Adsorption for removal of cd(ii) from effluents

Abstract

The adsorption of Cd(II) onto wollastonite has been reported. Adsorption increased from 55.7 to 93.6% by decreasing the concentration of Cd(II) from 2.0 x 10-4M to 0.5 x 10-4M. The rearranged Lagergren equation has been used for dynamic modelling of the process. However, the value of rate constant at 30°C was found to be 3.17 x 10-2min-1. Equilibrium modelling was carried out using the Freundlich isotherm equation and constants have been calculated. Thermodynamic studies were carried out and values of standard free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were calculated at various temperatures. Low temperatures favour the uptake of Cd(II) in the process. © 1990, Taylor & Francis Group, LLC. All rights reserved.