Investigation of mobility of trace elements in river sediments using ICP-OES

Abstract

This study focused on the pH dependant mobility of 15 trace elements in river sediments in South Africa. These river sediments originated from the Blesbokspruit (near Witbank in the Mpumalanga Province), the Crocodile River (near Hartebeespoort Dam in the Gauteng Province) and the Olifants River (near Ohrigstad in the Northern Province). A theoretical discussion on the properties of the measured trace elements and the ICP-OES technique were included in this study for the sake of completeness. Three different fractions of river sediment (smaller than 0.2 mm, bigger than 0.2 mm and unsieved) were investigated using two different leaching techniques and a digestion procedure to determine the total trace element content. The sediment was subjected to simulated pollution by trace element through the addition of standard solutions in know concentrations. These results it were evaluated to determine the possible behaviour of trace elements that is not presently present in the river sediment. The results obtained from this study were used to determine the impact that trace elements may have in the pollution of the underground water resources.