LAUSR

Abstract The present work describes the effect of surface modification of a high silica zeolite on removal of multiple ions [Pb(II), Fe(III), Cd(II)] and organics (Methylene blue, Aniline and p-nitrophenol) from contaminated water systems. Porous layer of ZnO nanoflakes (NFs) is grown on the surface of the zeolite in the form of a core-shell (CSPs) which alters the interface of the zeolite to convert the adsorption mechanism from slower chemisorption in zeolite to rapid physiochemisorption in CSPs as inferred from the comparative analysis of the adsorption dynamics. An inter-particle synergy encompassing ion exchange by zeolite and adsorption/photodegradation by the ZnO has been established by changed interfacial charge, enhanced surface area and increased porosity of the CSPs. Specificity of the developed CSPs for particular ions/organics and possible mechanism for enhanced adsorption of the CSPs has been discussed in detail. The specificity of adsorption follows the order of Pb (II) > Fe (III) > Cd (II) for heavy metal ions whereas for organics, the order of adsorption is methylene blue > p-nitrophenol > aniline. Results indicate that presence of ZnO nanoflakes as porous shell increases the equilibrium adsorption capacity of the CSPs to 74.661 mg/g in comparison to 45.96 mg/g of zeolite. The results of the specificity studies and significant increase in adsorption capacity prove that the altered interface leads to enhanced and rapid removal of toxic pollutants from water with highest specificity for Pb(II) and MB dye.