Removal of Cadmium Ion from Aqueous Solution by oyster-based Based Calcium Oxide Nanoparticles

Abstract

Environmental challenges associated with the management of non-biodegradable solid waste are best overcome by three cardinal waste management protocols, which are re-use, recover and recycle. The conversion of oyster shells to calcium oxide nanoparticles using the sol-gel method is reported in this work. The nanoparticles showed a crystal nature with average crystalline sizes of 16.85 and 2.705 nm based on the Scherrer and Williamson Hall equations respectively. The synthesized calcium oxide nanoparticles were characterized with XRD and employed in the removal of cadmium ions from aqueous solution through adsorption. Adsorption efficiency approaching 100% was observed at [Cd²⁺] at 4 pm, alkaline pH and contact period of 70 min.  The adsorption of the dye was spontaneous and accepted the mechanical of physical adsorption. The study confirmed that calcium oxide nanoparticles can completely remove cadmium ions from the solution.