Removal of Cadmium(II) and Lead(II) ions from aqueous phase on sodic bentonite

this paper describes the adsorption of cd2+and pb2+ions using sodic bentonite clay type fluidgel modified. the fluidgelbefore and after chemical modification and thermal activation was characterized by different techniques including x-ray diffraction, thermal analysis, fourier transform infrared, surface area, helium pycnometry, cation exchange capacity and scanning electron microscopy. pseudo-first order, pseudo-second order and intra-particle diffusion models were used to analyze the kinetic curves. equilibrium data were analyzed using langmuir and freundlich models. the thermodynamic study indicated that lead adsorption process is endothermic and interactions between clays and solutions of lead occurred spontaneously, while cadmium adsorption revealed an exothermic and spontaneous nature. the maximum removal efficiencies were 97.62% for cd(ii) using fluidgelmodified chemically and 91.08% for lead by fluidgel modified chemical and thermally.