MOBILITY OF CONTAMINANTS FROM ABANDONED GOLD MINE DUMPS TO STREAM WATERS IN AN AGRICULTURAL ACTIVITY AREA

Characterization of various streams within the Blesbokspruit located in South Africa are reported in this study following the global problem of environmental pollution. The study area is known to have been a hive of mining activities that has resulted in several mine tailings dumps some of which were poorly managed. Environmental concerns such as Acid Mine Drainage (AMD) has been associated with these areas due to metals and metalloids contamination from tailings produced from mining activities. With the increasing agricultural activities within these areas, there was a need to assess the quality of water that farm animals such as cattle drink. A procedural method was implemented in a bid to identify relations between tailings and stream water contamination. Representative samples of gold tailings and stream sediments samples were collected respectively. Mineralogical characterization of the tailings and sediments was carried out using XRF which revealed average values of major elements such as Na₂O (0.18%), MgO (0.63%), Al₂O₃ (6.51%), SiO₂ (81.83%), P₂O₅ (0.04%), SO₃ (3.40%), K₂O (1.98%), CaO (0.45%), TiO₂ (0.51%), Cr₂O₃ (0.17%), MnO (0.04%), Fe₂O₃ (3.59%), NiO (0.04%), and As₂O₃ (0.02%), while ICP-MS aided the determination of metal contents. In order to assess the mobility of metal, sequential leaching tests were carried out. Also characterized were samples of groundwater and various stream water in specific locations. There was a clear description of the link between tailings, water contamination and possible implications to animals and humans in a long run.

Key words: Contamination, livestock, acid mine drainage, water quality.