Ionic Strength and Ph Dependence of Sorption of Pd onto Illite, Bentonite, and Shale

Abstract

This paper examines sorption of palladium (Pd) onto illite, sodium-bentonite MX-80, and Queenston shale, under aerobic conditions, for Na-Ca-Cl solutions with ionic strengths(I) ranging from 0.1-6 mol/L (M) and pH_c ranging from 3-9.Sorption decreased as I increased. At pH < 5 sorption increased, while for pH > 5 sorption was essentially constant. Surface complexation modelling (SCM) for sorption of Pd onto illite and montmorillonite was developed using PHREEQC and compared to the experimental results. The results showed some agreement to the experimental data, however, the general shapes did not match.SC constants were able to be optimized for 0.1 M.