Removal of Pb<sup>+2</sup> and Cd<sup>+2</sup> from Aqueous Solution by Using Faujasite

Abstract

The excess amount of lead (Pb⁺²) and cadmium (Cd⁺²) in the drinking water system lead to affect immunity and kidney failure problems. To overcome such troubles by developing well-crystalline faujasite minerals that are synthesized from claystone by the hydrothermal process may be the current trend For the effective adsorption of these cations. The active functional group, thermal nature, crystallinity surface, texture properties, and porous surface nature of faujasite were investigated using X-ray diffraction, scanning electron microscopy, Fourier-transform infrared, and nitrogen sorption 77k studies. The maximum removal of Pb⁺² and Cd⁺² was found to be 98% and 85% respectively using 60 mg and 70 mg from the adsorbent material. Moreover, the measured uptake capacity of Pb⁺² and Cd⁺² was 351.3 mg/g and 97.2 mg/g at equilibrium times of 50 min and 80 min respectively. Therefore, different adsorption isotherm and kinetic models were investigated. Accordingly, adsorption isotherms were the best fit for the Langmuir isotherm model. Moreover, the adsorption process for the two adsorbate cation was followed by the pseudo-second-order kinetics (R² >0.9), Elovich (R² >0.9 for Pb⁺² and 0.86 for Cd⁺²), and Langmuir (R² >0.9 for Pb⁺² and 0.85 for Cd⁺²). This indicates that the adsorption process via monolayer formation with chemical sharing or/and ion exchange process occurs on the energetically heterogeneous surface.