Sorption of cadmium and lead ions on modified groundnut (<i>Arachis hypogea</i>) husks

Abstract

Abstract The removal of cadmium and lead ions from aqueous solutions by groundnut husks modified by reaction with EDTA (% N = 12.05) was examined by equilibrium sorption studies at 29°C. The maximum metal ion binding capacity of the EDTA‐modified husk determined from the sorption isotherm from solutions of pH 6.8 was found to be 0.36 mmol g −1 and 0.19 mmol g −1 for Cd(II) and Pb(II) ions, respectively. It was found that the rate of sorption was particle‐diffusion controlled, and the particle‐diffusion control rate coefficient was determined to be of the order of 10 −2 min −1 .