Abstract

This report describes use of Red Powdered Marble Waste (RPMW) for the removal of Cd2+ from aqueous matrix. RPMW is
considered as inexpensive and widespread solid waste which is directly exposed to environment. The removal of Cd2+ ions from
aqueous medium is achieved by optimizing various adsorption parameters along with the effect of temperature, pH, stirring
time, and Cd2+ ion concentration. Kinetic studies were carried out using Morris-Weber equation. Langmuir and Freundlich
adsorption isotherms are successfully employed for the study of adsorption of Cd2+ ions onto RPMW. Thermodynamic
parameters specifically Gibbs free energy change (∆G), enthalpy (∆H), and entropy (∆S) have also been calculated and their
values −4.537 KJ/mol, 68.53 KJ/mole, and 16.8621 J/mole, respectively. The highest removal of Cd2+ ion onto RPMW was
found to be 340.59 mg/gm. These findings suggested that the adsorption process of Cd(II) ion onto RPMW was endothermic
and spontaneous in nature.