Interactions of Metals with Clays in Aqueous Suspensions

The tremendous increase in the use of heavy metals over the past few decades has inevitably resulted in an increased flux of metallic substances in aquatic environment. The elimination of heavy metals from wastewater is of utmost importance to protect public health. Adsorption process is promising in this regard as it achieves higher level of removal over a wider range of solution concentrations and generally reduce the quantity of solid residual that need to be disposed of. The present work has been designed for using natural and modified clays as adsorbents with the objectives, namely (i) to prepare adsorbents from kaolinite and montmorillonite clays by intercalating with polyoxo and quaternary ammonium cations, and by acid treatment (ii) to use the adsorbents in batch processes for removing toxic metal cations from water (iii) to make a thorough study of the kinetics of adsorbate-adsorbent interactions (iv) to test the validity and applicability of different adsorption isotherms to find out adsorption affinity and adsorption capacity of the clays (v) to determine the relevant thermodynamic parameters for all clay-metal interaction.