A PH-DEPENDENT SEQUENTIAL EXTRACTION PROCEDURE TO DETERMINE MOBILIZATION AND TRANSPORT OF METALS IN SEDIMENTS

A pH-dependent sequential extraction procedure to determine mobilisati on and transport of metals from sediments in the Vaal River-Koekemoers pruit confluence area was developed. The study was preformed on the le ss than 0,2 mm particle size of the dried sediments. Ammonium/acetate extracting reagents were used and the extracts were analysed by using inductively coupled plasma (ICP) emission spectroscopy. The performanc e of the sequential extraction procedure was evaluated relative to a s tandard sediment. Differences can arise in using this sequential extra ction procedure when naturally occurring soil types and ligands, which influence the extraction behaviour, are other than those used in this study. Arsenic, copper, zinc and manganese are mobile elements in the Vaal River-Koekemoerspruit confluence area and may have a possible en vironmental impact on the water phase.