Synthesized iron oxide nanoparticles from Acacia nilotica leaves for the sequestration of some heavy metal ions in aqueous solutions

A batch adsorption system was applied to study the adsorption of Cd (II) , Co(II) and Pb(II) ions from aqueous solutions by iron oxide nano particle (IONP) synthesized from Acacia nilotica plant leaves. The influence of various operating parameters such as contact time, temperature, pH, adsorbent dosage and initial concentration of metal ions and on the adsorption capacity of IONP was investigated. The synthesized adsorbent was characterized by Energy Dispersive X-ray spectroscopy (EDX), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FT-IR) and X-Ray Diffraction (XRD). Results obtained clearly show that IONP is an effective adsorbent for the removal of the studied metal ions from aqueous solutions. The ease of adsorption of the studied metals onto IONP was found to be in this order: Co (II) > Cd (II) > Pb (II). The kinetic data corresponded well with the pseudo-second order equation, suggesting that the adsorption process is presumably achemisorption. The values oobtained from the thermodynamic parameters (〖∆G〗_ads^۰, 〖∆S〗_ads^۰, and 〖∆H〗_ads^۰) established that the adsorption process is feasible and endothermic in nature. The adsorption equilibrium data best fitted Freundlich adsorption isotherm. IONP may be a cost-effective alternative for waste water treatment

Keywords:

Acacia nilotica , Heavy metal , Adsorption , Nanoparticles , Low-cost adsorbents