Adsorption of Cu, Cd and Cr on selected soils

Abstract

Studies about heavy metal interactions with soils havereceived increasing attention due to land disposal of different kindsof sewage sludge. Of particular importance in this field is thesorption process of heavy metals which influences their mobility,determining their distribution between the liquid and the solidphase of the soil.In this work, heavy metal (Cu,Cd,Cr) sorption experimentswas carried out on six Turkish soil samples. The adsorptioncapacities (K) and adsorption intensities (l In) of these soils relatingto these metals were investigated by batch shaking method. Theinteractions between the four major adsorption characteristics,namely pH, cation exchange capacity (CEC), clay and organicmaterial contents of the soils, and the retention of Cu, Cd, and Crwas also examined by batch column experiments.The experimental results of were fitted to Freundlichadsorption isotherm model. The adsorption capacities of theexperimental soils were higher for cadmium than copper. Chromiumin the form of dichromate was not adsorbed by the soils. During thecolumn experiments the retention of the heavy metals tended toincrease as concentration increased and retention was very high inthe worked range of concentrations. Copper and cadmium showedsimilar behavior all through the experiments.Keywords: Soil Pollution, Adsorption, Copper, Cadmium,Hexavalent Chromium.