Application of chemically modified avocado seed for removal of Copper (II), Lead(II), and Cadmium(II) ions from aqueous solutions

The present study deals with the application of avocado seed, an agricultural waste, for the adsorptive removal of Cu (II), Pb (II) and Cd (II) from aqueous solutions. This paper incorporates the effects of time, dose, concentration, and pH. Scanning electron microscope and (SEM) and mid infrared spectroscopy techniques have been employed to find pore properties and characteristics of adsorbent materials. Batch kinetic and isotherm studies have also been performed to understand the ability of the adsorbents. The adsorption behavior of the metal ions has been studied using Freundlich and Langmuir isotherm models. The physical sorption capacity determined from the Freundlich adsorption equation has been found as 271.2 mg/g, 257.14 mg/g and 102 mg/g for Pb (II), Cd (II) and Cu (II) ions respectively. Kinetic measurements suggest the involvement of pseudo-second-order kinetics in adsorptions process. Adsorption of metal ions on adsorbent was found to increase on decreasing initial concentration and increasing pH upto pH 6. Overall, the present findings suggest that avocado seed is environmentally friendly, efficient and low-cost biosorbent which is useful for the removal of the metal ions from aqueous media.