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

Abstract

In this study, the column method was used to determine the leachable trace metals present in selected river sediments. In addition
the sediments were investigated using a shaker method and these two methods were compared for reliability. For both
these methods extract solutions associated with a sequential extraction method were used. However, the sediments were only
subjected to one extractant solution and not to the whole sequential procedure. The river sediments were also subjected to a
digestion procedure to determine the total trace metal content. Simulated pollution experiments were performed where the
sediments were also spiked to give known concentrations of trace metals. These results were very useful, especially in cases
where certain trace metals were not currently present in river sediments. From the results achieved in this study the general
trace metal status of the sediments can be established. From the results achieved it was established that in the case of the less
impacted rivers (Crocodile and Olifants Rivers) only slight changes in the river conditions are needed to mobilise the trace
metals present. From the results of the Blesbokspruit it was seen that urgent attention is needed to prevent further damage to
the system.

Water SA Vol. 31 (2) 2005: pp.183-192