanomaterials, magnetite iron, adsorption, isotherm, kinetics, thermodynamics